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Sample records for pvc-membrane sensor based

  1. Urea sensors based on PVC membrane pH electrode.

    Science.gov (United States)

    Głab, S; Koncki, R; Kopczewska, E; Wałcerz, I; Hulanicki, A

    1994-07-01

    Several procedures of urease immobilization on the surface of the polymeric membrane pH electrode with tri-n-dodecylamine as a neutral carrier were compared. The best results were obtained for the urea sensor with covalently bound urease. The sensor characteristics including the effect of buffer, pH and concentration and the effect of stirring rate are presented. These effects are in good agreement with theoretical expectations.

  2. Ionophore-based potentiometric PVC membrane sensors for determination of phenobarbitone in pharmaceutical formulations.

    Science.gov (United States)

    Alrabiah, Haitham; Al-Majed, Abdulrahman; Abounassif, Mohammed; Mostafa, Gamal A E

    2016-12-01

    The fabrication and development of two polyvinyl chloride (PVC) membrane sensors for assaying phenobarbitone sodium are described. Sensors 1 and 2 were fabricated utilizing β- or γ-cyclodextrin as ionophore in the presence of tridodecylmethylammonium chloride as a membrane additive, and PVC and dioctyl phthalate as plasticizer. The analytical parameters of both sensors were evaluated according to the IUPAC guidelines. The proposed sensors showed rapid, stable anionic response (-59.1 and -62.0 mV per decade) over a relatively wide phenobarbitone concentration range (5.0 × 10-6-1 × 10-2 and 8 × 10-6-1 × 10-2 mol L-1) in the pH range of 9-11. The limit of detection was 3.5 × 10-6 and 7.0 × 10-6 mol L-1 for sensors 1 and 2, respectively. The fabricated sensors showed high selectivity for phenobarbitone over the investigated foreign species. An average recovery of 2.54 μg mL-1 phenobarbitone sodium was 97.4 and 101.1 %, while the mean relative standard deviation was 3.0 and 2.1 %, for sensors 1 and 2, respectively. The results acquired for determination of phenobarbitone in its dosage forms utilizing the proposed sensors are in good agreement with those obtained by the British Pharmacopoeial method.

  3. Ionophore-based potentiometric PVC membrane sensors for determination of phenobarbitone in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    Alrabiah Haitham

    2016-12-01

    Full Text Available The fabrication and development of two polyvinyl chloride (PVC membrane sensors for assaying phenobarbitone sodium are described. Sensors 1 and 2 were fabricated utilizing β- or γ-cyclodextrin as ionophore in the presence of tridodecylmethylammonium chloride as a membrane additive, and PVC and dioctyl phthalate as plasticizer. The analytical parameters of both sensors were evaluated according to the IUPAC guidelines. The proposed sensors showed rapid, stable anionic response (-59.1 and -62.0 mV per decade over a relatively wide phenobarbitone concentration range (5.0 × 10-6-1 × 10-2 and 8 × 10-6-1 × 10-2 mol L-1 in the pH range of 9-11. The limit of detection was 3.5 × 10-6 and 7.0 × 10-6 mol L-1 for sensors 1 and 2, respectively. The fabricated sensors showed high selectivity for phenobarbitone over the investigated foreign species. An average recovery of 2.54 μg mL-1 phenobarbitone sodium was 97.4 and 101.1 %, while the mean relative standard deviation was 3.0 and 2.1 %, for sensors 1 and 2, respectively. The results acquired for determination of phenobarbitone in its dosage forms utilizing the proposed sensors are in good agreement with those obtained by the British Pharmacopoeial method.

  4. Europium (III) PVC membrane sensor based on N-pyridine-2-carboxamido-8-aminoquinoline as a sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Kamjoo, Rahman [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Zaferoni, Mojdeh; Rafati, Zynab [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Meghdadi, Soraia [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2012-04-01

    Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 Multiplication-Sign 10{sup -2} and 1.0 Multiplication-Sign 10{sup -6} mol L{sup -1}, Nernstian slope of 19.8 {+-} 0.3 mV per decade and a detection limit of 6.4 Multiplication-Sign 10{sup -7} mol L{sup -1}. The potentiometric response is pH independent in the range of 2.4-7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu{sup 3+} ions with EDTA and for determination of Eu{sup 3+} ion concentration in mixtures of two and three different ions. - Highlights: Black-Right-Pointing-Pointer A new ion carrier is introduced to preparation of a selective sensor for Eu{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple and it's not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The novelty of this work is the high affinity of the ionophore toward the Eu{sup 3+} ions. Black-Right-Pointing-Pointer The sensor is superior to the formerly reported Eu{sup 3+} sensors in terms of selectivity.

  5. Neodymium(III PVC Membrane Electrodchemical Sensor Based on N-benzoylethylidene-2-aminobenzylamine

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    Hassan Ali Zamani

    2012-01-01

    Full Text Available The N-benzoylethylidene-2-aminobenzylamine (BEA was used as a suitable ionophore in construction of neodymium ion selective electrode. The electrode with composition of 30% PVC, 58% solvent mediator (NB, 2% ionophore (BEA and 10% anionic additive (OA shows the best potentiometric response characteristics. The Nd3+ sensor exhibits a Nernstian slope of 21.2 ± 0.2 mV decade-1 over the concentration range of 1.0 × 10-6 to 1.0 × 10-2 mol L-1, and a detection limit of 6.3 × 10-7 mol L-1 of Nd3+ ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.4–8.5. It has a very short response time, in the whole concentration range (~7 s, and can be used for at least eight weeks. The proposed sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The Nd3+ sensor was successfully applied as an indicator electrode in the potentiometric titration of Nd3+ ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations.

  6. Fabrication of a Ho3+-PVC membrane sensor based on N-phenyl-2-(thiophen-2-ylmethylene)hydrazinecarbothioamide for determination of holmium ions

    Institute of Scientific and Technical Information of China (English)

    Hassan Ali Zamani

    2011-01-01

    In this research, a new poly(vinyl chloride) (PVC) membrane sensor for Ho3+ ion based on N-phenyl-2-(thiophen-2-ylmethylene)hydrazinecarbothioamide (PHC) as an ionophore was prepared. This sensor demonstrated good selectivity and sensitivity towards the holmium ion in comparison with variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The effect of membrane composition and pH on the response properties of the electrode was investigated. In detail, the suggested sensor exhibited a Nernstian behavior (with a slope of 20.4 ± 0.3 mV decade-1) in the range of 1.0 × 10-6 to 1.0 × 10-2 mol/L with a detection limit of 6.2 × 10-7 mol/L. The response time was relatively quick in the whole concentration range (~5 s). The sensor usage was found to be at least 10 weeks in a pH range of 3.3-10.9. It was successfully applied in determination of fluoride ions in mouth wash preparations.

  7. Fabrication of a PVC membrane samarium(III) sensor based on N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide as a selectophore

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Naghavi-Reyabbi, Fatemeh [Resident of General Surgery, Endoscopic and Minimaly Invasive Surgery Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Tadjarodi, Azadeh; Rad, Maryam [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2013-03-01

    A new ion-selective electrode for Sm{sup 3+} ion is described based on the incorporation of N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 {+-} 0.5 mV decade{sup -1} over a wide concentration range of 1.0 Multiplication-Sign 10{sup -2} and 1 Multiplication-Sign 10{sup -6} mol L{sup -1}, with a lower detection limit of 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} and satisfactor applicable pH range of 3.6-9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm{sup 3+} over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm{sup 3+}. Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. - Highlights: Black-Right-Pointing-Pointer A new Sm{sup 3+}-PVC membrane sensor is introduced for determination of Sm{sup 3+} ions in the solutions. Black-Right-Pointing-Pointer N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide was used as a suitable selectophore for samarium sensor. Black-Right-Pointing-Pointer Detection limit of the sensor is 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} with a short response time of less than 10 s.

  8. Erbium(Ⅲ) PVC membrane sensor based on N-(benzyloxycarbonyloxy)succinimide as a new neutral ionophore

    Institute of Scientific and Technical Information of China (English)

    Hassan Ali Zamani

    2011-01-01

    In this study, a new Er3+ sensor based on N-(benzyloxycarbonyloxy)succinimide (BCS) as a neutral carrier has been constructed. The sensor exhibits potential linear response with a Nernstian slope of 20.5 ± 0.4 mV/decade in the concentration range of 1.0 × 10-6 to 1.0 × 10-2 mol/L of Er3+. It has a very short response time (<10 s), detection limit of 6.3 × 10-7 mol/L and a good selectivity relative to a wide variety of other metal ions including common alkali, alkaline earth, heavy, and transition metal ions. It can be used in the pH range of 2.5-10.6 without any considerable divergence in potentials. The proposed sensor was successfully applied for the recovery of Er3+ ions spiked in tap and river water samples.

  9. Design of a Selective and Sensitive PVC-Membrane Potentiometric Sensor for Strontium Ion Based on 1,10-Diaza-5,6-benzo-4,7-dioxacyclohexadecane-2,9-dione as a Neutral Ionophore

    Science.gov (United States)

    Shamsipur, Mojtaba; Kazemi, Sayed Yahya; Sharghi, Hashem

    2007-01-01

    A novel PVC membrane sensor for the Sr2+ ion based on 1,10-diaza-5,6-benzo-4,7-dioxacyclohexadecane-2,9-dione has been prepared. The sensor possesses a Nernstian slope of 30.0 ± 0.6 mV decade-1 over a wide linear concentration range of 1.6 × 10-6-3.0 ×10-3 M with a detection limit of 6.3 ×10-7 M. It has a fast response time of <15 s and can be used for at least two months without any considerable divergence in potential. The potentiometric response is independent of the pH of test solution in the pH range 4.3-9.4. The proposed electrode shows good selectivities over a variety of alkali, alkaline earth, and transition metal ions.

  10. CHEMICALLY MODIFIED FIELD-EFFECT TRANSISTORS - POTENTIOMETRIC AG+ SELECTIVITY OF PVC MEMBRANES BASED ON MACROCYCLIC THIOETHERS

    NARCIS (Netherlands)

    BRZOZKA, Z; COBBEN, PLHM; REINHOUDT, DN; EDEMA, JJH; KELLOGG, RM

    1993-01-01

    A chemically modified field-effect transistor (CHEMFET) with satisfactory Ag+ selectivity is described. The potentiometric Ag+ selectivities of CHEMFETs with plasticized PVC membranes based on macrocyclic thioethers have been determined. All the macrocyclic thioethers tested showed silver response a

  11. PVC Membrane Sensors for Potentiometric Determination of Acebutolol

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    Abdulrahman Al-Majed

    2007-12-01

    Full Text Available The construction and general performance characteristics of two novelpotentiometric membrane sensors responsive to the acebutolol are described. Thesensors are based on the use of ion-association complexes of acebutolol (AC withtetraphenylborate(TPB (I and phosphomolybdate(PM (II as exchange sites in a PVCmatrix. The sensors show a fast, stable and near- Nernstian for the mono charge cationof AC over the concentration range 1×10-3 - ~10-6 M at 25 °C over the pH range 2.0 -6.0 with cationic slope of 51.5 ± 0.5 and 53.0 ± 0.5 per concentration decade for AC-Iand AC-II sensors respectively. The lower detection limit is 6×10-6 M and 4×0-6 M withthe response time 20-30 s in the same order of both sensors. Selectivity coefficients ofAC related to a number of interfering cation and some organic compounds wereinvestigated. There are negligible interferences are caused by most of the investigatedspecies. The direct determination of 3 - 370 μg/ml of AC shows an average recovery of 99.4 and 99.5% and a mean relative standard deviation of 1 . 5 % at 100.0 μg/ml forsensor I and II respectively. The results obtained by determination of AC in tablets usingthe proposed sensors which comparable favorably with those obtained by the Britishpharmacopoeia method. In the present investigation the electrodes have been utilized asend point indicator for some precipitation titration reactions.

  12. Comparative studies of neodymium (III)-selective PVC membrane sensors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinod K., E-mail: vinodfcy@iitr.ernet.in [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Goyal, Rajendra N.; Sharma, Ram A. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2009-08-04

    Sensors based on two neutral ionophores, N,N'-bis((1H-pyrrol-2-yl)methylene)cyclohexane-1,2-diamine (L{sub 1}) and 3,3'-(cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene) bis(methan-1-yl-1-ylidene)bis(5-hydroxymethyl)pyridine-2-ol) (L{sub 2}) are described for quantification of neodymium (III). Effect of various plasticizers; 2-nitrophenyloctylether (o-NPOE), dibutyl butylphosphonate (DBBP), tri-n-butyl phosphates (TBP), dioctylpthalate (DOP) and chloronapthalen (CN) and anion excluder, sodiumtetraphenylborate (NaTPB) has been studied. The membrane composition of PVC:o-NPOE:ionophore (L{sub 1}):NaTPB (w/w; mg) of 150:300:5:5 exhibited best performance. The sensor with ionophore (L{sub 1}) exhibits significantly enhanced selectivity towards neodymium (III) in the concentration range 5.0 x 10{sup -7} to 1.0 x 10{sup -2} M with a detection limit of 1.0 x 10{sup -7} M and a Nernstian compliance (19.8 {+-} 0.3 mV decade{sup -1} of activity) within pH range 4.0-8.0. The response time of sensor was found as 10 s. The influence of the membrane composition and possible interfering ions has also been investigated on the response properties of the electrode. The fast and stable response, good reproducibility and long-term stability of the sensor are observed. The sensor has been found to work satisfactorily in partially non-aqueous media up to 20% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for neodymium. The proposed electrode shows fairly good discrimination of neodymium (III) from other cations. The application of prepared sensor has been demonstrated in the determination of neodymium (III) in spiked water samples.

  13. Design of a Selective and Sensitive PVC-Membrane Potentiometric Sensor for Strontium Ion Based on 1,10-Diaza-5,6-benzo-4,7-dioxacyclohexadecane-2,9-dioneas a Neutral Ionophore

    Directory of Open Access Journals (Sweden)

    Hashem Sharghi

    2007-04-01

    Full Text Available A novel PVC membrane sensor for the Sr2+ ion based on 1,10-diaza-5,6-benzo-4,7- dioxacyclohexadecane-2,9-dione has been prepared. The sensor possesses a Nernstian slope of 30.0 ± 0.6 mV decade-1 over a wide linear concentration range of 1.6 × 10-6-3.0 ×10-3 M with a detection limit of 6.3 ×10-7 M. It has a fast response time of less than 15 s and can be used for at least two months without any considerable divergence in potential. The potentiometric response is independent of the pH of test solution in the pH range 4.3-9.4. The proposed electrode shows good selectivities over a variety of alkali, alkaline earth, and transition metal ions.

  14. Monitoring of praseodymium(III) ions in aqueous solutions, soil and sediment samples by a PVC membrane sensor based on a furan-triazole derivative

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavid, Mohammad Reza [Islamic Azad University, Tehran (Iran, Islamic Republic of). Dept. of Medicinal Chemistry. Nuclear Science and Technology Research Institute; Rezaee, Mohammad; Hosseini, Majid Haji [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Razavi, Taherehsadat, E-mail: pourjavid@gmail.com [Research Institute of Petroleum Industry, Tehran (Iran, Islamic Republic of). Instrumental Analysis Dept.

    2012-07-01

    A furan-triazole derivative has been explored as an ionophore for preparation of a highly selective Pr(III) membrane sensor. The proposed sensor exhibits a Nernstian response for Pr(III) activity over a wide concentration range with a detection limit of 5.2 x 10{sup -8}M. Its response is independent of pH of the solution in the range 3.0-8.8 and offers the advantages of fast response time. To investigate the analytical applicability of the sensor, it was applied successfully as an indicator electrode in potentiometric titration of Pr(III) solution and also in the direct and indirect determination of trace Pr(III) ions in some samples. (author)

  15. A Schiff base complex of Zn(II) as a neutral carrier for highly selective PVC membrane sensors for the sulfate ion.

    Science.gov (United States)

    Shamsipur, M; Yousefi, M; Hosseini, M; Ganjali, M R; Sharghi, H; Naeimi, H

    2001-07-01

    Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets.

  16. Novel PVC-membrane potentiometric sensors based on a recently synthesized sulfur-containing macrocyclic diamide for Cd2+ ion. Application to flow-injection potentiometry.

    Science.gov (United States)

    Shamsipur, Mojtaba; Dezaki, Abbas Shirmardi; Akhond, Morteza; Sharghi, Hashem; Paziraee, Zahra; Alizadeh, Kamal

    2009-12-30

    A new sulfur-containing macrocyclic diamide, 1,15-diaza-3,4,12,13-dibenzo-5,11-dithia-8-oxa-1,15-(2,6-pyrido)cyclooctadecan-2,14-dione, L, was synthesized, characterized and used as an active component for fabrication of PVC-based polymeric membrane (PME), coated graphite (CGE) and coated silver wire electrodes (CWE) for sensing Cd(2+) ion. The electrodes exhibited linear Nernstian responses to Cd(2+) ion in the concentration range of 3.3 x 10(-6) to 3.3 x 10(-1)M (for PME, LOD=1.2 x 10(-6)M), 2.0 x 10(-7) to 3.3 x 10(-1)M (for CWE, LOD=1.3 x 10(-7)M) and 1.6 x 10(-8) to 1.3 x 10(-1)M (for CGE, LOD=1.0 x 10(-8)M). The CGE was used as a proper detection system in flow-injection potentiometry (FIP) with a linear Nernstian range of 3.2 x 10(-8) to 1.4 x 10(-1)M (LOD=1.3 x 10(-8)M). The optimum pH range was 3.5-7.6. The electrodes revealed fairly good discriminating ability towards Cd(2+) in comparison with a large number of alkali, alkaline earth, transition and heavy metal ions. The electrodes found to be chemically inert, showing a fast response time of <5s, and could be used practically over a period of about 2-3 months. The practical utility of the proposed system has also been reported.

  17. Uranyl-selective PVC membrane electrodes based on some recently synthesized benzo-substituted macrocyclic diamides.

    Science.gov (United States)

    Shamsipur, Mojtaba; Soleymanpour, Ahmad; Akhond, Morteza; Sharghi, Hashem; Massah, Ahmad Reza

    2002-08-23

    Four different recently synthesized macrocyclic diamides were studied to characterize their abilities as uranyl ion carriers in PVC membrane electrodes. The electrodes based on macrocycle 1,18-diaza-3,4;15,16-dibenzo-5,8,11,14,21,24-hexaoxacyclohexaeicosane-2,17-dione resulted in a Nernstian response for UO(2)(2+) ion over wide concentration ranges. The linear concentration range for the polymeric membrane electrode (PME) is 3.0x10(-6)-8.2x10(-3) M with a detection limit of 2.2x10(-6) and that for the coated graphite electrode (CGE) is 5.0x10(-7)-1.5x10(-3) M with a detection limit of 3.5x10(-7) M. The electrodes manifest advantages of low resistance, very fast response and, most importantly, good selectivities relative to a wide variety of other cations.

  18. Construction of Tb3+ PVC-MembraneElectrode Based on N,N’-Bis(pyrrolylmethylene-2-aminobenzylamine

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    Hassan Ali Zamani

    2011-01-01

    Full Text Available In this work, we report as new Tb3+-PVC membrane sensor based on N,N’-bis(pyrrolylmethylene- 2-aminobenzylamine (PMA as a suitable ion carrier. Poly vinylchloride (PVC-based membrane composed of PMA with oleic acid (OA as anionic additives and acetophenone (AP as plasticizing solvent mediators. The Tb3+ sensor exhibits a Nernstian slope of 19.7±0.4 mV per decade over the concentration range of 1.0×10-5 to 1.0×10-2 M and a detection limit of 4.6×10-6 M of Tb3+ ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.9–8.1. It has a very short response time, in the whole concentration range (∼5 s. The recommended sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, some transition and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Tb(III ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations and the determination of Tb3+ ions concentration in mixtures of three different ions.

  19. An oxalate selective electrode based on modified PVC-membrane with tetra-butylammonium--Clinoptilolite nanoparticles.

    Science.gov (United States)

    Hoseini, Zohre; Nezamzadeh-Ejhieh, Alireza

    2016-03-01

    A modified PVC-membrane electrode with tetra-butylammonium bromide - Clinoptilolite nano-particles (TBA-NCP) showed good Nernstian slope (29.9±0.6 mV per decade of oxalate concentration) in concentration range of 3.1×10(-7)-8.3×10(-1) mol L(-1) with a detection limit of 1.5×10(-7) mol L(-1). The best performance was obtained with a membrane composition of 31.5% PVC, 62.5% DOP and 6% TBA-NCP in the temperature range of 20-35 °C and the pH range of 4-9. The fast response time and good reproducibility over a period of 3 months are other characteristics of the sensor. The proposed electrode was successfully used as an indicator electrode in titration of oxalate ions with CaCl2 solution. The proposed electrode was also used in direct potentiometric determination of oxalate in many real samples such as: mushroom, black and green tea, spinach and beet.

  20. An electronic tongue using potentiometric all-solid-state PVC-membrane sensors for the simultaneous quantification of ammonium and potassium ions in water.

    Science.gov (United States)

    Gallardo, J; Alegret, S; Muñoz, R; De-Román, M; Leija, L; Hernández, P R; del Valle, M

    2003-09-01

    The simultaneous determination of NH(4)(+) and K(+) in solution has been attempted using a potentiometric sensor array and multivariate calibration. The sensors used are rather non-specific and of all-solid-state type, employing polymeric (PVC) membranes. The subsequent data processing is based on the use of a multilayer artificial neural network (ANN). This approach is given the name "electronic tongue" because it mimics the sense of taste in animals. The sensors incorporate, as recognition elements, neutral carriers belonging to the family of the ionophoric antibiotics. In this work the ANN type is optimized by studying its topology, the training algorithm, and the transfer functions. Also, different pretreatments of the starting data are evaluated. The chosen ANN is formed by 8 input neurons, 20 neurons in the hidden layer and 2 neurons in the output layer. The transfer function selected for the hidden layer was sigmoidal and linear for the output layer. It is also recommended to scale the starting data before training. A correct fit for the test data set is obtained when it is trained with the Bayesian regularization algorithm. The viability for the determination of ammonium and potassium ions in synthetic samples was evaluated; cumulative prediction errors of approximately 1% (relative values) were obtained. These results were comparable with those obtained with a generalized regression ANN as a reference algorithm. In a final application, results close to the expected values were obtained for the two considered ions, with concentrations between 0 and 40 mmol L(-1).

  1. Immobilization of ionophore and surface characterization studies of the titanium(III) ion in a PVC-membrane sensor.

    Science.gov (United States)

    Rezayi, Majid; Heng, Lee Yook; Kassim, Anuar; Ahmadzadeh, Saeid; Abdollahi, Yadollah; Jahangirian, Hossein

    2012-01-01

    Novel ionophores comprising various hydroxide and amine structures were immobilized onto poly(vinyl chloride) (PVC) matrices, and these were examined to determine Ti(III) selectivity. To predict the selectivity of Ti(III), a PVC membrane was used to investigate the binding of Ti(III) to c-methylcalix[4]resorcinarene (CMCR). The study showed that the chelating ligand, CMCR, was coordinated selectively to Ti(III) at eight coordination sites involving the oxygen atoms at the interface of the membrane/solution. The membrane was prepared, based on CMCR as an ionophore, sodium tetrakis(4-fluorophenyl) borate (NaTFPB) as a lipophilic ionic additive, and dioctylphthalate (DOP) as a plasticizer. The immobilization of the ionophore and surface characterization studies revealed that the performance of CMCR-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs). The strengths of the ion-ionophore (CMCR-Ti(OH)(OH(2))(5) (2+)) interactions and the role of ionophores on membranes were studied via UV-Vis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and and X-ray diffraction (XRD).

  2. Immobilization of Ionophore and Surface Characterization Studies of the Titanium(III Ion in a PVC-Membrane Sensor

    Directory of Open Access Journals (Sweden)

    Majid Rezayi

    2012-06-01

    Full Text Available Novel ionophores comprising various hydroxide and amine structures were immobilized onto poly(vinyl chloride (PVC matrices, and these were examined to determine Ti(III selectivity. To predict the selectivity of Ti(III, a PVC membrane was used to investigate the binding of Ti(III to c-methylcalix[4]resorcinarene (CMCR. The study showed that the chelating ligand, CMCR, was coordinated selectively to Ti(III at eight coordination sites involving the oxygen atoms at the interface of the membrane/solution. The membrane was prepared, based on CMCR as an ionophore, sodium tetrakis(4-fluorophenyl borate (NaTFPB as a lipophilic ionic additive, and dioctylphthalate (DOP as a plasticizer. The immobilization of the ionophore and surface characterization studies revealed that the performance of CMCR-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs. The strengths of the ion-ionophore (CMCR-Ti(OH(OH252+ interactions and the role of ionophores on membranes were studied via UV-Vis, Fourier transform infrared spectroscopy (FT–IR, scanning electron microscopy (SEM and and X-ray diffraction (XRD.

  3. Determination of terbium(III) ions in phosphate rock samples by a Tb{sup 3+}-PVC membrane sensor based on N, N-Dimethyl-N', N''-bis(4-methoxyphenyl)phosphoramidate

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of)], E-mail: haszamani@yahoo.com; Ganjali, Mohammad Reza; Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Tadjarodi, Azadeh; Shahsavani, Encyeh [Faculty of Chemistry, Iran University of Science and Technology (IUST), Narmak, 16846, Tehran (Iran, Islamic Republic of)

    2008-12-01

    A poly (vinyl chloride)-based membrane of N, N-Dimethyl-N', N''-bis(4-methoxyphenyl)phosphoramidate (DMP) as a neutral carrier was prepared and investigated as a Tb{sup 3+}-selective electrode. This electrode constructed with sodium tetraphenylborate (NaTPB) as the anion excluder and 2-nitrophenyl octyl ether (NPOE) as the plasticizer. Its performance was found to be the following: a Nernstian slope of 19.7 {+-} 0.4 mV per decade across a broad range (1.0 x 10{sup -6} to 1.0 x 10{sup -1} M); a detection limit of 8.0 x 10{sup -7} M between the pH values of 3.5 and 8.0; additionally, the response time was about 10 s; usage of more than 2 months without any potential divergence; good Tb{sup 3+} selectivity over a wide variety of other metal ions. The membrane sensor was applied to the Tb{sup 3+} recovery from different water samples, determination of fluoride ions in mouth wash samples and the determination of Tb{sup 3+} in phosphate rock samples. It was also used as an indicator electrode in the potentiometric titration of Tb{sup 3+} ions with EDTA.

  4. Molecularly Imprinted Polymer (MIP Based PVC-Membrane-Coated Graphite Electrode for the Determination of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Yohandri Bow

    2015-01-01

    Full Text Available A PVC membrane based on molecularly imprinted polymer (MIP coated directly on graphite electrode for determination of heavy metals in real soil sample is describes. The composite membranes have been prepared by using methacrylic acid (MAA as functional monomer and ethylene glycol dimethyl acrylate (EGDMA as cross linker. MAA was chosen as a functional monomer, as it capable of strong electrostatic interactions with heavy metals. The chemical behaviour of the thin film (MIP were characterized using Scanning Electron Microscopy (SEM. The proposed electrode can be used in the pH range of 4.5-8.5 and revealed good selectivity for heavy metals over a wide variety of ions. Finally, the designed electrode was successfully applied as an indicator electrode to determine concentration of heavy metals in soil.

  5. An electronic tongue using potentiometric all-solid-state PVC-membrane sensors for the simultaneous quantification of ammonium and potassium ions in water

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J.; Alegret, S.; del Valle, M. [Sensors and Biosensors Group, Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193, Bellaterra, Catalonia (Spain); Munoz, R.; De-Roman, M.; Leija, L.; Hernandez, P.R. [Bioelectronics Section, Department of Electrical Engineering, CINVESTAV, Mexico DF (Mexico)

    2003-09-01

    The simultaneous determination of NH{sub 4}{sup +} and K{sup +} in solution has been attempted using a potentiometric sensor array and multivariate calibration. The sensors used are rather non-specific and of all-solid-state type, employing polymeric (PVC) membranes. The subsequent data processing is based on the use of a multilayer artificial neural network (ANN). This approach is given the name ''electronic tongue'' because it mimics the sense of taste in animals. The sensors incorporate, as recognition elements, neutral carriers belonging to the family of the ionophoric antibiotics. In this work the ANN type is optimized by studying its topology, the training algorithm, and the transfer functions. Also, different pretreatments of the starting data are evaluated. The chosen ANN is formed by 8 input neurons, 20 neurons in the hidden layer and 2 neurons in the output layer. The transfer function selected for the hidden layer was sigmoidal and linear for the output layer. It is also recommended to scale the starting data before training. A correct fit for the test data set is obtained when it is trained with the Bayesian regularization algorithm. The viability for the determination of ammonium and potassium ions in synthetic samples was evaluated; cumulative prediction errors of approximately 1% (relative values) were obtained. These results were comparable with those obtained with a generalized regression ANN as a reference algorithm. In a final application, results close to the expected values were obtained for the two considered ions, with concentrations between 0 and 40 mmol L{sup -1}. (orig.)

  6. PVC-MEMBRANE POTENTIOMETRIC SENSORS BASED ON A ...

    African Journals Online (AJOL)

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    2Group of Organometallic Catalysts, Shahid Bahonar University, Kerman, Iran. 3Mineral Industry ... Reagents and materials. Analytical .... The nature and amount of plasticizer on the dielectric constant of the membrane phase, the mobility of ...

  7. Application of N-Quinoline-2-carboxamido-8-aminoquinoline in Fabrication of a Ho(III-PVC Membrane Sensor

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2011-01-01

    Full Text Available The N-quinoline-2-carboxamido-8-aminoquinoline (QCA was used as a suitable ion carrier in the construction of a Ho(III PVC-based membrane sensor. This sensor demonstrated good selectivity and sensitivity towards the holmium ion for a broad variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The proposed electrode exhibits a linear dynamic range between 1.0×10-6 and 1.0×10-2 M, with a near Nernstian slope of 20.4±0.3 mV per decade and a detection limit of 4.2×10-7 M. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride, 56% nitrobenzene, 2% sodium tetraphenyl borate, 10% oleic acid and 2% QCA. The potentiometric response of the constructed electrode is pH independent in the range of 2.4-7.4. The sensor possesses the advantages of short conditioning time, fast response time (∼ 5 s and especially, good selectivity towards transition and heavy metal and some mono, di and trivalent cations. The Ho3+ sensor was successfully applied as an indicator electrode in the potentiometric titration of Ho(III ions with EDTA. The electrode was also used for the determination of Ho3+ ions in mixtures of different ions and the determination of the fluoride ion in mouth wash solutions.

  8. Hydroxy-thioxanthones as suitable neutral ionophores for the preparation of PVC-membrane potentiometric sensors for Al(III) ion.

    Science.gov (United States)

    Shamsipur, Mojtaba; Ershad, Sohrab; Yari, Absollah; Sharghi, Hashem; Salimi, Ali Reza

    2004-02-01

    The complexation of five recently synthesized hydroxy-thioxanthone derivatives with Al3+ ion was studied in a methanol solution spectrophotometrically, and the stepwise formation constants of the resulting 1:1 and 2:1 (ligand-to-metal) complexes were evaluated. The suitability of the thioxanthone derivatives as neutral ionophores for the preparation of a new Al3+ ion-selective PVC-membrane electrode was investigated, and 1-hydroxy-3-methyl-thiocanthone was selected as the best compound for this purpose. The prepared electrode exhibits a Nernstian response for Al3+ ions over a wide concentration range (2.0 x 10(-2) to 2.0 x 10(-6) M), with a limit of detection of 1.0 x 10(-6) M. It has a very fast response time of about 5 s and can be used for at least 3 months without any considerable divergence in the potentials. The proposed membrane sensor revealed very good selectivities for Al3+ over a wide variety of other metal ions, and could be used at a working pH range of 3.4 - 5.0. It was used as an indicator electrode in potentiometric titration of aluminum ions with EDTA, and in the determination of Al3+ in different real samples.

  9. Immobilization of tris(2 pyridyl methylamine in a PVC-Membrane Sensor and Characterization of the Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rezayi Majid

    2012-05-01

    Full Text Available Abstract Background Due to the increasing industrial use of titanium compounds, its determination is the subject of considerable efforts. The ionophore or membrane active recognition is the most important component of any polymeric membrane sensor. The sensor’s response depends on the ionophore and bonding between the ionophore and the target ion. Ionophores with molecule-sized dimensions containing cavities or semi-cavities can surround the target ion. The bond between the ionophore and target ion gives different selectivity and sensitivity toward the other ions. Therefore, ionophores with different binding strengths can be used in the sensor. Results In the present work, poly (vinyl chloride (PVC based membrane incorporating tris (2 pyridyl methylamine (tpm as an ionophore has been prepared and explored as a titanium(III selective sensor. Conclusions The strengths of the ion–ionophore (Ti(OH2+-tpm interactions and the role of ionophore on membrane were tested by various techniques such as elemental analysis, UV–vis, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, and powder X-ray diffraction (XRD. All data approved the successful incorporation of organic group via covalent bond.

  10. Polymeric plasticizer extends the lifetime of PVC-membrane ion-selective electrodes.

    Science.gov (United States)

    Zahran, Elsayed M; New, Andrea; Gavalas, Vasilis; Bachas, Leonidas G

    2014-02-21

    The nature of the plasticizer plays a pivotal role in the analytical performance of polymer membrane ion sensors. Conventional plasticizers suffer leaching or migration from the membrane and exudation, both of which could limit the lifetime of sensors based on plasticized membranes. Herein, we describe the use of polyester sebacate (PES), a model polymeric plasticizer, in the preparation of poly (vinyl chloride) (PVC) membrane ion-selective electrodes (ISEs) using valinomycin as ionophore. PVC membrane electrodes plasticized with polyester sebacate demonstrated potentiometric response characteristics that compared favorably to ones plasticized with the conventional and similarly structured plasticizer bis(2-ethylhexyl) sebacate (DOS). Increasing the content of polyester sebacate in the membrane enhanced the response and improved the selectivity of valinomycin-based ISEs toward potassium over sodium. Various methods, including electrochemical impedance spectroscopy, UV-vis spectroscopy, dark field optical microscopy, and potentiometry were employed to study the effect of plasticizer on the leaching of the membrane components and the lifetime of both DOS- and PES-plasticized membranes. PES-plasticized electrodes maintained Nernstian response and high selectivity for more than four months, an improvement over DOS-plasticized membrane electrodes. This was attributed to enhanced retention of the membrane components because of the high polymeric nature of the polyester sebacate. These characteristics suggest that polyester sebacate is a good candidate to replace the conventional plasticizers in preparing PVC membrane electrodes with longer lifetime.

  11. Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2016-09-01

    Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

  12. The Coated-Wire Ion Selective Electrode (CWISE of Chromate Using PVC-Membrane Based on Chitosan as A Carrier

    Directory of Open Access Journals (Sweden)

    Dedeh Kurniasih

    2012-10-01

    Full Text Available A coated-wire ion selective electrode (CWISE based on chitosan as a carrier for detection of chromate, was developed. CWISE has easy measurement for field analysis, good selectivity and sensitivity. The CWISE’s membrane consist of mixture an active material of chitosan, aliquat 336-chromate, polyvinylchloride (PVC and dioctylphtalate (DOP as plasticizer = 4:0.5:35:60.5 (% w/w dissolved in tetrahydrofuran (THF solvent (1:3 w/v. The electrode exhibited a good Nernstian slope of 29.77±0.03 mV/decade and a linear concentration range from 10-6 to 10-1 M for chromate. The limit of detection was 1.862 x 10-6 M. It had response time of 20 – 40 sec, and could be used for 49 days. This chromate selective-electrode was found more selective towards the chromate ion than other anions, useable in pH range of 5.0 – 9.0 and temperature of 20 – 50 oC. It was applied as an electrode for direct determination of chromate in water samples and their result compared to standard spectrophotometric method.

  13. Development of a PVC-membrane ion-selective bulk optode, for UO2(2+) ion, based on tri-n-octylphosphine oxide and dibenzoylmethane.

    Science.gov (United States)

    Shamsipur, Mojtaba; Tashkhourian, Javad; Sharghi, Hashem

    2005-06-01

    A novel uranyl ion-selective bulk optode membrane, incorporating tri-n-octylphosphine oxide for cation recognition and a lipophilic chromoionophore dibenzoylmethane, has been prepared. The PVC membrane composition was optimized to result in the widest working concentration range. The response range of the proposed optode is 4.1 x 10(-6) to 2.0 x 10(-4) mol L(-1) UO2(2+). The probe works at pH 4.0. Ion interference is low and selectivity, reproducibility, and stability are good.

  14. Development of a PVC-membrane ion-selective bulk optode, for UO{sub 2}{sup 2+} ion, based on tri-n-octylphosphine oxide and dibenzoylmethane

    Energy Technology Data Exchange (ETDEWEB)

    Shamsipur, Mojtaba [Razi University, Department of Chemistry, Kermanshah (Iran); Tashkhourian, Javad; Sharghi, Hashem [Shiraz University, Department of Chemistry, Shiraz (Iran)

    2005-06-01

    A novel uranyl ion-selective bulk optode membrane, incorporating tri-n-octylphosphine oxide for cation recognition and a lipophilic chromoionophore dibenzoylmethane, has been prepared. The PVC membrane composition was optimized to result in the widest working concentration range. The response range of the proposed optode is 4.1 x 10{sup -6} to 2.0 x 10{sup -4} mol L{sup -1} UO{sub 2}{sup 2+}. The probe works at pH 4.0. Ion interference is low and selectivity, reproducibility, and stability are good. (orig.)

  15. N1,N2-Bis [1-(2-hydroxyphenyl)methylidene]ethanedihydrazide as a neutral ionophore for preparation of a new Ho3+ PVC-membrane sensor

    Institute of Scientific and Technical Information of China (English)

    Hassan Ali Zamani

    2011-01-01

    N1,N2-Bis [1-(2-hydroxyphenyl)methylidene]ethanedihydrazide (MEH) was used as new compound which plays the role of an excellent ion carrier in the fabrication of a Ho(Ⅲ) membrane electrode. The electrode shows a good selectivity for Ho(Ⅲ) ion with respect to most common cations including alkali, alkaline earth, transition and heavy metal ions. This electrode has a wide linear dynamic range from 1.0 x 10-6 to 1.0 x 102 mol/L with a Nernstian slope of 19.8 ± 0.3 mV per decade and a low detection limit of 5.8 x 10-7 mol/L in the pH range of 2.5-9.8, while the response time was rapid (<10 s). The suggested sensor was applied to the determination of Ho(Ⅲ) ions in tap water and river water samples.

  16. PVC膜离子选择电极检测下限的优化%Improvement of Lower Detection Limit of Ion-Selective Electrodes Based on PVC Membrane

    Institute of Scientific and Technical Information of China (English)

    黄美荣; 丁永波; 李新贵

    2012-01-01

    Ion-selective electrodes (ISEs) based on polymeric membranes are characterized by small size, portability, low-energy consumption, and low cost, which are attractive features concerning practical applications. However, the lower detection limit is biased by the ion flux through PVC membrane, which limits the further development of ion-selective electrode. Therefore, the principles and attractive strategies to suppress such an ion flux to improve the lower detection limit of PVC membrane-based ion-selective electrodes are elaborated in this article. According to large amounts of data collected, the improvement of the detection limit via optimization of sensing membrane composition, electrode assembly and conditioning, electrode rotation, as well as current- polarized treatment, is quantitatively discussed. Furthermore, the modification regulations for expanding the lower detection limit are systematically summarized. The significant superiority and problems are analyzed. It is pointed out that we have to break the conventional PVC composition formulation via reducing the dosages of plasticizer and ion exchanger in order to largely depress the transmembrane ion flux. External-current application to the electrode is also an effective approach, among which, the best improvement for the lower detection limit can reach up to 5 orders of magnitude. This review reveals the future direction for developing the PVC membrane-based ion-selective electrodes with high performance.%价格低廉、携带方便、适用浓度宽、操作简单快捷、能耗低的离子选择电极在医院、分析实验室、野外等领域得到了越来越广泛的应用。尽管如此,由于PVC膜中存在的离子流严重破坏了更低检测下限的获取,限制了离子选择电极的进一步发展。因此,本文从减小甚至消除PVC膜中存在的离子流角度出发,系统论述了优化PVC膜离子选择电极检测下限的原理和优良策略,根据收集归纳的大量数

  17. The behaviour of polyaniline-coated PVC membrane based on 7, 16-didecyl-1, 4, 10, 13-tetraoxa-7, 16-diazacyclooctadecane for pH measurements in highly acidic media

    Indian Academy of Sciences (India)

    R Ansari; M Arvand; L Heydari

    2014-01-01

    Polyaniline(PANI) chemically coated on poly(vinyl chloride) (PVC) membrane based on a neutral carrier 7,16-didecyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (kryptofix 22 DD) as the active component has been developed for determination of pH values ranging from pH 0.1-1. The effect of experimental parameters such as membrane composition, nature and amount of plasticizer, lipophilic additives and thickness of PANI film on the potential response of the pH electrode was investigated. The electrode has an apparent Nernstian response slope of 54.5 ± 0.4 mV pH-1 (at 20°C). The equilibrium water content of the electrode was determined in pure water and NaCl solution (I = 0.1 mol Kg-1). The electrode had low electric resistance, good potential stability and reproducibility (±1.5 mV, = 10). It has a rapid potential response to changes of pH (15 s). The excellent performance in terms of linearity, stability and fast response makes this device suitable for pH measurements in highly acidic media.

  18. Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode

    OpenAIRE

    Clifton Carey

    2015-01-01

    The PVC membrane of an ion-selective electrode (ISE) sensitive to dibasic phosphate ions (HPO4-ISE) has not been optimized for maximum selectivity, sensitivity, and useable ISE lifetime and further work was necessary to improve its performance. Two areas of investigation are reported here: include the parameters for the lipophilicity of the plasticizer compound used and the amount of cyclic polyamine ionophore incorporated in the PVC membrane. Six candidate plasticizers with a range of lipoph...

  19. PVC-based 1,3,5-trithiane sensor for cerium(III) ions

    Science.gov (United States)

    Shamsipur; Yousefi; Ganjali

    2000-06-01

    A PVC membrane sensor for cerium(III) ions based on 1,3,5-trithiane as membrane carrier was prepared. The sensor has a linear dynamic range of 1.0 x 10(-1)-5.0 x 10(-5) M, with a Nernstian slope of 19.4+/-0.4 mV decade(-1), and a detection limit 3.0 x 10(-5) M. It has a fast response time of fluoride ions and in determination of F- ion in some mouth wash preparations.

  20. Novel potentiometric sensor for monitoring beryllium based on naphto-9-crown-3.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Daftari, Azadeh; Faal-Rastegar, Majid; Moghimi, Abolghasem

    2003-03-01

    A novel poly(vinyl chloride) (PVC) membrane electrode based on naphto-9-crown-3 was prepared and tested for the selective detection of beryllium ions. A suitable lipophilicity of the carrier and appropriate coordination ability were found to be essential for designing an electrode with good response characteristics. A PVC membrane with 9% naphtho-9-crown-3 carrier, 58% o-NPOE plasticizer, 3% tetraphenylborate anionic excluder and 30% poly(vinyl chloride) satisfied these requirements. The proposed sensor displayed a linear response to beryllium over a wide concentration range of 1.0 x 10(-1)-8.0 x 10(-6) M with a Nernstian slope of 29.5 mV per decade. The electrode showed very short response time (<15 s) and could be used in the pH range 3.5-9.0. The selectivity coefficient for alkali, alkaline earth, transition and heavy metal ions was smaller than 4.0 x 10(-4). The sensor was successfully used as an indicator electrode in the potentiometric titration of Be2+ with EDTA. The proposed Be(II) sensor was also used for the determination of Be2+ ions in binary mixtures.

  1. Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode.

    Science.gov (United States)

    Carey, Clifton

    2015-12-01

    The PVC membrane of an ion-selective electrode (ISE) sensitive to dibasic phosphate ions (HPO4-ISE) has not been optimized for maximum selectivity, sensitivity, and useable ISE lifetime and further work was necessary to improve its performance. Two areas of investigation are reported here: include the parameters for the lipophilicity of the plasticizer compound used and the amount of cyclic polyamine ionophore incorporated in the PVC membrane. Six candidate plasticizers with a range of lipophilicity were evaluated for their effect on the useable lifetime, sensitivity, and selectivity of the ISE against 13 different anions. Selectivity was determined by a modified fixed interferent method, sensitivity was determined without interferents, and the usable lifetime evaluated at the elapsed time where 50% of the HPO4-ISE failed (L50). The results show that choosing a plasticizer that has a lipophilicity similar to the ionophore's results in the best selectivity and sensitivity and the longest L50.

  2. Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode

    Directory of Open Access Journals (Sweden)

    Clifton Carey

    2015-12-01

    Full Text Available The PVC membrane of an ion-selective electrode (ISE sensitive to dibasic phosphate ions (HPO4-ISE has not been optimized for maximum selectivity, sensitivity, and useable ISE lifetime and further work was necessary to improve its performance. Two areas of investigation are reported here: include the parameters for the lipophilicity of the plasticizer compound used and the amount of cyclic polyamine ionophore incorporated in the PVC membrane. Six candidate plasticizers with a range of lipophilicity were evaluated for their effect on the useable lifetime, sensitivity, and selectivity of the ISE against 13 different anions. Selectivity was determined by a modified fixed interferent method, sensitivity was determined without interferents, and the usable lifetime evaluated at the elapsed time where 50% of the HPO4-ISE failed (L50. The results show that choosing a plasticizer that has a lipophilicity similar to the ionophore’s results in the best selectivity and sensitivity and the longest L50.

  3. Electrochemical methods for the determination of the diffusion coefficient of ionophores and ionophore-ion complexes in plasticized PVC membranes.

    Science.gov (United States)

    Bodor, Sándor; Zook, Justin M; Lindner, Erno; Tóth, Klára; Gyurcsányi, Róbert E

    2008-05-01

    The diffusion coefficients of active components in ion-selective membranes have a decisive influence on the life-time and detection limit of the respective ion-selective electrodes, as well as influencing the rate of polarization and relaxation processes of electrically perturbed ion sensors. Therefore, the rational design of mass transport controlled ion-selective electrodes with sub-nanomolar detection limits requires reliable data on the diffusion coefficients. We have implemented electrochemical methods for the quantitative assessment of both the diffusion coefficients of free ionophores and ion-ionophore complexes. The diffusion coefficients of the pH-sensitive chromoionophore ETH 5294 and the calcium-selective ionophore ETH 5234 were determined in plasticized PVC membranes with different PVC to plasticizer ratios. The diffusion coefficient of the free chromoionophore determined by a chronoamperometric method was validated with optical methods for a variety of membrane compositions. The calcium-selective ionophore ETH 5234 was used as a model compound to assess the diffusion coefficient of the ion-ionophore complex calculated from the time required for the complexes to cross a freshly prepared membrane during potentiometric ion-breakthrough experiments. The difference between the diffusion coefficients of the free ionophore ETH 5234 and the ion-ionophore complex was found to be significant and correlated well with the geometry of the respective species.

  4. Comparative Study of PVC-Free All-Solid-State, PVC Membrane, and Carbon Paste Ion-Selective Electrodes for the Determination of Dapoxetine Hydrochloride in Pharmaceutical Formulation.

    Science.gov (United States)

    Aziz, Azza; Khamees, Nesrin; Mohamed, Tagreed Abdel-Fattah; Derar, Abeer Rashad

    2016-11-01

    The potentiometric response characteristics and analytical applications of a poly(vinyl chloride) (PVC)-free all-solid-state ion-selective electrode for dapoxetine hydrochloride (DAP) are examined. The Nernstian response of the electrode was evaluated by comparison with PVC-based liquid membrane and carbon paste electrodes. The PVC-free electrode is prepared by direct incorporation of dapoxetine-tetraphenyl borate (DAP-TPB) as a sensing element into a commercial nail varnish containing cellulose acetate propionate. The composite was applied onto a 3 mm diameter graphite disk electrode. The electrode exhibited a Nernstian slope of 56.0 mV/decade in the concentration range of 1 × 10-4 to 1 × 10-2 mol/L with an LOD of 2 × 10-5 mol/L. The electrode is independent of pH in the range of 2 to 6 and showed good selectivity for DAP with respect to a large number of inorganic cations and amino acids. Comparable Nernstian slope, sensitivity, pH range, and selectivity pattern were obtained with a PVC membrane and a carbon paste incorporating DAP-TPB as a sensing element and dioctylphthalate as a solvent mediator. The electrodes were used for the determination of DAP in pure solution and in tablets without extraction with high accuracy and precision (RSD ≤ 2%). The nail varnish solid-state electrode is simple, economical, and rapid when compared with PVC membrane and carbon paste electrodes.

  5. Chemical cleaning of fouled PVC membrane during ultrafiltration of algal-rich water

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Jiayu Tian; Heng Liang; Jun Nan; Zhonglin Chen; Guibai Li

    2011-01-01

    Cleaning of hollow-fibre polyvinyl chloride (PVC) membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents (NaOH, HCl, EDTA, and NaClO), 100 mg/L NaClO exhibited the best performance (88.4% ± 1.1%) in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance (1.5% ± 1.0%) was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could effectively remove the foulants accumulated on the membrane surface.

  6. Lead-selective membrane potentiometric sensor based on a recently synthesized bis(anthraquinone) sulfide derivative

    Energy Technology Data Exchange (ETDEWEB)

    Pouretedal, H.R.; Forghaniha, A.; Sharghi, H. [Shiraz Univ. (Iran, Islamic Republic of). Dept. of Chemistry; Shamsipur, M. [Razi Univ., Kermanshah (Iran, Islamic Republic of). Dept. of Chemistry

    1998-12-01

    The need for monitoring of toxic heavy metal ions in environmental samples has prompted the development of ion-selective electrodes for these ions. A new PVC membrane electrode for lead ions, based on bis[(1-hydroxy-9,10-anthraquinone)-2-methyl]sulfide as membrane carrier, was prepared. The sensor exhibits a Nernstian response for Pb{sup 2+} over a wide concentration range (5.6 {times} 10{sup {minus}3}--4.0 {times} 10{sup {minus}6} M). It has a response time of about 30 s and can be used for at least 3 months without any divergence in potentials. The proposed membrane sensor revealed good selectivities for Pb{sup 2+} over a wide variety of other metal ions. It was used as an indicator electrode in potentiometric titration of lead ion.

  7. Gas permeability of ENR/PVC membrane with the addition of inorganic fillers

    Science.gov (United States)

    Nor, Farhan Mohd; Abdullah, Ibrahim; Othaman, Rizafizah

    2013-11-01

    Epoxidized natural rubber (ENR) was blended with polyvinyl chloride to form a flexible and porous membrane. SiO2 and MgO were added into the membrane for pore formation and the effects of the addition was investigated by means of FTIR, TGA, SEM, EDX and gas permeability towards CO2 and N2 gases. FTIR result showed the presence of Si-O-Si asymmetric stretching at the absorption peak of 467 cm-1 for ENR/PVC/SiO2 membrane and MgO signature peak at 3700 cm-1 for ENR/PVC/MgO membrane. Thermal analysis showed that the thermal stability of ENR/PVC membrane increased with the addition of fillers. Morphological studies prove that subsequently, the pores in the membranes increased showing that some of the added fillers were drawn towards the water leaving empty spaces and tracks. The remaining fillers are homogenously distributed on the surface of the membranes. CO2 and N2 gas permeability increased with increasing filler content and the permeability of ENR/PVC/SiO2 membranes towards CO2 and N2 gasses was higher than ENR/PVC/MgO membranes.

  8. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors.

    Science.gov (United States)

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

    2008-03-11

    Ionophore incorporated PVC membrane sensors are well-established analyticaltools routinely used for the selective and direct measurement of a wide variety of differentions in complex biological and environmental samples. Potentiometric sensors have someoutstanding advantages including simple design and operation, wide linear dynamic range,relatively fast response and rational selectivity. The vital component of such plasticizedPVC members is the ionophore involved, defining the selectivity of the electrodes' complexformation. Molecular recognition causes the formation of many different supramolecules.Different types of supramolecules, like calixarenes, cyclodextrins and podands, have beenused as a sensing material in the construction of ion selective sensors. Schiff's bases andcrown ethers, which feature prominently in supramolecular chemistry, can be used assensing materials in the construction of potentiometric ion selective electrodes. Up to now,more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anioncomplexes will be described. Liquid membrane sensors based on Schiff's bases and crownethers will then be discussed.

  9. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors

    Directory of Open Access Journals (Sweden)

    Siavash Riahi

    2008-03-01

    Full Text Available Ionophore incorporated PVC membrane sensors are well-established analyticaltools routinely used for the selective and direct measurement of a wide variety of differentions in complex biological and environmental samples. Potentiometric sensors have someoutstanding advantages including simple design and operation, wide linear dynamic range,relatively fast response and rational selectivity. The vital component of such plasticizedPVC members is the ionophore involved, defining the selectivity of the electrodes' complexformation. Molecular recognition causes the formation of many different supramolecules.Different types of supramolecules, like calixarenes, cyclodextrins and podands, have beenused as a sensing material in the construction of ion selective sensors. Schiff's bases andcrown ethers, which feature prominently in supramolecular chemistry, can be used assensing materials in the construction of potentiometric ion selective electrodes. Up to now,more than 200 potentiometric membrane sensors for cations and anions based on Schiff'sbases and crown ethers have been reported. In this review cation binding and anioncomplexes will be described. Liquid membrane sensors based on Schiff's bases and crownethers will then be discussed.

  10. A highly selective fluorescent sensor for Cu{sup 2+} based on 2-(2'-hydroxyphenyl)benzoxazole in a poly(vinyl chloride) matrix

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiaobing [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Peng Jing [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); He Chunlian [Medical college, Hunan Normal University, Changsha 410006 (China); Shen Guoli [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Yu Ruqin [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China)]. E-mail: rqyu@hnu.cn

    2006-05-17

    This paper describes a copper selective optical chemical sensor based on static quenching of the fluorescence of 2-(2'-hydroxyphenyl)benzoxazole entrapped in a poly(vinyl chloride) (PVC) membrane. The effect of the composition of the sensing membrane was studied, and experimental conditions were optimized. The sensors exhibit stable response over the concentration range from 4.0 x 10{sup -8} M to 5.0 x 10{sup -5} M Cu{sup 2+} at pH 4.0-6.5, and a high selectivity. The response time for Cu{sup 2+} with concentration {<=}5 x 10{sup -6} M is less than 7 min. The optode can be regenerated using 0.1 M HCl and acetate buffer solution. The sensor has been used for direct measurement of copper content in river water samples with a relative error less than 4% with reference to that obtained by atomic absorption spectrometry.

