WorldWideScience

Sample records for two-branch microfluidic network

  1. Microfluidic networks embedded in a printed circuit board

    Science.gov (United States)

    Dong, Liangwei; Hu, Yueli

    2017-07-01

    In order to improve the robustness of microfluidic networks in printed circuit board (PCB)-based microfluidic platforms, a new method was presented. A pattern in a PCB was formed using hollowed-out technology. Polydimethylsiloxane was partly filled in the hollowed-out fields after mounting an adhesive tape on the bottom of the PCB, and solidified in an oven. Then, microfluidic networks were built using soft lithography technology. Microfluidic transportation and dilution operations were demonstrated using the fabricated microfluidic platform. Results show that this method can embed microfluidic networks into a PCB, and microfluidic operations can be implemented in the microfluidic networks embedded into the PCB.

  2. Simulation of Droplet Trains in Microfluidic Networks

    CERN Document Server

    Behzad, Mehran Djalali; Ejtehadi, Mohammad Reza

    2009-01-01

    In this work we show that in a microfluidic network and in low Reynolds numbers a system can be irreversible because of hysteresis effects.The network, which is employed in our simulations, is taken from recent experiments. The network consists of one loop connected to input and output pipes. A train of droplets enter the system at a uniform rate, but they may leave it in different patterns, e.g. periodic or even chaotic. The out put pattern depends on the time interval among the incoming droplets as well as the network geometry and for some parameters the system is not reversible.

  3. Coding/decoding and reversibility of droplet trains in microfluidic networks.

    Science.gov (United States)

    Fuerstman, Michael J; Garstecki, Piotr; Whitesides, George M

    2007-02-09

    Droplets of one liquid suspended in a second, immiscible liquid move through a microfluidic device in which a channel splits into two branches that reconnect downstream. The droplets choose a path based on the number of droplets that occupy each branch. The interaction among droplets in the channels results in complex sequences of path selection. The linearity of the flow through the microchannels, however, ensures that the behavior of the system can be reversed. This reversibility makes it possible to encrypt and decrypt signals coded in the intervals between droplets. The encoding/decoding device is a functional microfluidic system that requires droplets to navigate a network in a precise manner without the use of valves, switches, or other means of external control.

  4. Integrated microfluidic platforms for investigating neuronal networks

    Science.gov (United States)

    Kim, Hyung Joon

    This dissertation describes the development and application of integrated microfluidics-based assay platforms to study neuronal activities in the nervous system in-vitro. The assay platforms were fabricated using soft lithography and micro/nano fabrication including microfluidics, surface patterning, and nanomaterial synthesis. The use of integrated microfluidics-based assay platform allows culturing and manipulating many types of neuronal tissues in precisely controlled microenvironment. Furthermore, they provide organized multi-cellular in-vitro model, long-term monitoring with live cell imaging, and compatibility with molecular biology techniques and electrophysiology experiment. In this dissertation, the integrated microfluidics-based assay platforms are developed for investigation of neuronal activities such as local protein synthesis, impairment of axonal transport by chemical/physical variants, growth cone path finding under chemical/physical cues, and synaptic transmission in neuronal circuit. Chapter 1 describes the motivation, objectives, and scope for developing in-vitro platform to study various neuronal activities. Chapter 2 introduces microfluidic culture platform for biochemical assay with large-scale neuronal tissues that are utilized as model system in neuroscience research. Chapter 3 focuses on the investigation of impaired axonal transport by beta-Amyloid and oxidative stress. The platform allows to control neuronal processes and to quantify mitochondrial movement in various regions of axons away from applied drugs. Chapter 4 demonstrates the development of microfluidics-based growth cone turning assay to elucidate the mechanism underlying axon guidance under soluble factors and shear flow. Using this platform, the behaviors of growth cone of mammalian neurons are verified under the gradient of inhibitory molecules and also shear flow in well-controlled manner. In Chapter 5, I combine in-vitro multicellular model with microfabricated MEA

  5. Evaporative Lithography in Open Microfluidic Channel Networks

    KAUST Repository

    Lone, Saifullah

    2017-02-24

    We demonstrate a direct capillary-driven method based on wetting and evaporation of various suspensions to fabricate regular two-dimensional wires in an open microfluidic channel through continuous deposition of micro- or nanoparticles under evaporative lithography, akin to the coffee-ring effect. The suspension is gently placed in a loading reservoir connected to the main open microchannel groove on a PDMS substrate. Hydrophilic conditions ensure rapid spreading of the suspension from the loading reservoir to fill the entire channel length. Evaporation during the spreading and after the channel is full increases the particle concentration toward the end of the channel. This evaporation-induced convective transport brings particles from the loading reservoir toward the channel end where this flow deposits a continuous multilayered particle structure. The particle deposition front propagates backward over the entire channel length. The final dry deposit of the particles is thereby much thicker than the initial volume fraction of the suspension. The deposition depth is characterized using a 3D imaging profiler, whereas the deposition topography is revealed using a scanning electron microscope. The patterning technology described here is robust and passive and hence operates without an external field. This work may well become a launching pad to construct low-cost and large-scale thin optoelectronic films with variable thicknesses and interspacing distances.