  11. [Tetrakis(4-N,N-dimethylaminobenzene)porphyrinato]manganese(III) acetate as a novel carrier for a selective iodide PVC membrane electrode.

    Science.gov (United States)

    Farhadi, Khalil; Maleki, Ramin; Yamchi, Rouhollah Hosseinzadeh; Sharghi, Hashem; Shamsipur, Mojtaba

    2004-05-01

    [5,10,15,20-Tetrakis(4-N,N-dimethylaminobenzene)porphyrinato]Mn(III) acetate (MnTDPAc) was applied as an ionophore for an iodide-selective PVC membrane electrode. The influences of the membrane composition, pH of the test solution and foreign ions on the electrode performance were investigated. The sensor exhibited not only excellent selectivity to iodide ion compared to Cl- and lipophilic anions such as ClO4- and salicylate, but also a Nernstian response with a slope of -59.4 +/- 1.2 mV per decade for iodide ions over a wide concentration range from 1.0 x 10(-2) to 7.5 x 10(-6) M at 25 degrees C. The potentiometric response was independent of the pH of the solution in the pH range of 2 - 8. The electrode could be used for at least 2 months without any considerable divergence in the potential. Good selectivity for iodide ion, a very short response time, simple preparation and relatively long-term stability were the silent characteristics of this electrode. It was successfully used as an indicator electrode in the potentiometric titration of iodide ions, and also in the determination of iodide from seawater samples and drug formulations.

  12. PVC Membrane Selective Electrode for Determination of Cadmium(II) Ion in Chocolate Samples

    Institute of Scientific and Technical Information of China (English)

    Sulekh Chandra; Deepshikha Singh; Anjana Sarkar

    2014-01-01

    Benzil bis(carbohydrazone) (BBC) is prepared and explored as new NN Schiff’s base, which plays the role of an excellent ion carrier in the construction of a Cd(II) ion membrane sensor. The tris(2-ethylhexyl) phosphate best performance corresponds to a membrane composition of 30%poly (vinyl chloride), 65%(TEHP), 3.5%BBC and 1.5%tetradodecyl-ammoniumtetrakis(4-chlorophenyl) borate (ETH 500). This sensor shows very good selectivity and sensitivity towards cadmium ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The effect of membrane composition, selectivity, pH and influence of additive on the response properties of electrode were investigated. The response mechanism was discussed in the view of UV-spectroscopy. The electrode exhibits a Nernstian behavior (with slope of 29.7 mV per decade) over a very wide concentration range from 1.0×10-1 to 1.0×10-8 mol·L-1 with a detection limit of 3.2×10-8 mol·L-1. It shows rela-tively fast response time in whole concentration range (<8 s) and can be used for at least 10 weeks in the pH range of 2.0-9.0. The proposed sensor is successfully used for the determination of cadmium in different chocolate sam-ples and as indicator electrode in titration with ethylene diamine tetraacetate (EDTA).

  13. Electrochemical Sensor for the Selective Determination of Prindopril Based on Phosphotungestic Acid Plastic Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Zareh, Mohsen M. [Univ. of Tabuk, Tabuk (Saudi Arabia); Wasel, Anower M. [Association of Drug Agency, Cairo (Egypt); Abd Alkreem, Yasser M. [Zagazig Univ., Zagazig (Egypt)

    2013-10-15

    A novel PVC membrane sensor for perindopril based on perindopril-phosphotungstate ion pair complex was prepared. The influence of membrane composition (i.e. percent of PVC, plasticizer, ion-pair complex, and kind of plasticizer), inner solution, pH of test solution and foreign cations on the electrode performance was investigated. The optimized membrane demonstrates Nernstian response (30.9 ± 1.0 mV per decade) for perindopril cations over a wide linear range from 9.0 Χ 10{sup -7} to 1 Χ 10{sup -2} M at 25 .deg. C. The potentiometric response is independent of the pH in the range of 4.0-9.5. The proposed sensor has the advantages of easy preparation, fast response time. The selectivity coefficients indicate excellent selectivity for perindopril over many common cations (e. g., Na{sup +}, K{sup +}, Mg{sup 2+}, Cu{sup 2+}, Ni{sup 2+}, rhamnose, maltose, glycine and benzamide). The practical applications of this electrode was demonstrated by measuring the concentrations of perindopril in pure solutions and pharmaceutical preparations with satisfactory results.

  14. Comparative studies of praseodymium(III) selective sensors based on newly synthesized Schiff's bases

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinod K., E-mail: vinodfcy@iitr.ernet.in [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Goyal, Rajendra N.; Pal, Manoj K.; Sharma, Ram A. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2009-10-27

    Praseodymium ion selective polyvinyl chloride (PVC) membrane sensors, based on two new Schiff's bases 1,3-diphenylpropane-1,3-diylidenebis(azan-1-ylidene)diphenol (M{sub 1}) and N,N'-bis(pyridoxylideneiminato) ethylene (M{sub 2}) have been developed and studied. The sensor having membrane composition of PVC: o-NPOE: ionophore (M{sub 1}): NaTPB (w/w; mg) of 150: 300: 8: 5 showed best performances in comparison to M{sub 2} based membranes. The sensor based on (M{sub 1}) exhibits the working concentration range 1.0 x 10{sup -8} to 1.0 x 10{sup -2} M with a detection limit of 5.0 x 10{sup -9} M and a Nernstian slope 20.0 {+-} 0.3 mV decade{sup -1} of activity. It exhibited a quick response time as <8 s and its potential responses were pH independent across the range of 3.5-8.5.The influence of the membrane composition and possible interfering ions have also been investigated on the response properties of the electrode. The sensor has been found to work satisfactorily in partially non-aqueous media up to 15% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for praseodymium(III) ions over wide variety of other cations. To asses its analytical applicability the prepared sensor was successfully applied for determination of praseodymium(III) in spiked water samples.

  15. Sensor for Silver(I Ion Based on Schiff-base-p-tertbutylcalix[4]arene

    Directory of Open Access Journals (Sweden)

    M. Kumar

    2002-10-01

    Full Text Available The preparation of polymer membrane selective to silver ion and its application to ion-selective electrode is reported here. PVC membrane contain silver-selective calix[4]arene derivative as ionophore. The membrane electrode is highly selective to silver ion and exhibit good linear response over a wide concentration range of 1.0×10-1 to 1.0×10-5M AgNO3 with Nernstian slope of 58.9 mV per decade. The detection limit of electrode is 6.31×10-6 M .The calix[4]arene based membrane electrode exhibit enhanced selectivities for silver ion over other cations; log KPotAg,Na = -2.35, log KPotAg,K= -2.65, log KPotAg,Mg = -4.57, log KPotAg,Ba = -4.10, log KPotAg,Cd = -3.42, log KPotAg,Pb = -3.45.Even the strongest interferent Hg2+ do not interfere to great extent, log KPotAg,Hg = -2.0.The electrode response is stable over wide pH range of 1.0-6.0. The response time of the sensor is 30 seconds and the membrane can be used for more than 6 months without observing any divergence. The sensor can also be applied as an indicator electrode for potentiometric titration of Ag+ ions with Cl-. It is possible to determine Ag(I in the natural water spiked with silver with this electrode assembly.

  16. Vehicle Based Vector Sensor

    Science.gov (United States)

    2015-09-28

    300001 1 of 16 VEHICLE-BASED VECTOR SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...unmanned underwater vehicle that can function as an acoustic vector sensor . (2) Description of the Prior Art [0004] It is known that a propagating...mechanics. An acoustic vector sensor measures the particle motion via an accelerometer and combines Attorney Docket No. 300001 2 of 16 the

  17. A Novel Tetraiodocadmate(Ⅱ)-PVC Membrane Electrode for the Potentiometric Determination of Cadmium(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Fu Chang WANG; Ya Qin CHAI; Ruo YUAN

    2006-01-01

    A novel tetraiodocadmate(Ⅱ)-selective membrane electrode consisting of tetraiodo-cadmate(Ⅱ)-rhodamin B ion pair (TICRhB) dispersed in a PVC matrix plasticized with 2-nitrophenyl octyl ether (o-NPOE) was prepared. The sensor demonstrated a near-Nernstian response for 1×10-2 to 2×10-6 mol/L cadmium (Ⅱ) at 25℃ with an anionic slope of 29.0. Itrevealed very good selectivity for Cd2+ with negligible interference from many cations and anions,and could be used in a pH range of 3 to 6.

  18. ISFET based enzyme sensors

    NARCIS (Netherlands)

    van der Schoot, Bart H.; Bergveld, Piet

    1987-01-01

    This paper reviews the results that have been reported on ISFET based enzyme sensors. The most important improvement that results from the application of ISFETs instead of glass membrane electrodes is in the method of fabrication. Problems with regard to the pH dependence of the response and the

  19. Nanoparticle-based Sensors

    Directory of Open Access Journals (Sweden)

    V.K. Khanna

    2008-09-01

    Full Text Available Nanoparticles exhibit several unique properties that can be applied to develop chemical and biosensorspossessing desirable features like enhanced sensitivity and lower detection limits. Gold nanoparticles arecoated with sugars tailored to recognise different biological substances. When mixed with a weak solution ofthe sugar-coated nanoparticles, the target substance, e.g., ricin or E.coli, attaches to the sugar, thereby alteringits properties and changing the colour. Spores of bacterium labeled with carbon dots have been found to glowupon illumination when viewed with a confocal microscope. Enzyme/nanoparticle-based optical sensors forthe detection of organophosphate (OP compounds employ nanoparticle-modified fluorescence of an inhibitorof the enzyme to generate the signal for the OP compound detection. Nanoparticles shaped as nanoprisms,built of silver atoms, appear red on exposure to light. These nanoparticles are used as diagnostic labels thatglow when target DNA, e.g., those of anthrax or HIV, are present. Of great importance are tools like goldnanoparticle-enhanced surface-plasmon resonance sensor and silver nanoparticle surface-enhanced portableRaman integrated tunable sensor. Nanoparticle metal oxide chemiresistors using micro electro mechanical systemhotplate are very promising devices for toxic gas sensing. Chemiresistors comprising thin films of nanogoldparticles, encapsulated in monomolecular layers of functionalised alkanethiols, deposited on interdigitatedmicroelectrodes, show resistance changes through reversible absorption of vapours of harmful gases. Thispaper reviews the state-of-the-art sensors for chemical and biological terror agents, indicates their capabilitiesand applications, and presents the future scope of these devices.Defence Science Journal, 2008, 58(5, pp.608-616, DOI:http://dx.doi.org/10.14429/dsj.58.1683

  20. Dysprosium selective potentiometric membrane sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2013-03-01

    A novel Dy(III) ion-selective PVC membrane sensor was made using a new synthesized organic compound, 3,4-diamino-N Prime -((pyridin-2-yl)methylene)benzohydrazide (L) as an excellent sensing element. The electrode showed a Nernstian slope of 19.8 {+-} 0.6 mV per decade in a wide concentration range of 1.0 Multiplication-Sign 10{sup -6}-1.0 Multiplication-Sign 10{sup -2} mol L{sup -1}, a detection limit of 5.5 Multiplication-Sign 10{sup -7} mol L{sup -1}, a short conditioning time, a fast response time (< 10 s), and high selectivity towards Dy(III) ion in contrast to other cations. The proposed sensor was successfully used as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor was also applied to the F{sup -} ion indirect determination of some mouth washing solutions and to the Dy{sup 3+} determination in binary mixtures. Highlights: Black-Right-Pointing-Pointer The novelty of this work is based on the high affinity of the ionophore toward the Dy{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple, fast and inexpensive and it is not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The newly developed sensor is superior to the formerly reported Dy{sup 3+} sensors in terms of selectivity.

  1. A new selectophore for gadolinium selective sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-10-01

    Based on a selective complexation of N′-(2-oxo-1,2-di(pyridin-2-yl)ethylidene)furan-2-carbohydrazide (L) with Gd(III) ions, it was used as a selectophore in construction of a Gd(III) selective PVC membrane sensor. Different compositions for the membrane were tested. The o-nitrophenyloctyl ether (NPOE) was used as suitable plasticizer, and a mixture of sodium tetraphenyl borate (NaTPB) and oleic acid (OA) as anion excluders. The proposed sensor displayed a Nernstian behavior with the slope of 19.9 ± 0.6 mV decade{sup −1} in concentration range of 1.0 × 10{sup −6} to 1.0 × 10{sup −2} mol L{sup −1}. Detection limit was 4.2 × 10{sup −7} mol L{sup −1} and response time was ∼ 10 s. Applicable pH range of the electrode was 4.2–8.0. Lifetime of the sensor is at least 10 weeks. Analysis of certified reference materials confirmed the accuracy of the proposed electrode. - Highlights: • This work reports design of membrane sensor for monitoring of Gd3+ ions. • The novelty of this work is the high affinity of the ionophore toward the Gd3+ ions. • The sensor is superior to the formerly reported Gd3+ sensors in terms of selectivity.

  2. Flexible sensors based on nanoparticles.

    Science.gov (United States)

    Segev-Bar, Meital; Haick, Hossam

    2013-10-22

    Flexible sensors can be envisioned as promising components for smart sensing applications, including consumer electronics, robotics, prosthetics, health care, safety equipment, environmental monitoring, homeland security and space flight. The current review presents a concise, although admittedly nonexhaustive, didactic review of some of the main concepts and approaches related to the use of nanoparticles (NPs) in flexible sensors. The review attempts to pull together different views and terminologies used in the NP-based sensors, mainly those established via electrical transduction approaches, including, but, not confined to: (i) strain-gauges, (ii) flexible multiparametric sensors, and (iii) sensors that are unaffected by mechanical deformation. For each category, the review presents and discusses the common fabrication approaches and state-of-the-art results. The advantages, weak points, and possible routes for future research, highlighting the challenges for NP-based flexible sensors, are presented and discussed as well.

  3. Graphene based piezoresistive pressure sensor

    NARCIS (Netherlands)

    Zhu, S.E.; Ghatkesar, M.K.; Zhang, C.; Janssen, G.C.A.M.

    2013-01-01

    We present a pressure sensor based on the piezoresistive effect of graphene. The sensor is a 100 nm thick, 280 μm wide square silicon nitride membrane with graphene meander patterns located on the maximum strain area. The multilayer, polycrystalline graphene was obtained by chemical vapor

  4. Graphene based piezoresistive pressure sensor

    NARCIS (Netherlands)

    Zhu, S.E.; Ghatkesar, M.K.; Zhang, C.; Janssen, G.C.A.M.

    2013-01-01

    We present a pressure sensor based on the piezoresistive effect of graphene. The sensor is a 100 nm thick, 280 μm wide square silicon nitride membrane with graphene meander patterns located on the maximum strain area. The multilayer, polycrystalline graphene was obtained by chemical vapor deposition

  5. Graphene based piezoresistive pressure sensor

    NARCIS (Netherlands)

    Zhu, S.E.; Ghatkesar, M.K.; Zhang, C.; Janssen, G.C.A.M.

    2013-01-01

    We present a pressure sensor based on the piezoresistive effect of graphene. The sensor is a 100 nm thick, 280 μm wide square silicon nitride membrane with graphene meander patterns located on the maximum strain area. The multilayer, polycrystalline graphene was obtained by chemical vapor deposition

  6. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...

  7. Micro technology based sun sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Pedersen, Martin; Fléron, René

    2003-01-01

    There is increasing interest among universities in the scientific and educational possibilities of picosatellites base on the CubeSat 5 concept. Due to sever mass and dimension constraints place on this type of satellites, new approaches and ideas regarding different systems arises to accommodate...... DTUsat sun sensors are needed along with a magnetometer to obtain unambiguous attitude determination for the ACDS and the payloads - an electrodynamic tether and a camera. The accuracy needed was not obtainable by employing conventional attitude sensors. Hence a linear slit sensor was designed...

  8. Radar based autonomous sensor module

    Science.gov (United States)

    Styles, Tim

    2016-10-01

    Most surveillance systems combine camera sensors with other detection sensors that trigger an alert to a human operator when an object is detected. The detection sensors typically require careful installation and configuration for each application and there is a significant burden on the operator to react to each alert by viewing camera video feeds. A demonstration system known as Sensing for Asset Protection with Integrated Electronic Networked Technology (SAPIENT) has been developed to address these issues using Autonomous Sensor Modules (ASM) and a central High Level Decision Making Module (HLDMM) that can fuse the detections from multiple sensors. This paper describes the 24 GHz radar based ASM, which provides an all-weather, low power and license exempt solution to the problem of wide area surveillance. The radar module autonomously configures itself in response to tasks provided by the HLDMM, steering the transmit beam and setting range resolution and power levels for optimum performance. The results show the detection and classification performance for pedestrians and vehicles in an area of interest, which can be modified by the HLDMM without physical adjustment. The module uses range-Doppler processing for reliable detection of moving objects and combines Radar Cross Section and micro-Doppler characteristics for object classification. Objects are classified as pedestrian or vehicle, with vehicle sub classes based on size. Detections are reported only if the object is detected in a task coverage area and it is classified as an object of interest. The system was shown in a perimeter protection scenario using multiple radar ASMs, laser scanners, thermal cameras and visible band cameras. This combination of sensors enabled the HLDMM to generate reliable alerts with improved discrimination of objects and behaviours of interest.

  9. Reputation-Based Secure Sensor Localization in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jingsha He

    2014-01-01

    Full Text Available Location information of sensor nodes in wireless sensor networks (WSNs is very important, for it makes information that is collected and reported by the sensor nodes spatially meaningful for applications. Since most current sensor localization schemes rely on location information that is provided by beacon nodes for the regular sensor nodes to locate themselves, the accuracy of localization depends on the accuracy of location information from the beacon nodes. Therefore, the security and reliability of the beacon nodes become critical in the localization of regular sensor nodes. In this paper, we propose a reputation-based security scheme for sensor localization to improve the security and the accuracy of sensor localization in hostile or untrusted environments. In our proposed scheme, the reputation of each beacon node is evaluated based on a reputation evaluation model so that regular sensor nodes can get credible location information from highly reputable beacon nodes to accomplish localization. We also perform a set of simulation experiments to demonstrate the effectiveness of the proposed reputation-based security scheme. And our simulation results show that the proposed security scheme can enhance the security and, hence, improve the accuracy of sensor localization in hostile or untrusted environments.

  10. Cobalt(II)-selective membrane electrode based on a recently synthesized benzo-substituted macrocyclic diamide.

    Science.gov (United States)

    Shamsipur, M; Poursaberi, T; Rouhani, S; Niknam, K; Sharghi, H; Ganjali, M R

    2001-09-01

    A PVC-membrane electrode based on a recently synthesized 18-membered macrocyclic diamide is presented. The electrode reveals a Nernstian potentiometric response for Co2+ over a wide concentration range (2.0 x 10(-6)-1.0 x 10(-2) M). The electrode has a response time of about 10 s and can be used for at least 2 months without any divergence. The proposed sensor revealed very good selectivities for Co2+ over a wide variety of other metal ions, and could be used over a wide pH range (3.0-8.0). The detection limit of the sensor is 6.0 x 10(-7) M. It was successfully applied to the direct determination and potentiometric titration of cobalt ion.

  11. Cesium-selective membrane electrode based on a recently synthesized 16-membered macrocyclic diamide.

    Science.gov (United States)

    Shamsipur, M; Kazemi, S Y; Sharghi, H; Niknam, K

    2001-12-01

    A PVC membrane sensor for the Cs+ ion based on 1,5-diaza-2,3,4-naphthyl-8,11,14-trioxacyclohexadecane-6,16-dione (L) has been prepared. The sensor has a linear dynamic range of 5.0 x 10(-1) - 6.9 x 10(-6) mol L(-1), a Nernstian slope of 59.5 +/- 0.8 mV decade(-1), and a detection limit of 4.7 x 10(-6) mol L(-1). It has a fast response time of <15 s and can be used for at least 8 weeks without any considerable divergence in potentials. The selectivity of the proposed electrode relative to alkali, alkaline earth, and transition metal ions was comparatively good. The electrode could be used in the pH range 4.5-11.0.

  12. A novel, fast responding, low noise potentiometric sensor containing a carbon-based polymeric membrane for measuring surfactants in industrial and environmental applications.

    Science.gov (United States)

    Samardžić, Mirela; Galović, Olivera; Hajduković, Mateja; Sak-Bosnar, Milan

    2017-01-01

    A new high-sensitivity potentiometric sensor for anionic surfactants was fabricated using the dimethyldioctadecylammonium-tetraphenylborate (DDA-TPB) ion associate as an ionophore that was incorporated into a liquid PVC membrane. Carbon powder was used for immobilization of the ionophore in the membrane, thus significantly reducing its ohmic resistance and reducing its signal drift. The sensor exhibits a sub-Nernstian response for both dodecylbenzenesulfonate (DBS) and dodecyl sulfate (DS) in H2O (55.3 and 58.5mV/decade of activity, respectively) in a range between 3.2×10(-7) and 4.6×10(-3)M for DS and 2.5×10(-7) and 1.2×10(-3)M for DBS. The sensor also exhibited a sub-Nernstian response for DS and DBS in 10mM Na2SO4 (55.4 and 57.7mV/decade of activity, respectively) between 2.5×10(-7) and 4.6×10(-3)M for DS and 1.5×10(-7) and 8.8×10(-4)M for DBS. The detection limits for DS and DBS in H2O were 2.5×10(-7) and 2.0×10(-7) M and in 10mM Na2SO4 the detection limits were 2.5×10(-7) and 1.2×10(-7) M, respectively. The response time of the sensor was less than 5s for changes at higher concentration levels (above 1×10(-4)M) in both water and 10mM Na2SO4. At lower concentrations (below 1×10(-5)M) the response times were 8 and 6s in water and 10mM Na2SO4, respectively. The signal drift of the sensor was 1.2mV/hour. The new carbon-based sensor exhibited excellent selectivity performance for DS over almost all of the anions commonly present in commercial formulations and it was successfully employed as an end-point detector in potentiometric titrations of anionic surfactants in a pH range from 3 to 12. Three-component mixtures containing sodium alkanesulfonate (C10, C12 and C14) were successfully differentially titrated.

  13. Determination of gadolinium(III) ions in soil and sediment samples by a novel gadolinium membrane sensor based on 6-methyl-4-{l_brace}[1-(2-thienyl)methylidene]amino{r_brace}3-thioxo-3,4-dihydro-1,2,4 -triazin-5-(2H)-one

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali [Department of Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of)], E-mail: haszamani@yahoo.com; Rajabzadeh, Ghadir [Khorasan Science and Technology Park, Mashhad (Iran, Islamic Republic of); Ganjali, Mohammad Reza; Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrine and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2007-08-15

    Highly selective and sensitive poly(vinyl chloride) (PVC) membrane electrodes based on 6-methyl-4-{l_brace}[1-(2-thienyl)methylidene]amino{r_brace}3-thioxo-3,4-dihydro-1,2,4 -triazin-5-(2H)-one (MATDTO) as new carriers for gadolinium ion-selective electrode was reported. The membrane solutions containing PVC, o-nitrophenyl octyl ether (NPOE) as plasticizer, sodium tetraphenyl borate (NaTPB) as lipophilic ionic additive, and MATDTO, displays a calibration response for Gd{sup 3+} ions over a wide concentration range of 1.0 x 10{sup -6}-1.0 x 10{sup -1} M with Nernstian slopes of 19.8 {+-} 0.2 mV per decade and a detection limit as 5.8 x 10{sup -7} M. The sensor has a relatively fast response time of <10 s and can be used in the pH range 3.2-8.7 for at least 2 months without any significant divergence in potentials. The selectivity coefficients for mono-, di-, and trivalent cations indicate good selectivity for Gd(III) ions over a large number of interfering cations. The membrane sensor was used as an indicator electrode in the potentiometric titration of Gd(III) ions with EDTA. The proposed electrode was also applied to the determination of concentration of Gd(III) ions in soil and sediment samples and validation with CRMs.

  14. Copper(II)-selective membrane electrode based on a recently synthesized naphthol-derivative Schiff's base

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, N.; Ershad, S. [Dept. of Chemistry, Tarbiat Moderres Univ., Tehran (Iran); Naeimi, H.; Sharghi, H. [Dept. of Chemistry, Shiraz Univ. (Iran); Shamsipur, M. [Dept. of Chemistry, Razi Univ., Kermanshah (Iran)

    1999-11-01

    A PVC membrane electrode for copper(II) ions based on a recently synthesized naphthol-derivative Schiff's base as membrane carrier was prepared. The sensor exhibits a Nernstian response for Cu{sup 2+} ions over a wide concentration range (5.0 x 10{sup -6}-5.0 x 10{sup -2} mol/L) with a detection limit of 3.1 x 10{sup -6} mol/L (0.2 {mu}g/mL). It has a very short response time of about 5 s and can be used for 3 months without any divergence in potential. The proposed electrode revealed good selectivities over a wide variety of other cations including alkali, alkaline earth, transition and heavy metal ions and could be used in a pH range of 4.0-7.0. It was successfully applied to the direct determination and potentiometric titration of copper ion. (orig.)

  15. Ion Sensor Based on Fluorous Liquid Phase Sensing Membrane with High Selectivity%基于高选择性氟液相传感膜的离子传感器

    Institute of Scientific and Technical Information of China (English)

    黄美荣; 丁永波; 施凤英; 李新贵

    2012-01-01

    本文基于国外最新研究工作,系统总结了电位型传感器中的一种新型传感膜——氟液相传感膜。对构成氟液相传感膜的所有组分:氟溶剂、溶解在氟溶剂中的亲氟离子交换剂和亲氟离子载体以及对氟溶剂起支撑作用的惰性微孔支撑膜等进行了全面归纳,重点讨论了这4种因素对传感器性能的影响。指出目前使用的亲氟离子交换剂分子和亲氟离子载体分子均含有2—8根链长为6—10的全氟碳链。氟液相传感膜具有优于传统PVC膜的检测下限,其中通过三维有序大孔碳以固体接触方式构建的氟液相传感膜电位传感器对Ag+的探测下限可达3.8×10-11mol/L。氟液相传感膜还具有十分出色的选择性,无任何离子载体的空白氟液相传感膜的选择系数对数值log Kpi,oJt的跨越宽度达16—18,比无载体的PVC膜宽8个数量级。这类全新的氟液相传感膜构建的电位型离子传感器将以其独特的优势在环境监测、食品卫生,尤其是在医疗诊断、生物物质检测中展示出不可替代的作用。%New fluorous liquid sensing membranes for the fabrication of potentiometric sensors are systematically summarized. Fluorous solvents, fluorophilic ion-exchangers and fluorophilic ionophores doped in the fluorous solvents, as well as inert fluorous porous supports, are reviewed thoroughly. The influence of the four factors on the performance of potentiometric sensors is concentrated. It is pointed out that both the fluorophilic ion- exchangers and ionophores used so far contain 2--8 perfluoroalkyl chains which are composed of 6--10 carbon atoms in each chain. Such a fluorous liquid phase sensing membrane possesses a superior lower detection limit compared with conventional poly(vinyl chloride)(PVC) membranes. For Ag( I ) potentiometric sensor based on the fluorous liquid membrane with solid contact through three-dimensionally ordered macroporous (3DOM) carbon, the lower

  16. Sensor management based on fisher information gain

    Institute of Scientific and Technical Information of China (English)

    Tian Kangsheng; Zhu Guangxi

    2006-01-01

    Multi-sensor system is becoming increasingly important in a variety of military and civilian applications. In general, single sensor system can only provide partial information about environment while multi-sensor system provides a synergistic effect, which improves the quality and availability of information. Data fusion techniques can effectively combine this environmental information from similar and/or dissimilar sensors. Sensor management, aiming at improving data fusion performance by controlling sensor behavior, plays an important role in a data fusion process. This paper presents a method using fisher information gain based sensor effectiveness metric for sensor assignment in multi-sensor and multi-target tracking applications. The fisher information gain is computed for every sensor-target pairing on each scan. The advantage for this metric over other ones is that the fisher information gain for the target obtained by multi-sensors is equal to the sum of ones obtained by the individual sensor, so standard transportation problem formulation can be used to solve this problem without importing the concept of pseudo sensor. The simulation results show the effectiveness of the method.

  17. A novel highly sensitive and selective optical sensor based on a symmetric tetradentate Schiff-base embedded in PVC polymeric film for determination of Zn{sup 2+} ion in real samples

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Aziz, Ayman A., E-mail: aymanaziz31@gmail.com [Chemistry Department, Faculty of Science, Ain Shams University, 11566 Cairo (Egypt); Chemistry Department, Faculty of Science, University of Tabuk, 71421, Tabuk (Saudi Arabia)

    2013-11-15

    A novel prepared Zn{sup 2+} ion PVC membrane sensor based on a novel Schiff base; N,N′bis(salicylaldehyde)2,3-diaminonaphthalene (SDN) for the determination of Zn{sup 2+} ion was described. The chemosensor was synthesized under microwave irradiation via condensation of 2,3-diaminonaphthalene and salicylaldehyde. Photoluminescence characteristics of the novel Schiff base ligand were investigated in different solvents including dicholoromethane (DCM), tetrahydrofuran (THF) and ethanol (EtOH). SDN was found to have higher emission intensity and Stoke’s shift value (Δλ{sub ST}) in EtOH solution. The sensor exhibited a specific fluorescent on response to Zn{sup 2+}. The response of the sensor is based on the fluorescence enhancement of SDN (LH{sub 2}) by Zn{sup 2+} ion as a result of formation the rigid structure L-Zn complex. The experiment results also show that the response behavior of SDN to Zn{sup 2+} is pH independent in the range of pH 6.0–8.0. At pH 7.0, the proposed sensor displays a calibration response for Zn{sup 2+} over a wide concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1} with a limit of detection (LOD) 8.1×10{sup −10} mol L{sup −1} (0.0529659 μg L{sup −1}). The sensor shows excellent selectivity toward Zn{sup 2+} with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to detect Zn{sup 2+} in human hair samples, different brands of powdered milk and some pharmaceuticals. -- Highlights: • A novel Zn(II) chemosensor has been developed. • Wide linear concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1}. • Application for determination of Zn(II) in real samples.

  18. Wireless SAW Based Temperature Gradient Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Prime Photonics proposes design and development of a surface acoustic wave (SAW) based temperature gradient sensor for instrumentation of thermal protection systems...

  19. Relational-Based Sensor Data Cleansing

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem; Liu, Xiufeng; Nordbjerg, Finn Ebertsen

    2015-01-01

    Today sensors are widely used in many monitoring applications. Due to some random environmental effects and/or sensing failures, the collected sensor data is typically noisy. Thus, it is critical to cleanse the sensor data before using it to answer queries or conduct data analysis. Popular data...... cleansing approaches, such as classification, prediction and moving average are not suited for embedded sensor devices, due to the limited storage and processing capabilities. In this paper, we propose a sensor data cleansing approach using the relational-based technologies, including constraints, triggers...

  20. Nanotube-Based Chemical and Biomolecular Sensors

    Institute of Scientific and Technical Information of China (English)

    J.Koh; B.Kim; S.Hong; H.Lim; H.C.Choi

    2008-01-01

    We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomolecular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) process or "surface programmed assembly" method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.

  1. Manganese(III Porphyrin-based Potentiometric Sensors for Diclofenac Assay in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Eugenia Fagadar-Cosma

    2010-09-01

    Full Text Available Two manganese(III porphyrins: manganese(III tetraphenylporphyrin chloride and manganese(III-tetrakis(3-hydroxyphenylporphyrin chloride were tested as ionophores for the construction of new diclofenac−selective electrodes. The electroactive material was incorporated either in PVC or a sol−gel matrix. The effect of different plasticizers and additives (anionic and cationic on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10−6 – 1 × 10−2 M with a slope of −59.7 mV/dec diclofenac, a detection limit of 1.5 × 10−6 M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

  2. Manganese(III) porphyrin-based potentiometric sensors for diclofenac assay in pharmaceutical preparations.

    Science.gov (United States)

    Vlascici, Dana; Pruneanu, Stela; Olenic, Liliana; Pogacean, Florina; Ostafe, Vasile; Chiriac, Vlad; Pica, Elena Maria; Bolundut, Liviu Calin; Nica, Luminita; Fagadar-Cosma, Eugenia

    2010-01-01

    Two manganese(III) porphyrins: manganese(III) tetraphenylporphyrin chloride and manganese(III)-tetrakis(3-hydroxyphenyl)porphyrin chloride were tested as ionophores for the construction of new diclofenac-selective electrodes. The electroactive material was incorporated either in PVC or a sol-gel matrix. The effect of different plasticizers and additives (anionic and cationic) on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10(-6) - 1 × 10(-2) M with a slope of -59.7 mV/dec diclofenac, a detection limit of 1.5 × 10(-6) M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

  3. Strontium-selective membrane electrodes based on some recently synthesized benzo-substituted macrocyclic diamides.

    Science.gov (United States)

    Shamsipur, M; Rouhani, S; Sharghi, H; Ganjali, M R; Eshghi, H

    1999-11-01

    Eight different recently synthesized macrocyclic diamides were studied to characterize their abilities as strontium ion carriers in PVC membrane electrodes. The electrode based on 1,13-diaza-2,3;11,12-dibenzo-4,7,10-trioxacyclopentadecane-14,15-dione exhibits a Nernstian response for Sr(2+) ions over a wide concentration range (1.0 × 10(-)(1)-3.2 × 10(-)(5) M) with a limit of detection of 8.0 × 10(-)(6) M (0.7 ppm). The response time of the sensor is ∼10 s, and the membrane can be used for more than three months without observing any deviation. The electrode revealed comparatively good selectivities with respect to many alkali, alkaline earth, and transition metal ions. It was used as an indicator electrode in potentiometric titration of carbonate ions with a strontium ion solution.

  4. Relational-Based Sensor Data Cleansing

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem; Nordbjerg, Finn Ebertsen

    2015-01-01

    Today sensors are widely used in many monitoring applications. Due to some random environmental effects and/or sensing failures, the collected sensor data is typically noisy. Thus, it is critical to cleanse the data before using it for answering queries or for data analysis. Popular data cleansing...... approaches, such as classification, prediction and moving average, are not suited for embedded sensor devices, due to their limit storage and processing capabilities. In this paper, we propose a sensor data cleansing approach using the relational-based technologies, including constraints, triggers...

  5. Review of graphene-based strain sensors

    Institute of Scientific and Technical Information of China (English)

    Zhao Jing; Zhang Guang-Yu; Shi Dong-Xia

    2013-01-01

    In this paper,we review various types of graphene-based strain sensors.Graphene is a monolayer of carbon atoms,which exhibits prominent electrical and mechanical properties and can be a good candidate in compact strain sensor applications.However,a perfect graphene is robust and has a low piezoresistive sensitivity.So scientists have been driven to increase the sensitivity using different kinds of methods since the first graphene-based strain sensor was reported.We give a comprehensive review of graphene-based strain sensors with different structures and mechanisms.It is obvious that graphene offers some advantages and has potential for the strain sensor application in the near future.

  6. SU-8 Based Piezoresistive Mechanical Sensor

    DEFF Research Database (Denmark)

    Thaysen, Jacob; Yalcinkaya, Arda Deniz; Vestergaard, R.K.

    2002-01-01

    We present the first SU-8 based piezoresistive mechanical sensor. Conventionally, silicon has been used as a piezoresistive material due to its high gauge factor and thereby high sensitivity to strain changes in a sensor. By using the fact that SU-8 is much softer than silicon and that a gold...

  7. Integrated Temperature Sensors based on Heat Diffusion

    NARCIS (Netherlands)

    Van Vroonhoven, C.P.L.

    2015-01-01

    This thesis describes the theory, design and implementation of a new class of integrated temperature sensors, based on heat diffusion. In such sensors, temperature is sensed by measuring the time it takes for heat to diffuse through silicon. An on-chip thermal delay can be determined by geometry and

  8. LPG based all plastic pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, R.; Leon-Saval, S.

    2015-01-01

    A prototype all-plastic pressure sensor is presented and characterized for potential use as an endoscope. The sensor is based on Long Period Gratings (LPG) inscribed with a CO2 laser in 6-ring microstructured PMMA fiber. Through a latex coated, plastic 3D-printed transducer pod, external pressure...

  9. Recent Advances in Paper-Based Sensors

    Directory of Open Access Journals (Sweden)

    Edith Chow

    2012-08-01

    Full Text Available Paper-based sensors are a new alternative technology for fabricating simple, low-cost, portable and disposable analytical devices for many application areas including clinical diagnosis, food quality control and environmental monitoring. The unique properties of paper which allow passive liquid transport and compatibility with chemicals/biochemicals are the main advantages of using paper as a sensing platform. Depending on the main goal to be achieved in paper-based sensors, the fabrication methods and the analysis techniques can be tuned to fulfill the needs of the end-user. Current paper-based sensors are focused on microfluidic delivery of solution to the detection site whereas more advanced designs involve complex 3-D geometries based on the same microfluidic principles. Although paper-based sensors are very promising, they still suffer from certain limitations such as accuracy and sensitivity. However, it is anticipated that in the future, with advances in fabrication and analytical techniques, that there will be more new and innovative developments in paper-based sensors. These sensors could better meet the current objectives of a viable low-cost and portable device in addition to offering high sensitivity and selectivity, and multiple analyte discrimination. This paper is a review of recent advances in paper-based sensors and covers the following topics: existing fabrication techniques, analytical methods and application areas. Finally, the present challenges and future outlooks are discussed.

  10. Information-based self-organization of sensor nodes of a sensor network

    Science.gov (United States)

    Ko, Teresa H.; Berry, Nina M.

    2011-09-20

    A sensor node detects a plurality of information-based events. The sensor node determines whether at least one other sensor node is an information neighbor of the sensor node based on at least a portion of the plurality of information-based events. The information neighbor has an overlapping field of view with the sensor node. The sensor node sends at least one communication to the at least one other sensor node that is an information neighbor of the sensor node in response to at least one information-based event of the plurality of information-based events.

  11. Refractometric sensor based on silicon photonic wires

    OpenAIRE

    2009-01-01

    We have characterized the refractive index sensing properties of a compact refractometric sensor based on a grated silicon photonic wire. A resolution of $10^{-5}$ in refractive index has been measured.

  12. Atmospheric corrosion sensor based on strain measurement

    Science.gov (United States)

    Kasai, Naoya; Hiroki, Masatoshi; Yamada, Toshirou; Kihira, Hiroshi; Matsuoka, Kazumi; Kuriyama, Yukihisa; Okazaki, Shinji

    2017-01-01

    In this paper, an in situ atmospheric corrosion sensor based on strain measurement is discussed. The theoretical background for measuring the reduction in thickness of low carbon steel is also presented. Based on the theoretical considerations, a test piece and apparatus for an atmospheric corrosion sensor were designed. Furthermore, in a dry–wet cyclic accelerated exposure experiment, the measured strain indicated thinning of the test piece, although the corrosion product generated on the surface of the test piece affected the results. The atmospheric corrosion sensor would be effective for evaluating atmospheric corrosion of many types of infrastructure.

  13. Nanowire-based gas sensors

    NARCIS (Netherlands)

    Chen, X.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.

    2013-01-01

    Gas sensors fabricated with nanowires as the detecting elements are powerful due to their many improved characteristics such as high surface-to-volume ratios, ultrasensitivity, higher selectivity, low power consumption, and fast response. This paper gives an overview on the recent process of the dev

  14. Soil moisture sensors based on metamaterials

    Directory of Open Access Journals (Sweden)

    Goran Kitić

    2012-12-01

    Full Text Available In this paper novel miniature metamaterial-based soil moisture sensors are presented. The sensors are based on resonant-type metamaterials and employ split-ring resonators (SRR, spiral resonators and fractal SRRs to achieve small dimensions, high sensitivity, and compatibility with standard planar fabrication technologies. All these features make the proposedsensors suitable for deployment in agriculture for precise mapping of soil humidity.

  15. Toward Sensor-Based Context Aware Systems

    Directory of Open Access Journals (Sweden)

    Kouhei Takada

    2012-01-01

    Full Text Available This paper proposes a methodology for sensor data interpretation that can combine sensor outputs with contexts represented as sets of annotated business rules. Sensor readings are interpreted to generate events labeled with the appropriate type and level of uncertainty. Then, the appropriate context is selected. Reconciliation of different uncertainty types is achieved by a simple technique that moves uncertainty from events to business rules by generating combs of standard Boolean predicates. Finally, context rules are evaluated together with the events to take a decision. The feasibility of our idea is demonstrated via a case study where a context-reasoning engine has been connected to simulated heartbeat sensors using prerecorded experimental data. We use sensor outputs to identify the proper context of operation of a system and trigger decision-making based on context information.

  16. Bulk disk resonator based ultrasensitive mass sensor

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Davis, Zachary James

    2009-01-01

    In the framework of developing an innovative label-free sensor for multiarrayed biodetection applications, we present a novel bulk resonator based mass sensor. The sensor is a polysilicon disk which shows a Q-factor of 6400 in air at 68.8 MHz, resulting in mass resolutions down in the femtogram...... range. The sensor has been characterized in terms of sensitivity both for distributed mass detection, performing six consecutive depositions of e-beam evaporated Au, and localized mass detection, depositing approximately 7.5 pg of Pt/Ga/C three times consecutively with a Focused Ion Beam system....... The sensor has an extremely high distributed mass to frequency shift sensitivity of 60104 Hzcm2/¿g and shows a localized mass to frequency sensitivity up to 4405 Hz/pg with a localized mass resolution down to 15 fg. The device has been fabricated with a new microfabrication process that uses only two...

  17. LPG based all plastic pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, R.; Leon-Saval, S.

    2015-01-01

    A prototype all-plastic pressure sensor is presented and characterized for potential use as an endoscope. The sensor is based on Long Period Gratings (LPG) inscribed with a CO2 laser in 6-ring microstructured PMMA fiber. Through a latex coated, plastic 3D-printed transducer pod, external pressure...... is converted to longitudinal elongation of the pod and therefore of the fiber containing the LPG. The sensor has been characterised for pressures of up to 160 mBar in an in-house built pressure chamber. Furthermore, the influence of the fiber prestrain, fiber thickness and the effect of different glues...

  18. Gas Sensors Based on Electrodeposited Polymers

    Directory of Open Access Journals (Sweden)

    Boris Lakard

    2015-07-01

    Full Text Available Electrochemically deposited polymers, also called “synthetic metals”, have emerged as potential candidates for chemical sensing due to their interesting and tunable chemical, electrical, and structural properties. In particular, most of these polymers (including polypyrrole, polyaniline, polythiophene and their derivatives can be used as the sensitive layer of conductimetric gas sensors because of their conducting properties. An important advantage of polymer-based gas sensors is their efficiency at room temperature. This characteristic is interesting since most of the commercially-available sensors, usually based on metal oxides, work at high temperatures (300–400 °C. Consequently, polymer-based gas sensors are playing a growing role in the improvement of public health and environment control because they can lead to gas sensors operating with rapid detection, high sensitivity, small size, and specificity in atmospheric conditions. In this review, the recent advances in electrodeposited polymer-based gas sensors are summarized and discussed. It is shown that the sensing characteristics of electrodeposited polymers can be improved by chemical functionalization, nanostructuration, or mixing with other functional materials to form composites or hybrid materials.

  19. A Raspberry Pi-Based Attitude Sensor

    Science.gov (United States)

    Sreejith, A. G.; Mathew, Joice; Sarpotdar, Mayuresh; Mohan, Rekhesh; Nayak, Akshata; Safonova, Margarita; Murthy, Jayant

    We have developed a lightweight low-cost attitude sensor, based on a Raspberry Pi, built with readily available commercial components. It can be used in experiments where weight and power are constrained, such as in high-altitude lightweight balloon flights. This attitude sensor will be used as a major building block in a closed-loop control system with driver motors to stabilize and point cameras and telescopes for astronomical observations from a balloon-borne payload.

  20. A Raspberry Pi-Based Attitude Sensor

    CERN Document Server

    Sreejith, A G; Sarpotdar, Mayuresh; Mohan, Rekhesh; Nayak, Akshata; Safonova, Margarita; Murthy, Jayant

    2014-01-01

    We have developed a lightweight low-cost attitude sensor, based on a Raspberry Pi, built with readily available commercial components. It can be used in experiments where weight and power are constrained, such as in high- altitude lightweight balloon flights. This attitude sensor will be used as a major building block in a closed-loop control system with driver motors to stabilize and point cameras and telescopes for astronomical observations from a balloon-borne payload.

  1. Hadoop-Based Distributed Sensor Node Management System

    National Research Council Canada - National Science Library

    Jung, In-Yong; Kim, Ki-Hyun; Han, Byong-John; Jeong, Chang-Sung

    2014-01-01

    ... and retrieve sensor data periodically from DFS. Additionally, it provides a flexible management scheme for sensor node by reconfiguring firmware or updating configurations and data formats of sensor nodes based on mapreduce framework...

  2. Piezoresistive Chemical Sensors Based on Functionalized Hydrogels

    Directory of Open Access Journals (Sweden)

    Margarita Guenther

    2014-06-01

    Full Text Available Thin films of analyte-specific hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain chemomechanical sensors that can serve as selective biochemical sensors for a continuous monitoring of metabolites. The gel swelling pressure has been monitored in simulated physiological solutions by means of the output signal of piezoresistive sensors. The interference by fructose, human serum albumin, pH, and ionic concentration on glucose sensing was studied. With the help of a database containing the calibration curves of the hydrogel-based sensors at different values of pH and ionic strength, the corrected values of pH and glucose concentration were determined using a novel calibration algorithm.

  3. Pristine carbon nanotubes based resistive temperature sensor

    Science.gov (United States)

    Alam, Md Bayazeed; Saini, Sudhir Kumar; Sharma, Daya Shankar; Agarwal, Pankaj B.

    2016-04-01

    A good sensor must be highly sensitive, faster in response, of low cost cum easily producible, and highly reliable. Incorporation of nano-dimensional particles/ wires makes conventional sensors more effective in terms of fulfilling the above requirements. For example, Carbon Nanotubes (CNTs) are promising sensing element because of its large aspect ratio, unique electronic and thermal properties. In addition to their use for widely reported chemical sensing, it has also been explored for temperature sensing. This paper presents the fabrication of CNTs based temperature sensor, prepared on silicon substrate using low cost spray coating method, which is reliable and reproducible method to prepare uniform CNTs thin films on any substrate. Besides this, simple and inexpensive method of preparation of dispersion of single walled CNTs (SWNTs) in 1,2 dichlorobenzene by using probe type ultrasonicator for debundling the CNTs for improving sensor response were used. The electrical contacts over the dispersed SWNTs were taken using silver paste electrodes. Fabricated sensors clearly show immediate change in resistance as a response to change in temperature of SWNTs. The measured sensitivity (change in resistance with temperature) of the sensor was found ˜ 0.29%/°C in the 25°C to 60°C temperature range.

  4. Wearable tactile sensor based on flexible microfluidics.

    Science.gov (United States)

    Yeo, Joo Chuan; Yu, Jiahao; Koh, Zhao Ming; Wang, Zhiping; Lim, Chwee Teck

    2016-08-16

    In this work, we develop a liquid-based thin film microfluidic tactile sensor of high flexibility, robustness and sensitivity. The microfluidic elastomeric structure comprises a pressure sensitive region and parallel arcs that interface with screen-printed electrodes. The microfluidic sensor is functionalized with a highly conductive metallic liquid, eutectic gallium indium (eGaIn). Microdeformation on the pressure sensor results in fluid displacement which corresponds to a change in electrical resistance. By emulating parallel electrical circuitry in our microchannel design, we reduced the overall electrical resistance of the sensor, therefore enhancing its device sensitivity. Correspondingly, we report a device workable within a range of 4 to 100 kPa and sensitivity of up to 0.05 kPa(-1). We further demonstrate its robustness in withstanding >2500 repeated loading and unloading cycles. Finally, as a proof of concept, we demonstrate that the sensors may be multiplexed to detect forces at multiple regions of the hand. In particular, our sensors registered unique electronic signatures in object grasping, which could provide better assessment of finger dexterity.

  5. An SPR based sensor for allergens detection.

    Science.gov (United States)

    Ashley, J; Piekarska, M; Segers, C; Trinh, L; Rodgers, T; Willey, R; Tothill, I E

    2017-02-15

    A simple, sensitive and label-free optical sensor method was developed for allergens analysis using α-casein as the biomarker for cow's milk detection, to be used directly in final rinse samples of cleaning in place systems (CIP) of food manufacturers. A Surface Plasmon Resonance (SPR) sensor chip consisting of four sensing arrays enabling the measurement of samples and control binding events simultaneously on the sensor surface was employed in this work. SPR offers several advantages in terms of label free detection, real time measurements and superior sensitivity when compared to ELISA based techniques. The gold sensor chip was used to immobilise α-casein-polyclonal antibody using EDC/NHS coupling procedure. The performance of the assay and the sensor was first optimised and characterised in pure buffer conditions giving a detection limit of 58ngmL(-1) as a direct binding assay. The assay sensitivity can be further improved by using sandwich assay format and amplified with nanoparticles. However, at this stage this is not required as the detection limit achieved exceeded the required allergens detection levels of 2µgmL(-1) for α-S1-casein. The sensor demonstrated good selectivity towards the α-casein as the target analyte and adequate recoveries from CIP final rinse wash samples. The sensor would be useful tool for monitoring allergen levels after cleaning procedures, providing additional data that may better inform upon wider food allergen risk management decision(s) that are made by food manufacturer. In particular, this sensor could potentially help validate or optimise cleaning practices for a given food manufacturing process.

  6. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  7. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  8. Sensor Fusion-based Event Detection in Wireless Sensor Networks

    NARCIS (Netherlands)

    Bahrepour, M.; Meratnia, N.; Havinga, P.J.M.

    2009-01-01

    Recently, Wireless Sensor Networks (WSN) community has witnessed an application focus shift. Although, monitoring was the initial application of wireless sensor networks, in-network data processing and (near) real-time actuation capability have made wireless sensor networks suitable candidate for ev

  9. Fuzzy-Based Sensor Fusion for Cognitive Radio-Based Vehicular Ad Hoc and Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mohammad Jalil Piran

    2015-01-01

    Full Text Available In wireless sensor networks, sensor fusion is employed to integrate the acquired data from diverse sensors to provide a unified interpretation. The best and most salient advantage of sensor fusion is to obtain high-level information in both statistical and definitive aspects, which cannot be attained by a single sensor. In this paper, we propose a novel sensor fusion technique based on fuzzy theory for our earlier proposed Cognitive Radio-based Vehicular Ad Hoc and Sensor Networks (CR-VASNET. In the proposed technique, we considered four input sensor readings (antecedents and one output (consequent. The employed mobile nodes in CR-VASNET are supposed to be equipped with diverse sensors, which cater to our antecedent variables, for example, The Jerk, Collision Intensity, and Temperature and Inclination Degree. Crash_Severity is considered as the consequent variable. The processing and fusion of the diverse sensory signals are carried out by fuzzy logic scenario. Accuracy and reliability of the proposed protocol, demonstrated by the simulation results, introduce it as an applicable system to be employed to reduce the causalities rate of the vehicles’ crashes.

  10. Platform Based Design for Automotive Sensor Conditioning

    CERN Document Server

    Fanucci, L; Iozzi, F; Marino, C; Rocchi, A

    2011-01-01

    In this paper a general architecture suitable to interface several kinds of sensors for automotive applications is presented. A platform based design approach is pursued to improve system performance while minimizing time-to-market.. The platform is composed by an analog front-end and a digital section. The latter is based on a microcontroller core (8051 IP by Oregano) plus a set of dedicated hardware dedicated to the complex signal processing required for sensor conditioning. The microcontroller handles also the communication with external devices (as a PC) for data output and fast prototyping. A case study is presented concerning the conditioning of a Gyro yaw rate sensor for automotive applications. Measured performance results outperform current state-of-the-art commercial devices.

  11. LWT Based Sensor Node Signal Processing in Vehicle Surveillance Distributed Sensor Network

    Science.gov (United States)

    Cha, Daehyun; Hwang, Chansik

    Previous vehicle surveillance researches on distributed sensor network focused on overcoming power limitation and communication bandwidth constraints in sensor node. In spite of this constraints, vehicle surveillance sensor node must have signal compression, feature extraction, target localization, noise cancellation and collaborative signal processing with low computation and communication energy dissipation. In this paper, we introduce an algorithm for light-weight wireless sensor node signal processing based on lifting scheme wavelet analysis feature extraction in distributed sensor network.

  12. Position sensor based on slit imaging

    Institute of Scientific and Technical Information of China (English)

    Aijun Zeng(曾爱军); Xiangzhao Wang(王向朝); Yang Bu(步扬); Dailin Li(李代林)

    2004-01-01

    A position sensor based on slit imaging is proposed and its measurement principle is described.An imaging slit is illuminated by a collimated laser beam with square-wave modulation and imaged on a detection double slit through a 4f system.A magnified image of the detection double slit is formed on a bi-cell detector.The position of the imaging slit is obtained by detecting light intensity on two parts of the bi-cell detector.In experiments,the feasibility of the sensor was verified.The repeatability was less than 40 nm.

  13. Soft sensor modeling based on Gaussian processes

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhi-hua; HUANG Guo-hong; SHAO Hui-he

    2005-01-01

    In order to meet the demand of online optimal running, a novel soft sensor modeling approach based on Gaussian processes was proposed. The approach is moderately simple to implement and use without loss of performance. It is trained by optimizing the hyperparameters using the scaled conjugate gradient algorithm with the squared exponential covariance function employed. Experimental simulations show that the soft sensor modeling approach has the advantage via a real-world example in a refinery. Meanwhile, the method opens new possibilities for application of kernel methods to potential fields.

  14. Graphene-Paper Based Electrochemical Sensors

    DEFF Research Database (Denmark)

    Zhang, Minwei; Halder, Arnab; Cao, Xianyi

    2017-01-01

    in electrochemical sensors and energy technologies amongothers. In this chapter, we present some examples to overview recent advances in theresearch and development of two-dimensional (2D) graphene papers as new materialsfor electrochemical sensors. The chapter covers the design, fabrication, functionalizationand...... functionalization ofgraphene papers with polymer and nanoscale functional building blocks for electrochemical-sensing purposes. In terms of electrochemical-sensing applications, the emphasis ison enzyme-graphene and nanoparticle-graphene paper-based systems for the detectionof glucose. We finally conclude...

  15. Porous Alumina Based Capacitive MEMS RH Sensor

    CERN Document Server

    Juhasz, L; Timar-Horvath, Veronika; Desmulliez, Marc; Dhariwal, Resh

    2008-01-01

    The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.

  16. Optic Fiber-Based Dynamic Pressure Sensor

    Institute of Scientific and Technical Information of China (English)

    Jiu-Lin Gan; Hai-Wen Cai; Jian-Xin Geng; Zheng-Qing Pan; Rong-Hui Qu; Zu-Jie Fang

    2008-01-01

    Weigh-in-Motion(WIM) technique is the process of measuring the dynamic tire forces of a moving vehicle and estimating the corresponding tire loads of the static vehicle. Compared with the static weigh station, WIM station is an efficient and cost effective choice that will minimize unneccessary stops and delay for truckers. The way to turn birefringence of single-mode fiber into a prime quality for a powerful and reliable sensor is shown. Preliminary results for the development of a weigh-in-motion (WIM) technique based on sagnac-loop sensor are presented. After a brief description of the sensor and its principle of operation, the theoretical model is developed. Then, a full characterization made in static conditions is presented.

  17. ECCE Toolkit: Prototyping Sensor-Based Interaction

    Science.gov (United States)

    Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

    2017-01-01

    Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit. PMID:28241502

  18. Electrochemical Sensors Based on Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Md. Aminur Rahman

    2009-03-01

    Full Text Available This review focuses on recent contributions in the development of the electrochemical sensors based on carbon nanotubes (CNTs. CNTs have unique mechanical and electronic properties, combined with chemical stability, and behave electrically as a metal or semiconductor, depending on their structure. For sensing applications, CNTs have many advantages such as small size with larger surface area, excellent electron transfer promoting ability when used as electrodes modifier in electrochemical reactions, and easy protein immobilization with retention of its activity for potential biosensors. CNTs play an important role in the performance of electrochemical biosensors, immunosensors, and DNA biosensors. Various methods have been developed for the design of sensors using CNTs in recent years. Herein we summarize the applications of CNTs in the construction of electrochemical sensors and biosensors along with other nanomaterials and conducting polymers.

  19. Gas sensors based on nanostructured materials.

    Science.gov (United States)

    Jiménez-Cadena, Giselle; Riu, Jordi; Rius, F Xavier

    2007-11-01

    Gas detection is important for controlling industrial and vehicle emissions, household security and environmental monitoring. In recent decades many devices have been developed for detecting CO(2), CO, SO(2), O(2), O(3), H(2), Ar, N(2), NH(3), H(2)O and several organic vapours. However, the low selectivity or the high operation temperatures required when most gas sensors are used have prompted the study of new materials and the new properties that come about from using traditional materials in a nanostructured mode. In this paper, we have reviewed the main research studies that have been made of gas sensors that use nanomaterials. The main quality characteristics of these new sensing devices have enabled us to make a critical review of the possible advantages and drawbacks of these nanostructured material-based sensors.

  20. Chemical Sensors Based on Piezoresistive Cantilever Array

    Institute of Scientific and Technical Information of China (English)

    于晓梅; 张大成; 王丛舜; 杜先锋; 王小宝; 阮勇

    2003-01-01

    U-shaped and rectangle piezoresistive cantilever arrays have been designed with the analysing results of stress,noise and sensitivity of the cantilevers. Based on silicon micromachining technology, the piezoresistive cantilevers were fabricated by using polysilicon as the piezoresistive materials. With the measurement results of noise and sensitivity, the Hooge factor is calculated to be 3 × 10-3, the gauge factor is 27, and the minimum detectable deflection of piezoresistive cantilevers are calculated to be 1.0nm for rectangle cantilever and 0.5 nm for the Ushaped cantilever at a 6 V bias voltage and a 1000 Hz measurement bandwidth. Using polymer-coated cantilevers as individual sensors, their responses to water vapour and ammonia were tested by measuring their output voltage signals. The measured results show that the sensor sensitivity to ammonia can reach a few ppm and the sensor responses are quick.

  1. ECCE Toolkit: Prototyping Sensor-Based Interaction.

    Science.gov (United States)

    Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

    2017-02-23

    Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit.

  2. ECCE Toolkit: Prototyping Sensor-Based Interaction

    Directory of Open Access Journals (Sweden)

    Andrea Bellucci

    2017-02-01

    Full Text Available Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators. Prototyping physical interaction is hindered by the challenges of: (1 programming interactions among physical sensors/actuators and digital interfaces; (2 implementing functionality for different platforms in different programming languages; and (3 building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems, a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit.

  3. Electrode-analytical properties of polyvinylchloride membranes based on triple metal-polymeric complexes

    Directory of Open Access Journals (Sweden)

    Katerina V. Matorina

    2015-10-01

    Full Text Available The influence of the nature of the electrode-active substances (EAS, the composition of the external and internal solutions on the formation of the analytical signal of polyvinylchloride (PVC membranes based on associates and triple metal-polymeric complexes (TMPC was established. Dehumidification of synthesized membranes increases with the content of polyvinylpyrrolidone (PVP. The value of the swelling degree is more than two times greater for membranes, which contain as EAS TMPC, relative to membranes based on associates. The value of water absorption of membranes is determined by the nature of EAS. They formed a series of increasing of the swelling degree such as associate < background membrane < TMPC. Swelling of the background membrane is explained by the physical sorption of water molecules on the surface of plasticized membrane. Hydration of PVP macromolecules varies with the introduction of metal ions, macromolecules unit undergoes a conformational transition. PVP macromolecules form tunnels or cavities where complex particles distributed and additional water accumulated through the second coordination layer. Constructed sensors based on TMPC have slope of electrode function equal to 25 mV/pC. Linear dependence of potential on the polymer concentration is observed in the range of 5–7 pC units. Sensors based on associates have slope of the electrode function of 20–25 mV/pC that can be varied depending on the nature of the EAS. Working range is 4–8 pC. Response time of sensor is less than 1 min. The optimal time for conditioning of the synthesized PVC membrane is 24 hours. Potentiometric sensors have been developed for the determination of residual amounts of low molecular PVP which is a food additive E 1201 commonly used for thickening, stabilizing and clarifying of food products. The content of PVP was determined in real objects (apple juice, beer, red wine and cognac with using the polyvinylpyrrolidone sensors (Sr < 0.08. The

  4. Electrospinning cellulose based nanofibers for sensor applications

    Science.gov (United States)

    Nartker, Steven

    2009-12-01

    Bacterial pathogens have recently become a serious threat to the food and water supply. A biosensor based on an electrochemical immunoassay has been developed for detecting food borne pathogens, such as Escherichia coli (E. coli) O157:H7. These sensors consist of several materials including, cellulose, cellulose nitrate, polyaniline and glass fibers. The current sensors have not been optimized in terms of microscale architecture and materials. The major problem associated with the current sensors is the limited concentration range of pathogens that provides a linear response on the concentration conductivity chart. Electrospinning is a process that can be used to create a patterned fiber mat design that will increase the linear range and lower the detection limit of these sensors by improving the microscale architecture. Using the electrospinning process to produce novel mats of cellulose nitrate will offer improved surface area, and the cellulose nitrate can be treated to further improve chemical interactions required for sensor activity. The macro and micro architecture of the sensor is critical to the performance of the sensors. Electrospinning technology can be used to create patterned architectures of nanofibers that will enhance sensor performance. To date electrospinning of cellulose nitrate has not been performed and optimization of the electrospinning process will provide novel materials suitable for applications such as filtration and sensing. The goal of this research is to identify and elucidate the primary materials and process factors necessary to produce cellulose nitrate nanofibers using the electrospinning process that will improve the performance of biosensors. Cellulose nitrate is readily dissolved in common organic solvents such as acetone, tetrahydrofuran (THF) and N,N dimethylformamide (DMF). These solvents can be mixed with other latent solvents such as ethanol and other alcohols to provide a solvent system with good electrospinning behavior

  5. Optical Slot-Waveguide Based Biochemical Sensors

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2009-06-01

    Full Text Available Slot-waveguides allow light to be guided and strongly confined inside a nanometer-scale region of low refractive index. Thus stronger light-analyte interaction can be obtained as compared to that achievable by a conventional waveguide, in which the propagating beam is confined to the high-refractive-index core of the waveguide. In addition, slot-waveguides can be fabricated by employing CMOS compatible materials and technology, enabling miniaturization, integration with electronic, photonic and fluidic components in a chip, and mass production. These advantages have made the use of slot-waveguides for highly sensitive biochemical optical integrated sensors an emerging field. In this paper, recent achievements in slot-waveguide based biochemical sensing will be reviewed. These include slot-waveguide ring resonator based refractometric label-free biosensors, label-based optical sensing, and nano-opto-mechanical sensors.

  6. Carbon nanotube based NEMS actuators and sensors

    Science.gov (United States)

    Forney, Michael; Poler, Jordan

    2011-03-01

    Single-walled carbon nanotubes (SWNTs) have been widely studied due to superior mechanical and electrical properties. We have grown vertically aligned SWNTs (VA-SWNTs) onto microcantilever (MC) arrays, which provides an architecture for novel actuators and sensors. Raman spectroscopy confirms that the CVD-grown nanotubes are SWNTs and SEM confirms aligned growth. As an actuator, this hybrid MC/VA-SWNT system can be electrostatically modulated. SWNTs are excellent electron acceptors, so we can charge up the VA-SWNT array by applying a voltage. The electrostatic repulsion among the charged SWNTs provides a surface stress that induces MC deflection. Simulation results show that a few electrons per SWNT are needed for measureable deflections, and experimental actuators are being characterized by SEM, Raman, and an AFM optical lever system. The applied voltage is sinusoidally modulated, and deflection is measured with a lock-in amplifier. These actuators could be used for nano-manipulation, release of drugs from a capsule, or nano-valves. As a sensor, this MC/VA-SWNT system offers an improved sensitivity for chemical and bio-sensing compared to surface functionalized MC-based sensors. Those sensors only have a 2D sensing surface, but a MC/VA-SWNT system has significantly more sensing surface because the VA-SWNTs extend microns off the MC surface.

  7. A magnetic cell-based sensor.

    Science.gov (United States)

    Wang, Hua; Mahdavi, Alborz; Tirrell, David A; Hajimiri, Ali

    2012-11-07

    Cell-based sensing represents a new paradigm for performing direct and accurate detection of cell- or tissue-specific responses by incorporating living cells or tissues as an integral part of a sensor. Here we report a new magnetic cell-based sensing platform by combining magnetic sensors implemented in the complementary metal-oxide-semiconductor (CMOS) integrated microelectronics process with cardiac progenitor cells that are differentiated directly on-chip. We show that the pulsatile movements of on-chip cardiac progenitor cells can be monitored in a real-time manner. Our work provides a new low-cost approach to enable high-throughput screening systems as used in drug development and hand-held devices for point-of-care (PoC) biomedical diagnostic applications.

  8. Temperature Sensors Based on WGM Optical Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Itchenko, Vladimir; Matsko, Andrey; Strekalov, Dmitry

    2008-01-01

    A proposed technique for measuring temperature would exploit differences between the temperature dependences of the frequencies of two different electromagnetic modes of a whispering gallery-mode (WGM) optical resonator. An apparatus based on this technique was originally intended to be part of a control system for stabilizing a laser frequency in the face of temperature fluctuations. When suitably calibrated, apparatuses based on this technique could also serve as precise temperature sensors for purposes other than stabilization of lasers. A sensor according to the proposal would include (1) a transparent WGM dielectric resonator having at least two different sets of modes characterized by different thermo-optical constants and (2) optoelectronic instrumentation for measuring the difference between the temperature-dependent shifts of the resonance frequencies of the two sets of modes.

  9. Miniaturized optical sensors based on lens arrays

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, M.L.; Larsen, H.E.

    2005-01-01

    A suite of optical sensors based on the use of lenticular arrays for probing mechanical deflections will be displayed. The optical systems are well suited for miniaturization, and utilize speckles as the information-carriers. This implementation allows for acquiring directional information of the...... of the displacement. Systems for probing lateral displacements and in-plane vibrations (1-D and 2-D) are displayed, as will systems for probing angular velocity and torsional vibrations of rotating objects....

  10. Fluorescence-lifetime-based sensors for anions

    Science.gov (United States)

    Teichmann, Maria; Draxler, Sonja; Kieslinger, Dietmar; Lippitsch, Max E.

    1997-05-01

    Sensing of anions has been investigated using the fluorescence decaytime as the information carrier. The sensing mechanism is based on the coextraction of an anion and a proton, and the presence of a fluorophore with a rather long fluorescence decaytime inside the membrane to act as a pH indicator. The relevant theory is discussed shortly. As an example a sensor for nitrate is shown, and the influence of ionic additives on the working function has been investigated.

  11. Ultrasonic Sensor Based 3D Mapping & Localization

    Directory of Open Access Journals (Sweden)

    Shadman Fahim Ahmad

    2016-04-01

    Full Text Available This article provides a basic level introduction to 3D mapping using sonar sensors and localization. It describes the methods used to construct a low-cost autonomous robot along with the hardware and software used as well as an insight to the background of autonomous robotic 3D mapping and localization. We have also given an overview to what the future prospects of the robot may hold in 3D based mapping.

  12. Polymer-based stress sensor with integrated readout

    DEFF Research Database (Denmark)

    Thaysen, Jacob; Yalcinkaya, Arda Deniz; Vettiger, P.

    2002-01-01

    We present a polymer-based mechanical sensor with an integrated strain sensor element. Conventionally, silicon has been used as a piezoresistive material due to its high gauge factor and thereby high sensitivity to strain changes in the sensor. By using the fact that the polymer SU-8 [1] is much...... softer than silicon and that a gold resistor is easily incorporated in SU-8, we have proven that a SU-8-based cantilever sensor is almost as sensitive to stress changes as the silicon piezoresistive cantilever. First, the surface stress sensing principle is discussed, from which it can be shown...... that the SU-8-based sensor is nearly as sensitive as the silicon based mechanical sensor. We hereafter demonstrate the chip fabrication technology of such a sensor, which includes multiple SU-8 and gold layer deposition. The SU-8-based mechanical sensor is finally characterized with respect to sensitivity...

  13. Nanomaterial-based robust oxygen sensor

    Science.gov (United States)

    Goswami, Kisholoy; Sampathkumaran, Uma; Alam, Maksudul; Tseng, Derek; Majumdar, Arun K.; Kazemi, Alex A.

    2007-09-01

    Since the TWA flight 800 accident in July 1996, significant emphasis has been placed on fuel tank safety. The Federal Aviation Administration (FAA) has focused research to support two primary methods of fuel tank protection - ground-based and on-board - both involving fuel tank inerting. Ground-based fuel tank inerting involves some combination of fuel scrubbing and ullage washing with Nitrogen Enriched Air (NEA) while the airplane is on the ground (applicable to all or most operating transport airplanes). On-board fuel tank inerting involves ullage washing with OBIGGS (on-board inert gas generating system), a system that generates NEA during aircraft operations. An OBIGGS generally encompasses an air separation module (ASM) to generate NEA, a compressor, storage tanks, and a distribution system. Essential to the utilization of OBIGGS is an oxygen sensor that can operate inside the aircraft's ullage and assess the effectiveness of the inerting systems. OBIGGS can function economically by precisely knowing when to start and when to stop. Toward achieving these goals, InnoSense LLC is developing an all-optical fuel tank ullage sensor (FTUS) prototype for detecting oxygen in the ullage of an aircraft fuel tank in flight conditions. Data would be presented to show response time and wide dynamic range of the sensor in simulated flight conditions and fuel tank environment.

  14. Dielectric Sensors Based on Electromagnetic Energy Tunneling

    Directory of Open Access Journals (Sweden)

    Omar Siddiqui

    2015-03-01

    Full Text Available We show that metallic wires embedded in narrow waveguide bends and channels demonstrate resonance behavior at specific frequencies. The electromagnetic energy at these resonances tunnels through the narrow waveguide channels with almost no propagation losses. Under the tunneling behavior, high-intensity electromagnetic fields are produced in the vicinity of the metallic wires. These intense field resonances can be exploited to build highly sensitive dielectric sensors. The sensor operation is explained with the help of full-wave simulations. A practical setup consisting of a 3D waveguide bend is presented to experimentally observe the tunneling phenomenon. The tunneling frequency is predicted by determining the input impedance minima through a variational formula based on the Green function of a probe-excited parallel plate waveguide.

  15. Carbon Nanotube-Based Chemical Sensors.

    Science.gov (United States)

    Meyyappan, M

    2016-04-27

    The need to sense gases and vapors arises in numerous scenarios in industrial, environmental, security and medical applications. Traditionally, this activity has utilized bulky instruments to obtain both qualitative and quantitative information on the constituents of the gas mixture. It is ideal to use sensors for this purpose since they are smaller in size and less expensive; however, their performance in the field must match that of established analytical instruments in order to gain acceptance. In this regard, nanomaterials as sensing media offer advantages in sensitivity, preparation of chip-based sensors and construction of electronic nose for selective detection of analytes of interest. This article provides a review of the use of carbon nanotubes in gas and vapor sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Bend-insensitive fiber based vibration sensor

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Baset, Farhana; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2014-05-01

    We report two novel fiber-optic vibration sensors based on standard telecom bend-insensitive fiber (BIF). A tapered BIF forming a fiber Mach-Zehnder interferometer could measure continuous and damped vibration from 1 Hz up to 500 kHz. An enclosed microcantilever is fabricated inside the BIF by chemical etching and fusion spliced with a readout singlemode fiber that exhibits a frequency range from 5 Hz to 10 kHz with high signal-to-noise ratio (SNR) up to 68 dB. The unique double cladding structure of the BIF ensures both sensors with advantages of compactness, high resistance to the external disturbance and stronger mechanical strength.

  17. Adaptive Sensing Based on Profiles for Sensor Systems

    Directory of Open Access Journals (Sweden)

    Yoshiteru Ishida

    2009-10-01

    Full Text Available This paper proposes a profile-based sensing framework for adaptive sensor systems based on models that relate possibly heterogeneous sensor data and profiles generated by the models to detect events. With these concepts, three phases for building the sensor systems are extracted from two examples: a combustion control sensor system for an automobile engine, and a sensor system for home security. The three phases are: modeling, profiling, and managing trade-offs. Designing and building a sensor system involves mapping the signals to a model to achieve a given mission.

  18. A Large Area Tactile Sensor Patch Based on Commercial Force Sensors

    Directory of Open Access Journals (Sweden)

    Alfonso García-Cerezo

    2011-05-01

    Full Text Available This paper reports the design of a tactile sensor patch to cover large areas of robots and machines that interact with human beings. Many devices have been proposed to meet such a demand. These realizations are mostly custom-built or developed in the lab. The sensor of this paper is implemented with commercial force sensors. This has the benefit of a more foreseeable response of the sensor if its behavior is understood as the aggregation of readings from all the individual force sensors in the array. A few reported large area tactile sensors are also based on commercial sensors. However, the one in this paper is the first of this kind based on the use of polymeric commercial force sensing resistors (FSR as unit elements of the array or tactels, which results in a robust sensor. The paper discusses design issues related to some necessary modifications of the force sensor, its assembly in an array, and the signal conditioning. The patch has 16 × 9 force sensors mounted on a flexible printed circuit board with a spatial resolution of 18.5 mm. The force range of a tactel is 6 N and its sensitivity is 0.6 V/N. The array is read at a rate of 78 frames per second. Finally, two simple application examples are also carried out with the sensor mounted on the forearm of a rescue robot that communicates with the sensor through a CAN bus.

  19. Challenges and opportunities of sensor based user empowerment

    OpenAIRE

    Lundberg, Jenny; Gustavsson, Rune

    2011-01-01

    Sensor and sensor networks technology are becoming an increasingly important part of information management infrastructures. Challenges related to collection, processing, analysis and user-centric presentation depending of context are of particular interest. Furthermore, design and implementation of proper respond actions to sensor based information is gaining interest in many applications. In this paper we focus on robust application of sensor based systems. With robust we mean in this conte...

  20. Photonic Crystal Sensors Based on Porous Silicon

    Directory of Open Access Journals (Sweden)

    Claudia Pacholski

    2013-04-01

    Full Text Available Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  1. Photonic crystal sensors based on porous silicon.

    Science.gov (United States)

    Pacholski, Claudia

    2013-04-09

    Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  2. Sensors based on SAW and FBAR technologies

    Science.gov (United States)

    García-Gancedo, L.; Milne, W. I.; Luo, J. K.; Flewitt, A. J.

    2013-08-01

    Over the last few years a number of sensing platforms are being investigated for their use in drug development, microanalysis or medical diagnosis. Lab-on-a-chip (LOC) are devices integrating more than one laboratory functions on a single device chip of a very small size, and typically consist of two main components: microfluidic handling systems and sensors. The physical mechanisms that are generally used for microfluidics and sensors are different, hence making the integration of these components difficult and costly. In this work we present a lab-on-a-chip system based on surface acoustic waves (for fluid manipulation) and film bulk acoustic resonators (for sensing). Coupling surface acoustic waves into liquids induces acoustic streaming and motion of micro-droplets, whilst it is well-known that bulk acoustic waves can be used to fabricate microgravimetric sensors. Both technologies offer exceptional sensitivity and can be fabricated from piezoelectric thin films deposited on Si substrates, reducing the fabrication time/cost of the LOC devices.

  3. Research of marine sensor web based on SOA and EDA

    Science.gov (United States)

    Jiang, Yongguo; Dou, Jinfeng; Guo, Zhongwen; Hu, Keyong

    2015-04-01

    A great deal of ocean sensor observation data exists, for a wide range of marine disciplines, derived from in situ and remote observing platforms, in real-time, near-real-time and delayed mode. Ocean monitoring is routinely completed using sensors and instruments. Standardization is the key requirement for exchanging information about ocean sensors and sensor data and for comparing and combining information from different sensor networks. One or more sensors are often physically integrated into a single ocean `instrument' device, which often brings in many challenges related to diverse sensor data formats, parameters units, different spatiotemporal resolution, application domains, data quality and sensors protocols. To face these challenges requires the standardization efforts aiming at facilitating the so-called Sensor Web, which making it easy to provide public access to sensor data and metadata information. In this paper, a Marine Sensor Web, based on SOA and EDA and integrating the MBARI's PUCK protocol, IEEE 1451 and OGC SWE 2.0, is illustrated with a five-layer architecture. The Web Service layer and Event Process layer are illustrated in detail with an actual example. The demo study has demonstrated that a standard-based system can be built to access sensors and marine instruments distributed globally using common Web browsers for monitoring the environment and oceanic conditions besides marine sensor data on the Web, this framework of Marine Sensor Web can also play an important role in many other domains' information integration.

  4. Membranes of 5,10,15,20-Tetrakis(4-Methoxyphenyl Porphyrinatocobalt (TMOPP-Co (I as MoO42- - Selective Sensors

    Directory of Open Access Journals (Sweden)

    R. Mangla

    2002-05-01

    Full Text Available Polyvinyl chloride (PVC membrane electrodes based on porphyrin 5,10,15,20-tetrakis(4methoxyphenylporphyrinatocobalt (TMOPP-Co (I incorporating sodium tetra phenyl borate (NaTPB as anion excluder and dibutyl phthalate (DBP, dioctyl phthalate (DOP, dibutyl butyl phosphonate (DBBP, tri-n-butyl phosphate (TBP, and 1-chloronaphthalene (CN as plasticizing solvent mediators were prepared and tested for selective detection of molybdate ions. The membrane having anion excluder, NaTPB and DBP as plasticizer (membrane no. 2 proved to be best in terms of working concentration range 5.0×10-5 – 1.0×10-1M with a near – Nernstian slope of 32.0±1.0 mV/decade of activity over the pH range 5.4- 10.5. The response time of this sensor is 18s with a lifetime of about 4 months. The sensor can be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of MoO42- in solutions having up to 25% (v/v non-aqueous fraction.

  5. Performance evaluation of sensor allocation algorithm based on covariance control

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The covariance control capability of sensor allocation algorithms based on covariance control strategy is an important index to evaluate the performance of these algorithms. Owing to lack of standard performance metric indices to evaluate covariance control capability, sensor allocation ratio, etc, there are no guides to follow in the design procedure of sensor allocation algorithm in practical applications. To meet these demands, three quantified performance metric indices are presented, which are average covariance misadjustment quantity (ACMQ), average sensor allocation ratio (ASAR) and matrix metric influence factor (MMIF), where ACMQ, ASAR and MMIF quantify the covariance control capability, the usage of sensor resources and the robustness of sensor allocation algorithm, respectively. Meanwhile, a covariance adaptive sensor allocation algorithm based on a new objective function is proposed to improve the covariance control capability of the algorithm based on information gain. The experiment results show that the proposed algorithm have the advantage over the preceding sensor allocation algorithm in covariance control capability and robustness.

  6. Optimal Sensor Decision Based on Particle Filter

    Institute of Scientific and Technical Information of China (English)

    XU Meng; WANG Hong-wei; HU Shi-qiang

    2006-01-01

    A novel infrared and radar synergistic tracking algorithm, which is based on the idea of closed loop control, and target's motion model identification and particle filter approach, was put forward. In order to improve the observability and filtering divergence of infrared search and tracking, the unscented Kalman filter algorithm that has stronger ability of non-linear approximation was adopted. The polynomial and least square method based on radar and IRST measurements to identify the parameters of the model was proposed, and a "pseudo sensor" was suggested to estimate the target position according to the identified model even if the radar is turned off. At last,the average Kullback-Leibler discrimination distance based on particle filter was used to measure the tracking performance, based on tracking performance and fuzzy stochastic decision, the idea of closed loop was used to retrieve the module parameter of "pseudo sensor". The experimental result indicates that the algorithm can not only limit the radar activity effectively but also keep the tracking accuracy of active/passive system well.

  7. Waveguide-based optical chemical sensor

    Science.gov (United States)

    Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo

    2007-03-13

    The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.

  8. Multimodal use of new coumarin-based fluorescent chemosensors: towards highly selective optical sensors for Hg(2+) probing.

    Science.gov (United States)

    Bazzicalupi, Carla; Caltagirone, Claudia; Cao, Zenfeng; Chen, Qibin; Di Natale, Corrado; Garau, Alessandra; Lippolis, Vito; Lvova, Larisa; Liu, Honglai; Lundström, Ingemar; Mostallino, M Cristina; Nieddu, Mattia; Paolesse, Roberto; Prodi, Luca; Sgarzi, Massimo; Zaccheroni, Nelsi

    2013-10-18

    Despite several types of fluorescent sensing molecules have been proposed and examined to signal Hg(2+) ion binding, the development of fluorescence-based devices for in-field Hg(2+) detection and screening in environmental and industrial samples is still a challenging task. Herein, we report the synthesis and characterization of three new coumarin-based fluorescent chemosensors featuring mixed thia/aza macrocyclic framework as receptors units, that is, ligands L1-L3. These probes revealed an OFF-ON selective response to the presence of Hg(2+) ions in MeCN/H2 O 4:1 (v/v), which allowed imaging of this metal ion in Cos-7 cells in vitro. Once included in silica core-polyethylene glycol (PEG) shell nanoparticles or supported on polyvinyl chloride (PVC)-based polymeric membranes, ligands L1-L3 can also selectively sense Hg(2+) ions in pure water. In particular we have developed an optical sensing array tacking advantage of the fluorescent properties of ligand L3 and based on the computer screen photo assisted technique (CSPT). In the device ligand L3 is dispersed into PVC membranes and it quantitatively responds to Hg(2+) ions in natural water samples.

  9. Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

    Directory of Open Access Journals (Sweden)

    Yuanyuan Li

    2014-01-01

    Full Text Available Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established to analyze the frequency, and a peripheral circuit is designed to measure the micro force. The SAW based micro force sensor is tested to show the reasonable design of detection circuit and the stability of frequency and amplitude.

  10. Resource Discovery in Activity-Based Sensor Networks

    DEFF Research Database (Denmark)

    Bucur, Doina; Bardram, Jakob

    This paper proposes a service discovery protocol for sensor networks that is specifically tailored for use in humancentered pervasive environments. It uses the high-level concept of computational activities (as logical bundles of data and resources) to give sensors in Activity-Based Sensor Networ...

  11. Wave front sensor based on holographic optical elements

    Science.gov (United States)

    Kovalev, M. S.; Krasin, G. K.; Malinina, P. I.; Odinokov, S. B.; Sagatelyan, H. R.

    2016-08-01

    A wavefront sensor (WFS) based on holographic optical elements, namely computer generated Fourier holograms is proposed as a perspective alternative to the Shack-Hartmann sensor. A possibility of single and multimode sensor and the dependence of their characteristics were investigated.

  12. Hydrogel-based sensor for CO2 measurements

    NARCIS (Netherlands)

    Herber, S.; Olthuis, W.; Bergveld, P.; Berg, van den A.

    2004-01-01

    A hydrogel-based sensor is presented for CO2 measurements. The sensor consists of a pressure sensor and porous silicon cover. A pH-sensitive hydrogel is confined between the two parts. Furthermore the porous cover contains a bicarbonate solution and a gaspermeable membrane. CO2 reacts with the solut

  13. Organic Thin-Film Transistor (OTFT-Based Sensors

    Directory of Open Access Journals (Sweden)

    Daniel Elkington

    2014-04-01

    Full Text Available Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

  14. Organic Thin-Film Transistor (OTFT)-Based Sensors

    OpenAIRE

    Daniel Elkington; Nathan Cooling; Warwick Belcher; Dastoor, Paul C; Xiaojing Zhou

    2014-01-01

    Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

  15. Wireless Sensor Network Based Smart Parking System

    National Research Council Canada - National Science Library

    Jeffrey Joseph; Roshan Gajanan Patil; Skanda Kumar Kaipu Narahari; Yogish Didagi; Jyotsna Bapat; Debabrata Das

    2014-01-01

    ... system. Wireless Sensor Networks are one such class of networks, which meet these criteria. These networks consist of spatially distributed sensor motes which work in a co-operative manner to sense and control the environment...

  16. All-plastic fiber-based pressure sensor.

    Science.gov (United States)

    Bundalo, Ivan-Lazar; Lwin, Richard; Leon-Saval, Sergio; Argyros, Alexander

    2016-02-01

    We present a feasibility study and a prototype of an all-plastic fiber-based pressure sensor. The sensor is based on long period gratings inscribed for the first time to the best of our knowledge by a CO2 laser in polymethyl methacrylate (PMMA) microstructured fibers and coupled to a pod-like transducer that converts pressure to strain. The sensor prototype was characterized for pressures up to 150 mbars, and various parameters related to its construction were also characterized in order to enhance sensitivity. We consider this sensor in the context of future applications in endoscopic pressure sensors.

  17. All-plastic fiber-based pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, Richard; Leon-Saval, Sergio

    2016-01-01

    We present a feasibility study and a prototype of an all-plastic fiber-based pressure sensor. The sensor is based on long period gratings inscribed for the first time to the best of our knowledge by a CO2 laser in polymethyl methacrylate (PMMA) microstructured fibers and coupled to a pod......-like transducer that converts pressure to strain. The sensor prototype was characterized for pressures up to 150 mbars, and various parameters related to its construction were also characterized in order to enhance sensitivity. We consider this sensor in the context of future applications in endoscopic pressure...... sensors....

  18. Optical Fiber Sensors Based on Nanoparticle-Embedded Coatings

    Directory of Open Access Journals (Sweden)

    Aitor Urrutia

    2015-01-01

    Full Text Available The use of nanoparticles (NPs in scientific applications has attracted the attention of many researchers in the last few years. The use of NPs can help researchers to tune the physical characteristics of the sensing coating (thickness, roughness, specific area, refractive index, etc. leading to enhanced sensors with response time or sensitivity better than traditional sensing coatings. Additionally, NPs also offer other special properties that depend on their nanometric size, and this is also a source of new sensing applications. This review focuses on the current status of research in the use of NPs within coatings in optical fiber sensing. Most used sensing principles in fiber optics are briefly described and classified into several groups: absorbance-based sensors, interferometric sensors, fluorescence-based sensors, fiber grating sensors, and resonance-based sensors, among others. For each sensor group, specific examples of the utilization of NP-embedded coatings in their sensing structure are reported.

  19. Optical stimulator for vision-based sensors

    DEFF Research Database (Denmark)

    Rössler, Dirk; Pedersen, David Arge Klevang; Benn, Mathias

    2014-01-01

    We have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical...... precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations...... stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high...

  20. Sensors Based on Spectroscopy of Guided Waves

    Science.gov (United States)

    Homola, Jiří

    The last two decades have witnessed remarkable progress in the develpment of affinity biosensors and their applications in areas such as environmental protection, biotechnology, medical diagnostics, drug screening, food safety, and security. An affinity biosensor consists of a transducer and a biological recognition element which is able to interact with a selected analyte. Various optical methods have been exploited in biosensors including fluorescence spectroscopy, interferometry (reflectometric white light interferometry, modal interferometry in optical waveguide structures), and spectroscopy of guided modes of optical waveguides. Optical biosensors based on spectroscopy of guided modes of optical waveguides - grating coupler, resonant mirror, and surface plasmon resonance (SPR) - rely on the measurement of binding-induced refractive index changes and thus are label-free technologies. This paper reviews fundamentals of optical sensors based on spectroscopy of guided modes of optical waveguides and their applications.

  1. Distributed query processing in flash-based sensor networks

    Institute of Scientific and Technical Information of China (English)

    Jianliang XU; Xueyan TANG; Wang-Chien LEE

    2008-01-01

    Wireless sensor networks are used in a large array of applications to capture,collect,and analyze physical environmental data.Many existing sensor systems instruct sensor nodes to report their measurements to central repositories outside the network,which is expensive in energy cost.Recent technological advances in flash memory have given rise to the development of storagecentric sensor networks,where sensor nodes are equipped with high-capacity flash memory storage such that sensor data can b.e stored and managed inside the network to reduce expensive communication.This novel architecture calls for new data management techniques to fully exploit distributed in-network data storage.This paper describes some of our research on distributed query processing in such flash-based sensor networks.Of particular interests are the issues that arise in the design of storage management and indexing structures combining sensor system workload and read/write/erase characteristics of flash memory.

  2. A fluorescent sensing membrane for iodine based on intramolecular excitation energy transfer of anthryl appended porphyrin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A single anthryl appended meso-tetraphenylporphyrin (TPP) dyad has been synthesized and applied in fluorescence sensing of iodine based on the intramolecular excitation energy transfer. The molecular recognition of the sensor is based on the interaction of iodine with inner anthracene moiety of the dyad, while the signal reporter for the recognition process is the TPP fluorescence quenching. Because the emission spectrum of anthracene is largely overlapped with the Soret band absorption of TPP, intramolecular excitation energy transfer interaction occurs between the donor, anthracene and acceptor, TPP. This energy transfer leads to TPP fluorescence emission by excitation of anthracene. The sensor was constructed by immobilizing the dyad in a plasticized poly(vinyl chloride) (PVC) membrane. The sensing membrane shows higher sensitivity compared to the sensors by using anthracene, TPP, or a mixture of anthracene and TPP as sensing materials. Under the optimum conditions, iodine in a sample solution can be determined from 2.04 to 23.6 mmol·L-1 with a detection limit of 33 nmol·L-1. The sensing membrane shows satisfactory response characteristics including good reproducibility, reversibility and stability, as well as the short response time of less than 60 s. Except for Cr2O72- and MnO4-, other common metal ions and anions in foodstuff do not interfere with iodine determination. The proposed method was applied in the determination of iodine in table salt samples. The results agree well with those obtained by other methods.

  3. A fluorescent sensing membrane for iodine based on intramolecular excitation energy transfer of anthryl appended porphyrin

    Institute of Scientific and Technical Information of China (English)

    LONG LiPing; YOU MingXu; WANG Hao; WANG YongXiang; YANG RongHua

    2009-01-01

    A single anthryl appended meso-tetraphenylporphyrin (TPP) dyed has been synthesized and applied in fluorescence sensing of iodine based on the intramolecular excitation energy transfer. The molecular recognition of the sensor is based on the interaction of iodine with inner anthracene moiety of the dyad, while the signal reporter for the recognition process is the TPP fluorescence quenching. Because the emission spectrum of anthracene is largely overlapped with the Soret band absorption of TPP, in-tremolecular excitation energy transfer interaction occurs between the donor, anthracene and acceptor, TPP. This energy transfer leads to TPP fluorescence emission by excitation of anthracene. The sensor was constructed by immobilizing the dyad in a plasticized poly(vinyl chloride) (PVC) membrane. The sensing membrane shows higher sensitivity compared to the sensors by using anthracene, TPP, or a mixture of anthracene and TPP as sensing materials. Under the optimum conditions, iodine in a sample membrane shows satisfactory response characteristics including good reproducibility, reversibility end stability, as well as the short response time of less than 60 s. Except for Cr2O2-7 and MnO-4, other common metal ions and anions in foodstuff do not interfere with iodine determination. The proposed method was applied in the determination of iodine in table salt samples. The results agree well with those obtained by other methods.

  4. Physiological sensor signals classification for healthcare using sensor data fusion and case-based reasoning.

    Science.gov (United States)

    Begum, Shahina; Barua, Shaibal; Ahmed, Mobyen Uddin

    2014-07-03

    Today, clinicians often do diagnosis and classification of diseases based on information collected from several physiological sensor signals. However, sensor signal could easily be vulnerable to uncertain noises or interferences and due to large individual variations sensitivity to different physiological sensors could also vary. Therefore, multiple sensor signal fusion is valuable to provide more robust and reliable decision. This paper demonstrates a physiological sensor signal classification approach using sensor signal fusion and case-based reasoning. The proposed approach has been evaluated to classify Stressed or Relaxed individuals using sensor data fusion. Physiological sensor signals i.e., Heart Rate (HR), Finger Temperature (FT), Respiration Rate (RR), Carbon dioxide (CO2) and Oxygen Saturation (SpO2) are collected during the data collection phase. Here, sensor fusion has been done in two different ways: (i) decision-level fusion using features extracted through traditional approaches; and (ii) data-level fusion using features extracted by means of Multivariate Multiscale Entropy (MMSE). Case-Based Reasoning (CBR) is applied for the classification of the signals. The experimental result shows that the proposed system could classify Stressed or Relaxed individual 87.5% accurately compare to an expert in the domain. So, it shows promising result in the psychophysiological domain and could be possible to adapt this approach to other relevant healthcare systems.

  5. Physiological Sensor Signals Classification for Healthcare Using Sensor Data Fusion and Case-Based Reasoning

    Directory of Open Access Journals (Sweden)

    Shahina Begum

    2014-07-01

    Full Text Available Today, clinicians often do diagnosis and classification of diseases based on information collected from several physiological sensor signals. However, sensor signal could easily be vulnerable to uncertain noises or interferences and due to large individual variations sensitivity to different physiological sensors could also vary. Therefore, multiple sensor signal fusion is valuable to provide more robust and reliable decision. This paper demonstrates a physiological sensor signal classification approach using sensor signal fusion and case-based reasoning. The proposed approach has been evaluated to classify Stressed or Relaxed individuals using sensor data fusion. Physiological sensor signals i.e., Heart Rate (HR, Finger Temperature (FT, Respiration Rate (RR, Carbon dioxide (CO2 and Oxygen Saturation (SpO2 are collected during the data collection phase. Here, sensor fusion has been done in two different ways: (i decision-level fusion using features extracted through traditional approaches; and (ii data-level fusion using features extracted by means of Multivariate Multiscale Entropy (MMSE. Case-Based Reasoning (CBR is applied for the classification of the signals. The experimental result shows that the proposed system could classify Stressed or Relaxed individual 87.5% accurately compare to an expert in the domain. So, it shows promising result in the psychophysiological domain and could be possible to adapt this approach to other relevant healthcare systems.

  6. Zirconia-based solid state chemical gas sensors

    CERN Document Server

    Zhuiykov, S

    2000-01-01

    This paper presents an overview of chemical gas sensors, based on solid state technology, that are sensitive to environmental gases, such as O sub 2 , SO sub x , NO sub x , CO sub 2 and hydrocarbons. The paper is focussed on performance of electrochemical gas sensors that are based on zirconia as a solid electrolyte. The paper considers sensor structures and selection of electrode materials. Impact of interfaces on sensor performance is discussed. This paper also provides a brief overview of electrochemical properties of zirconia and their effect on sensor performance. Impact of auxiliary materials on sensors performance characteristics, such as sensitivity, selectivity, response time and recovery time, is also discussed. Dual gas sensors that can be applied for simultaneous monitoring of the concentration of both oxygen and other gas phase components, are briefly considered

  7. Copper(II)-selective fluorimetric bulk optode membrane based on a 1-hydroxy-9,10-anthraquinone derivative having two propenyl arms as a neutral fluorogenic ionophore.

    Science.gov (United States)

    Shamsipur, Mojtaba; Poursaberi, Tahereh; Avanes, Armen; Sharghi, Hashem

    2006-01-01

    A new optical chemical sensor has been developed for the selective determination of copper(II) ions in aqueous solutions. The reversible sensing system was prepared by incorporating 1-hydroxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a neutral Cu2+-selective fluoroionophore in the plasticized PVC membrane with potassium tetrakis(p-chlorophenyl borate) as an anionic additive. The response of the sensor is based on the fluorescence quenching of AQ by Cu2+ ions. At a pH 5.5, the proposed sensor displays a calibration response for Cu2+ over a wide concentration range of 1.0 x 10(-2) to 1.0 x 10(-6) M, with a relatively fast response of less than 40 s. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Cu2+ ion with respect to common co-existing cations. The proposed fluorescence optode was applied successfully to the determination of copper(II) in black tea samples.

  8. Carbon-Nanotube-Based Chemical Gas Sensor

    Science.gov (United States)

    Kaul, Arunpama B.

    2010-01-01

    Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.

  9. Optical Sensors Based on Plastic Fibers

    Science.gov (United States)

    Bilro, Lúcia; Alberto, Nélia; Pinto, João L.; Nogueira, Rogério

    2012-01-01

    The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this paper, the current state of the art of plastic optical fiber technology will be reviewed, namely its main characteristics and sensing advantages. Several measurement techniques will be described, with a strong focus on interrogation approaches based on intensity variation in transmission and reflection. The potential applications involving structural health monitoring, medicine, environment and the biological and chemical area are also presented. PMID:23112707

  10. Optical Sensors Based on Plastic Fibers

    Directory of Open Access Journals (Sweden)

    Rogério Nogueira

    2012-09-01

    Full Text Available The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this paper, the current state of the art of plastic optical fiber technology will be reviewed, namely its main characteristics and sensing advantages. Several measurement techniques will be described, with a strong focus on interrogation approaches based on intensity variation in transmission and reflection. The potential applications involving structural health monitoring, medicine, environment and the biological and chemical area are also presented.

  11. ELECTRIC FIELD SENSORS BASED ON MEMS TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    Gong Chao; Xia Shanhong; Deng Kai; Bai Qiang; Chen Shaofeng

    2005-01-01

    The design and optimization of two types of novel miniature vibrating Electric Field Sensors (EFSs) based on Micro Electro Mechanical Systems (MEMS) technology are presented.They have different structures and vibrating modes. The volume is much smaller than other types of charge-induced EFSs such as field-mills. As miniaturizing, the induced signal is reduced enormously and a high sensitive circuit is needed to detect it. Elaborately designed electrodes can increase the amplitude of the output current, making the detecting circuit simplified and improving the signal-to-noise ratio. Computer simulations for different structural parameters of the EFSs and vibrating methods have been carried out by Finite Element Method (FEM). It is proved that the new structures are realizable and the output signals are detectable.

  12. Detection of Salmonella typhimurium using phage-based magnetostrictive sensor

    Science.gov (United States)

    Lakshmanan, Ramji S.; Hu, Jing; Guntupalli, Rajesh; Wan, Jiehui; Huang, Shichu; Yang, Hong; Petrenko, Valery A.; Barbaree, James M.; Chin, Bryan A.

    2006-05-01

    This article presents a contactless, remote sensing Salmonella typhimurium sensor based on the principle of magnetostriction. Magnetostrictive materials have been used widely for various types of sensor systems. In this work, the use of a magnetostrictive material for the detection of Salmonella typhimurium has been established. The mass of the bacteria attached to the sensor causes changes in the resonance frequency of the sensor. Filamentous bacteriophage was used as a probe order to ensure specific and selective binding of the bacteria onto the sensor surface. Thus changes in response of the sensor due to the mass added onto the sensor caused by specific attachment of bacteria can be monitored in absence of any contact to the sensor. The response of the sensor due to increasing concentrations (from 5x101 to 5x10 8 cfu/ml) of the bacteria was studied. A reduction in the physical dimensions enhances the sensitivity of these sensors and hence different dimensions of the sensor ribbons were studied. For a 2mm x 0.1mm x 0.02mm the detection limit was observed to be of the order of 10 4 cfu/mL and for a sensor of 1mm x 0.2mm x 0.02mm a reduced detection limit of 10 3 cfu/mL was achieved.

  13. Sensor-based demand controlled ventilation

    Energy Technology Data Exchange (ETDEWEB)

    De Almeida, A.T. [Universidade de Coimbra (Portugal). Dep. Eng. Electrotecnica; Fisk, W.J. [Lawrence Berkeley National Lab., CA (United States)

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  14. Ultra-Sensitivity Glucose Sensor Based on Field Emitters

    Directory of Open Access Journals (Sweden)

    Song Yinglin

    2009-01-01

    Full Text Available Abstract A new glucose sensor based on field emitter of ZnO nanorod arrays (ZNA was fabricated. This new type of ZNA field emitter-based sensor shows high sensitivity with experimental limit of detection of 1 nM glucose solution and a detection range from 1 nM to 50 μM in air at room temperature, which is lower than that of glucose sensors based on surface plasmon resonance spectroscopy, fluorescence signal transmission, and electrochemical signal transduction. The new glucose sensor provides a key technique for promising consuming application in biological system for detecting low levels of glucose on single cells or bacterial cultures.

  15. Development of GaN-based micro chemical sensor nodes

    Science.gov (United States)

    Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.

    2005-01-01

    Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.

  16. Neural network-based sensor signal accelerator.

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, M. C.

    2000-10-16

    A strategy has been developed to computationally accelerate the response time of a generic electronic sensor. The strategy can be deployed as an algorithm in a control system or as a physical interface (on an embedded microcontroller) between a slower responding external sensor and a higher-speed control system. Optional code implementations are available to adjust algorithm performance when computational capability is limited. In one option, the actual sensor signal can be sampled at the slower rate with adaptive linear neural networks predicting the sensor's future output and interpolating intermediate synthetic output values. In another option, a synchronized collection of predictors sequentially controls the corresponding synthetic output voltage. Error is adaptively corrected in both options. The core strategy has been demonstrated with automotive oxygen sensor data. A prototype interface device is under construction. The response speed increase afforded by this strategy could greatly offset the cost of developing a replacement sensor with a faster physical response time.

  17. Distance Based Fault detection in wireless sensor network

    Directory of Open Access Journals (Sweden)

    Ayasha Siddiqua

    2013-05-01

    Full Text Available Wireless Sensor Network (WSNs have become a new information collection and monitoring solution for a variety of application. In WSN, sensor nodes have strong hardware and software restrictionin terms of processing power, memory capability, power supply and communication throughput. Due to these restrictions, fault may occur in sensor. This paper presents a distance based fault detection (DBFDmethod for wireless sensor network using the average of confidence level and sensed data of sensor node. Simulation results show that sensor nodes with permanent faults and without fault which was judged as faulty are identified with high accuracy for a wide range of fault rate, and keep false alarm rate for different levels of sensor fault model and also correct nodes are identified by accuracy.

  18. Optical fiber based slide tactile sensor for underwater robots

    Institute of Scientific and Technical Information of China (English)

    TAN Ding-zhong; WANG Qi-ming; SONG Rui-han; YAO Xin; GU Yi-hua

    2008-01-01

    In the underwater environment,many visual sensors don't work,and many sensors which work well for robots working in space or on land can not be used underwater.Therefore,an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers.The principles and structure of the sensor are explained in detail.Its static and dynamic characteristics were analyzed theoretically and then simulated.A dynamic characteristic model was built and the simulation made using the GA based neural network.In order to improve sensor response,the recognition model of the sensor was designed based on the'inverse solution'principle of neural networks,increasing the control precision and the sensitivity of the manipulator.

  19. Applications of FBG-based sensors to ground stability monitoring

    Institute of Scientific and Technical Information of China (English)

    An-Bin Huang; Chien-Chih Wang; Jui-Ting Lee; Yen-Te Ho

    2016-01-01

    Over the past few decades, many optical fiber sensing techniques have been developed. Among these available sensing methods, optical fiber Bragg grating (FBG) is probably the most popular one. With its unique capabilities, FBG-based geotechnical sensors can be used as a sensor array for distributive (profile) measurements, deployed under water (submersible), for localized high resolution and/or dif-ferential measurements. The authors have developed a series of FBG-based transducers that include inclination, linear displacement and gauge/differential pore pressure sensors. Techniques that involve the field deployment of FBG inclination, extension and pore-pressure sensor arrays for automated slope stability and ground subsidence monitoring have been developed. The paper provides a background of FBG and the design concepts behind the FBG-based field monitoring sensors. Cases of field monitoring using the FBG sensor arrays are presented, and their practical implications are discussed.

  20. Catalytic sensor based continuous emissions monitor in boiler applications

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, P.F.; Devita, S.P.; Budd, A. [Monitor Labs, Inc., Englewood, CO (United States)

    1997-12-31

    Until the development of reliable, solid state NO{sub x} sensors, sensor based continuous monitoring of NO{sub x} emissions was primarily by predictive or parametric methods which use data collected from other types of sensors to predict what a NO{sub x} sensor would read. While some success has been achieved using these methods, direct measurement of desired exhaust gases provides greater confidence than can be achieved using modeling approaches. The recent development of a solid state catalytic NO{sub x} sensor allowed development of an analyzer combining the advantages of sensors with the direct measurement capability of traditional continuous emissions monitors. The new sensor based analyzer, the CEMcat{trademark} continuous emissions monitor, utilizes a single, compact, sensor module containing the three sensors for NO{sub x}, CO and O{sub 2} measurement. Its development was sponsored by the Gas Research Institute (GRI), and additional support was provided by the Southern California Gas Co. The use of the CEMcat analyzer to monitor emissions from gas turbine engines and large gas-fired reciprocating engines has previously been reported. In these applications, the CEMcat analyzer demonstrated its capability to meet 40CFR60 relative accuracy requirements. This sensor based analyzer has recently been applied in boiler applications.

  1. Mammalian Cell-Based Sensor System

    Science.gov (United States)

    Banerjee, Pratik; Franz, Briana; Bhunia, Arun K.

    Use of living cells or cellular components in biosensors is receiving increased attention and opens a whole new area of functional diagnostics. The term "mammalian cell-based biosensor" is designated to biosensors utilizing mammalian cells as the biorecognition element. Cell-based assays, such as high-throughput screening (HTS) or cytotoxicity testing, have already emerged as dependable and promising approaches to measure the functionality or toxicity of a compound (in case of HTS); or to probe the presence of pathogenic or toxigenic entities in clinical, environmental, or food samples. External stimuli or changes in cellular microenvironment sometimes perturb the "normal" physiological activities of mammalian cells, thus allowing CBBs to screen, monitor, and measure the analyte-induced changes. The advantage of CBBs is that they can report the presence or absence of active components, such as live pathogens or active toxins. In some cases, mammalian cells or plasma membranes are used as electrical capacitors and cell-cell and cell-substrate contact is measured via conductivity or electrical impedance. In addition, cytopathogenicity or cytotoxicity induced by pathogens or toxins resulting in apoptosis or necrosis could be measured via optical devices using fluorescence or luminescence. This chapter focuses mainly on the type and applications of different mammalian cell-based sensor systems.

  2. CMOS-based Integrated Wavefront Sensor

    NARCIS (Netherlands)

    De Lima Monteiro, D.W.

    2002-01-01

    This thesis addresses the design, implementation and performance of an integrated Hartmann-Shack wavefront sensor suitable for real-time operation and compatible with a standard technology. A wavefront sensor can be used for the detection of distortions in the profile of a light beam or of an optica

  3. Calculating Traffic based on Road Sensor Data

    NARCIS (Netherlands)

    Bisseling, Rob; Gao, Fengnan; Hafkenscheid, Patrick; Idema, Reijer; Jetka, Tomasz; Guerra Ones, Valia; Sikora, Monika

    2014-01-01

    Road sensors gather a lot of statistical data about traffic. In this paper, we discuss how a measure for the amount of traffic on the roads can be derived from this data, such that the measure is independent of the number and placement of sensors, and the calculations can be performed quickly for la

  4. MEMS-based thermoelectric infrared sensors: A review

    Science.gov (United States)

    Xu, Dehui; Wang, Yuelin; Xiong, Bin; Li, Tie

    2017-06-01

    In the past decade, micro-electromechanical systems (MEMS)-based thermoelectric infrared (IR) sensors have received considerable attention because of the advances in micromachining technology. This paper presents a review of MEMS-based thermoelectric IR sensors. The first part describes the physics of the device and discusses the figures of merit. The second part discusses the sensing materials, thermal isolation microstructures, absorber designs, and packaging methods for these sensors and provides examples. Moreover, the status of sensor implementation technology is examined from a historical perspective by presenting findings from the early years to the most recent findings.

  5. Coal mine gas monitoring system based on wireless sensor network

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; WANG Ru-lin; WANG Xue-min; SHEN Chuan-he

    2007-01-01

    Based on the nowadays'condition.it is urgent that the gas detection cable communication system must be replaced by the wireless communication systems.The wireless sensors distributed in the environment can achieve the intelligent gas monitoring system.Apply with multilayer data fuse to design working tactics,and import the artificial neural networks to analyze detecting result.The wireless sensors system communicates with the controI center through the optical fiber cable.All the gas sensor nodes distributed in coal mine are combined into an intelligent,flexible structure wireless network system.forming coal mine gas monitoring system based on wireless sensor network.

  6. Dynamic gesture recognition based on multiple sensors fusion technology.

    Science.gov (United States)

    Wenhui, Wang; Xiang, Chen; Kongqiao, Wang; Xu, Zhang; Jihai, Yang

    2009-01-01

    This paper investigates the roles of a three-axis accelerometer, surface electromyography sensors and a webcam for dynamic gesture recognition. A decision-level multiple sensor fusion method based on action elements is proposed to distinguish a set of 20 kinds of dynamic hand gestures. Experiments are designed and conducted to collect three kinds of sensor data stream simultaneously during gesture implementation and compare the performance of different subsets in gesture recognition. Experimental results from three subjects show that the combination of three kinds of sensor achieves recognition accuracies at 87.5%-91.8%, which are higher largely than that of the single sensor conditions. This study is valuable to realize continuous and dynamic gesture recognition based on multiple sensor fusion technology for multi-model interaction.

  7. Interoperability in wireless sensor networks based on IEEE 1451 standard

    OpenAIRE

    Higuera Portilla, Jorge Eduardo; Polo Cantero, José

    2012-01-01

    The syntactic and semantic interoperability is a challenge of the Wireless Sensor Networks (WSN) with smart sensors in pervasive computing environments to increase their harmonization in a wide variety of applications. This chapter contains a detailed description of interoperability in heterogeneous WSN using the IEEE 1451 standard. This work focuses on personal area networks (PAN) with smart sensors and actuators. Also, a technical, syntactic and semantic levels of interoperability based on ...

  8. Interoperability in wireless sensor networks based on IEEE 1451 standard

    OpenAIRE

    Higuera Portilla, Jorge Eduardo; Polo Cantero, José

    2012-01-01

    The syntactic and semantic interoperability is a challenge of the Wireless Sensor Networks (WSN) with smart sensors in pervasive computing environments to increase their harmonization in a wide variety of applications. This chapter contains a detailed description of interoperability in heterogeneous WSN using the IEEE 1451 standard. This work focuses on personal area networks (PAN) with smart sensors and actuators. Also, a technical, syntactic and semantic levels of interoperability based on ...

  9. Highly Sensitive Flexible Magnetic Sensor Based on Anisotropic Magnetoresistance Effect.

    Science.gov (United States)

    Wang, Zhiguang; Wang, Xinjun; Li, Menghui; Gao, Yuan; Hu, Zhongqiang; Nan, Tianxiang; Liang, Xianfeng; Chen, Huaihao; Yang, Jia; Cash, Syd; Sun, Nian-Xiang

    2016-11-01

    A highly sensitive flexible magnetic sensor based on the anisotropic magnetoresistance effect is fabricated. A limit of detection of 150 nT is observed and excellent deformation stability is achieved after wrapping of the flexible sensor, with bending radii down to 5 mm. The flexible AMR sensor is used to read a magnetic pattern with a thickness of 10 μm that is formed by ferrite magnetic inks.

  10. Platform-based Shear Force Sensor

    Directory of Open Access Journals (Sweden)

    Wang Wei-Chih

    2015-01-01

    Full Text Available In this paper, we will present the development of a flexible fiber optic bend loss sensor for the measurement of plantar pressure and shear stress for diabetic patients. The sensor will allow the measurement of shear stress on the foot, which is a critical parameter in studying diabetic foot ulcers. The basic configuration of the optical sensor systems incorporates a mesh that is comprised of two sets of parallel optical waveguide planes; the planes are configured so the parallel rows of waveguides of the top and bottom planes are perpendicular to each other. The planes are sandwiched together creating one sensing sheet. Two-dimensional information is determined by measuring the loss of light from each of the waveguide to map the overall pressure distribution. The shifting of the layers relative to each other produces different patterns of the sensor output, and shear force information is characterized through repeated training of the sensor and analysis of the training data. The latest development and improvement in the sensors design is presented. Fabrication and sensor characterization results will be presented.

  11. Reagentless, Structure-Switching, Electrochemical Aptamer-Based Sensors

    Science.gov (United States)

    Schoukroun-Barnes, Lauren R.; Macazo, Florika C.; Gutierrez, Brenda; Lottermoser, Justine; Liu, Juan; White, Ryan J.

    2016-06-01

    The development of structure-switching, electrochemical, aptamer-based sensors over the past ˜10 years has led to a variety of reagentless sensors capable of analytical detection in a range of sample matrices. The crux of this methodology is the coupling of target-induced conformation changes of a redox-labeled aptamer with electrochemical detection of the resulting altered charge transfer rate between the redox molecule and electrode surface. Using aptamer recognition expands the highly sensitive detection ability of electrochemistry to a range of previously inaccessible analytes. In this review, we focus on the methods of sensor fabrication and how sensor signaling is affected by fabrication parameters. We then discuss recent studies addressing the fundamentals of sensor signaling as well as quantitative characterization of the analytical performance of electrochemical aptamer-based sensors. Although the limits of detection of reported electrochemical aptamer-based sensors do not often reach that of gold-standard methods such as enzyme-linked immunosorbent assays, the operational convenience of the sensor platform enables exciting analytical applications that we address. Using illustrative examples, we highlight recent advances in the field that impact important areas of analytical chemistry. Finally, we discuss the challenges and prospects for this class of sensors.

  12. Reagentless, Structure-Switching, Electrochemical Aptamer-Based Sensors.

    Science.gov (United States)

    Schoukroun-Barnes, Lauren R; Macazo, Florika C; Gutierrez, Brenda; Lottermoser, Justine; Liu, Juan; White, Ryan J

    2016-06-12

    The development of structure-switching, electrochemical, aptamer-based sensors over the past ∼10 years has led to a variety of reagentless sensors capable of analytical detection in a range of sample matrices. The crux of this methodology is the coupling of target-induced conformation changes of a redox-labeled aptamer with electrochemical detection of the resulting altered charge transfer rate between the redox molecule and electrode surface. Using aptamer recognition expands the highly sensitive detection ability of electrochemistry to a range of previously inaccessible analytes. In this review, we focus on the methods of sensor fabrication and how sensor signaling is affected by fabrication parameters. We then discuss recent studies addressing the fundamentals of sensor signaling as well as quantitative characterization of the analytical performance of electrochemical aptamer-based sensors. Although the limits of detection of reported electrochemical aptamer-based sensors do not often reach that of gold-standard methods such as enzyme-linked immunosorbent assays, the operational convenience of the sensor platform enables exciting analytical applications that we address. Using illustrative examples, we highlight recent advances in the field that impact important areas of analytical chemistry. Finally, we discuss the challenges and prospects for this class of sensors.

  13. Patient Posture Monitoring System Based on Flexible Sensors

    Directory of Open Access Journals (Sweden)

    Youngsu Cha

    2017-03-01

    Full Text Available Monitoring patients using vision cameras can cause privacy intrusion problems. In this paper, we propose a patient position monitoring system based on a patient cloth with unobtrusive sensors. We use flexible sensors based on polyvinylidene fluoride, which is a flexible piezoelectric material. Theflexiblesensorsareinsertedintopartsclosetothekneeandhipoftheloosepatientcloth. We measure electrical signals from the sensors caused by the piezoelectric effect when the knee and hip in the cloth are bent. The measured sensor outputs are transferred to a computer via Bluetooth. We use a custom-made program to detect the position of the patient through a rule-based algorithm and the sensor outputs. The detectable postures are based on six human motions in and around a bed. The proposed system can detect the patient positions with a success rate over 88 percent for three patients.

  14. sensor for mainstream capnography based on TDLAS

    Science.gov (United States)

    Hartmann, A.; Strzoda, R.; Schrobenhauser, R.; Weigel, R.

    2014-09-01

    The setup and signal processing for a mainstream capnography sensor is presented in this paper. The probe exhibits an optical path length of 2.5 cm and is equipped with a vertical-cavity surface-emitting laser at 2 μm. The sensor does not need any calibration, since the CO2 absorption line as well as the laser background is measured using direct tunable diode laser absorption spectroscopy. Unavoidable optical fringes are reduced with a self-developed fringe rejection method. The sensor achieves a concentration resolution 30 Hz.

  15. Study of SAW Based on a Micro Force Sensor in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2017-01-01

    Full Text Available Wireless sensor network (WSN technology has increasingly assumed an active role in detection, identification, location, and tracking applications after more than ten years of development. However, its application still suffers from technology bottlenecks, which must be solved and perfected to eliminate the key problems of the technology. This article investigates WSN acquisition nodes and analyzes the relationship between the frequency and actual pressure values of sensor nodes. The sensitive mechanism of the surface acoustic wave (SAW based on a micro force sensor is researched, and the principle of least squares method is used to establish a transformation model of frequency and pressure for the SAW sensor. According to the model, polyfit function and matrix calculation are selected to solve and calculate the estimate of the polynomial coefficients, which simulate the data acquisition of WSN nodes and draw a polynomial curve fitting. The actual SAW sensor is tested to demonstrate the reasonableness of the device stability in WSNs.

  16. A Novel Fluorescent Optode for Recognition of Zn(2+) ion Based on N,N(')-bis-(1-Hydroxypheylimine)2,5-Thiophenedicarobxaldehyde (HPTD) Schiff Base.

    Science.gov (United States)

    Abdel Aziz, Ayman A; Seda, Sabry H

    2015-11-01

    A novel fluorescent sensing film has been proposed for sensitive determination of Zn(2+) ion in EtOH-HEPES buffer solution (20 mM HEPES, 50:50, v/v, pH 7.0). The novel sensor based on incorporating a novel qaudridentate Schiff base N,N(')-bis-(1-hydroxypheylimine)2,5-thiophenedicarobxaldehyde (HPTD) as ionophore in the plasticized PVC membrane containing bis(2-ethylhexyl)sebecate (DOS) as plasticizer. The novel optode membrane works on the basis of a cation-exchange mechanism and shows a significant fluorescent emission enhancement on exposure to HEPES buffer solution of pH 7.0 containing Zn(2+) ion. Under optimal conditions, the proposed sensing film displays a linear range of 1.0 × 10(-12) to 8.6 × 10(-4) M with a limit of detection 5.3 × 10(-13) M. The response characteristics of the sensor including reversibility, reproducibility, response time and lifetime are discussed in detail. The optode membrane has been applied to determine Zn(2+) in various real water samples.

  17. Fluorescent sensors based on bacterial fusion proteins

    Science.gov (United States)

    Prats Mateu, Batirtze; Kainz, Birgit; Pum, Dietmar; Sleytr, Uwe B.; Toca-Herrera, José L.

    2014-06-01

    Fluorescence proteins are widely used as markers for biomedical and technological purposes. Therefore, the aim of this project was to create a fluorescent sensor, based in the green and cyan fluorescent protein, using bacterial S-layers proteins as scaffold for the fluorescent tag. We report the cloning, expression and purification of three S-layer fluorescent proteins: SgsE-EGFP, SgsE-ECFP and SgsE-13aa-ECFP, this last containing a 13-amino acid rigid linker. The pH dependence of the fluorescence intensity of the S-layer fusion proteins, monitored by fluorescence spectroscopy, showed that the ECFP tag was more stable than EGFP. Furthermore, the fluorescent fusion proteins were reassembled on silica particles modified with cationic and anionic polyelectrolytes. Zeta potential measurements confirmed the particle coatings and indicated their colloidal stability. Flow cytometry and fluorescence microscopy showed that the fluorescence of the fusion proteins was pH dependent and sensitive to the underlying polyelectrolyte coating. This might suggest that the fluorescent tag is not completely exposed to the bulk media as an independent moiety. Finally, it was found out that viscosity enhanced the fluorescence intensity of the three fluorescent S-layer proteins.

  18. A wearable sensor based on CLYC scintillators

    Science.gov (United States)

    McDonald, Benjamin S.; Myjak, Mitchell J.; Zalavadia, Mital A.; Smart, John E.; Willett, Jesse A.; Landgren, Peter C.; Greulich, Christopher R.

    2016-06-01

    We have developed a wearable radiation sensor using Cs2LiYCl6:Ce (CLYC) for simultaneous gamma-ray and neutron detection. The system includes two ∅ 2.5 × 2.5cm3 crystals coupled to small, metal-body photomultiplier tubes. A custom, low-power electronics base digitizes the output signal at three time points and enables both pulse height and pulse shape discrimination of gamma rays and neutrons. The total counts, anomaly detection metrics, and identified isotopes are displayed on a small screen. Users may leave the device in unattended mode to collect long-dwell energy spectra. The system stores up to 18 h of one-second data, including energy spectra, and may transfer the data to a remote computer via a wired or wireless connection. The prototype is 18 × 13 × 7.5cm3, weighs 1.3 kg, not including the protective pouch, and runs on six AA alkaline batteries for 29 h with the wireless link active, or 41 h with the wireless link disabled. In this paper, we summarize the system design and present characterization results from the detector modules. The energy resolution is about 6.5% full width at half maximum at 662 keV due to the small photomultiplier tube selected, and the linearity and pulse shape discrimination performance are very good.

  19. A wearable sensor based on CLYC scintillators

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Benjamin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Myjak, Mitchell J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zalavadia, Mital A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smart, John E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Willett, Jesse A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Landgren, Peter C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greulich, Christopher R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-01

    We developed a wearable radiation sensor using Cs2LiYCl6:Ce (CLYC) for simultaneous gamma-ray and neutron detection. The system includes two ø2.5×2.5 cm3 crystals coupled to small, metal-body photomultiplier tubes. A custom, low-power electronics base digitizes the output signal at three time points and enables both pulse height and pulse shape discrimination of neutrons and gamma-rays. Data, including spectra, can be transferred via a wired or wireless connection. The total gamma-ray and neutron counts, anomaly detection metrics, and identified isotopes are displayed on a small screen on the device. Users may leave the system in unattended mode to collect long-dwell energy spectra. The prototype system has overall dimensions of 13×7.5×18 cm3 and weight of 1.3 kg, not including the protective pouch, and runs on six AA alkaline batteries for 29 hours with a 1% wireless transmission duty cycle and 41 hours with the wireless turned off . In this paper, we summarize the system design and present characterization results from the detector modules. The energy resolution is about 6.5% full width at half maximum at 662 keV due to the small photomultiplier tube selected, and the linearity and pulse shape discrimination performance are very good.

  20. Gum Sensor: A Stretchable, Wearable, and Foldable Sensor Based on Carbon Nanotube/Chewing Gum Membrane.

    Science.gov (United States)

    Darabi, Mohammad Ali; Khosrozadeh, Ali; Wang, Quan; Xing, Malcolm

    2015-12-02

    Presented in this work is a novel and facile approach to fabricate an elastic, attachable, and cost-efficient carbon nanotube (CNT)-based strain gauge which can be efficiently used as bodily motion sensors. An innovative and unique method is introduced to align CNTs without external excitations or any complicated procedure. In this design, CNTs are aligned and distributed uniformly on the entire chewing gum by multiple stretching and folding technique. The current sensor is demonstrated to be a linear strain sensor for at least strains up to 200% and can detect strains as high as 530% with a high sensitivity ranging from 12 to 25 and high durability. The gum sensor has been used as bodily motion sensors, and outstanding results are achieved; the sensitivity is quite high, capable of tracing slow breathing. Since the gum sensor can be patterned into various forms, it has wide applications in miniaturized sensors and biochips. Interestingly, we revealed that our gum sensor has the ability to monitor humidity changes with high sensitivity and fast resistance response capable of monitoring human breathing.

  1. A sequential injection electronic tongue employing the transient response from potentiometric sensors for anion multidetermination.

    Science.gov (United States)

    Cortina, M; Duran, A; Alegret, S; del Valle, M

    2006-08-01

    Intelligent and automatic systems based on arrays of non-specific-response chemical sensors were recently developed in our laboratory. For multidetermination applications, the normal choice is an array of potentiometric sensors to generate the signal, and an artificial neural network (ANN) correctly trained to obtain the calibration model. As a great amount of information is required for the proper modelling, we proposed its automated generation by using the sequential injection analysis (SIA) technique. First signals used were steady-state: the equilibrium signal after a step-change in concentration. We have now adapted our procedures to record the transient response corresponding to a sample step. The novelty in this approach is therefore the use of the dynamic components of the signal in order to better discriminate or differentiate a sample. In the developed electronic tongue systems, detection is carried out by using a sensor array formed by five potentiometric sensors based on PVC membranes. For the developed application we employed two different chloride-selective sensors, two nitrate-selective sensors and one generic response sensor. As the amount of raw data (fivefold recordings corresponding to the five sensors) is excessive for an ANN, some feature extraction step prior to the modelling was needed. In order to attain substantial data reduction and noise filtering, the data obtained were fitted with orthonormal Legendre polynomials. In this case, a third-degree Legendre polynomial was shown to be sufficient to fit the data. The coefficients of these polynomials were the input information fed into the ANN used to model the concentrations of the determined species (Cl-, NO3- and HCO3-). Best results were obtained by using a backpropagation neural network trained with the Bayesian regularisation algorithm; the net had a single hidden layer containing three neurons with the tansig transfer function. The results obtained from the time-dependent response were

  2. An efficient and selective flourescent optode membrane based on 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione as a novel fluoroionophore for determination of cobalt(II) ions.

    Science.gov (United States)

    Shamsipur, Mojtaba; Sadeghi, Marzieh; Alizadeh, Kamal; Sharghi, Hashem; Khalifeh, Reza

    2008-12-07

    A novel fluorescence chemical sensor for the highly sensitive and selective determination of Co(2+) ions in aqueous solutions is prepared. The cobalt sensing system was prepared by incorporating 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione (L) as a neutral cobalt-selective fluoroionophore in the plasticized PVC membrane containing sodium tetraphenylborate as a liphophilic anionic additive. The response of the sensor is based on the strong selective fluorescence quenching of L by Co(2+) ions. At a pH 5.0, the proposed sensor displays a calibration curve over a wide concentration range of 5.0 x 10(-7) to 2.0 x 10(-2)M with a relatively fast response time of less than 5 min. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Co(2+) ion with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to the determination of cobalt content of vitamin B12 ampoule, cobalt cake, cobalt alloy and tap water samples.

  3. Biomimetic virus-based colourimetric sensors

    Science.gov (United States)

    Oh, Jin-Woo; Chung, Woo-Jae; Heo, Kwang; Jin, Hyo-Eon; Lee, Byung Yang; Wang, Eddie; Zueger, Chris; Wong, Winnie; Meyer, Joel; Kim, Chuntae; Lee, So-Young; Kim, Won-Geun; Zemla, Marcin; Auer, Manfred; Hexemer, Alexander; Lee, Seung-Wuk

    2014-01-01

    Many materials in nature change colours in response to stimuli, making them attractive for use as sensor platform. However, both natural materials and their synthetic analogues lack selectivity towards specific chemicals, and introducing such selectivity remains a challenge. Here we report the self-assembly of genetically engineered viruses (M13 phage) into target-specific, colourimetric biosensors. The sensors are composed of phage-bundle nanostructures and exhibit viewing-angle independent colour, similar to collagen structures in turkey skin. On exposure to various volatile organic chemicals, the structures rapidly swell and undergo distinct colour changes. Furthermore, sensors composed of phage displaying trinitrotoluene (TNT)-binding peptide motifs identified from a phage display selectively distinguish TNT down to 300 p.p.b. over similarly structured chemicals. Our tunable, colourimetric sensors can be useful for the detection of a variety of harmful toxicants and pathogens to protect human health and national security.

  4. Development of sensor system for indoor location based service implementation

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Joo Heon; Lee, Kyung Ho [Kookmin Univ., Seoul (Korea, Republic of)

    2012-11-15

    This paper introduces a sensor system based on indoor locations in order to implement the Building Energy Management System. This system consists of a thermopile sensor and an ultrasonic sensor. The sensor module is rotated by 360 .deg. and yawed up and down by two electric motors. Therefore, it can simultaneously detect the number and location of the inhabitants in the room. It uses wireless technology to communicate with the building manager or the smart home server, and it can save electric energy by controlling the lighting system or heating/air conditioning equipment automatically. We also demonstrate the usefulness of the proposed system by applying it to a real environment.

  5. A simple optical fiber interferometer based breathing sensor

    Science.gov (United States)

    Li, Xixi; Liu, Dejun; Kumar, Rahul; Ng, Wai Pang; Fu, Yong-qing; Yuan, Jinhui; Yu, Chongxiu; Wu, Yufeng; Zhou, Guorui; Farrell, Gerald; Semenova, Yuliya; Wu, Qiang

    2017-03-01

    A breathing sensor has been experimentally demonstrated based on a singlemode-multimode-singlemode (SMS) fiber structure which is attached to a thin plastic film in an oxygen mask. By detecting power variations due to the macro bending applied to the SMS section by each inhalation and exhalation process, the breath state can be monitored. The proposed sensor is capable of distinguishing different types of breathing conditions including regular and irregular breath state. The sensor can be used in a strong electric/magnetic field and radioactive testing systems such as magnetic resonance imaging (MRI) systems and computed tomography (CT) examinations where electrical sensors are restricted.

  6. Optimization of Surface Acoustic Wave-Based Rate Sensors

    Directory of Open Access Journals (Sweden)

    Fangqian Xu

    2015-10-01

    Full Text Available The optimization of an surface acoustic wave (SAW-based rate sensor incorporating metallic dot arrays was performed by using the approach of partial-wave analysis in layered media. The optimal sensor chip designs, including the material choice of piezoelectric crystals and metallic dots, dot thickness, and sensor operation frequency were determined theoretically. The theoretical predictions were confirmed experimentally by using the developed SAW sensor composed of differential delay line-oscillators and a metallic dot array deposited along the acoustic wave propagation path of the SAW delay lines. A significant improvement in sensor sensitivity was achieved in the case of 128° YX LiNbO3, and a thicker Au dot array, and low operation frequency were used to structure the sensor.

  7. A carbon nanotube based ammonia sensor on cotton textile

    Science.gov (United States)

    Han, Jin-Woo; Kim, Beomseok; Li, Jing; Meyyappan, M.

    2013-05-01

    A single-wall carbon nanotube (CNT) based ammonia (NH3) sensor was implemented on a cotton yarn. Two types of sensors were fabricated: Au/sensing CNT/Au and conducting/sensing/conducting all CNT structures. Two perpendicular Au wires were designed to contact CNT-cotton yarn for metal-CNT sensor, whereas nanotubes were used for the electrode as well as sensing material for the all CNT sensor. The resistance shift of the CNT network upon NH3 was monitored in a chemiresistor approach. The CNT-cotton yarn sensors exhibited uniformity and repeatability. Furthermore, the sensors displayed good mechanical robustness against bending. The present approach can be utilized for low-cost smart textile applications.

  8. Parallel Microcracks-based Ultrasensitive and Highly Stretchable Strain Sensors.

    Science.gov (United States)

    Amjadi, Morteza; Turan, Mehmet; Clementson, Cameron P; Sitti, Metin

    2016-03-01

    There is an increasing demand for flexible, skin-attachable, and wearable strain sensors due to their various potential applications. However, achieving strain sensors with both high sensitivity and high stretchability is still a grand challenge. Here, we propose highly sensitive and stretchable strain sensors based on the reversible microcrack formation in composite thin films. Controllable parallel microcracks are generated in graphite thin films coated on elastomer films. Sensors made of graphite thin films with short microcracks possess high gauge factors (maximum value of 522.6) and stretchability (ε ≥ 50%), whereas sensors with long microcracks show ultrahigh sensitivity (maximum value of 11,344) with limited stretchability (ε ≤ 50%). We demonstrate the high performance strain sensing of our sensors in both small and large strain sensing applications such as human physiological activity recognition, human body large motion capturing, vibration detection, pressure sensing, and soft robotics.

  9. Biomimic Hairy Skin Tactile Sensor Based on Ferromagnetic Microwires.

    Science.gov (United States)

    Zhang, Jian; Hao, Lifeng; Yang, Fan; Jiao, Weicheng; Liu, Wenbo; Li, Yibin; Wang, Rongguo; He, Xiaodong

    2016-12-14

    We present a multifunctional tactile sensor inspired by human hairy skin structure, in which the sensitive hair sensor and the robust skin sensor are integrated into a single device via a pair of Co-based ferromagnetic microwire arrays in a very simple manner. The sensor possesses a self-tunable effective compliance with respect to the magnitude of the stimulus, allowing a wide range of loading force to be measured. The sensor also exhibits some amazing functions, such as air-flow detection, material property characterization, and excellent damage resistance. The novel sensing mechanism and structure provide a new strategy for designing multifunctional tactile sensors and show great potential applications on intelligent robot and sensing in harsh environments.

  10. Virtual speed sensors based algorithm for expressway traffic state estimation

    Institute of Scientific and Technical Information of China (English)

    XU DongWei; DONG HongHui; JIA LiMin; QIN Yong

    2012-01-01

    The accurate estimation of expressway traffic state can provide decision-making for both travelers and traffic managers.The speed is one of the most representative parameter of the traffic state.So the expressway speed spatial distribution can be taken as the expressway traffic state equivalent.In this paper,an algorithm based on virtual speed sensors (VSS) is presented to estimate the expressway traffic state (the speed spatial distribution).To gain the spatial distribution of expressway traffic state,virtual speed sensors are defined between adjacent traffic flow sensors.Then,the speed data extracted from traffic flow sensors in time series are mapped to space series to design virtual speed sensors.Then the speed of virtual speed sensors can be calculated with the weight matrix which is related with the speed of virtual speed sensors and the speed data extracted from traffic flow sensors and the speed data extracted from traffic flow sensors in time series.Finally,the expressway traffic state (the speed spatial distribution) can be gained.The acquisition of average travel speed of the expressway is taken for application of this traffic state estimation algorithm.One typical expressway in Beijing is adopted for the experiment analysis.The results prove that this traffic state estimation approach based on VSS is feasible and can achieve a high accuracy.

  11. In plane optical sensor based on organic electronic devices

    NARCIS (Netherlands)

    Koetse, M.M; Rensing, P.A.; Heck, G.T. van; Sharpe, R.B.A.; Allard, B.A.M.; Wieringa, F.P.; Kruijt, P.G.M.; Meulendijks, N.M.M.; Jansen, H.; Schoo, H.F.M.

    2008-01-01

    Sensors based on organic electronic devices are emerging in a wide range of application areas. Here we present a sensor platform using organic light emitting diodes (OLED) and organic photodiodes (OPD) as active components. By means of lamination and interconnection technology the functional foils w

  12. A capacitive RF power sensor based on MEMS technology

    NARCIS (Netherlands)

    Fernandez, Luis Jose

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a h

  13. In plane optical sensor based on organic electronic devices

    NARCIS (Netherlands)

    Koetse, M.M; Rensing, P.A.; Heck, G.T. van; Sharpe, R.B.A.; Allard, B.A.M.; Wieringa, F.P.; Kruijt, P.G.M.; Meulendijks, N.M.M.; Jansen, H.; Schoo, H.F.M.

    2008-01-01

    Sensors based on organic electronic devices are emerging in a wide range of application areas. Here we present a sensor platform using organic light emitting diodes (OLED) and organic photodiodes (OPD) as active components. By means of lamination and interconnection technology the functional foils w

  14. A capacitive rf power sensor based on mems technology

    NARCIS (Netherlands)

    Fernandez, L.J.

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a

  15. Foil-based optical technology platform for optochemical sensors

    NARCIS (Netherlands)

    Kalathimekkad, S.; Missinne, J.; Arias Espinoza, J.D.; Hoe, B. van; Bosman, E.; Smits, E.; Mandamparambil, R.; Steenberge, G. van; Vanfleteren, J.

    2012-01-01

    This paper describes the development of a low-cost technology platform for fluorescence-based optochemical sensors. These sensors were constructed by incorporating fluorescent sensing elements in the core of multimode waveguides or lightguides, and have applications in medical, biochemical and envir

  16. Combine harvester monitor system based on wireless sensor network

    Science.gov (United States)

    A measurement method based on Wireless Sensor Network (WSN) was developed to monitor the working condition of combine harvester for remote application. Three JN5139 modules were chosen for sensor data acquisition and another two as a router and a coordinator, which could create a tree topology netwo...

  17. Potassium selective chemically modified field effect transistors based on AlGaN/GaN two-dimensional electron gas heterostructures.

    Science.gov (United States)

    Alifragis, Y; Volosirakis, A; Chaniotakis, N A; Konstantinidis, G; Adikimenakis, A; Georgakilas, A

    2007-06-15

    We investigate the use of the AlGaN/GaN high electron mobility transistor (HEMT) as a novel transducer for the development of ion-selective chemically modified HEMT sensors (ChemHEMTs). For this, polyvinyl chloride (PVC) membrane doped with ion-selective ionophores is deposited onto the area of the gate for the chemical recognition step, while the AlGaN/GaN HEMT is used as the transducer. In particular, the use of a valinocycin doped membrane with thickness of 50 microm generates a sensor with excellent analytical characteristics for the monitoring of K(+). The K(+)-ChemHEMT has sensitivity of 52.4 mV/pK(+)in the linear range of 10(-5) to 10(-2)M, while the detection limit is in the order of 3.1 x 10(-6)M. Also, the sensor shows selectivity similar to valinomycin-based ISEs, while the signal stability over time and the measurement to measurement reproducibility are very good.

  18. Novel miniaturized sensors for potentiometric batch and flow-injection analysis (FIA) of perchlorate in fireworks and propellants.

    Science.gov (United States)

    Almeer, Saeed H M A; Zogby, Ibrahim A; Hassan, Saad S M

    2014-11-01

    Three planar miniaturized perchlorate membrane sensors (3×5 mm(2)) are prepared using a flexible Kaptan substrate coated with nitron-perchlorate (NT-ClO4) [sensor 1], methylene blue-perchlorate (MB-ClO4) [sensor II] and indium-porphyrin (In-Por) [sensor III] as electroactive materials in PVC membranes plasticized with 2-NPPE. Sensors I, II and III display near-Nernstian response for 1.0×10(-5)-1.0×10(-2), 3.1×10(-5)-1.0×10(-2) and 3.1×10(-6)-1.0×10(-2) mol L(-1) ClO4(-) with lower detection limits of 6.1×10(-6), 6.9×10(-6) and 1.2×10(-6) mol L(-1), and anionic calibration slopes of 50.9±0.4, 48.4±0.4 and 57.7±0.3 mV decade(-1), respectively. Methods for determining perchlorate using these sensors offer many attractive advantages including simplicity, flexibility, cost effectiveness, wide linear dynamic response range (0.1-1000 ppm), low detection limit (sensors show high selectivity in the presence of some inorganic ions (e.g., PO4(3-), SO4(2-), S2O3(2-), NO2(-), NO3(-), N3(-), CN(-), Cl(-), Br(-), I(-)) and automation feasibility. Indium-porphyrin based membrane sensor (sensor III) is used as a detector in a wall-jet flow injection set-up to enable accurate flow injection analysis (FIA) of perchlorate in some fireworks without interferences from the associated reducing agents (sulfur and charcoal), binders (dextrin, lactose), coloring agents (calcium, strontium, copper, iron, sodium), color brighten (linseed oil) and regulators (aluminum flakes) which are commonly used in the formulations. The sensor is also used for perchlorate assessment in some propellant powders. The results fairly agree with data obtained by ion-chromatography.

  19. Multipoint sensor based on fiber Bragg gratings

    Energy Technology Data Exchange (ETDEWEB)

    Mendez-Zepeda, O; Munoz-Aguirre, S; Beltran-Perez, G; Castillo-Mixcoatl, J, E-mail: mezeos9@yahoo.com [Facultad de Ciencias FIsico-Matematicas, BUAP Av. San Claudio y Rio Verde, Col. San Manuel, CU. C.P. 72570, Puebla, Puebla (Mexico)

    2011-01-01

    In some control and industrial measurement systems of physical variables (pressure, temperature, flow, etc) it is necessary one system and one sensor to control each process. On the other hand, there are systems such as PLC (Programmable Logic Control), which can process several signals simultaneously. However it is still necessary to use one sensor for each variable. Therefore, in the present work the use of a multipoint sensor to solve such problem has been proposed. The sensor consists of an optical fiber laser with two Fabry-Perot cavities constructed using fiber Bragg gratings (FBG). In the same system is possible to measure changes in two variables by detecting the intermodal separation frequency of each cavity and evaluate their amplitudes. The intermodal separation frequency depends on each cavity length. The sensor signals are monitored through an oscilloscope or a PCI card and after that acquired by PC, where they are analyzed and displayed. Results of the evaluation of the intermodal frequency separation peak amplitude behavior with FBG stretching are presented.

  20. A Risk-Based Sensor Placement Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ronald W [ORNL; Kulesz, James J [ORNL

    2006-08-01

    A sensor placement methodology is proposed to solve the problem of optimal location of sensors or detectors to protect population against the exposure to and effects of known and/or postulated chemical, biological, and/or radiological threats. Historical meteorological data are used to characterize weather conditions as wind speed and direction pairs with the percentage of occurrence of the pairs over the historical period. The meteorological data drive atmospheric transport and dispersion modeling of the threats, the results of which are used to calculate population at risk against standard exposure levels. Sensor locations are determined via a dynamic programming algorithm where threats captured or detected by sensors placed in prior stages are removed from consideration in subsequent stages. Moreover, the proposed methodology provides a quantification of the marginal utility of each additional sensor or detector. Thus, the criterion for halting the iterative process can be the number of detectors available, a threshold marginal utility value, or the cumulative detection of a minimum factor of the total risk value represented by all threats.

  1. Standards-Based Wireless Sensor Networking Protocols for Spaceflight Applications

    Science.gov (United States)

    Wagner, Raymond S.

    2010-01-01

    Wireless sensor networks (WSNs) have the capacity to revolutionize data gathering in both spaceflight and terrestrial applications. WSNs provide a huge advantage over traditional, wired instrumentation since they do not require wiring trunks to connect sensors to a central hub. This allows for easy sensor installation in hard to reach locations, easy expansion of the number of sensors or sensing modalities, and reduction in both system cost and weight. While this technology offers unprecedented flexibility and adaptability, implementing it in practice is not without its difficulties. Recent advances in standards-based WSN protocols for industrial control applications have come a long way to solving many of the challenges facing practical WSN deployments. In this paper, we will overview two of the more promising candidates - WirelessHART from the HART Communication Foundation and ISA100.11a from the International Society of Automation - and present the architecture for a new standards-based sensor node for networking and applications research.

  2. A Respiration Sensor for a Chest-Strap Based Wireless Body Sensor

    OpenAIRE

    2014-01-01

    In this paper we present a respiration sensor suitable for an integration into a wireless body sensor worn around the chest. The thorax expansion and contraction during in- and exhalation is captured using a force-sensing resistor. Based on the captured thoracic movements, the breaths are determined with a peak detection algorithm. For evaluation, a treadmill experiment with five subjects was conducted using an ergospirometry system as a reference. Overall, an average deviation of -0.32±0.68 ...

  3. Sensor selection for received signal strength-based source localization in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Generally, localization is a nonlinear problem, while linearization is used to simplify this problem. Reasonable approximations could be achieved when signal-to-noise ratio (SNR) is large enough. Energy is a critical resource in wireless sensor networks, and system lifetime needs to be prolonged through the use of energy efficient strategies during system operation. In this paper, a closed-form solution for received signal strength (RSS)-based source localization in wireless sensor network (WSN) is obtained...

  4. M13 Bacteriophage Based Protein Sensors

    Science.gov (United States)

    Lee, Ju Hun

    Despite significant progress in biotechnology and biosensing, early detection and disease diagnosis remains a critical issue for improving patient survival rates and well-being. Many of the typical detection schemes currently used possess issues such as low sensitivity and accuracy and are also time consuming to run and expensive. In addition, multiplexed detection remains difficult to achieve. Therefore, developing advanced approaches for reliable, simple, quantitative analysis of multiple markers in solution that also are highly sensitive are still in demand. In recent years, much of the research has primarily focused on improving two key components of biosensors: the bio-recognition agent (bio-receptor) and the transducer. Particular bio-receptors that have been used include antibodies, aptamers, molecular imprinted polymers, and small affinity peptides. In terms of transducing agents, nanomaterials have been considered as attractive candidates due to their inherent nanoscale size, durability and unique chemical and physical properties. The key focus of this thesis is the design of a protein detection and identification system that is based on chemically engineered M13 bacteriophage coupled with nanomaterials. The first chapter provides an introduction of biosensors and M13 bacteriophage in general, where the advantages of each are provided. In chapter 2, an efficient and enzyme-free sensor is demonstrated from modified M13 bacteriophage to generate highly sensitive colorimetric signals from gold nanocrystals. In chapter 3, DNA conjugated M13 were used to enable facile and rapid detection of antigens in solution that also provides modalities for identification. Lastly, high DNA loadings per phage was achieved via hydrozone chemistry and these were applied in conjunction with Raman active DNA-gold/silver core/shell nanoparticles toward highly sensitive SERS sensing.

  5. Ethanol sensor based on nanocrystallite cadmium ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Gadkari, Ashok B., E-mail: ashokgadkari88@yahoo.com [Department of Physics, GKG College, Kolhapur-416012 (India); Shinde, Tukaram J. [Department of Physics, KRP Kanya Mahavidyalaya, Islampur-415409 (India); Vasambekar, Pramod N. [Department of Electronics, Shivaji University Kolhapur-416004 (India)

    2015-06-24

    The cadmium ferrite was synthesized by oxalate co-precipitation method. The crystal structure and surface morphology were examined by X-ray diffraction and SEM techniques, respectively. The nanocrystallite CdFe{sub 2}O{sub 4} sensor was tested for LPG, Cl{sub 2} and C{sub 2}H{sub 5}OH. The sensitivity was measured at various operating temperatures in the range of 100-400°C. The sensor shows highest sensitivity and selectivity to C{sub 2}H{sub 5}OH at 350°C. The response and recovery time was measured at operating temperature of 350°C. The sensor exhibits a lower response and recovery time for LPG and Cl{sub 2} as compared to ethanol.

  6. Textile-based weft knitted strain sensors: effect of fabric parameters on sensor properties.

    Science.gov (United States)

    Atalay, Ozgur; Kennon, William Richard; Husain, Muhammad Dawood

    2013-08-21

    The design and development of textile-based strain sensors has been a focus of research and many investigators have studied this subject. This paper presents a new textile-based strain sensor design and shows the effect of base fabric parameters on its sensing properties. Sensing fabric could be used to measure articulations of the human body in the real environment. The strain sensing fabric was produced by using electronic flat-bed knitting technology; the base fabric was produced with elastomeric yarns in an interlock arrangement and a conductive yarn was embedded in this substrate to create a series of single loop structures. Experimental results show that there is a strong relationship between base fabric parameters and sensor properties.

  7. Textile-Based Weft Knitted Strain Sensors: Effect of Fabric Parameters on Sensor Properties

    Directory of Open Access Journals (Sweden)

    William Richard Kennon

    2013-08-01

    Full Text Available The design and development of textile-based strain sensors has been a focus of research and many investigators have studied this subject. This paper presents a new textile-based strain sensor design and shows the effect of base fabric parameters on its sensing properties. Sensing fabric could be used to measure articulations of the human body in the real environment. The strain sensing fabric was produced by using electronic flat-bed knitting technology; the base fabric was produced with elastomeric yarns in an interlock arrangement and a conductive yarn was embedded in this substrate to create a series of single loop structures. Experimental results show that there is a strong relationship between base fabric parameters and sensor properties.

  8. Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

    Directory of Open Access Journals (Sweden)

    Marwah Almasri

    2015-12-01

    Full Text Available Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot’s wheels, and 24 fuzzy rules for the robot’s movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

  9. Capillarity-based preparation system for optical colorimetric sensor arrays

    Science.gov (United States)

    Luo, Xiao-gang; Yi, Xin; Bu, Xiang-nan; Hou, Chang-jun; Huo, Dan-qun; Yang, Mei; Fa, Huan-bao; Lei, Jin-can

    2017-03-01

    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  10. Sensor Fusion Based Model for Collision Free Mobile Robot Navigation.

    Science.gov (United States)

    Almasri, Marwah; Elleithy, Khaled; Alajlan, Abrar

    2015-12-26

    Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot's wheels, and 24 fuzzy rules for the robot's movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

  11. Capillarity-based preparation system for optical colorimetric sensor arrays.

    Science.gov (United States)

    Luo, Xiao-Gang; Yi, Xin; Bu, Xiang-Nan; Hou, Chang-Jun; Huo, Dan-Qun; Yang, Mei; Fa, Huan-Bao; Lei, Jin-Can

    2017-03-01

    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  12. Micro-vibration-based slip detection in tactile force sensors.

    Science.gov (United States)

    Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan

    2014-01-03

    Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect slipping in other force sensors based on flexible parts. In particular, we show and compare the slip detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor.

  13. Semiconducting Metal Oxide Based Sensors for Selective Gas Pollutant Detection

    Directory of Open Access Journals (Sweden)

    Marsha C. Kanan

    2009-10-01

    Full Text Available A review of some papers published in the last fifty years that focus on the semiconducting metal oxide (SMO based sensors for the selective and sensitive detection of various environmental pollutants is presented.

  14. Applying Sensor-Based Technology to Improve Construction Safety Management

    Science.gov (United States)

    Zhang, Mingyuan; Cao, Tianzhuo; Zhao, Xuefeng

    2017-01-01

    Construction sites are dynamic and complicated systems. The movement and interaction of people, goods and energy make construction safety management extremely difficult. Due to the ever-increasing amount of information, traditional construction safety management has operated under difficult circumstances. As an effective way to collect, identify and process information, sensor-based technology is deemed to provide new generation of methods for advancing construction safety management. It makes the real-time construction safety management with high efficiency and accuracy a reality and provides a solid foundation for facilitating its modernization, and informatization. Nowadays, various sensor-based technologies have been adopted for construction safety management, including locating sensor-based technology, vision-based sensing and wireless sensor networks. This paper provides a systematic and comprehensive review of previous studies in this field to acknowledge useful findings, identify the research gaps and point out future research directions. PMID:28800061

  15. Portable Nanoparticle-Based Sensors for Food Safety Assessment.

    Science.gov (United States)

    Bülbül, Gonca; Hayat, Akhtar; Andreescu, Silvana

    2015-12-05

    The use of nanotechnology-derived products in the development of sensors and analytical measurement methodologies has increased significantly over the past decade. Nano-based sensing approaches include the use of nanoparticles (NPs) and nanostructures to enhance sensitivity and selectivity, design new detection schemes, improve sample preparation and increase portability. This review summarizes recent advancements in the design and development of NP-based sensors for assessing food safety. The most common types of NPs used to fabricate sensors for detection of food contaminants are discussed. Selected examples of NP-based detection schemes with colorimetric and electrochemical detection are provided with focus on sensors for the detection of chemical and biological contaminants including pesticides, heavy metals, bacterial pathogens and natural toxins. Current trends in the development of low-cost portable NP-based technology for rapid assessment of food safety as well as challenges for practical implementation and future research directions are discussed.

  16. Applying Sensor-Based Technology to Improve Construction Safety Management.

    Science.gov (United States)

    Zhang, Mingyuan; Cao, Tianzhuo; Zhao, Xuefeng

    2017-08-11

    Construction sites are dynamic and complicated systems. The movement and interaction of people, goods and energy make construction safety management extremely difficult. Due to the ever-increasing amount of information, traditional construction safety management has operated under difficult circumstances. As an effective way to collect, identify and process information, sensor-based technology is deemed to provide new generation of methods for advancing construction safety management. It makes the real-time construction safety management with high efficiency and accuracy a reality and provides a solid foundation for facilitating its modernization, and informatization. Nowadays, various sensor-based technologies have been adopted for construction safety management, including locating sensor-based technology, vision-based sensing and wireless sensor networks. This paper provides a systematic and comprehensive review of previous studies in this field to acknowledge useful findings, identify the research gaps and point out future research directions.

  17. Characterization of optical strain sensors based on silicon waveguides

    NARCIS (Netherlands)

    Westerveld, W.J.; Pozo Torres, J.M.; Muilwijk, P.M.; Leinders, S.M.; Harmsma, P.J.; Tabak, E.; Dool, T.C. van den; Dongen, K.W.A. van; Yousefi, M.; Urbach, H.P.

    2013-01-01

    Strain gauges are widely employed in microelectromechanical systems (MEMS) for sensing of, for example, deformation, acceleration, pressure, or sound [1]. Such gauges are typically based on electronic piezoresistivity. We propose integrated optical sensors which have particular benefits: insensitivi

  18. Semiconductor Nanomembrane based Flight Sensors and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Phase I program would develop and demonstrate semiconductor nanomembrane (NM) based flight sensors and arrays on flexible substrates, using SOI (Silicon on...

  19. Planar Laser-Based QEPAS Trace Gas Sensor

    Directory of Open Access Journals (Sweden)

    Yufei Ma

    2016-06-01

    Full Text Available A novel quartz enhanced photoacoustic spectroscopy (QEPAS trace gas detection scheme is reported in this paper. A cylindrical lens was employed for near-infrared laser focusing. The laser beam was shaped as a planar line laser between the gap of the quartz tuning fork (QTF prongs. Compared with a spherical lens-based QEPAS sensor, the cylindrical lens-based QEPAS sensor has the advantages of easier laser beam alignment and a reduction of stringent stability requirements. Therefore, the reported approach is useful in long-term and continuous sensor operation.

  20. Coverage analysis for sensor networks based on Clifford algebra

    Institute of Scientific and Technical Information of China (English)

    XIE WeiXin; CAO WenMing; MENG Shan

    2008-01-01

    The coverage performance is the foundation of information acquisition in distrib-uted sensor networks. The previously proposed coverage work was mostly based on unit disk coverage model or ball coverage model in 2D or 3D space, respectively. However, most methods cannot give a homogeneous coverage model for targets with hybrid types. This paper presents a coverage analysis approach for sensor networks based on Clifford algebra and establishes a homogeneous coverage model for sensor networks with hybrid types of targets. The effectiveness of the approach is demonstrated with examples.

  1. Intensity based sensor based on single mode optical fiber patchcords

    Science.gov (United States)

    Bayuwati, Dwi; Waluyo, Tomi Budi; Mulyanto, Imam

    2016-11-01

    This paper describes the use of several single mode (SM) fiber patchcords available commercially in the market for intensity based sensor by taking the benefit of bending loss phenomenon. Firtsly, the full transmission spectrum of all fiber patchcords were measured and analyzed to examine its bending properties at a series of wavelength using white light source and optical spectrum analyzer. Bending spectral at various bending diameter using single wavelength light sources were then measured for demonstration.Three good candidates for the intensity based sensor are SM600 fiber patchcord with 970 nm LED, SMF28 fiber patchcord with 1050 nm LED and 780HP fiber patchcord with 1310 nm LED which have noticeable bending sensitive area. Experiments show that the combination of the SMF28with 1050 nm LED has 30 mm measurement range which is the widest; with sensitivity 0.107 dB/mm and resolution 0.5 mm compared with combination of SM600 patchcord and LED 970 nm which has the best sensitivity (0.891 dB/mm) and resolution (0.06 mm) but smaller range measurement (10 mm). Some suitable applications for each fiber patchcord - light source pair have also been discussed.

  2. Sensor-based assessment of herbicide effects

    DEFF Research Database (Denmark)

    Streibig, Jens Carl; Rasmussen, Jesper; Andújar, D.;

    2014-01-01

    Non-destructive assessment of herbicide effects may be able to support integrated weed management. To test whether effects of herbicides on canopy variables could be detected by sensors, two crops were used as models and treated with herbicides at BBCH 20 using a logarithmic sprayer. Twelve days...

  3. MIS-based sensors with hydrogen selectivity

    Science.gov (United States)

    Li; ,Dongmei; Medlin, J. William; McDaniel, Anthony H.; Bastasz, Robert J.

    2008-03-11

    The invention provides hydrogen selective metal-insulator-semiconductor sensors which include a layer of hydrogen selective material. The hydrogen selective material can be polyimide layer having a thickness between 200 and 800 nm. Suitable polyimide materials include reaction products of benzophenone tetracarboxylic dianhydride 4,4-oxydianiline m-phenylene diamine and other structurally similar materials.

  4. The impact of MOSFET-based sensors

    NARCIS (Netherlands)

    Bergveld, P.

    1985-01-01

    The basic structure as well as the physical existence of the MOS field-effect transistor is without doubt of great importance for the development of a whole series of sensors for the measurement of physical and chemical environmental parameters. The equation for the MOSFET drain current already sho

  5. Sensor network based vehicle classification and license plate identification system

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, Janette Rose [Los Alamos National Laboratory; Brennan, Sean M [Los Alamos National Laboratory; Rosten, Edward J [Los Alamos National Laboratory; Raby, Eric Y [Los Alamos National Laboratory; Kulathumani, Vinod K [WEST VIRGINIA UNIV.

    2009-01-01

    Typically, for energy efficiency and scalability purposes, sensor networks have been used in the context of environmental and traffic monitoring applications in which operations at the sensor level are not computationally intensive. But increasingly, sensor network applications require data and compute intensive sensors such video cameras and microphones. In this paper, we describe the design and implementation of two such systems: a vehicle classifier based on acoustic signals and a license plate identification system using a camera. The systems are implemented in an energy-efficient manner to the extent possible using commercially available hardware, the Mica motes and the Stargate platform. Our experience in designing these systems leads us to consider an alternate more flexible, modular, low-power mote architecture that uses a combination of FPGAs, specialized embedded processing units and sensor data acquisition systems.

  6. A Novel Interdigital Capacitor Pressure Sensor Based on LTCC Technology

    Directory of Open Access Journals (Sweden)

    Qiulin Tan

    2014-01-01

    Full Text Available A novel passive wireless pressure sensor is proposed based on LTCC (low temperature cofired ceramic technology. The sensor employs a passive LC circuit, which is composed of a variable interdigital capacitor and a constant inductor. The inductor and capacitor were fabricated by screen-printing. Pressure measurement is tested using a wireless mutual inductance coupling method. The experimental sensitivity of the sensor is about 273.95 kHz/bar below 2 bar. Experimental results show that the sensor can be read out wirelessly by external antenna at 600°C. The max readout distance is 3 cm at room temperature. The sensors described can be applied for monitoring of gas pressure in harsh environments, such as environment with high temperature and chemical corrosion.

  7. Gas Sensors Based on Polymer Field-Effect Transistors

    Science.gov (United States)

    Lv, Aifeng; Pan, Yong; Chi, Lifeng

    2017-01-01

    This review focuses on polymer field-effect transistor (PFET) based gas sensor with polymer as the sensing layer, which interacts with gas analyte and thus induces the change of source-drain current (ΔISD). Dependent on the sensing layer which can be semiconducting polymer, dielectric layer or conducting polymer gate, the PFET sensors can be subdivided into three types. For each type of sensor, we present the molecular structure of sensing polymer, the gas analyte and the sensing performance. Most importantly, we summarize various analyte–polymer interactions, which help to understand the sensing mechanism in the PFET sensors and can provide possible approaches for the sensor fabrication in the future. PMID:28117760

  8. Gas Sensors Based on Polymer Field-Effect Transistors.

    Science.gov (United States)

    Lv, Aifeng; Pan, Yong; Chi, Lifeng

    2017-01-22

    This review focuses on polymer field-effect transistor (PFET) based gas sensor with polymer as the sensing layer, which interacts with gas analyte and thus induces the change of source-drain current (ΔISD). Dependent on the sensing layer which can be semiconducting polymer, dielectric layer or conducting polymer gate, the PFET sensors can be subdivided into three types. For each type of sensor, we present the molecular structure of sensing polymer, the gas analyte and the sensing performance. Most importantly, we summarize various analyte-polymer interactions, which help to understand the sensing mechanism in the PFET sensors and can provide possible approaches for the sensor fabrication in the future.

  9. Haem-based sensors: a still growing old superfamily.

    Science.gov (United States)

    Germani, Francesca; Moens, Luc; Dewilde, Sylvia

    2013-01-01

    The haem-based sensors are chimeric multi-domain proteins responsible for the cellular adaptive responses to environmental changes. The signal transduction is mediated by the sensing capability of the haem-binding domain, which transmits a usable signal to the cognate transmitter domain, responsible for providing the adequate answer. Four major families of haem-based sensors can be recognized, depending on the nature of the haem-binding domain: (i) the haem-binding PAS domain, (ii) the CO-sensitive carbon monoxide oxidation activator, (iii) the haem NO-binding domain, and (iv) the globin-coupled sensors. The functional classification of the haem-binding sensors is based on the activity of the transmitter domain and, traditionally, comprises: (i) sensors with aerotactic function; (ii) sensors with gene-regulating function; and (iii) sensors with unknown function. We have implemented this classification with newly identified proteins, that is, the Streptomyces avermitilis and Frankia sp. that present a C-terminal-truncated globin fused to an N-terminal cofactor-free monooxygenase, the structural-related class of non-haem globins in Bacillus subtilis, Moorella thermoacetica, and Bacillus anthracis, and a haemerythrin-coupled diguanylate cyclase in Vibrio cholerae. This review summarizes the structures, the functions, and the structure-function relationships known to date on this broad protein family. We also propose unresolved questions and new possible research approaches.

  10. Plasmonics Based Harsh Environment Compatible Chemical Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Michael Carpenter

    2012-01-15

    Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined

  11. Optical hydrogen sensors based on metal-hydrides

    Science.gov (United States)

    Slaman, M.; Westerwaal, R.; Schreuders, H.; Dam, B.

    2012-06-01

    For many hydrogen related applications it is preferred to use optical hydrogen sensors above electrical systems. Optical sensors reduce the risk of ignition by spark formation and are less sensitive to electrical interference. Currently palladium and palladium alloys are used for most hydrogen sensors since they are well known for their hydrogen dissociation and absorption properties at relatively low temperatures. The disadvantages of palladium in sensors are the low optical response upon hydrogen loading, the cross sensitivity for oxygen and carbon, the limited detection range and the formation of micro-cracks after some hydrogen absorption/desorption cycles. In contrast to Pd, we find that the use of magnesium or rear earth bases metal-hydrides in optical hydrogen sensors allow tuning of the detection levels over a broad pressure range, while maintaining a high optical response. We demonstrate a stable detection layer for detecting hydrogen below 10% of the lower explosion limit in an oxygen rich environment. This detection layer is deposited at the bare end of a glass fiber as a micro-mirror and is covered with a thin layer of palladium. The palladium layer promotes the hydrogen uptake at room temperature and acts as a hydrogen selective membrane. To protect the sensor for a long time in air a final layer of a hydrophobic fluorine based coating is applied. Such a sensor can be used for example as safety detector in automotive applications. We find that this type of fiber optic hydrogen sensor is also suitable for hydrogen detection in liquids. As example we demonstrate a sensor for detecting a broad range of concentrations in transformer oil. Such a sensor can signal a warning when sparks inside a high voltage power transformer decompose the transformer oil over a long period.

  12. Modeling Sensor Reliability in Fault Diagnosis Based on Evidence Theory.

    Science.gov (United States)

    Yuan, Kaijuan; Xiao, Fuyuan; Fei, Liguo; Kang, Bingyi; Deng, Yong

    2016-01-18

    Sensor data fusion plays an important role in fault diagnosis. Dempster-Shafer (D-R) evidence theory is widely used in fault diagnosis, since it is efficient to combine evidence from different sensors. However, under the situation where the evidence highly conflicts, it may obtain a counterintuitive result. To address the issue, a new method is proposed in this paper. Not only the statistic sensor reliability, but also the dynamic sensor reliability are taken into consideration. The evidence distance function and the belief entropy are combined to obtain the dynamic reliability of each sensor report. A weighted averaging method is adopted to modify the conflict evidence by assigning different weights to evidence according to sensor reliability. The proposed method has better performance in conflict management and fault diagnosis due to the fact that the information volume of each sensor report is taken into consideration. An application in fault diagnosis based on sensor fusion is illustrated to show the efficiency of the proposed method. The results show that the proposed method improves the accuracy of fault diagnosis from 81.19% to 89.48% compared to the existing methods.

  13. Analysis of Vehicle Detection with WSN-Based Ultrasonic Sensors

    Directory of Open Access Journals (Sweden)

    Youngtae Jo

    2014-08-01

    Full Text Available Existing traffic information acquisition systems suffer from high cost and low scalability. To address these problems, the application of wireless sensor networks (WSNs has been studied, as WSN-based systems are highly scalable and have a low cost of installing and replacing the systems. Magnetic, acoustic and accelerometer sensors have been considered for WSN-based traffic surveillance, but the use of ultrasonic sensors has not been studied. The limitations of WSN-based systems make it necessary to employ power saving methods and vehicle detection algorithms with low computational complexity. In this paper, we model and analyze optimal power saving methodologies for an ultrasonic sensor and present a computationally-efficient vehicle detection algorithm using ultrasonic data. The proposed methodologies are implemented and evaluated with a tiny microprocessor on real roads. The evaluation results show that the low computational complexity of our algorithm does not compromise the accuracy of vehicle detection.

  14. Analysis of vehicle detection with WSN-based ultrasonic sensors.

    Science.gov (United States)

    Jo, Youngtae; Jung, Inbum

    2014-08-04

    Existing traffic information acquisition systems suffer from high cost and low scalability. To address these problems, the application of wireless sensor networks (WSNs) has been studied, as WSN-based systems are highly scalable and have a low cost of installing and replacing the systems. Magnetic, acoustic and accelerometer sensors have been considered for WSN-based traffic surveillance, but the use of ultrasonic sensors has not been studied. The limitations of WSN-based systems make it necessary to employ power saving methods and vehicle detection algorithms with low computational complexity. In this paper, we model and analyze optimal power saving methodologies for an ultrasonic sensor and present a computationally-efficient vehicle detection algorithm using ultrasonic data. The proposed methodologies are implemented and evaluated with a tiny microprocessor on real roads. The evaluation results show that the low computational complexity of our algorithm does not compromise the accuracy of vehicle detection.

  15. POF based glucose sensor incorporating grating wavelength filters

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Aasmul, Søren; Bang, Ole

    2014-01-01

    AND RESEARCH IN POLYMER OPTICAL DEVICES; TRIPOD. Within the domain of TRIPOD, research is conducted on "Plastic Optical Fiber based Glucose Sensors Incorporating Grating Wavelength Filters". Research will be focused to optimized fiber tips for better coupling efficiency, reducing the response time of sensor......Medtronic has already developed a plastic fiber based optical sensor to detect the concentration of glucose both in vivo and in-vitro. The glucose sensor is based on a competitive glucose binding affinity assay consisting of a glucose receptor and glucose analog (ligand) contained in a compartment......, more donor acceptor pairs got separated resulting in high intensity and vice versa. This change in optical signal is correlated to glucose concentration. (Fig.1) Medtronic Diabetes and DTU FOTONIK has been working together under the consortium of Marie Curie Research Framework called TRAINING...

  16. A torsional sensor for MEMS-based RMS voltage measurements

    Directory of Open Access Journals (Sweden)

    J. Dittmer

    2008-05-01

    Full Text Available RF voltage measurement based on electrostatic RMS voltage-to-force conversion is an alternative method in comparison to the conventional thermal power dissipation method. It is based on a mechanical force induced by an RF voltage applied to a micro-mechanical system. For a theoretically adequate resolution and high precision measurements, the necessary geometrical dimensions of the sensor require the application of micro machining. In this contribution, the dependence between electrical and geometrical properties of different sensor designs is investigated. Based on these results, problems related to practical micro-machining and solutions with respect to possible sensor realizations are discussed. The evolution of different sensor generations is shown.

  17. Higher-order mode photonic crystal based nanofluidic sensor

    Science.gov (United States)

    Peng, Wang; Chen, Youping; Ai, Wu

    2017-01-01

    A higher-order photonic crystal (PC) based nanofluidic sensor, which worked at 532 nm, was designed and demonstrated. A systematical and detailed method for sculpturing a PC sensor for a given peak wavelength value (PWV) and specified materials was illuminated. It was the first time that the higher order mode was used to design PC based nanofluidic sensor, and the refractive index (RI) sensitivity of this sensor had been verified with FDTD simulation software from Lumerical. The enhanced electrical field of higher order mode structure was mostly confined in the channel area, where the enhance field is wholly interacting with the analytes in the channels. The comparison of RI sensitivity between fundamental mode and higher order mode shows the RI variation of higher order mode is 124.5 nm/RIU which is much larger than the fundamental mode. The proposed PC based nanofluidic structure pioneering a novel style for future optofluidic design.

  18. Sensor Technology Baseline Study for Enabling Condition Based Maintenance Plus in Army Ground Vehicles

    Science.gov (United States)

    2012-03-01

    and mechanisms are identified. Based on this analysis, baselines sensor technologies are determined to prognosticate these types failure causes early...Current/voltage sensor measured at sensor terminals; Fluid level sensor Excessive slippage and clutch chatter Internal transmission failure ... TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Sensor Technology Baseline Study for Enabling Condition Based Maintenance Plus in

  19. Force-compensated hydrogel-based pH sensor

    Science.gov (United States)

    Deng, Kangfa; Gerlach, Gerald; Guenther, Margarita

    2015-04-01

    This paper presents the design, simulation, assembly and testing of a force-compensated hydrogel-based pH sensor. In the conventional deflection method, a piezoresistive pressure sensor is used as a chemical-mechanical-electronic transducer to measure the volume change of a pH-sensitive hydrogel. In this compensation method, the pH-sensitive hydrogel keeps its volume constant during the whole measuring process, independent of applied pH value. In order to maintain a balanced state, an additional thermal actuator is integrated into the close-loop sensor system with higher precision and faster dynamic response. Poly (N-isopropylacrylamide) (PNIPAAm) with 5 mol% monomer 3-acrylamido propionic acid (AAmPA) is used as the temperature-sensitive hydrogel, while poly (vinyl alcohol) with poly (acrylic acid) (PAA) serves as the pH-sensitive hydrogel. A thermal simulation is introduced to assess the temperature distribution of the whole microsystem, especially the temperature influence on both hydrogels. Following tests are detailed to verify the working functions of a sensor based on pH-sensitive hydrogel and an actuator based on temperature-sensitive hydrogel. A miniaturized prototype is assembled and investigated in deionized water: the response time amounts to about 25 min, just half of that one of a sensor based on the conventional deflection method. The results confirm the applicability of t he compensation method to the hydrogel-based sensors.

  20. Research of three-dimensional force sensor based on multiplexed fiber Bragg grating strain sensors

    Science.gov (United States)

    Xu, Hui-Chao; Wang, Su; Miao, Xin-Gang

    2017-04-01

    Most safety problems of architectural structures are caused by structural deformation, and the structures usually deform in more than one direction. So it is important and necessary to collect the safety monitoring data from all directions. Conventional fiber Bragg grating (FBG) sensors cannot fully meet the requirements of a modern safety monitoring system in practical application. Therefore, the research of a three-dimensional (3-D) force sensor that can expand the application range of fiber optic sensing technology is necessary and significant. A 3-D force sensor based on multiplexed FBG strain sensors is proposed, which can be used to measure 3-D force on a structure under test, force distribution, and the trend of relative microdeformation. The sensor that has an integral structure with a design has been described in detail, and its sensing principle has been investigated. The results of calibration experiments show that it can accurately and effectively realize the 3-D force measurement with good linearity, repeatability, and consistency. Experimental and analytical results both demonstrate its feasibility. It can work in harsh environments due to its good stability and anti-interference ability. The sensor proposed in this paper has great engineering application value and application prospects in the field of structure health monitoring.

  1. Nanomaterial Based Sensors for NASA Missions

    Science.gov (United States)

    Koehne, Jessica E.

    2016-01-01

    Nanomaterials such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene and metal nanowires have shown interesting electronic properties and therefore have been pursued for a variety of space applications requiring ultrasensitive and light-weight sensor and electronic devices. We have been pursuing development of chemical and biosensors using carbon nanotubes and carbon nanofibers for the last several years and this talk will present the benefits of nanomaterials these applications. More recently, printing approaches to manufacturing these devices have been explored as a strategy that is compatible to a microgravity environment. Nanomaterials are either grown in house or purchased and processed as electrical inks. Chemical modification or coatings are added to the nanomaterials to tailor the nanomaterial to the exact application. The development of printed chemical sensors and biosensors will be discussed for applications ranging from crew life support to exploration missions.

  2. Enzyme-Based Fiber Optic Sensors

    Science.gov (United States)

    Kulp, Thomas J.; Camins, Irene; Angel, Stanley M.

    1988-06-01

    Fiber optic chemical sensors capable of detecting glucose and penicillin were developed. Each consists of a polymer membrane that is covalently attached to the tip of a glass optical fiber. The membrane contains the enzyme and a pH-sensitive fluorescent dye (fluorescein). A signal is produced when the enzyme catalyzes the conversion of the analyte (glucose or penicillin) into a product (gluconic or penicilloic acid, respectively) that lowers the microenvironmental pH of the membrane and, consequently, lowers the fluorescence intensity of the dye. Each sensor is capable of responding to analyte concentrations in the range of ~0.1 to 100 mM. The penicillin optrode response time is 40 to 60 s while that for glucose is ~5 to 12 min.

  3. Sensor-fusion-based biometric identity verification

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.J.; Bouchard, A.M.; Osbourn, G.C.; Martinez, R.F.; Bartholomew, J.W. [Sandia National Labs., Albuquerque, NM (United States); Jordan, J.B.; Flachs, G.M.; Bao, Z.; Zhu, L. [New Mexico State Univ., Las Cruces, NM (United States). Electronic Vision Research Lab.

    1998-02-01

    Future generation automated human biometric identification and verification will require multiple features/sensors together with internal and external information sources to achieve high performance, accuracy, and reliability in uncontrolled environments. The primary objective of the proposed research is to develop a theoretical and practical basis for identifying and verifying people using standoff biometric features that can be obtained with minimal inconvenience during the verification process. The basic problem involves selecting sensors and discovering features that provide sufficient information to reliably verify a person`s identity under the uncertainties caused by measurement errors and tactics of uncooperative subjects. A system was developed for discovering hand, face, ear, and voice features and fusing them to verify the identity of people. The system obtains its robustness and reliability by fusing many coarse and easily measured features into a near minimal probability of error decision algorithm.

  4. Lead-selective poly(vinyl chloride) electrodes based on some synthesized benzo-substituted macrocyclic diamides.

    Science.gov (United States)

    Kazemi, Sayed Yahya; Shamsipur, Mojtaba; Sharghi, Hashem

    2009-12-15

    A series of recently synthesized benzo- and pyridine-substituted macrocyclic diamides were studied to characterize their abilities as lead ion carriers in PVC membrane electrodes. The electrode based on 3,15,21-triaza-4,5;13,14-dibenzo-6,9,12-trioxabicycloheneicosa-1,17,19-triene-2,16-dione exhibits a Nernstian response for Pb2+ ions over a wide concentration range (1.3 x 10(-2) to 3.6 x 10(-6) mol L(-1)) with a limit of detection of 2.0 x 10(-6) mol L(-1) (0.4 ppm). The response time of the sensor is approximately 16 s, and the membrane can be used for more than two months without observing any deviation. The electrode revealed comparatively good selectivities with respect to many cations including alkali earth, transition and heavy metal ions. The proposed sensor could be used in pH range of 3.7-6.5. It was used as an indicator electrode in potentiometric titration of chromate ions with a lead ion solution.

  5. Electro-active material (EAM) based bend sensors

    Science.gov (United States)

    LaComb, Ronald; LaComb, Julie

    2010-04-01

    The capability to accurately estimate strain and orientation of cables in an undersea environment is important for a multitude of applications. One way to estimate the positional location of a submersed cable is to utilize a network of distributed bend sensors providing inputs to a curve fitting algorithm. In this work commercially available bend sensors are characterized for small deflections. In addition proto-type devices are presented which can potentially improve device sensitivity. Commercially available bend sensors are based upon electro-active materials and variable resistance materials. Electro-active materials (EAM) are known for their actuator functionality but certain EAMs are capable of sensing as well. New advances in materials such as Ionic Polymer Metal Composites (IPMC) are proving suitable for quasi-static sensor applications. These sensors are low power, conformal and produce directionally dependent output voltages which are linearly proportional to deflection, with voltage polarity representative of the deflection direction. IPMCs are capable of being morphed for increased sensitivity. Variable resistivity sensors are based on smart epoxy polymer and carbon loaded inks. These sensors are inexpensive and conformal and unlike EAMs provide static measurements.

  6. Transparent and flexible force sensor array based on optical waveguide.

    Science.gov (United States)

    Kim, Youngsung; Park, Suntak; Park, Seung Koo; Yun, Sungryul; Kyung, Ki-Uk; Sun, Kyung

    2012-06-18

    This paper suggests a force sensor array measuring contact force based on intensity change of light transmitted throughout optical waveguide. For transparency and flexibility of the sensor, two soft prepolymers with different refractive index have been developed. The optical waveguide consists of two cladding layers and a core layer. The top cladding layer is designed to allow light scattering at the specific area in response to finger contact. The force sensor shows a distinct tendency that output intensity decreases with input force and measurement range is from 0 to -13.2 dB.

  7. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors.

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-03-10

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  8. System modeling based measurement error analysis of digital sun sensors

    Institute of Scientific and Technical Information of China (English)

    WEI; M; insong; XING; Fei; WANG; Geng; YOU; Zheng

    2015-01-01

    Stringent attitude determination accuracy is required for the development of the advanced space technologies and thus the accuracy improvement of digital sun sensors is necessary.In this paper,we presented a proposal for measurement error analysis of a digital sun sensor.A system modeling including three different error sources was built and employed for system error analysis.Numerical simulations were also conducted to study the measurement error introduced by different sources of error.Based on our model and study,the system errors from different error sources are coupled and the system calibration should be elaborately designed to realize a digital sun sensor with extra-high accuracy.

  9. Calibration system of underwater robot sensor based on CID algorithm

    Science.gov (United States)

    Wang, Xiaolong; Wang, Sen; Gao, Lifu; Wu, Shan; Wei, Shuheng

    2017-06-01

    In the calibration of static characteristic of the sensor, the original measured data are usually a nonlinear distribution. Based on this situation, underwater robot sensor static calibration system is designed. The system consists of four parts: a sensor, I-V conversion with amplifying circuit, microcontroller STM32F107 and a PC. The lower computer and the upper computer communicate by USB. A kind of adaptive cyclic iterative denoising (CID) algorithm is presented for data processing. Finally the curve will be fitted with compensation processing.

  10. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Directory of Open Access Journals (Sweden)

    Milena Šetka

    2017-03-01

    Full Text Available The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  11. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-01-01

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols. PMID:28287435

  12. Chemical sensors based on molecularly modified metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haick, Hossam [Department of Chemical Engineering and Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000 (Israel)

    2007-12-07

    This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)

  13. A Passive Optical Fiber Current Sensor Based on YIG

    Institute of Scientific and Technical Information of China (English)

    Jing Shao; Wen Liu; Cui-Qing Liu; Duan Xu

    2008-01-01

    A research on passive optical fiber current sensor based on magneto-optical crystal and a new design of light path of the sensor head are presented. Both methods of dual-channel optical detection of the polarization state of the output light and signal processing are proposed. Signal processing can obtain the linear output of the current measurement of the wire more conveniently. Theoretical analysis on the magneto-optical fiber current sensor is given, followed by experiments. After that, further analysis is made according to the results, which leads to clarifying the exiting problems and their placements.

  14. Voronoi-based localisation algorithm for mobile sensor networks

    Science.gov (United States)

    Guan, Zixiao; Zhang, Yongtao; Zhang, Baihai; Dong, Lijing

    2016-11-01

    Localisation is an essential and important part in wireless sensor networks (WSNs). Many applications require location information. So far, there are less researchers studying on mobile sensor networks (MSNs) than static sensor networks (SSNs). However, MSNs are required in more and more areas such that the number of anchor nodes can be reduced and the location accuracy can be improved. In this paper, we firstly propose a range-free Voronoi-based Monte Carlo localisation algorithm (VMCL) for MSNs. We improve the localisation accuracy by making better use of the information that a sensor node gathers. Then, we propose an optimal region selection strategy of Voronoi diagram based on VMCL, called ORSS-VMCL, to increase the efficiency and accuracy for VMCL by adapting the size of Voronoi area during the filtering process. Simulation results show that the accuracy of these two algorithms, especially ORSS-VMCL, outperforms traditional MCL.

  15. RESTFul based heterogeneous Geoprocessing workflow interoperation for Sensor Web Service

    Science.gov (United States)

    Yang, Chao; Chen, Nengcheng; Di, Liping

    2012-10-01

    Advanced sensors on board satellites offer detailed Earth observations. A workflow is one approach for designing, implementing and constructing a flexible and live link between these sensors' resources and users. It can coordinate, organize and aggregate the distributed sensor Web services to meet the requirement of a complex Earth observation scenario. A RESTFul based workflow interoperation method is proposed to integrate heterogeneous workflows into an interoperable unit. The Atom protocols are applied to describe and manage workflow resources. The XML Process Definition Language (XPDL) and Business Process Execution Language (BPEL) workflow standards are applied to structure a workflow that accesses sensor information and one that processes it separately. Then, a scenario for nitrogen dioxide (NO2) from a volcanic eruption is used to investigate the feasibility of the proposed method. The RESTFul based workflows interoperation system can describe, publish, discover, access and coordinate heterogeneous Geoprocessing workflows.

  16. An ionic liquid based strain sensor for large displacement measurement.

    Science.gov (United States)

    Keulemans, Grim; Ceyssens, Frederik; Puers, Robert

    2017-03-01

    A robust and low cost ionic liquid based strain sensor is fabricated for high strain measurements in biomedical applications (up to 40 % and higher). A tubular 5 mm long silicone microchannel with an inner diameter of 310 µm and an outer diameter of 650 µm is filled with an ionic liquid. Three ionic liquids have been investigated: 1-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide, ethylammonium nitrate and cholinium ethanoate. When the channel is axially stretched, geometrical deformations change the electrical impedance of the liquid channel. The sensors display a linear response and low hysteresis with an average gauge factors of 1.99 for strains up to 40 %. Additionally, to fix the sensor by surgical stitching to soft biological tissue, a sensor with tube clamps consisting of photopatternable SU-8 epoxy-based resin is proposed.

  17. C60-based clustering scheme for sensor management in STSS

    Institute of Scientific and Technical Information of China (English)

    Yiyu Zhou

    2015-01-01

    Clustering-based sensor-management schemes have been widely used for various wireless sensor networks (WSNs), as they are wel suited to the distributive and col aborative nature of WSN. In this paper, a C60-based clustering algorithm is proposed for the specific planned network of space tracking and surveil ance system (STSS), where al the sensors are partitioned into 12 clus-ters according to the C60 (or footbal surface) architecture, and then a hierarchical sensor-management scheme is wel designed. Final y, the algorithm is applied to a typical STSS constel ation, and the simulation results show that the proposed method has bet-ter target-tracking performance than the nonclustering scheduling method.

  18. Optimize Etching Based Single Mode Fiber Optic Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2014-02-01

    Full Text Available This paper presents a description of etching process for fabrication single mode optical fiber sensors. The process of fabrication demonstrates an optimized etching based method to fabricate single mode fiber (SMF optic sensors in specified constant time and temperature. We propose a single mode optical fiber based temperature sensor, where the temperature sensing region is obtained by etching its cladding diameter over small length to a critical value. It is observed that the light transmission through etched fiber at 1550 nm wavelength optical source becomes highly temperature sensitive, compared to the temperature insensitive behavior observed in un-etched fiber for the range on 30ºC to 100ºC at 1550 nm. The sensor response under temperature cycling is repeatable and, proposed to be useful for low frequency analogue signal transmission over optical fiber by means of inline thermal modulation approach.

  19. Triangle-based key management scheme for wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    Hangyang DAI; Hongbing XU

    2009-01-01

    For security services in wireless sensor net-works, key management is a fundamental building block.In this article, we propose a triangle-based key predis-tribution approach and show that it can improve the effectiveness of key management in wireless sensor networks. This is achieved by using the bivariate polynomial in a triangle deployment system based on deployment information about expected locations of the sensor nodes. The analysis indicates that this scheme can achieve higher probability of both direct key establishment and indirect key establishment. On the other hand, the security analysis shows that its security against node capture would increase with a decrease of the sensor node deployment density and size of the deployment model and an increase of the polynomial degree.

  20. Ultrasensitive, Stretchable Strain Sensors Based on Fragmented Carbon Nanotube Papers

    KAUST Repository

    Zhou, Jian

    2017-01-17

    The development of strain sensors featuring both ultra high sensitivity and high stretchability is still a challenge. We demonstrate that strain sensors based on fragmented single-walled carbon nanotube (SWCNT) paper embedded in poly(dimethylsiloxane) (PDMS) can sustain their sensitivity even at very high strain levels (with a gauge factor of over 10(7) at 50% strain). This record sensitivity is ascribed to the low initial electrical resistance (5-28 Omega) of the SWCNT paper and the wide change in resistance (up to 10(6) Omega) governed by the percolated network of SWCNT in the cracked region. The sensor response remains nearly unchanged after 10 000 strain cycles at 20% proving the robustness of this technology. This fragmentation based sensing system brings opportunities to engineer highly sensitive stretchable sensors.

  1. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  2. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    OpenAIRE

    Zhenzhong Guo; Anca Florea; Mengjuan Jiang; Yong Mei; Weiying Zhang; Aidong Zhang; Robert Săndulescu; Nicole Jaffrezic-Renault

    2016-01-01

    The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF) for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclu...

  3. Fiber Optic Temperature Sensor Based on Multimode Interference Effects

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Soto, J G; Antonio-Lopez, J E; Sanchez-Mondragon, J J [Photonics and Optical Physics Laboratory, Optics Department, INAOE Apdo. Postal 51 and 216, Tonantzintla, Puebla 72000 (Mexico); May-Arrioja, D A, E-mail: darrioja@uat.edu.mx

    2011-01-01

    A novel fiber optic temperature sensor based on multimode interference was designed, fabricated and tested. The sensor is very simple and inexpensive since we only need to splice a section of multimode fiber between two single mode fibers. Using this device a sensing range of 25 deg. C to 375 deg. C is demonstrated. We should also highlight that due to the pass-band filter response of MMI devices, multiplexing is rather simple by just changing the length of the multimode section.

  4. A Hierarchical Sensor Network Based on Voronoi Diagram

    Institute of Scientific and Technical Information of China (English)

    SHANG Rui-qiang; ZHAO Jian-li; SUN Qiu-xia; WANG Guang-xing

    2006-01-01

    A hierarchical sensor network is proposed which places the sensing and routing capacity at different layer nodes.It thus simplifies the hardware design and reduces cost. Adopting Voronoi diagram in the partition of backbone network,a mathematical model of data aggregation based on hierarchical architecture is given. Simulation shows that the number of transmission data packages is sharply cut down in the network, thus reducing the needs in the bandwidth and energy resources and is thus well adapted to sensor networks.

  5. Noninvasive Temperature Measurement Based on Microwave Temperature Sensor

    OpenAIRE

    Shoucheng Ding

    2013-01-01

    In this study, we have a research of the noninvasive temperature measurement based on microwave temperature sensor. Moreover, in order to solve the surface temperature measurement for designing microwave temperature sensor, the microwave was issued by the transmitting antenna. Microwave encountered by the measured object to return back to the measured object and then convert it into electrical signals, the use of the quantitative relationship between this signal and input noise temperature to...

  6. Fiber Bragg Grating Pressure Sensor Based on Corrugated Diaphragm

    Institute of Scientific and Technical Information of China (English)

    FU Hai-wei; FU Jun-mei; QIAO Xue-guang

    2004-01-01

    A kind of fiber Bragg grating pressure sensor based on corrugated diaphragm is proposed. The relationship between the central wavelength of reflective wave of FBG and pressure is given, and the expression of the pressure sensitivity coefficient is also given. Within the range from results agree with the theoretical analysis. It is indicated that the expected pressure sensitivity of the sensor can be obtained by optimizing the size and mechanical parameters of the corrugated diaphragm.

  7. A Calibration Report for Wireless Sensor-Based Weatherboards

    Directory of Open Access Journals (Sweden)

    Muthoni Masinde

    2015-03-01

    Full Text Available Sub-Saharan Africa contains the highest number of people affected by droughts. Although this can easily be mitigated through the provision of timely, reliable and relevant weather forecasts, the sparse network of weather stations in most of these countries makes this difficult. Rapid development in wireless sensor networks has resulted in weatherboards capable of capturing weather parameters at the micro-level. Although these weatherboards offer a viable solution to Africa’s drought, the acceptability of such data by meteorologists is only possible if these sensors are calibrated and their field readiness scientifically evaluated. This is the contribution of this paper; we present results of a calibration exercise that was carried out to: (1 measure and correct lag, random and systematic errors; (2 determine if Perspex was an ideal material for building sensor boards’ enclosures; and (3 identify sensor boards’ battery charging and depletion rates. The result is a calibration report detailing actual error and uncertainty values for atmospheric pressure, humidity and temperature sensors, as well as the recharge and discharge curves of the batteries. The results further ruled out the use of Perspex for enclosing the sensor boards. These experiments pave the way for the design and implementation of a sensor-based weather monitoring system (SenseWeather that was piloted in two regions in Kenya.

  8. Magnetic Sensors Based on Amorphous Ferromagnetic Materials: A Review.

    Science.gov (United States)

    Morón, Carlos; Cabrera, Carolina; Morón, Alberto; García, Alfonso; González, Mercedes

    2015-11-11

    Currently there are many types of sensors that are used in lots of applications. Among these, magnetic sensors are a good alternative for the detection and measurement of different phenomena because they are a "simple" and readily available technology. For the construction of such devices there are many magnetic materials available, although amorphous ferromagnetic materials are the most suitable. The existence in the market of these materials allows the production of different kinds of sensors, without requiring expensive manufacture investments for the magnetic cores. Furthermore, these are not fragile materials that require special care, favouring the construction of solid and reliable devices. Another important feature is that these sensors can be developed without electric contact between the measuring device and the sensor, making them especially fit for use in harsh environments. In this review we will look at the main types of developed magnetic sensors. This work presents the state of the art of magnetic sensors based on amorphous ferromagnetic materials used in modern technology: security devices, weapon detection, magnetic maps, car industry, credit cards, etc.

  9. Vibration analysis based on surface acoustic wave sensors

    Directory of Open Access Journals (Sweden)

    Gnadinger Alfred P.

    2015-01-01

    Full Text Available It is important to know, whether a civil engineering structure is safe or unsafe. One way to determine this is to measure vibrations at critical locations and feeding this data into an appropriate algorithm. Albido Corporation has developed wireless strain sensors based on surface acoustic wave (SAW principles that are mainly employed on rotating structures and in harsh environments. Albido's sensors could also be used to measure vibrations in civil engineering structures. They are small (~1 × 3 mm, passive and inexpensive (< 1$ in volume. They are powered by the electromagnetic field emanating from the antenna of a Reader System, similar to an RFID. The Reader System is essentially a computer with special software and has signal processing capability. One Reader System can service a multitude of sensors. The Reader antenna has to be within the reading range of the sensor. If large distances are required, a small electronic component acting as a Reader System can be placed within the reading range of the sensor that receives the sensor signal, generates a radio signal and encodes the sensor information on the radio signal. Then, the final data processing center can be placed anywhere.

  10. Magnetic Sensors Based on Amorphous Ferromagnetic Materials: A Review

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2015-11-01

    Full Text Available Currently there are many types of sensors that are used in lots of applications. Among these, magnetic sensors are a good alternative for the detection and measurement of different phenomena because they are a “simple” and readily available technology. For the construction of such devices there are many magnetic materials available, although amorphous ferromagnetic materials are the most suitable. The existence in the market of these materials allows the production of different kinds of sensors, without requiring expensive manufacture investments for the magnetic cores. Furthermore, these are not fragile materials that require special care, favouring the construction of solid and reliable devices. Another important feature is that these sensors can be developed without electric contact between the measuring device and the sensor, making them especially fit for use in harsh environments. In this review we will look at the main types of developed magnetic sensors. This work presents the state of the art of magnetic sensors based on amorphous ferromagnetic materials used in modern technology: security devices, weapon detection, magnetic maps, car industry, credit cards, etc.

  11. A Review of Carbon Nanotubes-Based Gas Sensors

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2009-01-01

    Full Text Available Gas sensors have attracted intensive research interest due to the demand of sensitive, fast response, and stable sensors for industry, environmental monitoring, biomedicine, and so forth. The development of nanotechnology has created huge potential to build highly sensitive, low cost, portable sensors with low power consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials is ideal for the adsorption of gas molecules. Particularly, the advent of carbon nanotubes (CNTs has fuelled the inventions of gas sensors that exploit CNTs' unique geometry, morphology, and material properties. Upon exposure to certain gases, the changes in CNTs' properties can be detected by various methods. Therefore, CNTs-based gas sensors and their mechanisms have been widely studied recently. In this paper, a broad but yet in-depth survey of current CNTs-based gas sensing technology is presented. Both experimental works and theoretical simulations are reviewed. The design, fabrication, and the sensing mechanisms of the CNTs-based gas sensors are discussed. The challenges and perspectives of the research are also addressed in this review.

  12. An Optical Pressure Sensor Based on MEMS

    Institute of Scientific and Technical Information of China (English)

    Tong Zhang; Sheng Qiang; Frank Lewis; Yalin Wu; Xiaozhu Chi

    2006-01-01

    An optical fiber pressure sensor has been developed for the measurement in human body. The sensing element is possessed of a membrane structure, which is fabricated by micromachining. The fabrication process includes anisotropic wet etching on the silicon wafer. For the transmitting source and signal light, a multimode optical fiber 50/125 μm (core/clad) in diameter was used. The intensity of the light reflected back into the fiber varies with the membrane deflection, which is a function of pressure. The deflection of the membrane by applied pressure can be mathematically described.

  13. Silicon nanohybrid-based surface-enhanced Raman scattering sensors.

    Science.gov (United States)

    Wang, Houyu; Jiang, Xiangxu; Lee, Shuit-Tong; He, Yao

    2014-11-01

    Nanomaterial-based surface-enhanced Raman scattering (SERS) sensors are highly promising analytical tools, capable of ultrasensitive, multiplex, and nondestructive detection of chemical and biological species. Extensive efforts have been made to design various silicon nanohybrid-based SERS substrates such as gold/silver nanoparticle (NP)-decorated silicon nanowires, Au/Ag NP-decorated silicon wafers (AuNP@Si), and so forth. In comparison to free AuNP- and AgNP-based SERS sensors, the silicon nanohybrid-based SERS sensors feature higher enhancement factors (EFs) and excellent reproducibility, since SERS hot spots are efficiently coupled and stabilized through interconnection to the semiconducting silicon substrates. Consequently, in the past decade, giant advancements in the development of silicon nanohybrid-based SERS sensors have been witnessed for myriad sensing applications. In this review, the representative achievements related to the design of high-performance silicon nanohybrid-based SERS sensors and their use for chemical and biological analysis are reviewed in a detailed way. Furthermore, the major opportunities and challenges in this field are discussed from a broad perspective and possible future directions.

  14. Potentiometric response and mechanism of anionic recognition of heterocalixarene-based ion selective electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Shishkanova, T.V. [Department of Analytical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)]. E-mail: tatiana.shishkanova@vscht.cz; Sykora, D. [Department of Analytical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Sessler, J.L. [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712-0615 (United States); Kral, V. [Department of Analytical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2007-03-28

    The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means of characterizing the anion recognition sites in the molecular receptor calix[2]pyridino[2]pyrrole (CPP). In particular, potentiometric pH-measurements involving the use of experimental PVC-membranes based on CPP revealed the existence of both mono- and diprotonated forms of the receptor under readily accessible conditions. Based on these analyses, apparent surface protonation constants for this heterocalixarene were found to lie between 8.5-8.9 (pK {sub B1}) and 3.3-3.8 (pK {sub B2}). CPP was found to interact with targeted anionic analytes based on both coulombic and hydrogen bond interactions, as inferred from varying the kinds of ionic sites present within the membrane phase. Potentiometric selectivity studies revealed that CPP preferred 'Y-shaped' anions (e.g. acetate, lactate, benzoate) over spherical anions (e.g. fluoride and chloride), fluoride over chloride within the set of spherical anions, and the ortho-isomer over the corresponding meta- and para-isomers in the case of hydroxybenzoate (salicylate and congeners). In the context of this study, the advantages of potentiometric determinations of acetylsalicylic acid using optimized PVC-membranes based on CPP relative to more conventional PVC-membrane ISEs based on traditional anion exchanger were also demonstrated.

  15. Electrochemical sensors and biosensors based on less aggregated graphene.

    Science.gov (United States)

    Bo, Xiangjie; Zhou, Ming; Guo, Liping

    2017-03-15

    As a novel single-atom-thick sheet of sp(2) hybridized carbon atoms, graphene (GR) has attracted extensive attention in recent years because of its unique and remarkable properties, such as excellent electrical conductivity, large theoretical specific surface area, and strong mechanical strength. However, due to the π-π interaction, GR sheets are inclined to stack together, which may seriously degrade the performance of GR with the unique single-atom layer. In recent years, an increasing number of GR-based electrochemical sensors and biosensors are reported, which may reflect that GR has been considered as a kind of hot and promising electrode material for electrochemical sensor and biosensor construction. However, the active sites on GR surface induced by the irreversible GR aggregations would be deeply secluded inside the stacked GR sheets and therefore are not available for the electrocatalysis. So the alleviation or the minimization of the aggregation level for GR sheets would facilitate the exposure of active sites on GR and effectively upgrade the performance of GR-based electrochemical sensors and biosensors. Less aggregated GR with low aggregation and high dispersed structure can be used in improving the electrochemical activity of GR-based electrochemical sensors or biosensors. In this review, we summarize recent advances and new progress for the development of electrochemical sensors based on less aggregated GR. To achieve such goal, many strategies (such as the intercalation of carbon materials, surface modification, and structural engineering) have been applied to alleviate the aggregation level of GR in order to enhance the performance of GR-based electrochemical sensors and biosensors. Finally, the challenges associated with less aggregated GR-based electrochemical sensors and biosensors as well as related future research directions are discussed.

  16. A Solar Position Sensor Based on Image Vision

    Science.gov (United States)

    Ruelas, Adolfo; Velázquez, Nicolás; Villa-Angulo, Carlos; Rosales, Pedro; Suastegui, José

    2017-01-01

    Solar collector technologies operate with better performance when the Sun beam direction is normal to the capturing surface, and for that to happen despite the relative movement of the Sun, solar tracking systems are used, therefore, there are rules and standards that need minimum accuracy for these tracking systems to be used in solar collectors’ evaluation. Obtaining accuracy is not an easy job, hence in this document the design, construction and characterization of a sensor based on a visual system that finds the relative azimuth error and height of the solar surface of interest, is presented. With these characteristics, the sensor can be used as a reference in control systems and their evaluation. The proposed sensor is based on a microcontroller with a real-time clock, inertial measurement sensors, geolocation and a vision sensor, that obtains the angle of incidence from the sunrays’ direction as well as the tilt and sensor position. The sensor’s characterization proved how a measurement of a focus error or a Sun position can be made, with an accuracy of 0.0426° and an uncertainty of 0.986%, which can be modified to reach an accuracy under 0.01°. The validation of this sensor was determined showing the focus error on one of the best commercial solar tracking systems, a Kipp & Zonen SOLYS 2. To conclude, the solar tracking sensor based on a vision system meets the Sun detection requirements and components that meet the accuracy conditions to be used in solar tracking systems and their evaluation or, as a tracking and orientation tool, on photovoltaic installations and solar collectors. PMID:28758935

  17. Gas Sensors Based on Ceramic p-n Heterocontacts

    Energy Technology Data Exchange (ETDEWEB)

    Seymen Murat Aygun

    2004-12-19

    Ceramic p-n heterocontacts based on CuO/ZnO were successfully synthesized and a systematic study of their hydrogen sensitivity was conducted. The sensitivity and response rates of CuO/ZnO sensors were studied utilizing current-voltage, current-time, and impedance spectroscopy measurements. The heterocontacts showed well-defined rectifying characteristics and were observed to detect hydrogen via both dc and ac measurements. Surface coverage data were derived from current-time measurements which were then fit to a two-site Langmuir adsorption model quite satisfactorily. The fit suggested that there should be two energetically different adsorption sites in the system. The heterocontacts were doped in an attempt to increase the sensitivity and the response rate of the sensor. First, the effects of doping the p-type (CuO) on the sensor characteristics were investigated. Doping the p-type CuO with both acceptor and isovalent dopants greatly improved the hydrogen sensitivity. The sensitivity of pure heterocontact observed via I-V measurements was increased from {approx}2.3 to {approx}9.4 with Ni doping. Dopants also enhanced the rectifying characteristics of the heterocontacts. Small amounts of Li addition were shown to decrease the reverse bias (saturation) current to 0.2 mA at a bias level of -5V. No unambiguous trends were observed between the sensitivity, the conductivity, and the density of the samples. Comparing the two phase microstructure to the single phase microstructure there was no dramatic increase in the sensitivity. Kinetic studies also confirmed the improved sensor characteristics with doping. The dopants decreased the response time of the sensor by decreasing the response time of one of the adsorption sites. The n-type ZnO was doped with both acceptor and donor dopants. Li doping resulted in the degradation of the p-n junction and the response time of the sensor. However, the current-voltage behavior of Ga-doped heterocontacts showed the best rectifying

  18. Gas Sensors Based on Ceramic p-n Heterocontacts

    Energy Technology Data Exchange (ETDEWEB)

    Aygun, Seymen Murat [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Ceramic p-n heterocontacts based on CuO/ZnO were successfully synthesized and a systematic study of their hydrogen sensitivity was conducted. The sensitivity and response rates of CuO/ZnO sensors were studied utilizing current-voltage, current-time, and impedance spectroscopy measurements. The heterocontacts showed well-defined rectifying characteristics and were observed to detect hydrogen via both dc and ac measurements. Surface coverage data were derived from current-time measurements which were then fit to a two-site Langmuir adsorption model quite satisfactorily. The fit suggested that there should be two energetically different adsorption sites in the system. The heterocontacts were doped in an attempt to increase the sensitivity and the response rate of the sensor. First, the effects of doping the p-type (CuO) on the sensor characteristics were investigated. Doping the p-type CuO with both acceptor and isovalent dopants greatly improved the hydrogen sensitivity. The sensitivity of pure heterocontact observed via I-V measurements was increased from ~2.3 to ~9.4 with Ni doping. Dopants also enhanced the rectifying characteristics of the heterocontacts. Small amounts of Li addition were shown to decrease the reverse bias (saturation) current to 0.2 mA at a bias level of -5V. No unambiguous trends were observed between the sensitivity, the conductivity, and the density of the samples. Comparing the two phase microstructure to the single phase microstructure there was no dramatic increase in the sensitivity. Kinetic studies also confirmed the improved sensor characteristics with doping. The dopants decreased the response time of the sensor by decreasing the response time of one of the adsorption sites. The n-type ZnO was doped with both acceptor and donor dopants. Li doping resulted in the degradation of the p-n junction and the response time of the sensor. However, the current-voltage behavior of Ga-doped heterocontacts showed the best rectifying characteristics

  19. Microfluidic sensors based on perforated cantilevers

    DEFF Research Database (Denmark)

    Noeth, Nadine-Nicole

    Arbejdet presenteret i denne PhD afhandling omhandler udviklingen af en mikrofluide sensor basered på bjælke teknologi. Bjælkerne er fremstillet i den negative photo-resist SU-8 og i SiN. I bjælkerne er der inkorporeret et array af huller. To nye sensorer er udviklet på baggrund af de perforerede...... bjælker: en yderst sensitiv flow-meter og en partikel tæller med integreret filter funktion. En optisk udlæsningsteknik benyttes til at måle udbøjningen af bjælkerne. En laser stråle fokuseres på enden af bjælken og bjælke forskydningen måles ved at detekterer laser strålens forskydning ved hjælp af en...... strømningsmodstanden de inducerer i kanalen og af hastigheden på væsken i kanalen. Ved at kende geometrien og materiale parametrene kan strømningnshastigheden i kanalen bestemmes ud fra udbøjningen af bjælken. Sensitiviteten på flow-meteret kan varieres ved at ændre på geometrien og bjælke materialet. De perforerede...

  20. Performance Evaluation of Triangulation Based Range Sensors

    Directory of Open Access Journals (Sweden)

    Monica Bordegoni

    2010-07-01

    Full Text Available The performance of 2D digital imaging systems depends on several factors related with both optical and electronic processing. These concepts have originated standards, which have been conceived for photographic equipment and bi-dimensional scanning systems, and which have been aimed at estimating different parameters such as resolution, noise or dynamic range. Conversely, no standard test protocols currently exist for evaluating the corresponding performances of 3D imaging systems such as laser scanners or pattern projection range cameras. This paper is focused on investigating experimental processes for evaluating some critical parameters of 3D equipment, by extending the concepts defined by the ISO standards to the 3D domain. The experimental part of this work concerns the characterization of different range sensors through the extraction of their resolution, accuracy and uncertainty from sets of 3D data acquisitions of specifically designed test objects whose geometrical characteristics are known in advance. The major objective of this contribution is to suggest an easy characterization process for generating a reliable comparison between the performances of different range sensors and to check if a specific piece of equipment is compliant with the expected characteristics.

  1. A fiber Bragg based semi distributed pressure sensor system for in-vivo vascular applications

    NARCIS (Netherlands)

    Nieuwland, R.A.; Cheng, L.K.; Lemmen, M.H.J.; Oostenbrink, R.H.; Harmsma, P.J.; Schreuder, J.J.

    2014-01-01

    An overview of a fiber Bragg based sensor system, developed for in-vivo vascular pressure and temperature sensing, is presented. The focus is on sensor miniaturization and interrogator optimization to reach a viable sensor system.

  2. A Microring Resonator Based Negative Permeability Metamaterial Sensor

    Science.gov (United States)

    Sun, Jun; Huang, Ming; Yang, Jing-Jing; Li, Ting-Hua; Lan, Yao-Zhong

    2011-01-01

    Metamaterials are artificial multifunctional materials that acquire their material properties from their structure, rather than inheriting them directly from the materials they are composed of, and they may provide novel tools to significantly enhance the sensitivity and resolution of sensors. In this paper, we derive the dispersion relation of a cylindrical dielectric waveguide loaded on a negative permeability metamaterial (NPM) layer, and compute the resonant frequencies and electric field distribution of the corresponding Whispering-Gallery-Modes (WGMs). The theoretical resonant frequency and electric field distribution results are in good agreement with the full wave simulation results. We show that the NPM sensor based on a microring resonator possesses higher sensitivity than the traditional microring sensor since with the evanescent wave amplification and the increase of NPM layer thickness, the sensitivity will be greatly increased. This may open a door for designing sensors with specified sensitivity. PMID:22164062

  3. A flexible piezoelectric force sensor based on PVDF fabrics

    Science.gov (United States)

    Wang, Y. R.; Zheng, J. M.; Ren, G. Y.; Zhang, P. H.; Xu, C.

    2011-04-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensor and transducer material due to its high piezo-, pyro- and ferroelectric properties. To activate these properties, PVDF films require a mechanical treatment, stretching or poling. In this paper, we report on a force sensor based on PVDF fabrics with excellent flexibility and breathability, to be used as a specific human-related sensor. PVDF nanofibrous fabrics were prepared by using an electrospinning unit and characterized by means of scanning electron microscopy (SEM), FTIR spectroscopy and x-ray diffraction. Preliminary force sensors have been fabricated and demonstrated excellent sensitivity and response to external mechanical forces. This implies that promising applications can be made for sensing garment pressure, blood pressure, heartbeat rate, respiration rate and accidental impact on the human body.

  4. Affinity sensor based on immobilized molecular imprinted synthetic recognition elements.

    Science.gov (United States)

    Lenain, Pieterjan; De Saeger, Sarah; Mattiasson, Bo; Hedström, Martin

    2015-07-15

    An affinity sensor based on capacitive transduction was developed to detect a model compound, metergoline, in a continuous flow system. This system simulates the monitoring of low-molecular weight organic compounds in natural flowing waters, i.e. rivers and streams. During operation in such scenarios, control of the experimental parameters is not possible, which poses a true analytical challenge. A two-step approach was used to produce a sensor for metergoline. Submicron spherical molecularly imprinted polymers, used as recognition elements, were obtained through emulsion polymerization and subsequently coupled to the sensor surface by electropolymerization. This way, a robust and reusable sensor was obtained that regenerated spontaneously under the natural conditions in a river. Small organic compounds could be analyzed in water without manipulating the binding or regeneration conditions, thereby offering a viable tool for on-site application.

  5. Novel carbon dioxide gas sensor based on infrared absorption

    Science.gov (United States)

    Zhang, Guangjun; Lui, Junfang; Yuan, Mei

    2000-08-01

    The feasibility of sensing carbon dioxide with a IR single- beam optical structure is studied, and a novel carbon dioxide gas sensor based on IR absorption is achieved. Applying the Lambert-Beer law and some key techniques such as current stabilization for IR source, using a high-quality IR detector, and data compensation for the influences of ambience temperature and atmosphere total pressure, the sensor can measure carbon dioxide with high precision and efficiency. The mathematical models for providing temperature and pressure compensation for the sensor are established. Moreover the solutions to the models are proposed. Both the models and the solutions to the models are verified via experiments. The sensor possesses the advantages of small volume, light weight, low power consumption, and high reliability. Therefore it can be used in many associated fields, such as environmental protection, processing control, chemical analysis, medical diagnosis, and space environmental and control systems.

  6. A Microring Resonator Based Negative Permeability Metamaterial Sensor

    Directory of Open Access Journals (Sweden)

    Yao-Zhong Lan

    2011-08-01

    Full Text Available Metamaterials are artificial multifunctional materials that acquire their material properties from their structure, rather than inheriting them directly from the materials they are composed of, and they may provide novel tools to significantly enhance the sensitivity and resolution of sensors. In this paper, we derive the dispersion relation of a cylindrical dielectric waveguide loaded on a negative permeability metamaterial (NPM layer, and compute the resonant frequencies and electric field distribution of the corresponding Whispering-Gallery-Modes (WGMs. The theoretical resonant frequency and electric field distribution results are in good agreement with the full wave simulation results. We show that the NPM sensor based on a microring resonator possesses higher sensitivity than the traditional microring sensor since with the evanescent wave amplification and the increase of NPM layer thickness, the sensitivity will be greatly increased. This may open a door for designing sensors with specified sensitivity.

  7. Measuring intracellular redox conditions using GFP-based sensors

    DEFF Research Database (Denmark)

    Björnberg, Olof; Ostergaard, Henrik; Winther, Jakob R

    2006-01-01

    Recent years have seen the development of methods for analyzing the redox conditions in specific compartments in living cells. These methods are based on genetically encoded sensors comprising variants of Green Fluorescent Protein in which vicinal cysteine residues have been introduced at solvent......-exposed positions. Several mutant forms have been identified in which formation of a disulfide bond between these cysteine residues results in changes of their fluorescence properties. The redox sensors have been characterized biochemically and found to behave differently, both spectroscopically and in terms...... of redox properties. As genetically encoded sensors they can be expressed in living cells and used for analysis of intracellular redox conditions; however, which parameters are measured depends on how the sensors interact with various cellular redox components. Results of both biochemical and cell...

  8. An easily fabricated high performance ionic polymer based sensor network

    Science.gov (United States)

    Zhu, Zicai; Wang, Yanjie; Hu, Xiaopin; Sun, Xiaofei; Chang, Longfei; Lu, Pin

    2016-08-01

    Ionic polymer materials can generate an electrical potential from ion migration under an external force. For traditional ionic polymer metal composite sensors, the output voltage is very small (a few millivolts), and the fabrication process is complex and time-consuming. This letter presents an ionic polymer based network of pressure sensors which is easily and quickly constructed, and which can generate high voltage. A 3 × 3 sensor array was prepared by casting Nafion solution directly over copper wires. Under applied pressure, two different levels of voltage response were observed among the nine nodes in the array. For the group producing the higher level, peak voltages reached as high as 25 mV. Computational stress analysis revealed the physical origin of the different responses. High voltages resulting from the stress concentration and asymmetric structure can be further utilized to modify subsequent designs to improve the performance of similar sensors.

  9. An Architecture for Intelligent Systems Based on Smart Sensors

    Science.gov (United States)

    Schmalzel, John; Figueroa, Fernando; Morris, Jon; Mandayam, Shreekanth; Polikar, Robi

    2004-01-01

    Based on requirements for a next-generation rocket test facility, elements of a prototype Intelligent Rocket Test Facility (IRTF) have been implemented. A key component is distributed smart sensor elements integrated using a knowledgeware environment. One of the specific goals is to imbue sensors with the intelligence needed to perform self diagnosis of health and to participate in a hierarchy of health determination at sensor, process, and system levels. The preliminary results provide the basis for future advanced development and validation using rocket test stand facilities at Stennis Space Center (SSC). We have identified issues important to further development of health-enabled networks, which should be of interest to others working with smart sensors and intelligent health management systems.

  10. An improved sensor for electrochemical microcalorimetry, based on lithiumtantalate

    Science.gov (United States)

    Frittmann, Stefan; Halka, Vadym; Jaramillo, Carlos; Schuster, Rolf

    2015-06-01

    We have developed a pyroelectric sensor for electrochemical microcalorimetry, based on LiTaO3, which provides unprecedented sensitivity for the detection of electrochemically induced heat effects. Deterioration of the heat signal by electrostriction effects on the electrode surface is suppressed by a multilayered construction, where an intermediate sapphire sheet dampens mechanical deformations. Thus, well textured thin metal films become viable candidates as electrodes. We demonstrate the sensor performance for Cu underpotential deposition on (111)-textured Au films on sapphire. The sensor signal compares well with a purely thermal signal induced by heating with laser pulses. The high sensitivity of the sensor is demonstrated by measuring heat effects upon double layer charging in perchloric acid, i.e., in the absence of electrochemical charge- or ion-transfer reactions.

  11. Whitelists Based Multiple Filtering Techniques in SCADA Sensor Networks

    Directory of Open Access Journals (Sweden)

    DongHo Kang

    2014-01-01

    Full Text Available Internet of Things (IoT consists of several tiny devices connected together to form a collaborative computing environment. Recently IoT technologies begin to merge with supervisory control and data acquisition (SCADA sensor networks to more efficiently gather and analyze real-time data from sensors in industrial environments. But SCADA sensor networks are becoming more and more vulnerable to cyber-attacks due to increased connectivity. To safely adopt IoT technologies in the SCADA environments, it is important to improve the security of SCADA sensor networks. In this paper we propose a multiple filtering technique based on whitelists to detect illegitimate packets. Our proposed system detects the traffic of network and application protocol attacks with a set of whitelists collected from normal traffic.

  12. Research on Stealthy Headphone Detector Based on Geomagnetic Sensor

    Directory of Open Access Journals (Sweden)

    Liu Ya

    2016-01-01

    Full Text Available A kind of stealth headphone detector based on geomagnetic sensor has been developed to deal with the stealth headphones which are small, extremely stealthy and hard to detect. The U.S. PNI geomagnetic sensor is chosen to obtain magnetic field considering the strong magnetic performance of stealth headphones. The earth’s magnetic field at the geomagnetic sensor is eliminated by difference between two geomagnetic sensors, and then weak variations of magnetic field is detected. STM8S103K2 is chosen as the central controlling chip, which is connected to LED, buzzer and LCD 1602. As shown by the experimental results, the probe is not liable to damage by the magnetic field and the developed device has high sensitivity, low False Positive Rate (FAR and satisfactory reliability.

  13. Matching sensors to missions using a knowledge-based approach

    Science.gov (United States)

    Preece, Alun; Gomez, Mario; de Mel, Geeth; Vasconcelos, Wamberto; Sleeman, Derek; Colley, Stuart; Pearson, Gavin; Pham, Tien; La Porta, Thomas

    2008-04-01

    Making decisions on how best to utilise limited intelligence, surveillance and reconnaisance (ISR) resources is a key issue in mission planning. This requires judgements about which kinds of available sensors are more or less appropriate for specific ISR tasks in a mission. A methodological approach to addressing this kind of decision problem in the military context is the Missions and Means Framework (MMF), which provides a structured way to analyse a mission in terms of tasks, and assess the effectiveness of various means for accomplishing those tasks. Moreover, the problem can be defined as knowledge-based matchmaking: matching the ISR requirements of tasks to the ISR-providing capabilities of available sensors. In this paper we show how the MMF can be represented formally as an ontology (that is, a specification of a conceptualisation); we also represent knowledge about ISR requirements and sensors, and then use automated reasoning to solve the matchmaking problem. We adopt the Semantic Web approach and the Web Ontology Language (OWL), allowing us to import elements of existing sensor knowledge bases. Our core ontologies use the description logic subset of OWL, providing efficient reasoning. We describe a prototype tool as a proof-of-concept for our approach. We discuss the various kinds of possible sensor-mission matches, both exact and inexact, and how the tool helps mission planners consider alternative choices of sensors.

  14. APTAMER-BASED SERRS SENSOR FOR THROMBIN DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H; Baker, B R; Wachsmann-Hogiu, S; Pagba, C V; Laurence, T A; Lane, S M; Lee, L P; Tok, J B

    2008-07-02

    We describe an aptamer-based Surface Enhanced Resonance Raman Scattering (SERRS) sensor with high sensitivity, specificity, and stability for the detection of a coagulation protein, human a-thrombin. The sensor achieves high sensitivity and a limit of detection of 100 pM by monitoring the SERRS signal change upon the single step of thrombin binding to immobilized thrombin binding aptamer. The selectivity of the sensor is demonstrated by the specific discrimination of thrombin from other protein analytes. The specific recognition and binding of thrombin by the thrombin binding aptamer is essential to the mechanism of the aptamer-based sensor, as shown through measurements using negative control oligonucleotides. In addition, the sensor can detect 1 nM thrombin in the presence of complex biofluids, such as 10% fetal calf serum, demonstrating that the immobilized, 5{prime}-capped, 3{prime}-capped aptamer is sufficiently robust for clinical diagnostic applications. Furthermore, the proposed sensor may be implemented for multiplexed detection using different aptamer-Raman probe complexes.

  15. Energy Efficient Cluster Based Scheduling Scheme for Wireless Sensor Networks.

    Science.gov (United States)

    Janani, E Srie Vidhya; Kumar, P Ganesh

    2015-01-01

    The energy utilization of sensor nodes in large scale wireless sensor network points out the crucial need for scalable and energy efficient clustering protocols. Since sensor nodes usually operate on batteries, the maximum utility of network is greatly dependent on ideal usage of energy leftover in these sensor nodes. In this paper, we propose an Energy Efficient Cluster Based Scheduling Scheme for wireless sensor networks that balances the sensor network lifetime and energy efficiency. In the first phase of our proposed scheme, cluster topology is discovered and cluster head is chosen based on remaining energy level. The cluster head monitors the network energy threshold value to identify the energy drain rate of all its cluster members. In the second phase, scheduling algorithm is presented to allocate time slots to cluster member data packets. Here congestion occurrence is totally avoided. In the third phase, energy consumption model is proposed to maintain maximum residual energy level across the network. Moreover, we also propose a new packet format which is given to all cluster member nodes. The simulation results prove that the proposed scheme greatly contributes to maximum network lifetime, high energy, reduced overhead, and maximum delivery ratio.

  16. Fabrication of strain gauge based sensors for tactile skins

    Science.gov (United States)

    Baptist, Joshua R.; Zhang, Ruoshi; Wei, Danming; Saadatzi, Mohammad Nasser; Popa, Dan O.

    2017-05-01

    Fabricating cost effective, reliable and functional sensors for electronic skins has been a challenging undertaking for the last several decades. Application of such skins include haptic interfaces, robotic manipulation, and physical human-robot interaction. Much of our recent work has focused on producing compliant sensors that can be easily formed around objects to sense normal, tension, or shear forces. Our past designs have involved the use of flexible sensors and interconnects fabricated on Kapton substrates, and piezoresistive inks that are 3D printed using Electro Hydro Dynamic (EHD) jetting onto interdigitated electrode (IDE) structures. However, EHD print heads require a specialized nozzle and the application of a high-voltage electric field; for which, tuning process parameters can be difficult based on the choice of inks and substrates. Therefore, in this paper we explore sensor fabrication techniques using a novel wet lift-off photolithographic technique for patterning the base polymer piezoresistive material, specifically Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) or PEDOT:PSS. Fabricated sensors are electrically and thermally characterized, and temperaturecompensated designs are proposed and validated. Packaging techniques for sensors in polymer encapsulants are proposed and demonstrated to produce a tactile interface device for a robot.

  17. Electrode-analytical properties of polyvinylchloride membranes based on triple metal-polymeric complexes

    OpenAIRE

    Matorina, Katerina V.; Chmilenko, Tetyana S.; Chmilenko, Fedor O.

    2015-01-01

    The influence of the nature of the electrode-active substances (EAS), the composition of the external and internal solutions on the formation of the analytical signal of polyvinylchloride (PVC) membranes based on associates and triple metal-polymeric complexes (TMPC) was established. Dehumidification of synthesized membranes increases with the content of polyvinylpyrrolidone (PVP). The value of the swelling degree is more than two times greater for membranes, which contain as EAS TMPC, relati...

  18. Development of a specific and highly sensitive optical chemical sensor for determination of Hg(II) based on a new synthesized ionophore.

    Science.gov (United States)

    Firooz, Ali R; Ensafi, Ali A; Karimi, K; Sharghi, H

    2013-10-01

    A novel optode for determination of Hg(II) ions is developed based on immobilization of a recently synthesized ionophore, 7-(1H-imidazol-1-ylmethyl)-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10 benzodioxatriaza cyclopentadecine-3,11(4H,12H)-dione, in a PVC membrane. Dioctyl sebacate was used as a plasticizer, sodium tetraphenylborate as an anionic additive and ETH5294 as a chromoionophore. The response of the optode was based on the complexation of Hg(II) with the ionophore in the membrane phase, resulting an ion exchange process between Hg(II) in the sample solution and H(+) in the membrane. The effects of pH and amounts of the ionophore, chromoionophore, ionic additive and type of plasticizer on the optode response were investigated. The selectivity of the optode was studied in the present of several cations. The optode has a linear response to Hg(II) in the range of 7.2×10(-13)-4.7×10(-4) mol L(-1) with detection limit of 0.18 pmol L(-1). The optode was successfully applied to the determination of Hg(II) in real samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Vehicle passes detector based on multi-sensor analysis

    Science.gov (United States)

    Bocharov, D.; Sidorchuk, D.; Konovalenko, I.; Koptelov, I.

    2015-02-01

    The study concerned deals with a new approach to the problem of detecting vehicle passes in vision-based automatic vehicle classification system. Essential non-affinity image variations and signals from induction loop are the events that can be considered as detectors of an object presence. We propose several vehicle detection techniques based on image processing and induction loop signal analysis. Also we suggest a combined method based on multi-sensor analysis to improve vehicle detection performance. Experimental results in complex outdoor environments show that the proposed multi-sensor algorithm is effective for vehicles detection.

  20. Optical sensor array platform based on polymer electronic devices

    Science.gov (United States)

    Koetse, Marc M.; Rensing, Peter A.; Sharpe, Ruben B. A.; van Heck, Gert T.; Allard, Bart A. M.; Meulendijks, Nicole N. M. M.; Kruijt, Peter G. M.; Tijdink, Marcel W. W. J.; De Zwart, René M.; Houben, René J.; Enting, Erik; van Veen, Sjaak J. J. F.; Schoo, Herman F. M.

    2007-10-01

    Monitoring of personal wellbeing and optimizing human performance are areas where sensors have only begun to be used. One of the reasons for this is the specific demands that these application areas put on the underlying technology and system properties. In many cases these sensors will be integrated in clothing, be worn on the skin, or may even be placed inside the body. This implies that flexibility and wearability of the systems is essential for their success. Devices based on polymer semiconductors allow for these demands since they can be fabricated with thin film technology. The use of thin film device technology allows for the fabrication of very thin sensors (e.g. integrated in food product packaging), flexible or bendable sensors in wearables, large area/distributed sensors, and intrinsically low-cost applications in disposable products. With thin film device technology a high level of integration can be achieved with parts that analyze signals, process and store data, and interact over a network. Integration of all these functions will inherently lead to better cost/performance ratios, especially if printing and other standard polymer technology such as high precision moulding is applied for the fabrication. In this paper we present an optical transmission sensor array based on polymer semiconductor devices made by thin film technology. The organic devices, light emitting diodes, photodiodes and selective medium chip, are integrated with classic electronic components. Together they form a versatile sensor platform that allows for the quantitative measurement of 100 channels and communicates wireless with a computer. The emphasis is given to the sensor principle, the design, fabrication technology and integration of the thin film devices.

  1. Laser-based sensors for oil spill remote sensing

    Science.gov (United States)

    Brown, Carl E.; Fingas, Mervin F.; Mullin, Joseph V.

    1997-07-01

    Remote sensing is becoming an increasingly important tool for the effective direction of oil spill countermeasures. Cleanup personnel have recognized that remote sensing can increase spill cleanup efficiency. It has long been recognized that there is no one sensor which is capable of detecting oil and related petroleum products in all environments and spill scenarios. There are sensors which possess a wide field-of- view and can therefore be used to map the overall extent of the spill. These sensors, however lack the capability to positively identify oil and related products, especially along complicated beach and shoreline environments where several substrates are present. The laser-based sensors under development by the Emergencies Science Division of Environment Canada are designed to fill specific roles in oil spill response. The scanning laser environmental airborne fluorosensor (SLEAF) is being developed to detect and map oil and related petroleum products in complex marine and shoreline environments where other non-specific sensors experience difficulty. The role of the SLEAF would be to confirm or reject suspected oil contamination sites that have been targeted by the non-specific sensors. This confirmation will release response crews from the time-consuming task of physically inspecting each site, and direct crews to sites that require remediation. The laser ultrasonic remote sensing of oil thickness (LURSOT) sensor will provide an absolute measurement of oil thickness from an airborne platform. There are presently no sensors available, either airborne or in the laboratory which can provide an absolute measurement of oil thickness. This information is necessary for the effective direction of spill countermeasures such as dispersant application and in-situ burning. This paper describes the development of laser-based airborne oil spill remote sensing instrumentation at Environment Canada and identifies the anticipated benefits of the use of this technology

  2. Optical Sensors based on Raman Effects

    DEFF Research Database (Denmark)

    Jernshøj, Kit Drescher

    Formålet med denne afhandling er at give en systematisk og uddybende videnskabelig diskussion af molekylær Raman spredning, som kan danne grundlag for udviklingen af molekylespecifikke optiske sensorer til on-site, ikke-destruktiv måling. Afhandlingen falder i tre dele, to teoriafsnit, hvor første...... data fra denne type eksperimenter betyde et øget informationsindhold til anvendelse i den multivariate analyse. Diskussionen er bygget op omkring tre forskellige typer klassifikationsproblemer, hvor der i den første type sker en perturbering, som resulterer i enten en nedgang i symmetri eller en...... energiopsplitning for den ene molekylære specie ud af to tilstede i en opløsning. I det andet type klassifikationsproblem bygger det øgede informationsindhold på en forskydning af den elektroniske absorption og endelig i det tredje klassifikationsproblem er det en molekylær aggregering, der finder sted. I...

  3. Vision communications based on LED array and imaging sensor

    Science.gov (United States)

    Yoo, Jong-Ho; Jung, Sung-Yoon

    2012-11-01

    In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

  4. DNA chip based sensor for amperometric detection of infectious pathogens.

    Science.gov (United States)

    Singh, Swati; Kaushal, Ankur; Khare, Shashi; Kumar, Ashok

    2017-10-01

    Several infectious pathogens are found in human whose detection is essential for rapid cure of diseases. The most commonly found pathogen in human is Streptococcus pyogenes which leads to a wide range of infections from mild pharyngitis to rheumatic heart disease. An ultrasensitive DNA chip based sensor was developed for quick identification of pathogen S. pyogenes from patient throat swab samples. The amperometric response was measured after hybridization of specific probe with single stranded genomic DNA (ssG-DNA) from the patient samples. The DNA chip was characterized by FTIR, SEM and validated with suspected patient real samples. The sensitivity of the DNA chip based sensor was found 951.34(μA/cm(2))/ng DNA and lower limit of detection (LOD) was 130fg/6μL samples. The DNA chip based sensor is highly specific and takes only 30min for identification of specific pathogen. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Aptamer based electrochemical sensors for emerging environmental pollutants

    Directory of Open Access Journals (Sweden)

    Akhtar eHAYAT

    2014-06-01

    Full Text Available Environmental contaminants monitoring is one of the key issues in understanding and managing hazards to human health and ecosystems. In this context, aptamer based electrochemical sensors have achieved intense significance because of their capability to resolve a potentially large number of problems and challenges in environmental contamination. An aptasensor is a compact analytical device incorporating an aptamer (oligonulceotide as the sensing element either integrated within or intimately associated with a physiochemical transducer surface. Nucleic acid is well known for the function of carrying and passing genetic information, however, it has found a key role in analytical monitoring during recent years. Aptamer based sensors represent a novelty in environmental analytical science and there are great expectations for their promising performance as alternative to conventional analytical tools. This review paper focuses on the recent advances in the development of aptamer based electrochemical sensors for environmental applications with special emphasis on emerging pollutants.

  6. Aptamer based electrochemical sensors for emerging environmental pollutants

    Science.gov (United States)

    Hayat, Akhtar; Marty, Jean Louis

    2014-06-01

    Environmental contaminants monitoring is one of the key issues in understanding and managing hazards to human health and ecosystems. In this context, aptamer based electrochemical sensors have achieved intense significance because of their capability to resolve a potentially large number of problems and challenges in environmental contamination. An aptasensor is a compact analytical device incorporating an aptamer (oligonulceotide) as the sensing element either integrated within or intimately associated with a physiochemical transducer surface. Nucleic acid is well known for the function of carrying and passing genetic information, however, it has found a key role in analytical monitoring during recent years. Aptamer based sensors represent a novelty in environmental analytical science and there are great expectations for their promising performance as alternative to conventional analytical tools. This review paper focuses on the recent advances in the development of aptamer based electrochemical sensors for environmental applications with special emphasis on emerging pollutants.

  7. RKP based secure tracking in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To enhancing the wireless sensor network's security in target tracking and locating application,this article proposes a tracking cluster based mobile cluster distributed group rekeying protocol (MCDGR).Based on the given sensitivity,sensors can locate the moving object in the monitored area and form a tracking cluster around it.This tracking cluster can follow the target logically,process data on the target and report to the sink node,and thus achieve the tracking function.We introduce a multi-path reinforcement scheme,q-composition scheme and one-way cryptographic hash function based random key predietribution algorithm (RKP),which can guarantee a high accuracy and security and a low energy consumption on the same time in large-scale sensor networks.

  8. A novel symmetrical microwave power sensor based on MEMS technology

    Institute of Scientific and Technical Information of China (English)

    Wang Debo; Liao Xiaoping

    2009-01-01

    A novel symmetrical microwave power sensor based on MEMS technology is presented. In this power sensor, the left section inputs the microwave power, while the right section inputs the DC power. Because of its symmetrical structure, this power sensor provides more accurate microwave power measurement capability without mismatch uncertainty and temperature drift. The loss caused by the microwave signal is simulated in this power sensor. This power sensor is designed and fabricated using GaAs MMIC technology. And it is measured in the frequency range up to 20 GHz with an input power in the 0-80 mW range. Over the 80 mW dynamic range, the sensitivity can achieve about 0.2 mV/mW. The difference between the input power in the two sections is below 0.1% for an equal output voltage. In short, the key aspect of this power sensor is that the microwave power measurement is replaced with a DC power measurement.

  9. Illicit material detector based on gas sensors and neural networks

    Science.gov (United States)

    Grimaldi, Vincent; Politano, Jean-Luc

    1997-02-01

    In accordance with its missions, le Centre de Recherches et d'Etudes de la Logistique de la Police Nationale francaise (CREL) has been conducting research for the past few years targeted at detecting drugs and explosives. We have focused our approach of the underlying physical and chemical detection principles on solid state gas sensors, in the hope of developing a hand-held drugs and explosives detector. The CREL and Laboratory and Scientific Services Directorate are research partners for this project. Using generic hydrocarbon, industrially available, metal oxide sensors as illicit material detectors, requires usage precautions. Indeed, neither the product's concentrations, nor even the products themselves, belong to the intended usage specifications. Therefore, the CREL is currently investigating two major research topics: controlling the sensor's environment: with environmental control we improve the detection of small product concentration; determining detection thresholds: both drugs and explosives disseminate low gas concentration. We are attempting to quantify the minimal concentration which triggers detection. In the long run, we foresee a computer-based tool likely to detect a target gas in a noisy atmosphere. A neural network is the suitable tool for interpreting the response of heterogeneous sensor matrix. This information processing structure, alongside with proper sensor environment control, will lessen the repercussions of common MOS sensor sensitivity characteristic dispersion.

  10. Sensor-based navigation of air duct inspection mobile robots

    Science.gov (United States)

    Koh, Kyoungchul; Choi, H. J.; Kim, Jae-Seon; Ko, Kuk Won; Cho, Hyungsuck

    2001-02-01

    12 This paper deals with an image sensor system and its position estimation algorithm for autonomous duct cleaning and inspection mobile robots. For the real application, a hierarchical control structure that consists of robot motion controller and image sensor system is designed considering the efficient and autonomous motion behaviors in narrow space such as air ducts. The sensor's system consists of a CCD camera and two laser sources to generate slit beams. The image of the structured lights is used for calculating the geometric parameters of the air ducts which are usually designed with a rectangular section. With the acquired 3D information about the environment, the mobile robot with two differential driving wheels is able to autonomously navigates along the duct path without any human intervention. For real time navigation, the relative position estimation of the robot are performed from 3D image reconstructed by the sensor system. The calibration and image processing methods used for the sensor system are presented with the experimental data. The experimental results show the possibility of the sensor based navigation which is important for effective duct cleaning by small mobile robots.

  11. Resonant Magnetic Field Sensors Based On MEMS Technology

    Science.gov (United States)

    Herrera-May, Agustín L.; Aguilera-Cortés, Luz A.; García-Ramírez, Pedro J.; Manjarrez, Elías

    2009-01-01

    Microelectromechanical systems (MEMS) technology allows the integration of magnetic field sensors with electronic components, which presents important advantages such as small size, light weight, minimum power consumption, low cost, better sensitivity and high resolution. We present a discussion and review of resonant magnetic field sensors based on MEMS technology. In practice, these sensors exploit the Lorentz force in order to detect external magnetic fields through the displacement of resonant structures, which are measured with optical, capacitive, and piezoresistive sensing techniques. From these, the optical sensing presents immunity to electromagnetic interference (EMI) and reduces the read-out electronic complexity. Moreover, piezoresistive sensing requires an easy fabrication process as well as a standard packaging. A description of the operation mechanisms, advantages and drawbacks of each sensor is considered. MEMS magnetic field sensors are a potential alternative for numerous applications, including the automotive industry, military, medical, telecommunications, oceanographic, spatial, and environment science. In addition, future markets will need the development of several sensors on a single chip for measuring different parameters such as the magnetic field, pressure, temperature and acceleration. PMID:22408480

  12. Ionic Liquid based polymer electrolytes for electrochemical sensors

    Directory of Open Access Journals (Sweden)

    Jakub Altšmíd

    2015-09-01

    Full Text Available Amperometric NO2 printed sensor with a new type of solid polymer electrolyte and a carbon working electrode has been developed. The electrolytes based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [EMIM][N(Tf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquids were immobilized in poly(vinylidene fluoride matrix [PVDF]. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum pseudoreference electrode. The sensors showed a linear behavior in the whole tested range, i.e., 0 - 5 ppm and their sensitivities were in order of 0.3 x∙10-6 A/ppm. The sensor sensitivity was influenced by the electric conductivity of printing formulation; the higher the conductivity, the higher the sensor sensitivity. The rise/recovery times were in order of tens of seconds. The use of  screen printing technology and platinum pseudoreference electrode simplify the sensor fabrication and it does not have any negative effect on the sensor stability.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7371

  13. Probing the kinetics of quantum dot-based proteolytic sensors.

    Science.gov (United States)

    Díaz, Sebastián A; Malonoski, Anthony P; Susumu, Kimihiro; Hofele, Romina V; Oh, Eunkeu; Medintz, Igor L

    2015-09-01

    As an enzyme superfamily, proteases are rivaled only by kinases in terms of their abundance within the human genome. Two ratiometric quantum dot (QD) Förster resonance energy transfer-based sensors designed to monitor the activity of the proteolytic enzymes collagenase and elastase are investigated here. Given the unique material constraints of these sensing constructs, assays are realized utilizing excess enzyme and fixed substrate in progress curve format to yield enzyme specificity or k cat/K m ratios. The range of k cat/Km values derived is 0.5-1.1 mM(-1) s(-1) for the collagenase sensor and 3.7-4.2 mM(-1) s(-1) for the elastase sensor. Of greater interest is the observation that the elastase sensor can be well represented by the Michaelis-Menten model while the collagenase sensor cannot. The latter demonstrates increased specificity at higher peptide substrate/QD loading values and an apparent QD-caused reversible inhibition as the reaction progresses. Understanding the detailed kinetic mechanisms that underpin these types of sensors will be important especially for their further quantitative utilization.

  14. A bionic camera-based polarization navigation sensor.

    Science.gov (United States)

    Wang, Daobin; Liang, Huawei; Zhu, Hui; Zhang, Shuai

    2014-07-21

    Navigation and positioning technology is closely related to our routine life activities, from travel to aerospace. Recently it has been found that Cataglyphis (a kind of desert ant) is able to detect the polarization direction of skylight and navigate according to this information. This paper presents a real-time bionic camera-based polarization navigation sensor. This sensor has two work modes: one is a single-point measurement mode and the other is a multi-point measurement mode. An indoor calibration experiment of the sensor has been done under a beam of standard polarized light. The experiment results show that after noise reduction the accuracy of the sensor can reach up to 0.3256°. It is also compared with GPS and INS (Inertial Navigation System) in the single-point measurement mode through an outdoor experiment. Through time compensation and location compensation, the sensor can be a useful alternative to GPS and INS. In addition, the sensor also can measure the polarization distribution pattern when it works in multi-point measurement mode.

  15. Adaptive inferential sensors based on evolving fuzzy models.

    Science.gov (United States)

    Angelov, Plamen; Kordon, Arthur

    2010-04-01

    A new technique to the design and use of inferential sensors in the process industry is proposed in this paper, which is based on the recently introduced concept of evolving fuzzy models (EFMs). They address the challenge that the modern process industry faces today, namely, to develop such adaptive and self-calibrating online inferential sensors that reduce the maintenance costs while keeping the high precision and interpretability/transparency. The proposed new methodology makes possible inferential sensors to recalibrate automatically, which reduces significantly the life-cycle efforts for their maintenance. This is achieved by the adaptive and flexible open-structure EFM used. The novelty of this paper lies in the following: (1) the overall concept of inferential sensors with evolving and self-developing structure from the data streams; (2) the new methodology for online automatic selection of input variables that are most relevant for the prediction; (3) the technique to detect automatically a shift in the data pattern using the age of the clusters (and fuzzy rules); (4) the online standardization technique used by the learning procedure of the evolving model; and (5) the application of this innovative approach to several real-life industrial processes from the chemical industry (evolving inferential sensors, namely, eSensors, were used for predicting the chemical properties of different products in The Dow Chemical Company, Freeport, TX). It should be noted, however, that the methodology and conclusions of this paper are valid for the broader area of chemical and process industries in general. The results demonstrate that well-interpretable and with-simple-structure inferential sensors can automatically be designed from the data stream in real time, which predict various process variables of interest. The proposed approach can be used as a basis for the development of a new generation of adaptive and evolving inferential sensors that can address the

  16. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Md. Mahbubur Rahman

    2015-02-01

    Full Text Available Conducting polymers (CPs are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective.

  17. Towards Scalable Strain Gauge-Based Joint Torque Sensors

    Science.gov (United States)

    D’Imperio, Mariapaola; Cannella, Ferdinando; Caldwell, Darwin G.; Cuschieri, Alfred

    2017-01-01

    During recent decades, strain gauge-based joint torque sensors have been commonly used to provide high-fidelity torque measurements in robotics. Although measurement of joint torque/force is often required in engineering research and development, the gluing and wiring of strain gauges used as torque sensors pose difficulties during integration within the restricted space available in small joints. The problem is compounded by the need for a scalable geometric design to measure joint torque. In this communication, we describe a novel design of a strain gauge-based mono-axial torque sensor referred to as square-cut torque sensor (SCTS), the significant features of which are high degree of linearity, symmetry, and high scalability in terms of both size and measuring range. Most importantly, SCTS provides easy access for gluing and wiring of the strain gauges on sensor surface despite the limited available space. We demonstrated that the SCTS was better in terms of symmetry (clockwise and counterclockwise rotation) and more linear. These capabilities have been shown through finite element modeling (ANSYS) confirmed by observed data obtained by load testing experiments. The high performance of SCTS was confirmed by studies involving changes in size, material and/or wings width and thickness. Finally, we demonstrated that the SCTS can be successfully implementation inside the hip joints of miniaturized hydraulically actuated quadruped robot-MiniHyQ. This communication is based on work presented at the 18th International Conference on Climbing and Walking Robots (CLAWAR). PMID:28820446

  18. Ligand exchange based paraoxon imprınted QCM sensor.

    Science.gov (United States)

    Özkütük, Ebru Birlik; Diltemiz, Sibel Emir; Özalp, Elif; Say, Rıdvan; Ersöz, Arzu

    2013-03-01

    In the present work, a paraoxon imprinted QCM sensor has been developed for the determination of paraoxon based on the modification of paraoxon imprinted film onto a quartz crystal combining the advantages of high selectivity of the piezoelectric microgravimetry using MIP film technique and high sensitivity of QCM detection. The paraoxon selective memories have formed on QCM electrode surface by using a new metal-chelate interaction based on pre-organized monomer and the paraoxon recognition activity of these molecular memories was investigated. Molecular imprinted polymer (MIP) film for the detection of paraoxon was developed and the analytical performance of paraoxon imprinted sensor was studied. The molecular imprinted polymer were characterized by FTIR measurements. Paraoxon imprinted sensor was characterized with AFM and ellipsometer. The study also includes the measurement of binding interaction of paraoxon imprinted quartz crystal microbalance (QCM) sensor, selectivity experiments and analytical performance of QCM electrode. The detection limit and the affinity constant (K(affinity)) were found to be 0.06 μM and 2.25 × 10(4) M(-1) for paraoxon [MAAP-Cu(II)-paraoxon] based thin film, respectively. Also, it has been observed that the selectivity of the prepared paraoxon imprinted sensor is high compared to a similar chemical structure which is parathion.

  19. A sensor-based motion planner:Situated-Bug

    Institute of Scientific and Technical Information of China (English)

    居鹤华; 崔平远; 崔祜涛

    2003-01-01

    Propose a new sensor-based motion planning approach of Situated-Bug, which is composed of goal-oriented behavior, boundary following behavior and goal-oriented obstacle avoidance behavior, which are based on fuzzy control. The situated-Bug selects its behaviors according to robot orientation, instead of positions and hit points like other Bug algorithms, and its convergence proves robust to sensor noise, and it can guide the robots running for long rang traverse. At the same time, the design of the Situated-Bug is presented. Simulation results show that the approach is effective and practical.

  20. Reflective all-fiber current sensor based on magnetic fluids

    Science.gov (United States)

    Li, Lin; Han, Qun; Liu, Tiegen; Chen, Yaofei; Zhang, Rongxiang

    2014-08-01

    A reflective all-fiber current sensor based on magnetic fluid (MF) is reported. The MF is used as the cladding of a piece of no-core fiber which is spliced between two sections of singlemode fiber to form a singlemode-multimode-singlemode structure. An intensity based interrogation scheme with a superluminescent diode as the light source and the dual-balanced detection method is used in the sensing system. The influence of the direction of the magnetic field on the sensitivity of the sensor is also experimentally investigated and analyzed.

  1. Robust signals from a quantum-based magnetic compass sensor

    CERN Document Server

    Procopio, Maria

    2013-01-01

    A quantum-based magnetic compass sensor, mediated through radical pair reactions, has been suggested to underlie the sensory ability of migrating birds to receive directional information from the geomagnetic field. Here we extend the currently available models by considering the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

  2. SiC-based Schottky diode gas sensors

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, G.W.; Neudeck, P.G.; Chen, L.Y. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Knight, D. [Cortez/NASA Lewis Research Center, Cleveland, OH (United States); Liu, C.C.; Wu, Q.H. [Electronics Design Center, Case Western Reserve Univ., Cleveland, OH (United States)

    1998-08-01

    Silicon carbide based Schottky diode gas sensors are being developed for high temperature applications such as emission measurements. Two different types of gas sensitive diodes will be discussed in this paper. By varying the structure of the diode, one can affect the diode stability as well as the diode sensitivity to various gases. It is concluded that the ability of SiC to operate as a high temperature semiconductor significantly enhances the versatility of the Schottky diode gas sensing structure and will potentially allow the fabrication of a SiC-based gas sensor array for versatile high temperature gas sensing applications. (orig.) 6 refs.

  3. SiC-Based Schottky Diode Gas Sensors

    Science.gov (United States)

    Hunter, Gary W.; Neudeck, Philip G.; Chen, Liang-Yu; Knight, Dak; Liu, Chung-Chiun; Wu, Quing-Hai

    1997-01-01

    Silicon carbide based Schottky diode gas sensors are being developed for high temperature applications such as emission measurements. Two different types of gas sensitive diodes will be discussed in this paper. By varying the structure of the diode, one can affect the diode stability as well as the diode sensitivity to various gases. It is concluded that the ability of SiC to operate as a high temperature semiconductor significantly enhances the versatility of the Schottky diode gas sensing structure and will potentially allow the fabrication of a SiC-based gas sensor arrays for versatile high temperature gas sensing applications.

  4. Flow-Injection Amperometric Determination of Tacrine based on Ion Transfer across a Water–Plasticized Polymeric Membrane Interface

    OpenAIRE

    Rueda, C.; Joaquin A. Ortuño

    2007-01-01

    A flow-injection pulse amperometric method for determining tacrine, based on ion transfer across a plasticized poly(vinyl chloride) (PVC) membrane, was developed. A four-electrode potentiostat with ohmic drop compensation was used, while a flow-through cell incorporated the four electrodes and the membrane, which contained tetrabutylammonium tetraphenylborate. The influence of the applied potential and of the flow-injection variables on the determination of tacrine was studied. In the selecte...

  5. Optical Sensors based on Raman Effects

    DEFF Research Database (Denmark)

    Jernshøj, Kit Drescher

    Formålet med denne afhandling er at give en systematisk og uddybende videnskabelig diskussion af molekylær Raman spredning, som kan danne grundlag for udviklingen af molekylespecifikke optiske sensorer til on-site, ikke-destruktiv måling. Afhandlingen falder i tre dele, to teoriafsnit, hvor første...... del omhandler den tilgangelige molekylære information ved overfladeforstærket resonans Raman spredning (SERRS), samt hvordan adgangen til denne information kan optimeres. Anden del omhandler, hvordan det molekylære informationsindhold kan forøges ved at kombinere polariserede Raman og resonans Raman...... målinger på frie molekyler med multivariat analyse. I tredje og sidste del, som er et eksperimentelt afsnit, præsenteres og diskuteres overfladeforstærkede Raman målinger (SERS) på tre udvalgte pesticider. Afhandlingen indledes med en diskussion af teorien bag SERRS med speciel fokus på den molekylære...

  6. Validation of Underwater Sensor Package Using Feature Based SLAM

    Directory of Open Access Journals (Sweden)

    Christopher Cain

    2016-03-01

    Full Text Available Robotic vehicles working in new, unexplored environments must be able to locate themselves in the environment while constructing a picture of the objects in the environment that could act as obstacles that would prevent the vehicles from completing their desired tasks. In enclosed environments, underwater range sensors based off of acoustics suffer performance issues due to reflections. Additionally, their relatively high cost make them less than ideal for usage on low cost vehicles designed to be used underwater. In this paper we propose a sensor package composed of a downward facing camera, which is used to perform feature tracking based visual odometry, and a custom vision-based two dimensional rangefinder that can be used on low cost underwater unmanned vehicles. In order to examine the performance of this sensor package in a SLAM framework, experimental tests are performed using an unmanned ground vehicle and two feature based SLAM algorithms, the extended Kalman filter based approach and the Rao-Blackwellized, particle filter based approach, to validate the sensor package.

  7. Validation of Underwater Sensor Package Using Feature Based SLAM.

    Science.gov (United States)

    Cain, Christopher; Leonessa, Alexander

    2016-03-17

    Robotic vehicles working in new, unexplored environments must be able to locate themselves in the environment while constructing a picture of the objects in the environment that could act as obstacles that would prevent the vehicles from completing their desired tasks. In enclosed environments, underwater range sensors based off of acoustics suffer performance issues due to reflections. Additionally, their relatively high cost make them less than ideal for usage on low cost vehicles designed to be used underwater. In this paper we propose a sensor package composed of a downward facing camera, which is used to perform feature tracking based visual odometry, and a custom vision-based two dimensional rangefinder that can be used on low cost underwater unmanned vehicles. In order to examine the performance of this sensor package in a SLAM framework, experimental tests are performed using an unmanned ground vehicle and two feature based SLAM algorithms, the extended Kalman filter based approach and the Rao-Blackwellized, particle filter based approach, to validate the sensor package.

  8. Prediction-based Dynamic Energy Management in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-03-01

    Full Text Available Energy consumption is a critical constraint in wireless sensor networks. Focusing on the energy efficiency problem of wireless sensor networks, this paper proposes a method of prediction-based dynamic energy management. A particle filter was introduced to predict a target state, which was adopted to awaken wireless sensor nodes so that their sleep time was prolonged. With the distributed computing capability of nodes, an optimization approach of distributed genetic algorithm and simulated annealing was proposed to minimize the energy consumption of measurement. Considering the application of target tracking, we implemented target position prediction, node sleep scheduling and optimal sensing node selection. Moreover, a routing scheme of forwarding nodes was presented to achieve extra energy conservation. Experimental results of target tracking verified that energy-efficiency is enhanced by prediction-based dynamic energy management.

  9. Colorimetric Sensor Arrays System Based on FPGA for Image Recognition

    Institute of Scientific and Technical Information of China (English)

    Rui Chen; Jian-Hua Xu; Ya-Dong Jiang

    2009-01-01

    A FPGA-based image recognition system is designed for colorimetric sensor array in order to recognize a wide range of volatile organic compounds. The gas molecule is detected by the responsive sensor array and the responsive image is obtained. The image is decomposed to RGB color components using CMOS image sensor. An embedded image recognition archi- tecture based on Xilinx Spartan-3 FPGA is designed to implement the algorithms of image recognition. The algorithm of color coherence vector is discussed in detail[X1] compared with the algorithm of color histograms, and experimental results demonstrate that both of the two algorithms could be analyzed effectively to represent different volatile organic compounds according to their different responsive images in this system.

  10. QCM Sensors Based on PEI Films for CO2Detection

    Institute of Scientific and Technical Information of China (English)

    Guang-Zhong Xie; Ting Kang; Yong Zhou; Tao Xie; Hui-Ling Tai; Ya-Dong Jiang

    2015-01-01

    In this paper, quartz crystal microbalance (QCM) gas sensors coated with polyehtyleneimine (PEI) was utilized for carbon dioxide (CO2) detection. The sensing mechanism is based on the availability of reversible acid-base reactions between CO2 molecules and PEI at room temperature. The experimental results revealed that the PEI/starch sensor exhibited much higher sensitivity than that of pure PEI, and showed approximate linearity over a concentration region ranging from 500ppm to 8000ppm. The influence of humidity had also been investigated. Furthermore, the response and recovery time deceased as the operation temperatures increased. Finally, sensitivity loss after conservation for several days and reversibility of the sensors had been discussed.

  11. Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications

    Science.gov (United States)

    Li, Jing; Lu, Yijiang

    2009-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.

  12. Fluorescence-lifetime-based sensors using inhomogeneous waveguiding

    Science.gov (United States)

    Draxler, Sonja; Kieslinger, Dietmar; Trznadel, Karolina; Lippitsch, Max E.

    1996-12-01

    Most intrinsic fiberoptic sensors are based on the evanescent-wave scheme, where the evanescent field of modes guided in a fiber reaches out into a chemically sensitive coating. In the commonly used multimode waveguides, the evanescent field contains only a small part of the total energy, however, thus making evanescent-wave sensors rather insensitive. Combining a transparent substrate and a transparent sensing layer of rather similar refractive index into a common waveguiding structure produces an inhomogeneous waveguide, where a large portion of the total energy transverses the sensing layer. This yields much superior sensor performance. The transmission through a waveguide is subject to various disturbing influences. Thus it is advantageous to combine the inhomogeneous waveguiding approach with a measuring scheme that is not prone to those disturbances. Such a scheme is available with fluorescence lifetime-based sensors. The fluorescence lifetime of an indicator incorporated into the sensing layer is changed by the presence of the respective analyte. This lifetime is independent of the transmission through the waveguide. Thus inhomogeneous waveguiding together with fluorescence lifetime measurement paves the way for optical chemical sensors with high analyte sensitivity and immunity to external disturbances.

  13. A Universal Intelligent System-on-Chip Based Sensor Interface

    Directory of Open Access Journals (Sweden)

    Gabriele Ferri

    2010-08-01

    Full Text Available The need for real-time/reliable/low-maintenance distributed monitoring systems, e.g., wireless sensor networks, has been becoming more and more evident in many applications in the environmental, agro-alimentary, medical, and industrial fields. The growing interest in technologies related to sensors is an important indicator of these new needs. The design and the realization of complex and/or distributed monitoring systems is often difficult due to the multitude of different electronic interfaces presented by the sensors available on the market. To address these issues the authors propose the concept of a Universal Intelligent Sensor Interface (UISI, a new low-cost system based on a single commercial chip able to convert a generic transducer into an intelligent sensor with multiple standardized interfaces. The device presented offers a flexible analog and/or digital front-end, able to interface different transducer typologies (such as conditioned, unconditioned, resistive, current output, capacitive and digital transducers. The device also provides enhanced processing and storage capabilities, as well as a configurable multi-standard output interface (including plug-and-play interface based on IEEE 1451.3. In this work the general concept of UISI and the design of reconfigurable hardware are presented, together with experimental test results validating the proposed device.

  14. High performance liquid-level sensor based on mPOFBG for aircraft applications

    DEFF Research Database (Denmark)

    Marques, C. A. F.; Pospori, A.; Saez-Rodriguez, D.

    2015-01-01

    A high performance liquid-level sensor based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported in detail. The sensor sensitivity is found to be 98pm/cm of liquid, enhanced by more than a factor of 9 compared to a reported silica fiber-based sensor....

  15. Conductive polymer-based sensors for biomedical applications.

    Science.gov (United States)

    Nambiar, Shruti; Yeow, John T W

    2011-01-15

    A class of organic polymers, known as conducting polymers (CPs), has become increasingly popular due to its unique electrical and optical properties. Material characteristics of CPs are similar to those of some metals and inorganic semiconductors, while retaining polymer properties such as flexibility, and ease of processing and synthesis, generally associated with conventional polymers. Owing to these characteristics, research efforts in CPs have gained significant traction to produce several types of CPs since its discovery four decades ago. CPs are often categorised into different types based on the type of electric charges (e.g., delocalized pi electrons, ions, or conductive nanomaterials) responsible for conduction. Several CPs are known to interact with biological samples while maintaining good biocompatibility and hence, they qualify as interesting candidates for use in a numerous biological and medical applications. In this paper, we focus on CP-based sensor elements and the state-of-art of CP-based sensing devices that have potential applications as tools in clinical diagnosis and surgical interventions. Representative applications of CP-based sensors (electrochemical biosensor, tactile sensing 'skins', and thermal sensors) are briefly discussed. Finally, some of the key issues related to CP-based sensors are highlighted.

  16. Development of capacitance-based and impedance-based wireless sensors and sensor nodes for structural health monitoring applications

    Science.gov (United States)

    Mascarenas, David D. L.; Flynn, Eric B.; Todd, Michael D.; Overly, Timothy G.; Farinholt, Kevin M.; Park, Gyuhae; Farrar, Charles R.

    2010-06-01

    A field demonstration of a new and hybrid wireless sensing network paradigm for structural health monitoring (SHM) is presented. In this paradigm, both power and data interrogation commands are conveyed via a mobile agent that is sent to each sensor node to perform individual interrogations, which can alleviate several limitations of traditional sensing networks. This paper will discuss such prototype systems, which will be used to interrogate capacitive-based and impedance-based sensors for SHM applications. The capacitive-based wireless sensor node is specifically built to collect peak displacement measurements. In addition, a wireless sensor node for collecting electromechanical impedance data has also been developed. Both sensor nodes are specifically designed to accept various power sources and to be wirelessly triggered on an as-needed basis so that they can be used for the hybrid sensing network approach. The capabilities of these miniaturized and portable devices are demonstrated in the laboratory and the field, which was performed at the Alamosa Canyon Bridge in southern New Mexico.

  17. All-solid-state carbonate-selective electrode based on screen-printed carbon paste electrode

    Science.gov (United States)

    Li, Guang; Lyu, Xiaofeng; Wang, Zhan; Rong, Yuanzhen; Hu, Ruifen; Luo, Zhiyuan; Wang, You

    2017-02-01

    A novel disposable all-solid-state carbonate-selective electrode based on a screen-printed carbon paste electrode using poly(3-octylthiophene-2,5-diyl) (POT) as an ion-to-electron transducer has been developed. The POT was dropped onto the reaction area of the carbon paste electrode covered by the poly(vinyl chloride) (PVC) membrane, which contains N,N-Dioctyl-3α,12α-bis(4-trifluoroacetylbenzoyloxy)-5β-cholan-24-amide as a carbonate ionophore. The electrode showed a near-Nernstian slope of  -27.5 mV/decade with a detection limit of 3.6 * 10-5 mol l-1. Generally, the detection time was 30 s. Because these electrodes are fast, convenient and low in cost, they have the potential to be mass produced and used in on-site testing as disposable sensors. Furthermore, the repeatability, reproducibility and stability have been studied to evaluate the properties of the electrodes. Measurement of the carbonate was also conducted in a human blood solution and achieved good performance.

  18. Sensor of hydrostatic pressure based on gallium antimonide microcrystals

    Directory of Open Access Journals (Sweden)

    Druzhinin A. A.

    2015-08-01

    Full Text Available Currently, silicon and germanium, the most common materials in the production of discrete semiconductor devices and integrated circuits, do not always meet all the requirements to the sensing elements of mechanical quantities sensors. Therefore, it is logical to research the properties of other semiconductor materials that could be used as sensing elements in such sensors. A3B5 semiconductor compounds seem promising for such purpose. Effect of hydrostatic pressure up to 5000 bar on the resistance of n-type antimonide gallium whiskers doped by Se or Te was studied. Coefficient of hydrostatic pressure for this crystals was determined, it equals Kh = (16,5—20,0•10–5 bar–1 at 20°N. Temperature dependence of resistance and coefficient Kh for this crystals in the temperature range ±60°N was studied. Design of the developed hydrostatic pressure sensor based on GaSb whiskers and its characteristics are presented. The possibility to decrease the temperature dependence of sensitive element resistance by mounting GaSb whiskers on the substrates fabricated from materials with different temperature coefficient of expansion was examined. It was shown that mounting of GaSb crystals on Cu substrate gives the optimal result, in this case the temperature coefficient decrease to 0,05%•°N–1, that leads to decrease of output temperature dependence. The main advantages of developed pressure sensor are: the simplified design in comparison with pressure sensors with strain gauges mounted on spring elements; the high sensitivity to pressure that is constant in the wide pressure range; the improvement of sensors metrological characteristics owing to hysteresis absence. The possible application fields of developed sensors are measuring of high and extremely high pressure, chemical and oil industries, measuring of pressure in oil bore-holes, investigation of explosive processes.

  19. Coating based Fiber Bragg Grating humidity sensor array

    NARCIS (Netherlands)

    Cheng, L.K.; Boersma, A.; Jansen, T.H.

    2012-01-01

    A coating based FBG humidity sensor is developed for distributed humidity sensing. The sensitivity of the coated FBG is optimized by varying the chemical composition and the thickness of the coating. A sensitivity of ~2 pm/%RH and a rapid response are demonstrated. The composition of the coating can

  20. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se

  1. SOI based integrated on-chip photonic pressure sensor

    NARCIS (Netherlands)

    Chakkalakkal Abdulla, S.M.C.; Harmsma, P.J.; Nieuwland, R.A.; Pozo Torres, J.M.; Lemmen, M.H.J.; Sadeghian Marnani, H.; Berg, J.H. van den; Bodis, P.

    2012-01-01

    A compact, mass producible Silicon On Insulator (SOI) based pressure sensor consisting of a folded Micro Ring Resonator (MRR) on a circular diaphragm is successfully designed, fabricated and characterized [1-3]. The MRR is designed to be single mode for TE polarized light at 1550 nm. The folded MRR

  2. Connected Dominating Set Based Topology Control in Wireless Sensor Networks

    Science.gov (United States)

    He, Jing

    2012-01-01

    Wireless Sensor Networks (WSNs) are now widely used for monitoring and controlling of systems where human intervention is not desirable or possible. Connected Dominating Sets (CDSs) based topology control in WSNs is one kind of hierarchical method to ensure sufficient coverage while reducing redundant connections in a relatively crowded network.…

  3. Palladium nanoparticle-based surface acoustic wave hydrogen sensor.

    Science.gov (United States)

    Sil, Devika; Hines, Jacqueline; Udeoyo, Uduak; Borguet, Eric

    2015-03-18

    Palladium (Pd) nanoparticles (5-20 nm) are used as the sensing layer on surface acoustic wave (SAW) devices for detecting H2. The interaction with hydrogen modifies the conductivity of the Pd nanoparticle film, producing measurable changes in acoustic wave propagation, which allows for the detection of this explosive gas. The nanoparticle-based SAW sensor responds rapidly and reversibly at room temperature.

  4. Automatic Recognition of Object Use Based on Wireless Motion Sensors

    NARCIS (Netherlands)

    Bosch, S.; Marin Perianu, Raluca; Havinga, Paul J.M.; Marin Perianu, Mihai; Horst, Arie; Vasilescu, Andrei

    2010-01-01

    In this paper, we present a method for automatic, online detection of a user’s interaction with objects. This represents an essential building block for improving the performance of distributed activity recognition systems. Our method is based on correlating features extracted from motion sensors

  5. Optical refractometric sensors based on embedded nanowire microcoil resonators

    OpenAIRE

    2007-01-01

    We present a novel, robust, and compact refractometric sensor based on a high Q factor embedded nanowire microcoil resonator with an intrinsic fluidic channel. Ideally, sensitivities as high as 1000 nm/RIU and a refractive index resolution of 10 can be achieved.

  6. Demonstration of a refractometric sensor based on optical microfiber resonator

    OpenAIRE

    2008-01-01

    We experimentally demonstrated a refractometric sensor based on a coated optical microfiber coil resonator. It is robust, compact, and comprises an intrinsic fluidic channel. A sensitivity of about 40 nm/RIU (refractive index unit) has been measured, in agreement with predictions.

  7. A displacement sensor of dual-light based on FPGA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dual-light displacement sensor is presented to obtain a higher accuracy compared with the single. The structure and principle of the system are also introduced, and the hardware and software are brought in too. The function of the system is feasible through the experiments and simulating the data process based on FPGA.

  8. Characterization of Integrated Optical Strain Sensors Based on Silicon Waveguides

    NARCIS (Netherlands)

    Westerveld, W.J.; Leinders, S.M.; Muilwijk, P.M.; Pozo, J.

    2013-01-01

    Microscale strain gauges are widely used in micro electro-mechanical systems (MEMS) to measure strains such as those induced by force, acceleration, pressure or sound. We propose all-optical strain sensors based on micro-ring resonators to be integrated with MEMS. We characterized the strain-induced

  9. Gamma measurement based on CMOS sensor and ARM microcontroller

    National Research Council Canada - National Science Library

    Cheng, Qian-Qian; Yuan, Yan-Zhong; Ma, Chun-Wang; Wang, Fang

    2017-01-01

    A setup based on CMOS sensor and ARM microcontroller is designed to measure the γ-rays. STM32F103 is used as the main platform to control real-time online analysis of the image collected by the OV7670 CAMERACHIP...

  10. Connected Dominating Set Based Topology Control in Wireless Sensor Networks

    Science.gov (United States)

    He, Jing

    2012-01-01

    Wireless Sensor Networks (WSNs) are now widely used for monitoring and controlling of systems where human intervention is not desirable or possible. Connected Dominating Sets (CDSs) based topology control in WSNs is one kind of hierarchical method to ensure sufficient coverage while reducing redundant connections in a relatively crowded network.…

  11. Vision Based Navigation Sensors for Spacecraft Rendezvous and Docking

    DEFF Research Database (Denmark)

    Benn, Mathias

    is a technological demonstration mission, where all aspects of space rendezvous and docking to both a cooperative and a non-cooperative target is researched, with the use of novel methods, instruments and technologies. Amongst other equipment, DTU has delivered a vision based sensor package to the Main spacecraft...

  12. Topology control based on quantum genetic algorithm in sensor networks

    Institute of Scientific and Technical Information of China (English)

    SUN Lijuan; GUO Jian; LU Kai; WANG Ruchuan

    2007-01-01

    Nowadays,two trends appear in the application of sensor networks in which both multi-service and quality of service (QoS)are supported.In terms of the goal of low energy consumption and high connectivity,the control on topology is crucial.The algorithm of topology control based on quantum genetic algorithm in sensor networks is proposed.An advantage of the quantum genetic algorithm over the conventional genetic algorithm is demonstrated in simulation experiments.The goals of high connectivity and low consumption of energy are reached.

  13. Distributed optical fiber dynamic magnetic field sensor based on magnetostriction.

    Science.gov (United States)

    Masoudi, Ali; Newson, Trevor P

    2014-05-01

    A distributed optical fiber sensor is introduced which is capable of quantifying multiple magnetic fields along a 1 km sensing fiber with a spatial resolution of 1 m. The operation of the proposed sensor is based on measuring the magnetorestrictive induced strain of a nickel wire attached to an optical fiber. The strain coupled to the optical fiber was detected by measuring the strain-induced phase variation between the backscattered Rayleigh light from two segments of the sensing fiber. A magnetic field intensity resolution of 0.3 G over a bandwidth of 50-5000 Hz was demonstrated.

  14. Water Pollution Detection Based on Hypothesis Testing in Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xu Luo

    2017-01-01

    Full Text Available Water pollution detection is of great importance in water conservation. In this paper, the water pollution detection problems of the network and of the node in sensor networks are discussed. The detection problems in both cases of the distribution of the monitoring noise being normal and nonnormal are considered. The pollution detection problems are analyzed based on hypothesis testing theory firstly; then, the specific detection algorithms are given. Finally, two implementation examples are given to illustrate how the proposed detection methods are used in the water pollution detection in sensor networks and prove the effectiveness of the proposed detection methods.

  15. Novel gas sensors based on carbon nanotube networks

    Energy Technology Data Exchange (ETDEWEB)

    Sayago, I; Aleixandre, M; Horrillo, M C; Fernandez, M J; Gutierrez, J [Laboratorio de Sensores IFA-CSIC, Serrano 144, 28006 Madrid (Spain); Terrado, E; Lafuente, E; Maser, W K; Benito, A M; Martinez, M T; Munoz, E [Instituto de CarboquImica CSIC, Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Urriolabeitia, E P; Navarro, R [Departamento de Quimica Inorganica, ICMA (Universidad de Zaragoza-CSIC), 50009 Zaragoza (Spain)], E-mail: sayago@ifa.cetef.csic.es, E-mail: edgar@icb.csic.es

    2008-08-15

    Novel resistive gas sensors based on single-walled carbon nanotube (SWNT) networks as the active sensing element nave been investigated for gas detection. SWNTs networks were fabricated by airbrushing on alumina substrates. As-produced- and Pd-decorated SWNT materials were used as sensitive layers for the detection of NO{sub 2} and H{sub 2}, respectively. The studied sensors provided good response to NO{sub 2} and H{sub 2} as well as excellent selectivities to interfering gases.

  16. Condition-Based Maintenance using Sensor Arrays and Telematics

    CERN Document Server

    Palem, Gopalakrishna

    2013-01-01

    Emergence of uniquely addressable embeddable devices has raised the bar on Telematics capabilities. Though the technology itself is not new, its application has been quite limited until now. Sensor based telematics technologies generate volumes of data that are orders of magnitude larger than what operators have dealt with previously. Real-time big data computation capabilities have opened the flood gates for creating new predictive analytics capabilities into an otherwise simple data log systems, enabling real-time control and monitoring to take preventive action in case of any anomalies. Condition-based-maintenance, usage-based-insurance, smart metering and demand-based load generation etc. are some of the predictive analytics use cases for Telematics. This paper presents the approach of condition-based maintenance using real-time sensor monitoring, Telematics and predictive data analytics.

  17. 基于等离子体修饰的PVC膜脲酶传感器%New Urease Biosensor Based on the Plasma-Modified pH-Sensitive PVC Membrane

    Institute of Scientific and Technical Information of China (English)

    吴朝阳; 石清丽; 倪文山; 沈国励; 俞汝勤

    2006-01-01

    报道了一种基于等离子体修饰的PVC膜脲酶生物传感器.应用微波等离子体化学气相沉积技术,在pH敏感PVC膜上修饰一层带有氨基的乙二胺等离子体聚合物薄层,通过戊二醛共价交联固定脲酶分子,制成脲酶传感器.这种乙二胺等离子体聚合物薄层对pH敏感膜的响应特性影响小,且其表面氨基使得pH敏感膜更加易于与H+结合,检测范围向高pH方向偏移,响应斜率为45.73 mV/pH,比未修饰的pH敏感膜电极的响应斜率42.81 mV/pH有所提高.该脲酶传感器对尿素显示了良好的传感性能,其响应时间约为200 s;在6.0×10-4~8.4×10-3 mol/L范围,脲酶传感器的电位响应值与尿素浓度的对数存在良好的线性关系,相关系数为0.997 8,检测下限为5.0×10-5 mol/L.

  18. Fiber-Laser-Based Ultrasound Sensor for Photoacoustic Imaging

    Science.gov (United States)

    Liang, Yizhi; Jin, Long; Wang, Lidai; Bai, Xue; Cheng, Linghao; Guan, Bai-Ou

    2017-01-01

    Photoacoustic imaging, especially for intravascular and endoscopic applications, requires ultrasound probes with miniature size and high sensitivity. In this paper, we present a new photoacoustic sensor based on a small-sized fiber laser. Incident ultrasound waves exert pressures on the optical fiber laser and induce harmonic vibrations of the fiber, which is detected by the frequency shift of the beating signal between the two orthogonal polarization modes in the fiber laser. This ultrasound sensor presents a noise-equivalent pressure of 40 Pa over a 50-MHz bandwidth. We demonstrate this new ultrasound sensor on an optical-resolution photoacoustic microscope. The axial and lateral resolutions are 48 μm and 3.3 μm. The field of view is up to 1.57 mm2. The sensor exhibits strong resistance to environmental perturbations, such as temperature changes, due to common-mode cancellation between the two orthogonal modes. The present fiber laser ultrasound sensor offers a new tool for all-optical photoacoustic imaging.

  19. Silicon nanowires-based fluorescence sensor for Cu(II).

    Science.gov (United States)

    Mu, Lixuan; Shi, Wensheng; Chang, Jack C; Lee, Shuit-Tong

    2008-01-01

    Si nanowires (SiNWs) were covalently modified by fluorescence ligand, N-(quinoline-8-yl)-2-(3-triethoxysilyl-propylamino)-acetamide (QlOEt) and finally formed an optical sensor to realize a highly sensitive and selective detection for Cu(II). The QlOEt-modified SiNWs sensor has sensitivity for Cu(II) down to 10(-8) M, which is more sensitive than QlOEt alone. Metal ions interferences have no observable effect on the sensitivity and selectivity of QlOEt-modified SiNWs sensor. The SiNWs-based fluorescence sensor is reversible by addition of acid to replace Cu(II). The sensing mechanisms of QlOEt-modified SiNWs to Cu(II) and the rationale for the increase in sensitivity and selectivity of QlOEt-modified SiNWs over QlOEt on Cu(II) are discussed. The current sensor structure may be extendable to other chemo- and biosensors, and even to nanosensors for direct detection of specific materials in intracellular environment.

  20. Single Wall Carbon Nanotubes Based Cryogenic Temperature Sensor Platforms.

    Science.gov (United States)

    Monea, Bogdan Florian; Ionete, Eusebiu Ilarian; Spiridon, Stefan Ionut; Leca, Aurel; Stanciu, Anda; Petre, Emil; Vaseashta, Ashok

    2017-09-10

    We present an investigation consisting of single walled carbon nanotubes (SWCNTs) based cryogenic temperature sensors, capable of measuring temperatures in the range of 2-77 K. Carbon nanotubes (CNTs) due to their extremely small size, superior thermal and electrical properties have suggested that it is possible to create devices that will meet necessary requirements for miniaturization and better performance, by comparison to temperature sensors currently available on the market. Starting from SWCNTs, as starting material, a resistive structure was designed. Employing dropcast method, the carbon nanotubes were deposited over pairs of gold electrodes and in between the structure electrodes from a solution. The procedure was followed by an alignment process between the electrodes using a dielectrophoretic method. Two sensor structures were tested in cryogenic field down to 2 K, and the resistance was measured using a standard four-point method. The measurement results suggest that, at temperatures below 20 K, the temperature coefficient of resistance average for sensor 1 is 1.473%/K and for sensor 2 is 0.365%/K. From the experimental data, it can be concluded that the dependence of electrical resistance versus temperature can be approximated by an exponential equation and, correspondingly, a set of coefficients are calculated. It is further concluded that the proposed approach described here offers several advantages, which can be employed in the fabrication of a microsensors for cryogenic applications.

  1. Ratiometric Alcohol Sensor based on a Polymeric Nile Blue

    Directory of Open Access Journals (Sweden)

    Sherif Ibrahim

    2008-04-01

    Full Text Available We present a sterilizable ratiometric fluorescent ethanol sensor with sensitivity over a wide range (0-100% of ethanol concentration v/v. The sensor is composed of a near infra red fluorescent solvatochromic dye, nile blue methacrylamide polymerized into a polyethylene (glycol dimethacrylate matrix. The dye can typically exhibit two or more wavelength dependent shifts in the fluorescence intensities based on its different micropolar environments. Two different concentrations of the nile blue methacrylamide dye were prepared and polymerized into homogenous films. The fluorescence properties of the two different films were investigated with a view to determining their ethanol sensing capabilities. The sensor was immersed in a water-ethanol solvent mixture. Excitation of the dye was performed at 470 nm. The range of emission wavelengths was 480-800 nm. The ratio of the fluorescence intensities at 620 nm and 554 nm was obtained for ethanol concentrations varying from 0-100% and the calibration curve of the ratiometric fluorescence intensities over the entire concentration range of ethanol was plotted. A ratiometric intensity change of over 33% has been obtained for pure ethanol compared to that obtained for pure water. The sensor response was rapid (≤10 minutes. The sterilizable ethanol sensor exhibits good potential for on-line monitoring of the ethanol generated in an LB fermentation chamber.

  2. Gas Sensors Based on Semiconducting Nanowire Field-Effect Transistors

    Directory of Open Access Journals (Sweden)

    Ping Feng

    2014-09-01

    Full Text Available One-dimensional semiconductor nanostructures are unique sensing materials for the fabrication of gas sensors. In this article, gas sensors based on semiconducting nanowire field-effect transistors (FETs are comprehensively reviewed. Individual nanowires or nanowire network films are usually used as the active detecting channels. In these sensors, a third electrode, which serves as the gate, is used to tune the carrier concentration of the nanowires to realize better sensing performance, including sensitivity, selectivity and response time, etc. The FET parameters can be modulated by the presence of the target gases and their change relate closely to the type and concentration of the gas molecules. In addition, extra controls such as metal decoration, local heating and light irradiation can be combined with the gate electrode to tune the nanowire channel and realize more effective gas sensing. With the help of micro-fabrication techniques, these sensors can be integrated into smart systems. Finally, some challenges for the future investigation and application of nanowire field-effect gas sensors are discussed.

  3. Fiber-Laser-Based Ultrasound Sensor for Photoacoustic Imaging

    Science.gov (United States)

    Liang, Yizhi; Jin, Long; Wang, Lidai; Bai, Xue; Cheng, Linghao; Guan, Bai-Ou

    2017-01-01

    Photoacoustic imaging, especially for intravascular and endoscopic applications, requires ultrasound probes with miniature size and high sensitivity. In this paper, we present a new photoacoustic sensor based on a small-sized fiber laser. Incident ultrasound waves exert pressures on the optical fiber laser and induce harmonic vibrations of the fiber, which is detected by the frequency shift of the beating signal between the two orthogonal polarization modes in the fiber laser. This ultrasound sensor presents a noise-equivalent pressure of 40 Pa over a 50-MHz bandwidth. We demonstrate this new ultrasound sensor on an optical-resolution photoacoustic microscope. The axial and lateral resolutions are 48 μm and 3.3 μm. The field of view is up to 1.57 mm2. The sensor exhibits strong resistance to environmental perturbations, such as temperature changes, due to common-mode cancellation between the two orthogonal modes. The present fiber laser ultrasound sensor offers a new tool for all-optical photoacoustic imaging. PMID:28098201

  4. Carbon Nanotube-Based Structural Health Monitoring Sensors

    Science.gov (United States)

    Wincheski, Russell; Jordan, Jeffrey; Oglesby, Donald; Watkins, Anthony; Patry, JoAnne; Smits, Jan; Williams, Phillip

    2011-01-01

    Carbon nanotube (CNT)-based sensors for structural health monitoring (SHM) can be embedded in structures of all geometries to monitor conditions both inside and at the surface of the structure to continuously sense changes. These CNTs can be manipulated into specific orientations to create small, powerful, and flexible sensors. One of the sensors is a highly flexible sensor for crack growth detection and strain field mapping that features a very dense and highly ordered array of single-walled CNTs. CNT structural health sensors can be mass-produced, are inexpensive, can be packaged in small sizes (0.5 micron(sup 2)), require less power than electronic or piezoelectric transducers, and produce less waste heat per square centimeter than electronic or piezoelectric transducers. Chemically functionalized lithographic patterns are used to deposit and align the CNTs onto metallic electrodes. This method consistently produces aligned CNTs in the defined locations. Using photo- and electron-beam lithography, simple Cr/Au thin-film circuits are patterned onto oxidized silicon substrates. The samples are then re-patterned with a CNT-attracting, self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) to delineate the desired CNT locations between electrodes. During the deposition of the solution-suspended single- wall CNTs, the application of an electric field to the metallic contacts causes alignment of the CNTs along the field direction. This innovation is a prime candidate for smart skin technologies with applications ranging from military, to aerospace, to private industry.

  5. Ultrafast response sensor to formaldehyde gas based on metal oxide.

    Science.gov (United States)

    Choi, N-J; Lee, H-K; Moon, S E; Kim, J; Yang, W S

    2014-08-01

    Thick film semiconductor gas sensors based on indium oxide were fabricated on Si substrate. The sensing materials on Si substrate were characterized using optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), and so on. They were very fine and uniform and we found out that particle sizes were about 20~30 nm through XRD analysis. Gas responses of fabricated sensors were measured in a chamber where gas flow was controlled by mass flow controller (MFC). Their resistance changes were monitored in real time by using data acquisition board and personal computer. Gas response characteristics were examined for formaldehyde (HCHO) gas which was known as the cause of sick building syndrome. Particularly, the sensors showed responses to formaldehyde gas at sub ppm (cf, standard of natural environment in building is about 80 ppb by ministry of environment in Korea), as a function of operating temperatures and gas concentrations. Also, we investigated sensitivity, repetition, selectivity, response speed and reproducibility of the sensors. The lowest detection limit is HCHO 25 ppb and sensitivity at 800 ppb is over 25% at 350 °C operating temperature. The response time (8 s) and recovery time (15 s) to HCHO gas at 200 ppb were very fast compared to other commercial products in flow type measurement condition. Repetition measurement was very good with ±3% in full measurement range. The fabricated metal oxide gas sensor showed good performance to HCHO gas and proved that it could be adaptable to indoor environment in building.

  6. A Blade Tip Timing Method Based on a Microwave Sensor

    Directory of Open Access Journals (Sweden)

    Jilong Zhang

    2017-05-01

    Full Text Available Blade tip timing is an effective method for blade vibration measurements in turbomachinery. This method is increasing in popularity because it is non-intrusive and has several advantages over the conventional strain gauge method. Different kinds of sensors have been developed for blade tip timing, including optical, eddy current and capacitance sensors. However, these sensors are unsuitable in environments with contaminants or high temperatures. Microwave sensors offer a promising potential solution to overcome these limitations. In this article, a microwave sensor-based blade tip timing measurement system is proposed. A patch antenna probe is used to transmit and receive the microwave signals. The signal model and process method is analyzed. Zero intermediate frequency structure is employed to maintain timing accuracy and dynamic performance, and the received signal can also be used to measure tip clearance. The timing method uses the rising and falling edges of the signal and an auto-gain control circuit to reduce the effect of tip clearance change. To validate the accuracy of the system, it is compared experimentally with a fiber optic tip timing system. The results show that the microwave tip timing system achieves good accuracy.

  7. Diaphragm Based Fiber Bragg Grating Acceleration Sensor with Temperature Compensation.

    Science.gov (United States)

    Li, Tianliang; Tan, Yuegang; Han, Xue; Zheng, Kai; Zhou, Zude

    2017-01-23

    A novel fiber Bragg grating (FBG) sensing-based acceleration sensor has been proposed to simultaneously decouple and measure temperature and acceleration in real-time. This design applied a diaphragm structure and utilized the axial property of a tightly suspended optical fiber, enabling improvement in its sensitivity and resonant frequency and achieve a low cross-sensitivity. The theoretical vibrational model of the sensor has been built, and its design parameters and sensing properties have been analyzed through the numerical analysis. A decoupling method has been presented with consideration of the thermal expansion of the sensor structure to realize temperature compensation. Experimental results show that the temperature sensitivity is 8.66 pm/°C within the range of 30-90 °C. The acceleration sensitivity is 20.189 pm/g with a linearity of 0.764% within the range of 5~65 m/s². The corresponding working bandwidth is 10~200 Hz and its resonant frequency is 600 Hz. This sensor possesses an excellent impact resistance for the cross direction, and the cross-axis sensitivity is below 3.31%. This implementation can avoid the FBG-pasting procedure and overcome its associated shortcomings. The performance of the proposed acceleration sensor can be easily adjusted by modifying their corresponding physical parameters to satisfy requirements from different vibration measurements.

  8. Diaphragm Based Fiber Bragg Grating Acceleration Sensor with Temperature Compensation

    Directory of Open Access Journals (Sweden)

    Tianliang Li

    2017-01-01

    Full Text Available A novel fiber Bragg grating (FBG sensing-based acceleration sensor has been proposed to simultaneously decouple and measure temperature and acceleration in real-time. This design applied a diaphragm structure and utilized the axial property of a tightly suspended optical fiber, enabling improvement in its sensitivity and resonant frequency and achieve a low cross-sensitivity. The theoretical vibrational model of the sensor has been built, and its design parameters and sensing properties have been analyzed through the numerical analysis. A decoupling method has been presented with consideration of the thermal expansion of the sensor structure to realize temperature compensation. Experimental results show that the temperature sensitivity is 8.66 pm/°C within the range of 30–90 °C. The acceleration sensitivity is 20.189 pm/g with a linearity of 0.764% within the range of 5~65 m/s2. The corresponding working bandwidth is 10~200 Hz and its resonant frequency is 600 Hz. This sensor possesses an excellent impact resistance for the cross direction, and the cross-axis sensitivity is below 3.31%. This implementation can avoid the FBG-pasting procedure and overcome its associated shortcomings. The performance of the proposed acceleration sensor can be easily adjusted by modifying their corresponding physical parameters to satisfy requirements from different vibration measurements.

  9. Enhanced Sensing Characteristics in MEMS-based Formaldehyde Gas Sensor

    CERN Document Server

    Wang, Yu-Hsiang; Lee, Chia-Yen; Ma, R -H; Chou, Po-Cheng

    2008-01-01

    This study has successfully demonstrated a novel self-heating formaldehyde gas sensor based on a thin film of NiO sensing layer. A new fabrication process has been developed in which the Pt micro heater and electrodes are deposited directly on the substrate and the NiO thin film is deposited above on the micro heater to serve as sensing layer. Pt electrodes are formed below the sensing layer to measure the electrical conductivity changes caused by formaldehyde oxidation at the oxide surface. Furthermore, the upper sensing layer and NiO/Al2O3 co-sputtering significantly increases the sensitivity of the gas sensor, improves its detection limit capability. The microfabricated formaldehyde gas sensor presented in this study is suitable not only for industrial process monitoring, but also for the detection of formaldehyde concentrations in buildings in order to safeguard human health.

  10. Coumarin Based Neutral Sensor for Biologically Important Anions

    Institute of Scientific and Technical Information of China (English)

    SHAO Jie

    2011-01-01

    A coumarin Shiff-base derivative,salicylaldehyde-N-(6-phenylazo-coumarin-3-formyl)-hydrazone(1),was obtained by simple organic synthesis from cheap and commercially available starting materials.Sensor 1 exhibits a very weak fluorescence emission,however,in the presence of acetate ions “turn-on” fluorescence is observed,which results from binding-induced conformational restriction of the fluorophore.Importantly,sensor 1 can also be used as colorimetric chemosensor for the anions with strong basicity,which is easily observed from yellow to red by naked eyes.Consequently,compound l can behave as a colorimetric and fluorescence sensor for biologically important F,CH3COO and H2PO4- in the presence of the other anions tested such as Cl-,Br- and I- in dimethyl sulfoxide(DMSO).

  11. External Force Estimation for Teleoperation Based on Proprioceptive Sensors

    Directory of Open Access Journals (Sweden)

    Enrique del Sol

    2014-03-01

    Full Text Available This paper establishes an approach to external force estimation for telerobotic control in radioactive environments by the use of an identified manipulator model and pressure sensors, without employing a force/torque sensor. The advantages of - and need for - force feedback have been well-established in the field of telerobotics, where electrical and back-drivable manipulators have traditionally been used. This research proposes a methodology employing hydraulic robots for telerobotics tasks based on a model identification scheme. Comparative results of a force sensor and the proposed approach using a hydraulic telemanipulator are presented under different conditions. This approach not only presents a cost effective solution but also a methodology for force estimation in radioactive environments, where the dose rates limit the use of electronic devices such as sensing equipment.

  12. Optical sensor based on a single CdS nanobelt.

    Science.gov (United States)

    Li, Lei; Yang, Shuming; Han, Feng; Wang, Liangjun; Zhang, Xiaotong; Jiang, Zhuangde; Pan, Anlian

    2014-04-23

    In this paper, an optical sensor based on a cadmium sulfide (CdS) nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT) method. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL) technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 10⁴, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions.

  13. Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

    Institute of Scientific and Technical Information of China (English)

    XIE Zhi-Guo; LU Yong-Hua; WANG Pei; LIN Kai-Qun; YAN Jie; MING Hai

    2008-01-01

    @@ A photonic crystal fibre (PCF) surface enhanced Raman scattering (SERS) sensor is developed based on silver nanoparticle colloid.Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome maes-transport constraints, allowing more silver nanoparticles involved in SERS activity.This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture.We demonstrate the detection of 4-mercaptobenzoic acid (4-MBA ) molecules with the injecting way and the common dipping measurement.The injecting way shows obviously better results than the dipping one.Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area.

  14. [Active crop canopy sensor-based nitrogen diagnosis for potato].

    Science.gov (United States)

    Yu, Jing; Li, Fei; Qin, Yong-Lin; Fan, Ming-Shou

    2013-11-01

    In the present study, two potato experiments involving different N rates in 2011 were conducted in Wuchuan County and Linxi County, Inner Mongolia. Normalized difference vegetation index (NDVI) was collected by an active GreenSeeker crop canopy sensor to estimate N status of potato. The results show that the NDVI readings were poorly correlated with N nutrient indicators of potato at vegetative Growth stage due to the influence of soil background. With the advance of growth stages, NDVI values were exponentially related to plant N uptake (R2 = 0.665) before tuber bulking stage and were linearly related to plant N concentration (R2 = 0.699) when plant fully covered soil. In conclusion, GreenSeeker active crop sensor is a promising tool to estimate N status for potato plants. The findings from this study may be useful for developing N recommendation method based on active crop canopy sensor.

  15. Space magnetometer based on an anisotropic magnetoresistive hybrid sensor

    Science.gov (United States)

    Brown, P.; Whiteside, B. J.; Beek, T. J.; Fox, P.; Horbury, T. S.; Oddy, T. M.; Archer, M. O.; Eastwood, J. P.; Sanz-Hernández, D.; Sample, J. G.; Cupido, E.; O'Brien, H.; Carr, C. M.

    2014-12-01

    We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45 000 nT ambient field.

  16. Optofluidic refractive index sensor based on partial reflection

    Science.gov (United States)

    Zhang, Lei; Zhang, Zhang; Wang, Yichuan; Ye, Meiying; Fang, Wei; Tong, Limin

    2017-06-01

    We demonstrate a novel optofluidic refractive index (RI) sensor with high sensitivity and wide dynamic range based on partial reflection. Benefited from the divergent incident light and the output fibers with different tilting angles, we have achieved highly sensitive RI sensing in a wide range from 1.33 to 1.37. To investigate the effectiveness of this sensor, we perform a measurement of RI with a resolution of ca. 5.0×10-5 refractive index unit (RIU) for ethylene glycol solutions. Also, we have measured a series of liquid solutions by using different output fibers, achieving a resolution of ca. 0.52 mg/mL for cane surge. The optofluidic RI sensor takes advantage of the high sensitivity, wide dynamic range, small footprint, and low sample consumption, as well as the efficient fluidic sample delivery, making it useful for applications in the food industry.

  17. Space magnetometer based on an anisotropic magnetoresistive hybrid sensor.

    Science.gov (United States)

    Brown, P; Whiteside, B J; Beek, T J; Fox, P; Horbury, T S; Oddy, T M; Archer, M O; Eastwood, J P; Sanz-Hernández, D; Sample, J G; Cupido, E; O'Brien, H; Carr, C M

    2014-12-01

    We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45,000 nT ambient field.

  18. Pressure sensor based on flexible photonic crystal membrane.

    Science.gov (United States)

    Karrock, Torben; Gerken, Martina

    2015-12-01

    We demonstrate a pressure sensor based on deformation of a periodically nanostructured Bragg grating waveguide on a flexible 50 µm polydimethylsiloxane membrane and remote optical read out. A pressure change causes deformation of this 2 mm diameter photonic crystal membrane sealing a reference volume. The resulting shift of the guided mode resonances is observed by a remote camera as localized color change. Crossed polarization filters are employed for enhancing the visibility of the guided mode resonances. Pressure values are calculated from the intensity change in the green color channel using a calibration curve in the range of 2000 Pa to 4000 Pa. A limit of detection (LOD) of 160 Pa is estimated. This LOD combined with the small size of the sensor and its biocompatibility render it promising for application as an implantable intraocular pressure sensor.

  19. Personal Navigation Algorithms Based on Wireless Networks and Inertial Sensors

    Science.gov (United States)

    Kaňa, Zdenek; Bradáč, Zdenek; Fiedler, Petr

    2014-08-01

    The work aims at a development of positioning algorithm suitable for low-cost indoor or urban pedestrian navigation application. The sensor fusion was applied to increase the localization accuracy. Due to required low application cost only low grade inertial sensors and wireless network based ranging were taken into account. The wireless network was assumed to be preinstalled due to other required functionality (for example: building control) therefore only received signal strength (RSS) range measurement technique was considered. Wireless channel loss mapping method was proposed to overcome the natural uncertainties and restrictions in the RSS range measurements The available sensor and environment models are summarized first and the most appropriate ones are selected secondly. Their effective and novel application in the navigation task, and favorable fusion (Particle filtering) of all available information are the main objectives of this thesis.

  20. A Neuron Model Based Ultralow Current Sensor System for Bioapplications

    Directory of Open Access Journals (Sweden)

    A. K. M. Arifuzzman

    2016-01-01

    Full Text Available An ultralow current sensor system based on the Izhikevich neuron model is presented in this paper. The Izhikevich neuron model has been used for its superior computational efficiency and greater biological plausibility over other well-known neuron spiking models. Of the many biological neuron spiking features, regular spiking, chattering, and neostriatal spiny projection spiking have been reproduced by adjusting the parameters associated with the model at hand. This paper also presents a modified interpretation of the regular spiking feature in which the firing pattern is similar to that of the regular spiking but with improved dynamic range offering. The sensor current ranges between 2 pA and 8 nA and exhibits linearity in the range of 0.9665 to 0.9989 for different spiking features. The efficacy of the sensor system in detecting low amount of current along with its high linearity attribute makes it very suitable for biomedical applications.

  1. Enhanced Voting based Secure Localization for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    M. B. Nirmala

    2015-11-01

    Full Text Available Development of location estimation algorithms with improvement in location precision with lower cost, less energy consumption and less hardware support has become more important for many applications in Wireless Sensor Networks (WSNs. This paper addresses the problem of secure location determination, known as secure localization in WSNs using voting based technique which gives a search region in presence of anchor nodes. From the obtained search region trilateration is applied to know the position of sensor nodes. To avoid the involvement of sensor nodes in further location estimation process, bilateration is applied. Experimental analysis shows that the maximum number of nodes can be localized and accurate location of a node can be determined efficiently with low estimation error. To avoid the attacks and involvement of malicious nodes in the localization process, we implement an improved authentication and security algorithm. Using few location reference points in the localization process reduces the communication cost. The proposed scheme also provides very good localization accuracy.

  2. A piezopaint-based sensor for monitoring structure dynamics

    Science.gov (United States)

    Lahtinen, R.; Muukkonen, T.; Koskinen, J.; Hannula, S.-P.; Heczko, O.

    2007-12-01

    Piezoceramic materials are used today in a variety of applications. By combining a piezoceramic powder with paint resin it is possible to fabricate a new type of piezomaterial, which can easily be applied to almost any surface. This paper describes the development of such a paint. The thermal stability and sensitivity as a function of frequency were investigated. Furthermore, a sensor based on an optimized epoxy piezopaint having a thickness of 80 µm was fixed on a steel beam of a footbridge to study the performance of the sensor and its long-term stability. It was demonstrated that the sensor could detect signals easily both from bridge movement and from pedestrian traffic on the bridge. The signal remained constant for a period of over thirteen months of monitoring.

  3. Terahertz Metamaterial Sensor Based on Electromagnetically Induced Transparency Effect

    Institute of Scientific and Technical Information of China (English)

    Shao-Xian Li; Hong-Wei Zhao; Jia-Guang Han

    2015-01-01

    A terahertz metamaterial sensor adopting the metamaterial-based electromagnetically induced transparency (EIT) effect is presented for determining the 1,4-dioxane concentration in its aqueous solution. The metamaterial sensor, which consists of an EIT element unit with a cut-wire metallic resonator and two split-ring metallic resonators fabricated on a 490-µm thick silicon substrate, operates in a transmission geometry. The EIT peak was red-shifted and decreased with the increase of the water volume. A maximum red- shift about 54GHz of the EIT peak was detected between the 1,4-dioxane and water. The presented linear behavior and high sensitivity of the EIT peak depending on the water concentration pave a novel avenue for sensor applications.

  4. Optical Sensor Based on a Single CdS Nanobelt

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-04-01

    Full Text Available In this paper, an optical sensor based on a cadmium sulfide (CdS nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT method. X-Ray Diffraction (XRD and Transmission Electron Microscopy (TEM results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 104, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions.

  5. Hydrogen Gas Sensors Based on Semiconductor Oxide Nanostructures

    Directory of Open Access Journals (Sweden)

    Yongming Hu

    2012-04-01

    Full Text Available Recently, the hydrogen gas sensing properties of semiconductor oxide (SMO nanostructures have been widely investigated. In this article, we provide a comprehensive review of the research progress in the last five years concerning hydrogen gas sensors based on SMO thin film and one-dimensional (1D nanostructures. The hydrogen sensing mechanism of SMO nanostructures and some critical issues are discussed. Doping, noble metal-decoration, heterojunctions and size reduction have been investigated and proved to be effective methods for improving the sensing performance of SMO thin films and 1D nanostructures. The effect on the hydrogen response of SMO thin films and 1D nanostructures of grain boundary and crystal orientation, as well as the sensor architecture, including electrode size and nanojunctions have also been studied. Finally, we also discuss some challenges for the future applications of SMO nanostructured hydrogen sensors.

  6. Acoustic vibration sensor based on nonadiabatic tapered fibers.

    Science.gov (United States)

    Xu, Ben; Li, Yi; Sun, Miao; Zhang, Zhen-Wei; Dong, Xin-Yong; Zhang, Zai-Xuan; Jin, Shang-Zhong

    2012-11-15

    A simple and low-cost vibration sensor based on single-mode nonadiabatic fiber tapers is proposed and demonstrated. The environmental vibrations can be detected by demodulating the transmission loss of the nonadiabatic fiber taper. Theoretical simulations show that the transmission loss is related to the microbending of the fiber taper induced by vibrations. Unlike interferometric sensors, this vibration sensor does not need any feedback loop to control the quadrature point to obtain a stable performance. In addition, it has no requirement for the coherence of the light source and is insensitive to temperature changes. Experimental results show that this sensing system has a wide frequency response range from a few hertz to tens of kilohertz with the maximal signal to noise ratio up to 73 dB.

  7. Magnetic field sensor using a polymer-based vibrator

    Science.gov (United States)

    Wu, Jiang; Hasebe, Kazuhiko; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-09-01

    In this technical note, a polymer-based magnetic sensor with a high resolution was devised for sensing the high magnetic field. It consisted of a bimorph (vibrator) made of poly (phenylene sulfide) (PPS) and a phosphor-bronze foil glued on the free end of the bimorph. According to Faraday’s law of induction, when a magnetic field in the direction perpendicular to the bimorph was applied, the foil cut the magnetic flux, and generated an alternating voltage across the leads at the natural frequency of the bimorph. Because PPS has low mechanical loss, low elastic modulus, and low density, high vibration velocity can be achieved if it is employed as the elastomer of the bimorph. The devised sensor was tested in the magnetic field range of 0.1-570 mT and exhibited a minimum detectable magnetic field of 0.1 mT. At a zero-to-peak driving voltage of 60 V, the sensitivity of the PPS-based magnetic sensor reached 10.5 V T-1, which was 1.36 times the value of the aluminum-based magnetic sensor with the same principle and dimensions.

  8. Chain-Based Communication in Cylindrical Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2015-02-01

    Full Text Available Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs. Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS and Congestion adjusted PEGASIS (C-PEGASIS. Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

  9. Graphene-based composite sensors for energy applications

    Science.gov (United States)

    Chadhari, S.; Graves, A. R.; Cain, M. V.; Stinespring, C. D.

    2016-05-01

    The long range objectives of this research are to develop and demonstrate the use of graphene-nanoparticle composites as a high sensitivity, rapid response electronic nose for gas sensing in energy applications. Graphene based device structures suitable for temperatures as high as 1000 °C are targeted. The scope of work includes: a) development of procedures for controllable nucleation and growth of nanoparticles on graphene surfaces, b) fabrication graphene-nanoparticle composite sensors, c) measurement of electrical properties of graphene-nanoparticle composites, and d) determination of sensor characteristics (selectivity and sensitivity). The graphene films are synthesized on 6H-SiC (0001) surfaces using a halogen based plasma etching followed by rapid thermal annealing in atmospheric pressure Ar or under ultrahigh vacuum conditions. Lithography free methods are then used to produce simple sensor structures consisting of interdigitated fingers. This is followed by the nucleation of either Ag, Au, Pt, or Ir nanoparticles on the graphene surfaces using solution based techniques. Atomic force microscopy is used to characterize the particle size distribution of the nucleated nanoparticles. Electrical properties of the graphene and graphenenanoparticle composites are characterized using two point current-voltage measurements. Gas sensor response as a function of temperature is characterized for H2 in Ar gas mixtures.

  10. Chain-based communication in cylindrical underwater wireless sensor networks.

    Science.gov (United States)

    Javaid, Nadeem; Jafri, Mohsin Raza; Khan, Zahoor Ali; Alrajeh, Nabil; Imran, Muhammad; Vasilakos, Athanasios

    2015-01-01

    Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

  11. Significant Storage on Sensor Storage Space, Energy Consumption and Better Security Based on Routing in Hybrid Sensor Networks

    Directory of Open Access Journals (Sweden)

    K.Nageswara rao

    2011-12-01

    Full Text Available WSNs are characterized by limited resources in term s of communication, computation and energy supply. A critical constraint on sensors networks is that s ensor nodes employ batteries. A second constraint i s that sensors will be deployed unattended and in large nu mbers, so that it will be difficult to change or re charge batteries in the sensors .The Energy Consumption in wireless sensor networks varies greatly based on t he protocols the sensors use and computations used to generate keys for communication among neighbor nodes. Previous research on sensor network security mainly considers homogeneous sensor networks, where all sensor nodes have the same capabilities. Research has shown that homogeneous ad hoc networks have poor performance and scalability. The many-to- one traffic pattern dominates in sensor networks, a nd hence a sensor may only communicate with a small po rtion of its neighbors. Key Management is a fundamental security operation. Most existing key m anagement schemes try to establish shared keys for all pairs of neighbor sensors, no matter whether these nodes communicate with each other or not, and this causes large overhead and more energy consumption a nd more storage requirement. In this paper, we adopt a Hybrid Sensor Network (HSN model for bette r performance and security. We propose a novel routing-driven key establishment scheme, which only establishes shared keys for neighbor sensors that communicate with each other. We utilize Elliptic Cu rve Cryptography in the design of an efficient key Establishment scheme for sensor nodes. The performa nce evaluation and security analysis show that our key Establishment scheme can provide better securit y with significant reductions on communication overhead, storage space and energy consumption than other key Establishment schemes.

  12. Graphene-Based Chemical Vapor Sensors for Electronic Nose Applications

    Science.gov (United States)

    Nallon, Eric C.

    chemiresistor device and used as a chemical sensor, where its resistance is temporarily modified while exposed to chemical compounds. The inherent, broad selective nature of graphene is demonstrated by testing a sensor against a diverse set of volatile organic compounds and also against a set of chemically similar compounds. The sensor exhibits excellent selectivity and is capable of achieving high classification accuracies. The kinetics of the sensor's response are further investigated revealing a relationship between the transient behavior of the response curve and physiochemical properties of the compounds, such as the molar mass and vapor pressure. This kinetic information is also shown to provide important information for further pattern recognition and classification, which is demonstrated by increased classification accuracy of very similar compounds. Covalent modification of the graphene surface is demonstrated by means of plasma treatment and free radical exchange, and sensing performance compared to an unmodified graphene sensor. Finally, the first example of a graphene-based, cross-reactive chemical sensor array is demonstrated by applying various polymers as coatings over an array of graphene sensors. The sensor array is tested against a variety of compounds, including the complex odor of Scotch whiskies, where it is capable of perfect classification of 10 Scotch whiskey variations.

  13. CO Responses of Sensors Based on Cerium Oxide Thick Films Prepared from Clustered Spherical Nanoparticles

    OpenAIRE

    Woosuck Shin; Takafumi Akamatsu; Toshio Itoh; Ichiro Matsubara; Noriya Izu

    2013-01-01

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nano...

  14. Framework of sensor-based monitoring for pervasive patient care.

    Science.gov (United States)

    Triantafyllidis, Andreas K; Koutkias, Vassilis G; Chouvarda, Ioanna; Adami, Ilia; Kouroubali, Angelina; Maglaveras, Nicos

    2016-09-01

    Sensor-based health systems can often become difficult to use, extend and sustain. The authors propose a framework for designing sensor-based health monitoring systems aiming to provide extensible and usable monitoring services in the scope of pervasive patient care. The authors' approach relies on a distributed system for monitoring the patient health status anytime-anywhere and detecting potential health complications, for which healthcare professionals and patients are notified accordingly. Portable or wearable sensing devices measure the patient's physiological parameters, a smart mobile device collects and analyses the sensor data, a Medical Center system receives notifications on the detected health condition, and a Health Professional Platform is used by formal caregivers in order to review the patient condition and configure monitoring schemas. A Service-oriented architecture is utilised to provide extensible functional components and interoperable interactions among the diversified system components. The framework was applied within the REMOTE ambient-assisted living project in which a prototype system was developed, utilising Bluetooth to communicate with the sensors and Web services for data exchange. A scenario of using the REMOTE system and preliminary usability results show the applicability, usefulness and virtue of our approach.

  15. Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

    Directory of Open Access Journals (Sweden)

    Gino Rinaldi

    2012-01-01

    Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

  16. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    Science.gov (United States)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

  17. Determination of Lead with a Copper-Based Electrochemical Sensor.

    Science.gov (United States)

    Kang, Wenjing; Pei, Xing; Rusinek, Cory A; Bange, Adam; Haynes, Erin N; Heineman, William R; Papautsky, Ian

    2017-03-21

    This work demonstrates determination of lead (Pb) in surface water samples using a low-cost copper (Cu)-based electrochemical sensor. Heavy metals require careful monitoring due to their toxicity, yet current methods are too complex or bulky for point-of-care (POC) use. Electrochemistry offers a convenient alternative for metal determination, but the traditional electrodes, such as carbon or gold/platinum, are costly and difficult to microfabricate. Our copper-based sensor features a low-cost electrode material-copper-that offers simple fabrication and competitive performance in electrochemical detection. For anodic stripping voltammetry (ASV) of Pb, our sensor shows 21 nM (4.4 ppb) limit of detection, resistance to interfering metals such as cadmium (Cd) and zinc (Zn), and stable response in natural water samples with minimum sample pretreatment. These results suggest this electrochemical sensor is suitable for environmental and potentially biological applications, where accurate and rapid, yet inexpensive, on-site monitoring is necessary.

  18. Commercialization Issues For Catheter-Based Electrochemical Sensors

    Science.gov (United States)

    Nikolchev, Julian; Gaisford, Scott

    1989-08-01

    The need for continuous monitoring of key clinical parameters in hospitals is well recognized. Figure 1 shows typical time constants for blood gases, ions and enzymes in response to acute ventilatory changes and interventions. Although it can be seen that relatively low rates of data collection are necessary for many medical measurements, it is also clear that intermittent measurement of P02, PCO2 and pH are not sufficient to provide safe and effective management of the patient. Very frequent or continuous monitoring is often essential. This figure also shows why the emphasis of a large number of research efforts in this country and in Europe and Japan have as their goal the development of continuous blood gas sensors, i.e., sensors that continuously monitor blood pH, partial pressure of oxygen and partial pressure of carbon dioxide. These are three (3) of the most frequent parameters measured in hospitals and the ones having the shortest time constant. Considering that in the United States alone close to 25 million blood gas samples per year are taken from patients, the potential market for continuous monitoring sensors is enormous. The emergence of microelectronics and microfabrication technologies over the past 30 years are now pointing to a possible resolution of the well recognized need for real time monitoring of critically ill patients through catheter-based sensors. Although physicians will always prefer non-invasive monitoring techniques, there are a number of parameters that presently can only be monitored by invasive method. The emerging ability to miniaturize chemical sensors using silicon microfabrication or fiber-optic techniques offer an excellent opportunity to solve this need. In fact, the development of in vivo biomedical sensors with satisfactory performance characteristics has long been considered the ultimate application of these emerging technologies.

  19. Smart sensor-based geospatial architecture for dike monitoring

    Science.gov (United States)

    Herle, S.; Becker, R.; Blankenbach, J.

    2016-04-01

    Artificial hydraulic structures like dams or dikes used for water level regulations or flood prevention are continuously under the influence of the weather and variable river regimes. Thus, ongoing monitoring and simulation is crucial in order to determine the inner condition. Potentially life-threatening situations, in extreme case a failure, must be counteracted by all available means. Nowadays flood warning systems rely exclusively on water level forecast without considering the state of the structure itself. Area-covering continuous knowledge of the inner state including time dependent changes increases the capability of recognizing and locating vulnerable spots for early treatment. In case of a predicted breach, advance warning time for alerting affected citizens can be extended. Our approach is composed of smart sensors integrated in a service-oriented geospatial architecture to monitor and simulate artificial hydraulic structures continuously. The sensors observe the inner state of the construction like the soil moisture or the stress and deformation over time but also various external influences like water levels or wind speed. They are interconnected in distributed network architecture by a so-called sensor bus system based on lightweight protocols like Message Queue Telemetry Transport for Sensor Networks (MQTT-SN). These sensor data streams are transferred into an OGC Sensor Web Enablement (SWE) data structure providing high-level geo web services to end users. Bundled with 3rd party geo web services (WMS etc.) powerful processing and simulation tools can be invoked using the Web Processing Service (WPS) standard. Results will be visualized in a geoportal allowing user access to all information.

  20. Monitoring and Control Interface Based on Virtual Sensors

    Directory of Open Access Journals (Sweden)

    Ricardo F. Escobar

    2014-10-01

    Full Text Available In this article, a toolbox based on a monitoring and control interface (MCI is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based control law. The MCI helps to maintain the heat exchanger under operation, even if a temperature outlet sensor fault occurs; in the case of outlet temperature sensor failure, the MCI will display an alarm. The monitoring and control interface is used as a practical tool to support electronic engineering students with heat transfer and control concepts to be applied in a double-pipe heat exchanger pilot plant. The method aims to teach the students through the observation and manipulation of the main variables of the process and by the interaction with the monitoring and control interface (MCI developed in LabVIEW©. The MCI provides the electronic engineering students with the knowledge of heat exchanger behavior, since the interface is provided with a thermodynamic model that approximates the temperatures and the physical properties of the fluid (density and heat capacity. An advantage of the interface is the easy manipulation of the actuator for an automatic or manual operation. Another advantage of the monitoring and control interface is that all algorithms can be manipulated and modified by the users.

  1. Multiple sensors-based kernel machine learning in smart environment

    Science.gov (United States)

    Li, Jun-Bao; Pan, Jeng-Shyang

    2017-01-01

    Sensor-based monitoring systems use multiple sensors to identify high-level information based on the events that take place in a monitored environment. Identification and health care are important tasks in the smart environment. This paper presents a framework for multisensory multimedia data analysis using a kernel optimization-based principal analysis for identification and health care in a smart environment. Images of faces, palmprints, and fingerprints are used to identify a person, and a wrist pulse signal is used to analyze the person's health condition. The recognition performance evaluations are implemented on the complex dataset of face, palmprint, fingerprint, and wrist pulse signals. The experimental results show that the proposed algorithms perform well for identification and heath analysis.

  2. Distance Based Method for Outlier Detection of Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Haibin Zhang

    2016-01-01

    Full Text Available We propose a distance based method for the outlier detection of body sensor networks. Firstly, we use a Kernel Density Estimation (KDE to calculate the probability of the distance to k nearest neighbors for diagnosed data. If the probability is less than a threshold, and the distance of this data to its left and right neighbors is greater than a pre-defined value, the diagnosed data is decided as an outlier. Further, we formalize a sliding window based method to improve the outlier detection performance. Finally, to estimate the KDE by training sensor readings with errors, we introduce a Hidden Markov Model (HMM based method to estimate the most probable ground truth values which have the maximum probability to produce the training data. Simulation results show that the proposed method possesses a good detection accuracy with a low false alarm rate.

  3. Wheel-Based Ice Sensors for Road Vehicles

    Science.gov (United States)

    Arndt, G. Dickey; Fink, Patrick W.; Ngo, Phong H.; Carl, James R.

    2011-01-01

    Wheel-based sensors for detection of ice on roads and approximate measurement of the thickness of the ice are under development. These sensors could be used to alert drivers to hazardous local icing conditions in real time. In addition, local ice-thickness measurements by these sensors could serve as guidance for the minimum amount of sand and salt required to be dispensed locally onto road surfaces to ensure safety, thereby helping road crews to utilize their total supplies of sand and salt more efficiently. Like some aircraft wing-surface ice sensors described in a number of previous NASA Tech Briefs articles, the wheelbased ice sensors are based, variously, on measurements of changes in capacitance and/or in radio-frequency impedance as affected by ice on surfaces. In the case of ice on road surfaces, the measurable changes in capacitance and/or impedance are attributable to differences among the electric permittivities of air, ice, water, concrete, and soil. In addition, a related phenomenon that can be useful for distinguishing between ice and water is a specific transition in the permittivity of ice at a temperature- dependent frequency. This feature also provides a continuous calibration of the sensor to allow for changing road conditions. Several configurations of wheel-based ice sensors are under consideration. For example, in a simple two-electrode capacitor configuration, one of the electrodes would be a circumferential electrode within a tire, and the ground would be used as the second electrode. Optionally, the steel belts that are already standard parts of many tires could be used as the circumferential electrodes. In another example (see figure), multiple electrodes would be embedded in rubber between the steel belt and the outer tire surface. These electrodes would be excited in alternating polarities at one or more suitable audio or radio frequencies to provide nearly continuous monitoring of the road surface under the tire. In still another

  4. Certificate Based Security Services in Adhoc Sensor Network

    Directory of Open Access Journals (Sweden)

    Shahin Fatima

    2014-10-01

    Full Text Available The paper entitled “CERTIFICATE BASED SECURITY SERVICES IN ADHOC SENSOR NETWORK” proposed an approach in which the aim is to find the method for authentication which is more energy efficient and reduces the transmission time of the network. MANETs are of dynamic topology and have no predefined infrastructure. Due to its dynamic topology this network is prone to various kinds of vulnerable attacks. Sensor networks are battery operated and is a major concern. Methods on ID based Authentication consumes more network bandwidth and increases the computation and transmission time of the network. So for better operation, authentication must be the major factor of concern. In this paper a method for authentication in adhoc sensor network is proposed which is based on certificate based security services. Here we will make use of X.509 certificate format. In this some modification is made to the certificate format such that the transmission time and energy consumption of the network is reduced. Our proposed model will provide authentication among nodes and security in MANET. The proposed work is implemented in MATLAB and the result will show the effectiveness of proposed certificate in MANET. The objective of certificate based authentication is to ensure that messages can be read by authorized person only. It also overcomes the non repudiation attacks thereby minimizing the computation and shows how energy varies by making changes in certificate of node.

  5. Using Custom Fiber Bragg Grating-Based Sensors to Monitor Artificial Landslides.

    Science.gov (United States)

    Zhang, Qinghua; Wang, Yuan; Sun, Yangyang; Gao, Lei; Zhang, Zhenglin; Zhang, Wenyuan; Zhao, Pengchong; Yue, Yin

    2016-09-02

    Four custom fiber Bragg grating (FBG)-based sensors are developed to monitor an artificial landslide located in Nanjing, China. The sensors are composed of a rod and two FBGs. Based on the strength of the rods, two sensors are referred to as "hard sensors" (Sensor 1 and Sensor 2), the other two are referred to as "soft sensors" (Sensor 3 and Sensor 4). The two FBGs are fixed on each sensor rod at distances of 50 cm and 100 cm from the top of the rod (an upper FBG and a lower FBG). In the experiment presented in this paper, the sensors are installed on a slope on which an artificial landslide is generated through both machine-based and manual excavation. The fiber sensing system consists of the four custom FBG-based sensors, optical fiber, a static fiber grating demodulation instrument (SM125), and a PC with the necessary software. Experimental data was collected in the presence of an artificial landslide, and the results show that the lower FBGs are more sensitive than the upper FBGs for all four of the custom sensors. It was also found that Sensor 2 and Sensor 4 are more capable of monitoring small-scale landslides than Sensor 1 and Sensor 3, and this is mainly due to their placement location with respect to the landslide. The stronger rods used in the hard sensors make them more adaptable to the harsh environments of large landslides. Thus, hard sensors should be fixed near the landslide, while soft sensors should be placed farther away from the landslide. In addition, a clear tendency of strain variation can be detected by the soft sensors, which can be used to predict landslides and raise a hazard alarm.

  6. Flat Panel Space Based Space Surveillance Sensor

    Science.gov (United States)

    Kendrick, R.; Duncan, A.; Wilm, J.; Thurman, S. T.; Stubbs, D. M.; Ogden, C.

    2013-09-01

    Traditional electro-optical (EO) imaging payloads consist of an optical telescope to collect the light from the object scene and map the photons to an image plane to be digitized by a focal plane detector array. The size, weight, and power (SWaP) for the traditional EO imager is dominated by the optical telescope, driven primarily by the large optics, large stiff structures, and the thermal control needed to maintain precision free-space optical alignments. We propose a non-traditional Segmented Planar Imaging Detector for EO Reconnaissance (SPIDER) imager concept that is designed to substantially reduce SWaP, by at least an order of magnitude. SPIDER maximizes performance by providing a larger effective diameter (resolution) while minimizing mass and cost. SPIDER replaces the traditional optical telescope and digital focal plane detector array with a densely packed interferometer array based on emerging photonic integrated circuit (PIC) technologies. Lenslets couple light from the object into a set of waveguides on a PIC. Light from each lenslet is distributed among different waveguides by both field angle and optical frequency, and the lenslets are paired up to form unique interferometer baselines by combining light from different waveguides. The complex spatial coherence of the object (for each field angle, frequency, and baseline) is measured with a balanced four quadrature detection scheme. By the Van-Cittert Zernike Theorem, each measurement corresponds to a unique Fourier component of the incoherent object intensity distribution. Finally, an image reconstruction algorithm is used to invert all the data and form an image. Our approach replaces the large optics and structures required by a conventional telescope with PICs that are accommodated by standard lithographic fabrication techniques (e.g., CMOS fabrication). The standard EO payload integration and test process which involves precision alignment and test of optical components to form a diffraction

  7. FPGA-Based Embedded Motion Estimation Sensor

    Directory of Open Access Journals (Sweden)

    Zhaoyi Wei

    2008-01-01

    Full Text Available Accurate real-time motion estimation is very critical to many computer vision tasks. However, because of its computational power and processing speed requirements, it is rarely used for real-time applications, especially for micro unmanned vehicles. In our previous work, a FPGA system was built to process optical flow vectors of 64 frames of 640×480 image per second. Compared to software-based algorithms, this system achieved much higher frame rate but marginal accuracy. In this paper, a more accurate optical flow algorithm is proposed. Temporal smoothing is incorporated in the hardware structure which significantly improves the algorithm accuracy. To accommodate temporal smoothing, the hardware structure is composed of two parts: the derivative (DER module produces intermediate results and the optical flow computation (OFC module calculates the final optical flow vectors. Software running on a built-in processor on the FPGA chip is used in the design to direct the data flow and manage hardware components. This new design has been implemented on a compact, low power, high performance hardware platform for micro UV applications. It is able to process 15 frames of 640×480 image per second and with much improved accuracy. Higher frame rate can be achieved with further optimization and additional memory space.

  8. Sensor Based Effective Monitoring of Coal Handling System (CHS

    Directory of Open Access Journals (Sweden)

    Kuttalakkani.M

    2013-06-01

    Full Text Available Coal level detection is an important aspect to assess the performance of a coal-fired power plant. Coal has to be transported, via a coal handling system. The fuel in a coal-fired power plant is stored in silos, bunkers or stock piles. Coal is stored in silos in a small plant, Bunkers for handling a day’s operation and Stock piling methods for large plants. So, fuel handling had to done efficiently. To accurately sense the coal height, Real-time feedback is deployed within the bunker or stock pile. The real time range information is then fedback to the control system. Of the different types of ranging sensors, radar based system is used. Also a real-time temperature monitoring system is developed to protect the coal. The range and temperature data from sensors are sent to the main system through GSM modem by means of SMS. The range information is used to start the conveyor belt to draw the coal from coal yard. If the temperature exceeds the limit, the SMS will be sent through the software or it will call the respective person to monitor the process. A fire sensor is also used to extinguish the fire by initiating the water spraying system. A PIC Microcontroller is interfaced all the sensors for effective handling of thermal power plant.

  9. Nanoporous Pirani sensor based on anodic aluminum oxide

    Science.gov (United States)

    Jeon, Gwang-Jae; Kim, Woo Young; Shim, Hyun Bin; Lee, Hee Chul

    2016-09-01

    A nanoporous Pirani sensor based on anodic aluminum oxide (AAO) is proposed, and the quantitative relationship between the performance of the sensor and the porosity of the AAO membrane is characterized with a theoretical model. The proposed Pirani sensor is composed of a metallic resistor on a suspended nanoporous membrane, which simultaneously serves as the sensing area and the supporting structure. The AAO membrane has numerous vertically-tufted nanopores, resulting in a lower measurable pressure limit due to both the increased effective sensing area and the decreased effective thermal loss through the supporting structure. Additionally, the suspended AAO membrane structure, with its outer periphery anchored to the substrate, known as a closed-type design, is demonstrated using nanopores of AAO as an etch hole without a bulk micromachining process used on the substrate. In a CMOS-compatible process, a 200 μm × 200 μm nanoporous Pirani sensor with porosity of 25% was capable of measuring the pressure from 0.1 mTorr to 760 Torr. With adjustment of the porosity of the AAO, the measurable range could be extended toward lower pressures of more than one decade compared to a non-porous membrane with an identical footprint.

  10. Energy Aware Cluster Based Routing Scheme For Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Roy Sohini

    2015-09-01

    Full Text Available Wireless Sensor Network (WSN has emerged as an important supplement to the modern wireless communication systems due to its wide range of applications. The recent researches are facing the various challenges of the sensor network more gracefully. However, energy efficiency has still remained a matter of concern for the researches. Meeting the countless security needs, timely data delivery and taking a quick action, efficient route selection and multi-path routing etc. can only be achieved at the cost of energy. Hierarchical routing is more useful in this regard. The proposed algorithm Energy Aware Cluster Based Routing Scheme (EACBRS aims at conserving energy with the help of hierarchical routing by calculating the optimum number of cluster heads for the network, selecting energy-efficient route to the sink and by offering congestion control. Simulation results prove that EACBRS performs better than existing hierarchical routing algorithms like Distributed Energy-Efficient Clustering (DEEC algorithm for heterogeneous wireless sensor networks and Energy Efficient Heterogeneous Clustered scheme for Wireless Sensor Network (EEHC.

  11. ENERGY OPTIMIZATION IN CLUSTER BASED WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    T. SHANKAR

    2014-04-01

    Full Text Available Wireless sensor networks (WSN are made up of sensor nodes which are usually battery-operated devices, and hence energy saving of sensor nodes is a major design issue. To prolong the networks lifetime, minimization of energy consumption should be implemented at all layers of the network protocol stack starting from the physical to the application layer including cross-layer optimization. Optimizing energy consumption is the main concern for designing and planning the operation of the WSN. Clustering technique is one of the methods utilized to extend lifetime of the network by applying data aggregation and balancing energy consumption among sensor nodes of the network. This paper proposed new version of Low Energy Adaptive Clustering Hierarchy (LEACH, protocols called Advanced Optimized Low Energy Adaptive Clustering Hierarchy (AOLEACH, Optimal Deterministic Low Energy Adaptive Clustering Hierarchy (ODLEACH, and Varying Probability Distance Low Energy Adaptive Clustering Hierarchy (VPDL combination with Shuffled Frog Leap Algorithm (SFLA that enables selecting best optimal adaptive cluster heads using improved threshold energy distribution compared to LEACH protocol and rotating cluster head position for uniform energy dissipation based on energy levels. The proposed algorithm optimizing the life time of the network by increasing the first node death (FND time and number of alive nodes, thereby increasing the life time of the network.

  12. A Microring Temperature Sensor Based on the Surface Plasmon Wave

    Directory of Open Access Journals (Sweden)

    Wenchao Li

    2015-01-01

    Full Text Available A structure of microring sensor suitable for temperature measurement based on the surface plasmon wave is put forward in this paper. The sensor uses surface plasmon multilayer waveguiding structure in the vertical direction and U-shaped microring structure in the horizontal direction and utilizes SOI as the thermal material. The transfer function derivation of the structure of surface plasmon microring sensor is according to the transfer matrix method. While the change of refractive index of Si is caused by the change of ambient temperature, the effective refractive index of the multilayer waveguiding structure is changed, resulting in the drifting of the sensor output spectrum. This paper focuses on the transmission characteristics of multilayer waveguide structure and the impact on the output spectrum caused by refractive index changes in temperature parts. According to the calculation and simulation, the transmission performance of the structure is stable and the sensitivity is good. The resonance wavelength shift can reach 0.007 μm when the temperature is increased by 100 k and FSR can reach about 60 nm. This structure achieves a high sensitivity in the temperature sense taking into account a wide range of filter frequency selections, providing a theoretical basis for the preparation of microoptics.

  13. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  14. Interferometric and localized surface plasmon based fiber optic sensor

    Science.gov (United States)

    Muri, Harald Ian D. I.; Bano, Andon; Hjelme, Dag Roar

    2017-02-01

    We demonstrate a novel single point, multi-parameter, fiber optic sensor concept based on a combination of interferometric and plasmonic sensor modalities on an optical fiber end face. The sensor consists of a micro-Fabry-Perot interferometer in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanoparticles. We present results of proof-of-concept experiments demonstrating local surface plasmon resonance (LSPR) sensing of refractive index (RI) in the visible range and interferometric measurements of volumetric changes of the pH stimuli-responsive hydrogel in near infrared range. The response of LSPR to RI (Δλr/ΔRI 877nm/RI) and the free spectral range (FSR) to pH (ΔpH/ΔFSR = 0.09624/nm) were measured with LSPR relatively constant for hydrogel swelling degree and FSR relatively constant for RI. We expect this novel sensor concept to be of great value for biosensors for medical applications.

  15. Design of Fixed Beamformers Based on Vector-Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Matthew Hawes

    2015-01-01

    Full Text Available Vector-sensor arrays such as those composed of crossed dipole pairs are used as they can account for a signal’s polarisation in addition to the usual direction of arrival information, hence allowing expanded capacity of the system. The problem of designing fixed beamformers based on such an array, with a quaternionic signal model, is considered in this paper. Firstly, we consider the problem of designing the weight coefficients for a fixed set of vector-sensor locations. This can be achieved by minimising the sidelobe levels while keeping a unitary response for the main lobe. The second problem is then how to find a sparse set of sensor locations which can be efficiently used to implement a fixed beamformer. We propose solving this problem by converting the traditional l1 norm minimisation associated with compressive sensing into a modified l1 norm minimisation which simultaneously minimises all four parts of the quaternionic weight coefficients. Further improvements can be made in terms of sparsity by converting the problem into a series of iteratively solved reweighted minimisations, as well as being able to enforce a minimum spacing between active sensor locations. Design examples are provided to verify the effectiveness of the proposed design methods.

  16. Development of fluorescent FeIII sensor based on chalcone

    Energy Technology Data Exchange (ETDEWEB)

    Wei Yanli, E-mail: weiyanli@sxu.edu.cn [Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006 (China); Qin Guojie [Institute of Horticulture, Shanxi Academy of Agriculture Science, Taiyuan 030031 (China); Wang Wenyan; Bian Wei; Shuang Shaomin [Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006 (China); Dong Chuan, E-mail: dc@sxu.edu.cn [Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006 (China)

    2011-08-15

    In this paper, 4-dimethylamino 2,5-dihydroxy chalcone (DMADHC), which exhibits excited state intramolecular charge transfer (ICT) characteristics, was synthesized and characterized. A sensitive optochemical sensor for Fe{sup 3+} ion was developed using DMADHC as fluorescence receptor. The fluorescence of DMADHC was gradually quenched with the addition of Fe{sup 3+} ion, which attributed to the formation of 1:1 complex between DMADHC and Fe{sup 3+} ion. The sensor exhibited excellent selectivity for Fe{sup 3+} ion over a large number of cation ions such as alkali, alkaline earth and transitional metal ions with a linear range of 3.984x10{sup -7}-1.135x10{sup -5} and a limit of detection of 8.223x10{sup -8} mol/L. On this basis, the sensor was preliminary applied to the determination of the content of iron ions in multi-vitamin tablet with satisfied results and the recoveries were in the 95-100% interval, and precision (n=5) was better than 5%. - Highlights: > A fluorescence receptor, 4-dimethylamino 2,5-dihydroxy chalcone was synthesis by one-step reaction. > Its intramolecular charge transfer fluorescence characteristics could be blocked by Fe{sup 3+} ion. > Based on this, an optochemical sensor for Fe{sup 3+} ion was developed. > Importantly, our proposed method is particularly useful for determination of Fe{sup 3+} ion in real sample.

  17. A Fiber Bragg Grating Sensing Based Triaxial Vibration Sensor.

    Science.gov (United States)

    Li, Tianliang; Tan, Yuegang; Liu, Yi; Qu, Yongzhi; Liu, Mingyao; Zhou, Zude

    2015-09-18

    A fiber Bragg grating (FBG) sensing based triaxial vibration sensor has been presented in this paper. The optical fiber is directly employed as elastomer, and the triaxial vibration of a measured body can be obtained by two pairs of FBGs. A model of a triaxial vibration sensor as well as decoupling principles of triaxial vibration and experimental analyses are proposed. Experimental results show that: sensitivities of 86.9 pm/g, 971.8 pm/g and 154.7 pm/g for each orthogonal sensitive direction with linearity are separately 3.64%, 1.50% and 3.01%. The flat frequency ranges reside in 20-200 Hz, 3-20 Hz and 4-50 Hz, respectively; in addition, the resonant frequencies are separately 700 Hz, 40 Hz and 110 Hz in the x/y/z direction. When the sensor is excited in a single direction vibration, the outputs of sensor in the other two directions are consistent with the outputs in the non-working state. Therefore, it is effectively demonstrated that it can be used for three-dimensional vibration measurement.

  18. Robot Positioning and Navigation Based on Hybrid Wireless Sensor Network

    Institute of Scientific and Technical Information of China (English)

    Shun-cai YAO; Jin-dong TAN; Hong-xia PAN

    2010-01-01

    Traditional sensor network and robot navigation are based an the map of detecting the fields available in advance.The optimal algorithms are developed to solve the energy saving,the shortest path problems,etc.However,in the practical encironment,there are many fields,whose map is difficult to get,and needs to be detected.In this paper a kind of ad-hoc navigation algorithm is explored,which is based on the hybrid sensor network without the prior map in advance.The navigation system is composed of static nodes and dynamic nodes.The static nodes monitor the occurrances of the events and broadcast them.In the system,a kind of algorithm is to locate the robot,which is based on cluster broadcasting.The dynamic nodes detect the adversary or dangerous fields and broadcast warning messages.The robot gets the message and follows ad-hoc routine to arrive where the events occur.In the whole process,energy saving has been taken into account.The algorithms,which are based on the hybrid sensor network,are given in this paper.The simulation and practical results are also available.

  19. ZnO Coated Nanospring-Based Gas Sensors

    Science.gov (United States)

    Bakharev, Pavel Viktorovich

    . The experimental and computational analyses of the sensing properties of the 3-D (nanospring-based) and flat thin films structures show that the complexity and periodic boundary conditions of the nanospring-based devices result in a lower detection limit, while flat thin films exhibit higher sensitivity to small analyte concentration fluctuations. Our analysis shows that the productive approach to fabrication of integrated sensors (electronic noses) is to use both the structures (3D and flat geometries) as the receptors for a prompt and reliable detection and recognition of the target chemical compounds. Analog lock-in amplifier (LIA) AC measurements of the electrical response have been performed to significantly improve the signal-to-noise ratio (SNR) and reduce the detection limit of the single ZnO coated nanospring chemiresistor from the ppm to the ppb analyte concentration ranges. The LIA-based sensor signal recognition technique has shown to extend the capabilities of the gas sensor array for a linear discrimination analysis (LDA), an independent component analysis (ICA), a principal component analysis (PCA) and other multiple odor recognition methods.

  20. A Sensitive DNAzyme-Based Chiral Sensor for Lead Detection

    Directory of Open Access Journals (Sweden)

    Chuanlai Xu

    2013-11-01

    Full Text Available A DNAzyme-based sensor for the determination and quantification of lead ions (Pb2+ has been established, which combines the recognition and catalysis of DNAzyme with the optical properties of nanomaterials. Circular dichroism (CD signals were obtained by a DNAzyme-based assembly of asymmetric silver nanoparticle (AgNPs dimers. A good linear relationship between CD signals and Pb2+ concentration was obtained ranging from 0.05 ng∙mL−1 to 10 ng∙mL−1 with a limit of detection (LOD of 0.02 ng∙mL−1. The specificity of this sensor in lead ion detection was excellent, and a satisfactory recovery was obtained in the analysis of tap water samples. The proposed technique possesses both high sensitivity and good specificity, giving it great potential for the analysis of Pb2+ in water.

  1. Comparison of CSMA based MAC protocols of wireless sensor networks

    CERN Document Server

    singh, Himanshu

    2012-01-01

    Energy conservation has been an important area of interest in Wireless Sensor networks (WSNs). Medium Access Control (MAC) protocols play an important role in energy conservation. In this paper, we describe CSMA based MAC protocols for WSN and analyze the simulation results of these protocols. We implemented S-MAC, T-MAC, B-MAC, B-MAC+, X-MAC, DMAC and Wise-MAC in TOSSIM, a simulator which unlike other simulators simulates the same code running on real hardware. Previous surveys mainly focused on the classification of MAC protocols according to the techniques being used or problem dealt with and presented a theoretical evaluation of protocols. This paper presents the comparative study of CSMA based protocols for WSNs, showing which MAC protocol is suitable in a particular environment and supports the arguments with the simulation results. The comparative study can be used to find the best suited MAC protocol for wireless sensor networks in different environments.

  2. Sensitivity Analysis of a Bioinspired Refractive Index Based Gas Sensor

    Institute of Scientific and Technical Information of China (English)

    Yang Gao; Qi Xia; Guanglan Liao; Tielin Shi

    2011-01-01

    It was found out that the change of refractive index of ambient gas can lead to obvious change of the color of Morpho butterfly's wing. Such phenomenon has been employed as a sensing principle for detecting gas. In the present study, Rigorous Coupled-Wave Analysis (RCWA) was described briefly, and the partial derivative of optical reflection efficiency with respect to the refractive index of ambient gas, i.e., sensitivity of the sensor, was derived based on RCWA. A bioinspired grating model was constructed by mimicking the nanostructure on the ground scale of Morpho didius butterfly's wing. The analytical sensitivity was verified and the effect of the grating shape on the reflection spectra and its sensitivity were discussed. The results show that by tuning shape parameters of the grating, we can obtain desired reflection spectra and sensitivity, which can be applied to the design of the bioinspired refractive index based gas sensor.

  3. The Design of Tools for Sketching Sensor-Based Interaction

    DEFF Research Database (Denmark)

    Brynskov, Martin; Lunding, Rasmus; Vestergaard, Lasse Steenbock

    2012-01-01

    In this paper we motivate, present, and give an initial evaluation of DUL Radio, a small wireless toolkit for sketching sensor-based interaction. In the motivation, we discuss the purpose of this specific platform, which aims to balance ease-of-use (learning, setup, initialization), size, speed......, flexibility and cost, aimed at wearable and ultra-mobile prototyping where fast reaction is needed (e.g. in controlling sound), and we discuss the general issues facing this category of embodied interaction design tools. We then present the platform in more detail, both regarding hard- ware and software....... In the brief evaluation, we present our initial experiences with the platform both in design projects and in teaching. We conclude that DUL Radio does seem to be a relatively easy-to-use tool for sketching sensor-based interaction compared to other solutions, but that there are many ways to improve it. Target...

  4. AGV Trajectory Control Based on Laser Sensor Navigation

    Directory of Open Access Journals (Sweden)

    Thanh Luan Bui

    2013-01-01

    Full Text Available Autonomous Guided Vehicle Systems (AGVs are used to transport goods and products in manufacturing fields where navigation can be done in a structured environment. In order to track the given trajectory, a tracking control based on Lyapunov stability theory is introduced. The use of the nonlinear Lyapunov technique provides robustness for load disturbance and sensor noise. To apply Lyapunov's theorem, the kinematic model of AGV is given. To recognize its position in indoor environment, in this paper, a laser sensor device NAV200 is used to detect the AGV position in real-time. For simulation and experiment, software and hardware are described. The AGV consists of 4 wheels with two passive wheels and two driving wheels. A controller is developed based on industrial computer. The effectiveness of the proposed controller is proved by simulation and experimental results

  5. A ph sensor based on a flexible substrate

    Science.gov (United States)

    Huang, Wen-Ding

    pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on low-cost sol-gel fabrication process of iridium oxide (IrOx) sensing film (IROF). A pair of flexible miniature IrOx/AgCl electrode generated the action potential from the solution by electrochemical mechanism to obtain the pH level of the reagent. The fabrication process including sol-gel, thermal oxidation, and the electro-plating process of the silver chloride (AgCl) reference electrode were reported in the work. The IrOx film was verified and characterized using electron dispersive analysis (EDAX), scanning electron microscope (SEM), and x-ray diffraction (XRD). The flexible pH sensor's performance and characterization have been investigated with different testing parameters such as sensitivity, response time, stability, reversibility, repeatability, selectivity and temperature dependence. The flexible IrOx pH sensors exhibited promising sensing performance with a near-Nernstian response of sensitivity which is between --51.1mV/pH and --51.7mV/pH in different pH levels ranging from 1.5 to 12 at 25°C. Two applications including gastroesophageal reflux disease (GERD) diagnosis and food freshness wireless monitoring using our micro-flexible IrOx pH sensors were demonstrated. For the GERD diagnosing system, we embedded the micro flexible pH sensor on a 1.2cmx3.8cm of the capsule size of wireless sensor

  6. A Portable Laser Photoacoustic Methane Sensor Based on FPGA

    Science.gov (United States)

    Wang, Jianwei; Wang, Huili; Liu, Xianyong

    2016-01-01

    A portable laser photoacoustic sensor for methane (CH4) detection based on a field-programmable gate array (FPGA) is reported. A tunable distributed feedback (DFB) diode laser in the 1654 nm wavelength range is used as an excitation source. The photoacoustic signal processing was implemented by a FPGA device. A small resonant photoacoustic cell is designed. The minimum detection limit (1σ) of 10 ppm for methane is demonstrated. PMID:27657079

  7. A Portable Laser Photoacoustic Methane Sensor Based on FPGA.

    Science.gov (United States)

    Wang, Jianwei; Wang, Huili; Liu, Xianyong

    2016-09-21

    A portable laser photoacoustic sensor for methane (CH₄) detection based on a field-programmable gate array (FPGA) is reported. A tunable distributed feedback (DFB) diode laser in the 1654 nm wavelength range is used as an excitation source. The photoacoustic signal processing was implemented by a FPGA device. A small resonant photoacoustic cell is designed. The minimum detection limit (1σ) of 10 ppm for methane is demonstrated.

  8. Nanotube-based Sensors and Systems for Outer Planetary Exploration

    Science.gov (United States)

    Noca, F.; Hunt, B. D.; Hoenk, M. E.; Choi, D.; Kowalczyk, R.; Williams, R.; Xu, J.; Koumoutsakos, P.

    2001-01-01

    Direct sensing and processing at the nanometer scale offer NASA the opportunity to expand its capabilities in deep space exploration, particularly for the search for signatures of life, the analysis of planetary oceans and atmospheres, and communications systems. Carbon nanotubes, with their unique mechanical, electrical, and radiation-tolerant properties, are a promising tool for this exploration. We are developing devices based on carbon nanotubes, including sensors, actuators, and oscillators. Additional information is contained in the original extended abstract.

  9. Plasmonic Sensors Based on Doubly-Deposited Tapered Optical Fibers

    Directory of Open Access Journals (Sweden)

    Agustín González-Cano

    2014-03-01

    Full Text Available A review of the surface plasmon resonance (SPR transducers based on tapered fibers that have been developed in the last years is presented. The devices have proved their good performance (specifically, in terms of sensitivity and their versatility and they are a very good option to be considered as basis for any kind of chemical and biological sensor. The technology has now reached its maturity and here we summarize some of the characteristics of the devices produced.

  10. Micro electro mechanical systems based sensor for mechanomyography

    OpenAIRE

    Murphy, Chris; Campbell, Niall; Caulfield, Brian; Ward, Tomas; Deegan, Catherine

    2008-01-01

    The purpose of this work was to design a micro electrical mechanical sensor (MEMS) based system to measure the mechanomyogram of electrically stimulated muscle. The measuring device for the mechanomyography (MMG) system consisted of a dual axis accelerometer and a signal conditioning circuit designed specifically to enhance raw MMG signals . Currently electromyography (EMG) is the standard tool for measuring muscle contraction. During electrical stimulation however, EMG measure...

  11. Hydrogen sensor based on metallic photonic crystal slabs.

    Science.gov (United States)

    Nau, D; Seidel, A; Orzekowsky, R B; Lee, S-H; Deb, S; Giessen, H

    2010-09-15

    We present a hydrogen sensor based on metallic photonic crystal slabs. Tungsten trioxide (WO(3)) is used as a waveguide layer below an array of gold nanowires. Hydrogen exposure influences the optical properties of this photonic crystal arrangement by gasochromic mechanisms, where the photonic crystal geometry leads to sharp spectral resonances. Measurements reveal a change of the transmission depending on the hydrogen concentration. Theoretical limits for the detection range and sensitivity of this approach are discussed.

  12. Research of optical rainfall sensor based on CCD linear array

    Institute of Scientific and Technical Information of China (English)

    YANG; Bifeng; LIU; Yuyan; LU; Ying; WU; Shangqian

    2015-01-01

    Rainfall monitoring is one of the most important meteorological observation elements for the disaster weather. The maintenance of current tipping bucket rain gauge and weighing type rain gauge is a critical issue. The optical rainfall sensor based on CCD linear array is mainly studied in this paper. Because of the maintenance-free time and good adaptability,it can be widely used in the automatic rainfall monitoring in severe environment and have a good perspective in using.

  13. An Astigmatic Detection System for Polymeric Cantilever-based Sensors

    DEFF Research Database (Denmark)

    Hwu, En-Te; Liao, Hsien-Shun; Bosco, Filippo;

    2012-01-01

    We demonstrate the use of an astigmatic detection system (ADS) for resonance frequency identification of polymer microcantilever sensors. The ADS technology is based on a DVD optical head combined with an optical microscope (OM). The optical head has a signal bandwidth of 80 MHz, allowing thermal...... submicrometer-sized cantilevers. The resonant frequency of SU-8 microcantilevers is measured by both thermal fluctuation and excited vibration measurement modes of the ADS....

  14. Hierarchical Compressed Sensing for Cluster Based Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Vishal Krishna Singh

    2016-02-01

    Full Text Available Data transmission consumes significant amount of energy in large scale wireless sensor networks (WSNs. In such an environment, reducing the in-network communication and distributing the load evenly over the network can reduce the overall energy consumption and maximize the network lifetime significantly. In this work, the aforementioned problem of network lifetime and uneven energy consumption in large scale wireless sensor networks is addressed. This work proposes a hierarchical compressed sensing (HCS scheme to reduce the in-network communication during the data gathering process. Co-related sensor readings are collected via a hierarchical clustering scheme. A compressed sensing (CS based data processing scheme is devised to transmit the data from the source to the sink. The proposed HCS is able to identify the optimal position for the application of CS to achieve reduced and similar number of transmissions on all the nodes in the network. An activity map is generated to validate the reduced and uniformly distributed communication load of the WSN. Based on the number of transmissions per data gathering round, the bit-hop metric model is used to analyse the overall energy consumption. Simulation results validate the efficiency of the proposed method over the existing CS based approaches.

  15. Efficient Vector-Based Forwarding for Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Peng Xie

    2010-01-01

    Full Text Available Underwater Sensor Networks (UWSNs are significantly different from terrestrial sensor networks in the following aspects: low bandwidth, high latency, node mobility, high error probability, and 3-dimensional space. These new features bring many challenges to the network protocol design of UWSNs. In this paper, we tackle one fundamental problem in UWSNs: robust, scalable, and energy efficient routing. We propose vector-based forwarding (VBF, a geographic routing protocol. In VBF, the forwarding path is guided by a vector from the source to the target, no state information is required on the sensor nodes, and only a small fraction of the nodes is involved in routing. To improve the robustness, packets are forwarded in redundant and interleaved paths. Further, a localized and distributed self-adaptation algorithm allows the nodes to reduce energy consumption by discarding redundant packets. VBF performs well in dense networks. For sparse networks, we propose a hop-by-hop vector-based forwarding (HH-VBF protocol, which adapts the vector-based approach at every hop. We evaluate the performance of VBF and HH-VBF through extensive simulations. The simulation results show that VBF achieves high packet delivery ratio and energy efficiency in dense networks and HH-VBF has high packet delivery ratio even in sparse networks.

  16. Graphene Based Electrochemical Sensors and Biosensors: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yuyan; Wang, Jun; Wu, Hong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-05-01

    Graphene, emerging as a true 2-dimensional material, has received increasing attention due to its unique physicochemical properties (high surface area, excellent conductivity, high mechanical strength, and ease of functionalization and mass production). This article selectively reviews recent advances in graphene-based electrochemical sensors and biosensors. In particular, graphene for direct electrochemistry of enzyme, its electrocatalytic activity toward small biomolecules (hydrogen peroxide, NADH, dopamine, etc.), and graphene-based enzyme biosensors have been summarized in more detail; Graphene-based DNA sensing and environmental analysis have been discussed. Future perspectives in this rapidly developing field are also discussed.

  17. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch

    Directory of Open Access Journals (Sweden)

    Tao Huang

    2016-01-01

    Full Text Available Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture.

  18. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch.

    Science.gov (United States)

    Huang, Tao; Yan, Siyu; Yang, Fan; Pan, Tian; Liu, Jiang

    2016-01-19

    Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture.

  19. Artificial intelligence based event detection in wireless sensor networks

    NARCIS (Netherlands)

    Bahrepour, M.

    2013-01-01

    Wireless sensor networks (WSNs) are composed of large number of small, inexpensive devices, called sensor nodes, which are equipped with sensing, processing, and communication capabilities. While traditional applications of wireless sensor networks focused on periodic monitoring, the focus of more

  20. Nano-based sensor for assessment of weaponry structural degradation

    Science.gov (United States)

    Brantley, Christina L.; Edwards, Eugene; Ruffin, Paul B.; Kranz, Michael

    2016-04-01

    Missiles and weaponry-based systems are composed of metal structures that can degrade after prolonged exposure to environmental elements. A particular concern is accumulation of corrosion that generally results from prolonged environmental exposure. Corrosion, defined as the unintended destruction or deterioration of a material due to its interaction with the environment, can negatively affect both equipment and infrastructure. System readiness and safety can be reduced if corrosion is not detected, prevented and managed. The current corrosion recognition methods (Visual, Radiography, Ultrasonics, Eddy Current, and Thermography) are expensive and potentially unreliable. Visual perception is the most commonly used method for determining corrosion in metal. Utilization of an inductance-based sensor system is being proposed as part of the authors' research. Results from this research will provide a more efficient, economical, and non-destructive sensing approach. Preliminary results demonstrate a highly linear degradation within a corrosive environment due to the increased surface area available on the sensor coupon. The inductance of the devices, which represents a volume property of the coupon, demonstrated sensitivity to corrosion levels. The proposed approach allows a direct mass-loss measurement based on the change in the inductance of the coupon when placed in an alternating magnetic field. Prototype devices have demonstrated highly predictable corrosion rates that are easily measured using low-power small electronic circuits and energy harvesting methods to interrogate the sensor. Preliminary testing demonstrates that the device concept is acceptable and future opportunities for use in low power embedded applications are achievable. Key results in this paper include the assessment of typical Army corrosion cost, degradation patterns of varying metal materials, and application of wireless sensors elements.

  1. A fuzzy behaviorist approach to sensor-based robot control

    Energy Technology Data Exchange (ETDEWEB)

    Pin, F.G.

    1996-05-01

    Sensor-based operation of autonomous robots in unstructured and/or outdoor environments has revealed to be an extremely challenging problem, mainly because of the difficulties encountered when attempting to represent the many uncertainties which are always present in the real world. These uncertainties are primarily due to sensor imprecisions and unpredictability of the environment, i.e., lack of full knowledge of the environment characteristics and dynamics. An approach. which we have named the {open_quotes}Fuzzy Behaviorist Approach{close_quotes} (FBA) is proposed in an attempt to remedy some of these difficulties. This approach is based on the representation of the system`s uncertainties using Fuzzy Set Theory-based approximations and on the representation of the reasoning and control schemes as sets of elemental behaviors. Using the FBA, a formalism for rule base development and an automated generator of fuzzy rules have been developed. This automated system can automatically construct the set of membership functions corresponding to fuzzy behaviors. Once these have been expressed in qualitative terms by the user. The system also checks for completeness of the rule base and for non-redundancy of the rules (which has traditionally been a major hurdle in rule base development). Two major conceptual features, the suppression and inhibition mechanisms which allow to express a dominance between behaviors are discussed in detail. Some experimental results obtained with the automated fuzzy, rule generator applied to the domain of sensor-based navigation in aprion unknown environments. using one of our autonomous test-bed robots as well as a real car in outdoor environments, are then reviewed and discussed to illustrate the feasibility of large-scale automatic fuzzy rule generation using the {open_quotes}Fuzzy Behaviorist{close_quotes} concepts.

  2. Using Custom Fiber Bragg Grating-Based Sensors to Monitor Artificial Landslides

    Science.gov (United States)

    Zhang, Qinghua; Wang, Yuan; Sun, Yangyang; Gao, Lei; Zhang, Zhenglin; Zhang, Wenyuan; Zhao, Pengchong; Yue, Yin

    2016-01-01

    Four custom fiber Bragg grating (FBG)-based sensors are developed to monitor an artificial landslide located in Nanjing, China. The sensors are composed of a rod and two FBGs. Based on the strength of the rods, two sensors are referred to as “hard sensors” (Sensor 1 and Sensor 2), the other two are referred to as “soft sensors” (Sensor 3 and Sensor 4). The two FBGs are fixed on each sensor rod at distances of 50 cm and 100 cm from the top of the rod (an upper FBG and a lower FBG). In the experiment presented in this paper, the sensors are installed on a slope on which an artificial landslide is generated through both machine-based and manual excavation. The fiber sensing system consists of the four custom FBG-based sensors, optical fiber, a static fiber grating demodulation instrument (SM125), and a PC with the necessary software. Experimental data was collected in the presence of an artificial landslide, and the results show that the lower FBGs are more sensitive than the upper FBGs for all four of the custom sensors. It was also found that Sensor 2 and Sensor 4 are more capable of monitoring small-scale landslides than Sensor 1 and Sensor 3, and this is mainly due to their placement location with respect to the landslide. The stronger rods used in the hard sensors make them more adaptable to the harsh environments of large landslides. Thus, hard sensors should be fixed near the landslide, while soft sensors should be placed farther away from the landslide. In addition, a clear tendency of strain variation can be detected by the soft sensors, which can be used to predict landslides and raise a hazard alarm. PMID:27598163

  3. Vision Sensor-Based Road Detection for Field Robot Navigation.

    Science.gov (United States)

    Lu, Keyu; Li, Jian; An, Xiangjing; He, Hangen

    2015-11-24

    Road detection is an essential component of field robot navigation systems. Vision sensors play an important role in road detection for their great potential in environmental perception. In this paper, we propose a hierarchical vision sensor-based method for robust road detection in challenging road scenes. More specifically, for a given road image captured by an on-board vision sensor, we introduce a multiple population genetic algorithm (MPGA)-based approach for efficient road vanishing point detection. Superpixel-level seeds are then selected in an unsupervised way using a clustering strategy. Then, according to the GrowCut framework, the seeds proliferate and iteratively try to occupy their neighbors. After convergence, the initial road segment is obtained. Finally, in order to achieve a globally-consistent road segment, the initial road segment is refined using the conditional random field (CRF) framework, which integrates high-level information into road detection. We perform several experiments to evaluate the common performance, scale sensitivity and noise sensitivity of the proposed method. The experimental results demonstrate that the proposed method exhibits high robustness compared to the state of the art.

  4. Vision Sensor-Based Road Detection for Field Robot Navigation

    Directory of Open Access Journals (Sweden)

    Keyu Lu

    2015-11-01

    Full Text Available Road detection is an essential component of field robot navigation systems. Vision sensors play an important role in road detection for their great potential in environmental perception. In this paper, we propose a hierarchical vision sensor-based method for robust road detection in challenging road scenes. More specifically, for a given road image captured by an on-board vision sensor, we introduce a multiple population genetic algorithm (MPGA-based approach for efficient road vanishing point detection. Superpixel-level seeds are then selected in an unsupervised way using a clustering strategy. Then, according to the GrowCut framework, the seeds proliferate and iteratively try to occupy their neighbors. After convergence, the initial road segment is obtained. Finally, in order to achieve a globally-consistent road segment, the initial road segment is refined using the conditional random field (CRF framework, which integrates high-level information into road detection. We perform several experiments to evaluate the common performance, scale sensitivity and noise sensitivity of the proposed method. The experimental results demonstrate that the proposed method exhibits high robustness compared to the state of the art.

  5. Mobility-based Time References for Wireless Sensor Networks

    CERN Document Server

    Sebastiano, Fabio; Makinwa, Kofi A A

    2013-01-01

     This book describes the use of low-power low-cost and extremely small radios to provide essential time reference for wireless sensor networks.  The authors explain how to integrate such radios in a standard CMOS process to reduce both cost and size, while focusing on the challenge of designing a fully integrated time reference for such radios. To enable the integration of the time reference, system techniques are proposed and analyzed, several kinds of integrated time references are reviewed, and mobility-based references are identified as viable candidates to provide the required accuracy at low-power consumption. Practical implementations of a mobility-based oscillator and a temperature sensor are also presented, which demonstrate the required accuracy over a wide temperature range, while drawing 51-uW from a 1.2-V supply in a 65-nm CMOS process. Provides system analysis to understand requirements for time/frequency accuracy in wireless sensor networks; Describes system optimization for time references i...

  6. Noninvasive Temperature Measurement Based on Microwave Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Shoucheng Ding

    2013-01-01

    Full Text Available In this study, we have a research of the noninvasive temperature measurement based on microwave temperature sensor. Moreover, in order to solve the surface temperature measurement for designing microwave temperature sensor, the microwave was issued by the transmitting antenna. Microwave encountered by the measured object to return back to the measured object and then convert it into electrical signals, the use of the quantitative relationship between this signal and input noise temperature to real-time calibration. In order to calculate the antenna brightness temperature and then after signal conditioning circuit, which can show the temperature value, in order to achieve the detection of microwave temperature. Microwave-temperature measurement system hardware based on 89C51 microcontroller consists of the microwave temperature sensor, signal conditioning circuitry and chip control circuit, AD converter circuit and display circuit. The system software is by the main program, the AD conversion routines, subroutines and delay subprogram. The microwave temperature measurement characterize has: without gain fluctuations, without the impact of changes in the noise of the machine, to provide continuous calibration, wide dynamic range.

  7. Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2017-03-01

    Full Text Available In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast, second technique is the improved Hydrocast (improved-Hydrocast, and third one is the cooperative improved Hydrocast (Co-improved Hydrocast. In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR of the received signal is not within the predefined threshold then the maximal ratio combining (MRC is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast.

  8. Miniature fiber optic sensor based on fluorescence energy transfer

    Science.gov (United States)

    Meadows, David L.; Schultz, Jerome S.

    1992-04-01

    Optical fiber biosensors based on fluorescence assays have several distinct advantages when measuring biological analytes such as metabolites, cofactors, toxins, etc. Not only are optical signals immune to electronic interferences, but the polychromatic nature of most fluorochemical assays provides more potentially useful data about the system being studied. One of the most common difficulties normally encountered with optical biosensors is the inability to routinely recalibrate the optical and electronic components of the system throughout the life of the sensor. With this in mind, we present an optical fiber assay system for glucose based on a homogeneous singlet/singlet energy transfer assay along with the electronic instrumentation built to support the sensor system. In the sensor probe, glucose concentrations are indirectly measured from the level of fluorescence quenching caused by the homogeneous competition assay between TRITC labeled concanavalin A (receptor) and FITC labeled Dextran (ligand). The FITC signal is used to indicate glucose concentrations and the TRITC signal is used for internal calibration. Data is also presented on a protein derivatization procedure that was used to prevent aggregation of the receptor protein in solution. Also, a molecular model is described for the singlet/singlet energy transfer interactions that can occur in a model system composed of a monovalent ligand (FITC labeled papain) and a monovalent receptor (TRITC labeled concanavalin A).

  9. Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks.

    Science.gov (United States)

    Javaid, Nadeem; Muhammad; Sher, Arshad; Abdul, Wadood; Niaz, Iftikhar Azim; Almogren, Ahmad; Alamri, Atif

    2017-03-19

    In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs) are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast), second technique is the improved Hydrocast (improved-Hydrocast), and third one is the cooperative improved Hydrocast (Co-improved Hydrocast). In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR) of the received signal is not within the predefined threshold then the maximal ratio combining (MRC) is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast.

  10. CO responses of sensors based on cerium oxide thick films prepared from clustered spherical nanoparticles.

    Science.gov (United States)

    Izu, Noriya; Matsubara, Ichiro; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

    2013-03-08

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nanoparticles have been reported to have a unique structure: The core consists of a cluster of ceria crystallites several nanometers in size. We compared the characteristics of the sensors based on thick films prepared from core-shell nanoparticles with those of sensors based on thick films prepared from conventionally used precipitated nanoparticles. The sensors prepared from the core-shell nanoparticles exhibited a resistance that was ten times greater than that of the sensors prepared from the precipitated nanoparticles. The response values of the gas sensors based on the core-shell nanoparticles also was higher than that of the sensors based on the precipitated nanoparticles. Finally, improvements in sensor response were also noticed after the addition of Au nanoparticles to the thick films used to fabricate the two types of sensors.

  11. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  12. Methane sensor based on palladium/MWNT nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Zhong Ping Li; Yong Guo; Suo Zhu Wu; Shao Min Shuang; Chuan Dong

    2009-01-01

    Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO) glass substrates.A linear response for methane was obtained in the range of 0-16% (v/v) with a detection limit of 0.167% (v/v) and R.S.D.of 4.1%.After 100 times sensing or stable stored more than 12 months in atmosphere,unconspicuous measurable decrease was observed.The response time was less than 60 s at room temperature and ambient pressure.Some common potential interferents in samples such as N2,CO,CO2,ethane,propane,pentane,methanol,ethanol,H2 and NH3 were investigated and all the effects were less than 5% on the response for 3.0% (v/v) methane.The sensor was applied to methane determinations in man-made gas samples,the results are satisfied.

  13. An Optical Fibre-Based Sensor for Respiratory Monitoring

    Directory of Open Access Journals (Sweden)

    Marek Krehel

    2014-07-01

    Full Text Available In this paper, a textile-based respiratory sensing system is presented. Highly flexible polymeric optical fibres (POFs that react to applied pressure were integrated into a carrier fabric to form a wearable sensing system. After the evaluation of different optical fibres, different setups were compared. To demonstrate the feasibility of such a wearable sensor, the setup featuring the best performance was placed on the human torso, and thus it was possible to measure the respiratory rate. Furthermore, we show that such a wearable system enables to keep track of the way of breathing (diaphragmatic, upper costal and mixed when the sensor is placed at different positions of the torso. A comparison of the results with the output of some commercial respiratory measurements devices confirmed the utility of such a monitoring device.

  14. Human Ensuing Self-balancing Automaton Based on Motion Sensor

    Directory of Open Access Journals (Sweden)

    R. Kishhanth

    2014-10-01

    Full Text Available Travel has become one among rudimentary necessities for every individual. Handling baggage plays an important role while travelling and for typical nomads it is cumbersome when heavy. With the proposed concept which will be dealt in this study, the baggage need not be pulled by us; it just follows us detecting our presence. Hence, the baggage is simply nothing but a robot. Prototype of motion sensor based human following robot that can balance itself in two wheels, thus behaving as a suitcase with intelligence and hence named Smart Suitcase. Concept of inverted pendulum helps in balancing. Regenerative power saving is established, when on its normal movement by the user wherein the saved power can be used for charging mobiles, laptops, torch lights etc. (low voltage applications. Passive infrared sensors fed with inbuilt intelligence in responding only to human presence helps this robot get even smarter.

  15. Optical fiber temperature sensor based on wavelength-dependent detection

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li(李志刚); Zhenhui Du(杜振辉); Baoguang Wang(王宝光); Chengzhi Jiang(蒋诚志)

    2004-01-01

    Semiconductor fiber temperature sensors have been used widely in many fields, but most of them pick up temperature by measuring the optical intensity of certain fixed narrow-band in absorption spectrum.Furthermore, they are sensitive to the loss of optical intensity and the fluctuation of light source power.The novel temperature measurement system proposed in this paper is based on the semiconductor absorption theory and the spectral analysis of method. To measure temperature, the sensor model detects not the certain narrow-band spectrum but the most spectra of the optical absorption edge. Therefore the measurement accuracy and the stability can be improved greatly. Experimental results are in agreement with theoretical analysis results perfectly.

  16. Observer Based Detection of Sensor Faults in Wind Turbines

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Nielsen, R.

    2009-01-01

    An observer based scheme is proposed to detect sensor faults in wind  turbines. In the example used for the proposed scheme the wind turbine  drive train is considered. A model of the drive train is used to  design the observer, and in this model the wind speed is an important  input, however......, if an unknown input observer the fault detection  scheme can be non dependent on the actual wind speed. The scheme  is validated on data from a more advanced and detailed simulation  model. The proposed scheme detects the sensor faults a few samples  after the beginning of the faults....

  17. Numeral eddy current sensor modelling based on genetic neural network

    Institute of Scientific and Technical Information of China (English)

    Yu A-Long

    2008-01-01

    This paper presents a method used to the numeral eddy current sensor modelling based on the genetic neural network to settle its nonlinear problem. The principle and algorithms of genetic neural network are introduced. In this method, the nonlinear model parameters of the numeral eddy current sensor are optimized by genetic neural network (GNN) according to measurement data. So the method remains both the global searching ability of genetic algorithm and the good local searching ability of neural network. The nonlinear model has the advantages of strong robustness,on-line modelling and high precision.The maximum nonlinearity error can be reduced to 0.037% by using GNN.However, the maximum nonlinearity error is 0.075% using the least square method.

  18. Identity-based Trusted Authentication in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yusnani Mohd Yussoff

    2012-05-01

    Full Text Available Secure communication mechanisms in Wireless Sensor Networks (WSNs have been widely deployed to ensure confidentiality, authenticity and integrity of the nodes and data. Recently many WSNs applications rely on trusted communication to ensure large user acceptance. Indeed, the trusted relationship thus far can only be achieved through Trust Management System (TMS or by adding external security chip on the WSN platform. In this study an alternative mechanism is proposed to accomplish trusted communication between sensors based on the principles defined by Trusted Computing Group (TCG. The results of other related study have also been analyzed to validate and support our findings. Finally the proposed trusted mechanism is evaluated for the potential application on resource constraint devices by quantifying their power consumption on selected major processes. The result proved the proposed scheme can establish trust in WSN with less computation and communication and most importantly eliminating the need for neighboring evaluation for TMS or relying on external security chip.

  19. Polymer-Based Self-Standing Flexible Strain Sensor

    Directory of Open Access Journals (Sweden)

    Fernando Martinez

    2010-01-01

    Full Text Available The design and characterization of polymer-based self-standing flexible strain sensors are presented in this work. Properties as lightness and flexibility make them suitable for the measurement of strain in applications related with wearable electronics such as robotics or rehabilitation devices. Several sensors have been fabricated to analyze the influence of size and electrical conductivity on their behavior. Elongation and applied charge were precisely controlled in order to measure different parameters as electrical resistance, gauge factor (GF, hysteresis, and repeatability. The results clearly show the influence of size and electrical conductivity on the gauge factor, but it is also important to point out the necessity of controlling the hysteresis and repeatability of the response for precision-demanding applications.

  20. A Peptoid-Based Fluorescent Sensor for Cyanide Detection

    Directory of Open Access Journals (Sweden)

    Bumhee Lim

    2016-03-01

    Full Text Available Peptoids, N-substituted glycine oligomers, are versatile peptidomimetics with diverse biomedical applications. However, strategies to the development of novel fluorescent peptoids as chemical sensors have not been extensively explored, yet. Here, we synthesized a novel peptoid-based fluorescent probe in which a coumarin moiety was incorporated via copper(I-catalyzed azide-alkyne cycloaddition reaction. Fluorescence of the newly generated coumarin-peptoid was dramatically quenched upon coordination of the Cu2+ ion, and the resulting peptoid-Cu2+ complex exhibited significant Turn-ON fluorescence following the addition of CN−. The rapid and reversible response, combined with cyanide selectivity of the synthesized peptoid, reflects a multistep photo-process and supports its utility as a new type of CN− sensor.

  1. Measurement system for nitrous oxide based on amperometric gas sensor

    Science.gov (United States)

    Siswoyo, S.; Persaud, K. C.; Phillips, V. R.; Sneath, R.

    2017-03-01

    It has been well known that nitrous oxide is an important greenhouse gas, so monitoring and control of its concentration and emission is very important. In this work a nitrous oxide measurement system has been developed consisting of an amperometric sensor and an appropriate lab-made potentiostat that capable measuring picoampere current ranges. The sensor was constructed using a gold microelectrode as working electrode surrounded by a silver wire as quasi reference electrode, with tetraethyl ammonium perchlorate and dimethylsulphoxide as supporting electrolyte and solvent respectively. The lab-made potentiostat was built incorporating a transimpedance amplifier capable of picoampere measurements. This also incorporated a microcontroller based data acquisition system, controlled by a host personal computer using a dedicated computer program. The system was capable of detecting N2O concentrations down to 0.07 % v/v.

  2. Amylin Detection with a Miniature Optical-Fiber Based Sensor

    Science.gov (United States)

    Liu, Zhaowen; Ann, Matsko; Hughes, Adam; Reeves, Mark

    We present results of a biosensor based on shifts in the localized surface plasmon resonance of gold nanoparticles self-assembled on the end of an optical fiber. This system allows for detection of protein expression in low sensing volumes and for scanning in cell cultures and tissue samples. Positive and negative controls were done using biotin/avidin and the BSA/Anti-BSA system. These demonstrate that detection is specific and sensitive to nanomolar levels. Sensing of amylin, an important protein for pancreatic function, was performed with polyclonal and monoclonal antibodies. The measured data demonstrates the difference in sensitivity to the two types of antibodies, and titration experiments establish the sensitivity of the sensor. Further experiments demonstrate that the sensor can be regenerated and then reused.

  3. Silicon nanowire based Pirani sensor for vacuum measurements

    Science.gov (United States)

    Brun, T.; Mercier, D.; Koumela, A.; Marcoux, C.; Duraffourg, L.

    2012-10-01

    Nano-Pirani vacuum gauges based on the physical properties of suspended silicon nanowires have been fabricated and characterized. With a 160 × 260 nm2 rectangular section and a 5.2 μm length, they are 50 times smaller than the smallest silicon based vacuum sensor and they exhibits much lower power consumption. The nano-Pirani constructed are capable of measuring pressures from 50 to 105 Pa. Moreover, their fabrication is compatible with microelectronic and micromachining fabrication techniques making them suitable for in-situ monitoring of micro and nano systems vacuum packaging.

  4. Relative Distance Based Routing for Delay Tolerant Mobile Sensor Network

    Directory of Open Access Journals (Sweden)

    Jieyan Liu

    2011-08-01

    Full Text Available Delay Tolerant Mobile Sensor Network (DTMSN is the network for pervasive information gathering. Traditional static routing approaches may not fit for DTMSN due to its intermittent connectivity. This paper proposes an relative distance based routing (RDBR strategy for DTMSN, in which nodes delivery probabilities are calculated and updated according to the latest relative distance from themselves to the sink node, and data are delivered according to nodes’ delivery probabilities. RDBR also introduces a redundant copies controlling technique based on the message priority. Simulation results show that RDBR achieves a well tradeoff between the data delivery ratio/delay and the delivery overhead.

  5. Neurochip Based on Light-addressable Potentiometric Sensor

    Institute of Scientific and Technical Information of China (English)

    Qingjun Liu; Hua Cai; Ying Xu; Lifeng Qin; Lijiang Wang; Ping Wang

    2006-01-01

    A novel neurochip based on light addressable potentiometric sensor (LAPS) is designed. Using its light addressable characteristic. The problems of the limitations of restricted discrete active sites of current neurochips, such as microelectrode array and field effect transistor array can be settled easily. Based on the theoretical analysis of the interface between cells and LAPS, spontaneously discharges of hippocampal neurons induced by Mg2+-free media treatment were recorded by LAPS. The results demonstrate that this kind of neurochip has potential to monitor electrophysiology of cultured cells in a non-invasive way.

  6. EEG sensor based classification for assessing psychological stress.

    Science.gov (United States)

    Begum, Shahina; Barua, Shaibal

    2013-01-01

    Electroencephalogram (EEG) reflects the brain activity and is widely used in biomedical research. However, analysis of this signal is still a challenging issue. This paper presents a hybrid approach for assessing stress using the EEG signal. It applies Multivariate Multi-scale Entropy Analysis (MMSE) for the data level fusion. Case-based reasoning is used for the classification tasks. Our preliminary result indicates that EEG sensor based classification could be an efficient technique for evaluation of the psychological state of individuals. Thus, the system can be used for personal health monitoring in order to improve users health.

  7. Graphene Electronic Device Based Biosensors and Chemical Sensors

    Science.gov (United States)

    Jiang, Shan

    Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their

  8. Sensors on speaking terms: Schedule-based medium access control protocols for wireless sensor networks

    NARCIS (Netherlands)

    van Hoesel, L.F.W.

    2007-01-01

    Wireless sensor networks make the previously unobservable, observable. The basic idea behind these networks is straightforward: all wires are cut in traditional sensing systems and the sensors are equipped with batteries and radio's to virtually restore the cut wires. The resulting sensors can be pl

  9. Sensors on speaking terms : schedule-based medium access control protocols for wireless sensor networks

    NARCIS (Netherlands)

    Hoesel, van Lodewijk Frans Willem

    2007-01-01

    Wireless sensor networks make the previously unobservable, observable. The basic idea behind these networks is straightforward: all wires are cut in traditional sensing systems and the sensors are equipped with batteries and radio’s to virtually restore the cut wires. The resulting sensors can be pl

  10. Conductive fiber-based ultrasensitive textile pressure sensor for wearable electronics.

    Science.gov (United States)

    Lee, Jaehong; Kwon, Hyukho; Seo, Jungmok; Shin, Sera; Koo, Ja Hoon; Pang, Changhyun; Son, Seungbae; Kim, Jae Hyung; Jang, Yong Hoon; Kim, Dae Eun; Lee, Taeyoon

    2015-04-17

    A flexible and sensitive textile-based pressure sensor is developed using highly conductive fibers coated with dielectric rubber materials. The pressure sensor exhibits superior sensitivity, very fast response time, and high stability, compared with previous textile-based pressure sensors. By using a weaving method, the pressure sensor can be applied to make smart gloves and clothes that can control machines wirelessly as human-machine interfaces.

  11. A Task Allocation Algorithm Based on Score Incentive Mechanism for Wireless Sensor Networks

    OpenAIRE

    Feng Wang; Guangjie Han; Jinfang Jiang; Wei Li; Lei Shu

    2015-01-01

    A wireless sensor network (WSN) consists of many resource constraint sensor nodes, which are always deployed in unattended environment. Therefore, the sensor nodes are vulnerable to failure and malicious attacks. The failed nodes have a heavily negative impact on WSNs’ real-time services. Therefore, we propose a task allocation algorithm based on score incentive mechanism (TASIM) for WSNs. In TASIM, the score is proposed to reward or punish sensor nodes’ task execution in cluster-based WSNs, ...

  12. Zone Based Routing Protocol for Homogeneous Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    S. Taruna

    2011-09-01

    Full Text Available Wireless Sensor Networks, are made of low-cost, low -power, small in size, and multifunctional sensor nodes. The efficient energy utilization is one of t he important performance factors for wireless senso r networks survivability be-cause nodes operate with limited battery power. In this paper we propose and analyze a new approach of zone based clustering hea d selection algorithm for wireless sensor network o f homogeneous nodes. Nodes in the network are uniform ly distributed. In this clustering algorithm, netwo rk performance is improved by selecting cluster heads on the basis of the residual energy of existing clu ster heads, and nearest hop distance of the node. In thi s paper we evaluate various performance metrics lik e energy consumption, network life time, number of ch annel heads metrics in each round and compare these with respect to random algorithm i.e. LEACH. We con clude that proposed protocol effectively extends th e network lifetime without degrading the other critic al overheads and perform-ance metrics.

  13. Organic electronics based pressure sensor towards intracranial pressure monitoring

    Science.gov (United States)

    Rai, Pratyush; Varadan, Vijay K.

    2010-04-01

    The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

  14. Sphere-based calibration method for trinocular vision sensor

    Science.gov (United States)

    Lu, Rui; Shao, Mingwei

    2017-03-01

    A new method to calibrate a trinocular vision sensor is proposed and two main tasks are finished in this paper, i.e. to determine the transformation matrix between each two cameras and the trifocal tensor of the trinocular vision sensor. A flexible sphere target with several spherical circles is designed. As the isotropy of a sphere, trifocal tensor of the three cameras can be determined exactly from the feature on the sphere target. Then the fundamental matrix between each two cameras can be obtained. Easily, compatible rotation matrix and translation matrix can be deduced base on the singular value decomposition of the fundamental matrix. In our proposed calibration method, image points are not requested one-to-one correspondence. When image points locates in the same feature are obtained, the transformation matrix between each two cameras with the trifocal tensor of trinocular vision sensor can be determined. Experiment results show that the proposed calibration method can obtain precise results, including measurement and matching results. The root mean square error of distance is 0.026 mm with regard to the view field of about 200×200 mm and the feature matching of three images is strict. As a sphere projection is not concerned with its orientation, the calibration method is robust and with an easy operation. Moreover, our calibration method also provides a new approach to obtain the trifocal tensor.

  15. Optical-Based Artificial Palpation Sensors for Lesion Characterization

    Directory of Open Access Journals (Sweden)

    Hee-Jun Park

    2013-08-01

    Full Text Available Palpation techniques are widely used in medical procedures to detect the presence of lumps or tumors in the soft breast tissues. Since these procedures are very subjective and depend on the skills of the physician, it is imperative to perform detailed a scientific study in order to develop more efficient medical sensors to measure and generate palpation parameters. In this research, we propose an optical-based, artificial palpation sensor for lesion characterization. This has been developed using a multilayer polydimethylsiloxane optical waveguide. Light was generated at the critical angle to reflect totally within the flexible and transparent waveguide. When a waveguide was compressed by an external force, its contact area would deform and cause the light to scatter. The scattered light was captured by a high-resolution camera and saved as an image format. To test the performance of the proposed system, we used a realistic tissue phantom with embedded hard inclusions. The experimental results show that the proposed sensor can detect inclusions and provide the relative value of size, depth, and Young’s modulus of an inclusion.

  16. Recent developments in nanostructure based electrochemical glucose sensors.

    Science.gov (United States)

    Zaidi, Shabi Abbas; Shin, Jae Ho

    2016-01-01

    Diabetes is a major health problem causing 4 million deaths each year and 171 million people suffering worldwide. Although there is no cure for diabetes, nevertheless, the blood glucose level of diabetic patients should be monitored tightly to avoid further complications. Thus, monitoring of glucose in blood has become an inevitable need leading to fabrication of accurate and sensitive advanced blood sugar detection devices for clinical diagnosis and personal care. It led to the development of enzymatic glucose sensing approach. Later on, various types of nanostructures have been utilized owing to their high surface area, great stability, and cost effectiveness for the fabrication of enzymatic as well as for nonenzymatic glucose sensing approach. This work reviews on both categories, however it is not intended to discuss all the research reports published regarding nanostructure based enzymatic and nonenzymatic approaches between mid-2010 and mid-2015. We, do, however, focused to describe the details of many substantial articles explaining the design of sensors, and utilities of the prepared sensors, so that readers might get the principles behind such devices and relevant detection strategies. This work also focuses on biocompatibility and toxicity of nanomaterials as well as provides a critical opinion and discussions about misconceptions in glucose sensors.

  17. Optimal sensor placement using FRFs-based clustering method

    Science.gov (United States)

    Li, Shiqi; Zhang, Heng; Liu, Shiping; Zhang, Zhe

    2016-12-01

    The purpose of this work is to develop an optimal sensor placement method by selecting the most relevant degrees of freedom as actual measure position. Based on observation matrix of a structure's frequency response, two optimal criteria are used to avoid the information redundancy of the candidate degrees of freedom. By using principal component analysis, the frequency response matrix can be decomposed into principal directions and their corresponding singular. A relatively small number of principal directions will maintain a system's dominant response information. According to the dynamic similarity of each degree of freedom, the k-means clustering algorithm is designed to classify the degrees of freedom, and effective independence method deletes the sensors which are redundant of each cluster. Finally, two numerical examples and a modal test are included to demonstrate the efficient of the derived method. It is shown that the proposed method provides a way to extract sub-optimal sets and the selected sensors are well distributed on the whole structure.

  18. Technology towards a SAW based phononic crystal sensor

    Science.gov (United States)

    Schmidt, Marc-Peter; Oseev, Aleksandr; Lucklum, Ralf; Hirsch, Soeren

    2015-05-01

    Phononic crystals (PnC) with a specifically designed defect have been recently introduced as novel sensor platform. Those sensors feature a band gap covering the typical input span of the measurand as well as a narrow transmission peak within the band gap where the frequency of maximum transmission is governed by the measurand. This innovative approach has been applied for determination of compounds in liquids [1]. Improvement of sensitivity requires higher probing frequencies around 100 MHz and above. In this range surface acoustic wave devices (SAW) provide a promising basis for PnC based microsensors [2]. The respective feature size of the PnC SAW sensor has dimensions in the range of 100 μm and below. Whereas those dimensions are state of the art for common MEMS materials, etching of holes and cavities in piezoelectric materials having an aspect ratio diameter/depth is challenging. In this contribution we describe an improved technological process to manufacture considerably deep and uniform phononic crystal structures inside of SAW substrates.

  19. An information-based approach to decentralized multiplatform sensor management

    Science.gov (United States)

    Kreucher, Christopher M.; Kastella, Keith D.; Wegrzyn, John W.; Rickenbach, Brent L.

    2006-05-01

    This paper describes a decentralized low communication approach to multi-platform sensor management. The method is based on a physicomimetic relaxation to a joint information theoretic optimization, which inherits the benefits of information theoretic scheduling while maintaining tractability. The method uses only limited message passing, only neighboring nodes communicate, and each node makes its own sensor management decisions. We show by simulation that the method allows a network of sensor nodes to automatically self organize and perform a global task. In the model problem, a group of unmanned aerial vehicles (UAVs) hover above a ground surveillance region. An initially unknown number of moving ground targets inhabit the region. Each UAV is capable of making noisy measurements of the patch of ground directly below, which provide evidence as to the presence or absence of targets in that sub-region. The goal of the network is to determine the number of targets and their individual states (positions and velocities) in the entire surveillance region through repeated interrogation by the individual nodes. As the individual nodes can only see a small portion of the ground, they must move in a manner that is both responsive to measurements and coordinated with other nodes.

  20. A magnonic gas sensor based on magnetic nanoparticles.

    Science.gov (United States)

    Matatagui, D; Kolokoltsev, O V; Qureshi, N; Mejía-Uriarte, E V; Saniger, J M

    2015-06-07

    In this paper, we propose an innovative, simple and inexpensive gas sensor based on the variation in the magnetic properties of nanoparticles due to their interaction with gases. To measure the nanoparticle response a magnetostatic spin wave (MSW) tunable oscillator has been developed using an yttrium iron garnet (YIG) epitaxial thin film as a delay line (DL). The sensor has been prepared by coating a uniform layer of CuFe2O4 nanoparticles on the YIG film. The unperturbed frequency of the oscillator is determined by a bias magnetic field, which is applied parallel to the YIG film and perpendicularly to the wave propagation direction. In this device, the total bias magnetic field is the superposition of the field of a permanent magnet and the field associated with the layer of magnetic nanoparticles. The perturbation produced in the magnetic properties of the nanoparticle layer due to its interaction with gases induces a frequency shift in the oscillator, allowing the detection of low concentrations of gases. In order to demonstrate the ability of the sensor to detect gases, it has been tested with organic volatile compounds (VOCs) which have harmful effects on human health, such as dimethylformamide, isopropanol and ethanol, or the aromatic hydrocarbons like benzene, toluene and xylene more commonly known by its abbreviation (BTX). All of these were detected with high sensitivity, short response time, and good reproducibility.