  6. Evaporative Lithography in Open Microfluidic Channel Networks.

    Science.gov (United States)

    Lone, Saifullah; Zhang, Jia Ming; Vakarelski, Ivan U; Li, Er Qiang; Thoroddsen, Sigurdur T

    2017-03-13

    We demonstrate a direct capillary-driven method based on wetting and evaporation of various suspensions to fabricate regular two-dimensional wires in an open microfluidic channel through continuous deposition of micro- or nanoparticles under evaporative lithography, akin to the coffee-ring effect. The suspension is gently placed in a loading reservoir connected to the main open microchannel groove on a PDMS substrate. Hydrophilic conditions ensure rapid spreading of the suspension from the loading reservoir to fill the entire channel length. Evaporation during the spreading and after the channel is full increases the particle concentration toward the end of the channel. This evaporation-induced convective transport brings particles from the loading reservoir toward the channel end where this flow deposits a continuous multilayered particle structure. The particle deposition front propagates backward over the entire channel length. The final dry deposit of the particles is thereby much thicker than the initial volume fraction of the suspension. The deposition depth is characterized using a 3D imaging profiler, whereas the deposition topography is revealed using a scanning electron microscope. The patterning technology described here is robust and passive and hence operates without an external field. This work may well become a launching pad to construct low-cost and large-scale thin optoelectronic films with variable thicknesses and interspacing distances.

  7. Microfluidics without pumps: reinventing the T-sensor and H-filter in paper networks

    Science.gov (United States)

    Lutz, Barry; Fu, Elain; Kauffman, Peter; Stevens, Dean Y.; Yager, Paul

    2016-01-01

    Conventional microfluidic devices typically require highly precise pumps or pneumatic control systems, which add considerable cost and the requirement for power. These restrictions have limited the adoption of microfluidic technologies for point-of-care (POC) applications. Paper networks provide an extremely low-cost and pumpless alternative to conventional microfluidic devices by generating fluid tranport through capilarity. We revisit well-known microfluidic devices for hydrodynamic focusing, sized-based extraction of molecules from complex mixtures, micromixing, and dilution, and demonstrate that paper-based devices can replace their expensive conventional microfluidic counterparts. PMID:20680208

  8. Dynamics of blood flow in a microfluidic ladder network

    Science.gov (United States)

    Maddala, Jeevan; Zilberman-Rudenko, Jevgenia; McCarty, Owen

    The dynamics of a complex mixture of cells and proteins, such as blood, in perturbed shear flow remains ill-defined. Microfluidics is a promising technology for improving the understanding of blood flow under complex conditions of shear; as found in stent implants and in tortuous blood vessels. We model the fluid dynamics of blood flow in a microfluidic ladder network with dimensions mimicking venules. Interaction of blood cells was modeled using multiagent framework, where cells of different diameters were treated as spheres. This model served as the basis for predicting transition regions, collision pathways, re-circulation zones and residence times of cells dependent on their diameters and device architecture. Based on these insights from the model, we were able to predict the clot formation configurations at various locations in the device. These predictions were supported by the experiments using whole blood. To facilitate platelet aggregation, the devices were coated with fibrillar collagen and tissue factor. Blood was perfused through the microfluidic device for 9 min at a physiologically relevant venous shear rate of 600 s-1. Using fluorescent microscopy, we observed flow transitions near the channel intersections and at the areas of blood flow obstruction, which promoted larger thrombus formation. This study of integrating model predictions with experimental design, aids in defining the dynamics of blood flow in microvasculature and in development of novel biomedical devices.

  9. Fungi use efficient algorithms for the exploration of microfluidic networks.

    Science.gov (United States)

    Hanson, Kristi L; Nicolau, Dan V; Filipponi, Luisa; Wang, Lisen; Lee, Abraham P; Nicolau, Dan V

    2006-10-01

    Fungi, in particular, basidiomycetous fungi, are very successful in colonizing microconfined mazelike networks (for example, soil, wood, leaf litter, plant and animal tissues), a fact suggesting that they may be efficient solving agents of geometrical problems. We therefore evaluated the growth behavior and optimality of fungal space-searching algorithms in microfluidic mazes and networks. First, we found that fungal growth behavior was indeed strongly modulated by the geometry of microconfinement. Second, the fungus used a complex growth and space-searching strategy comprising two algorithmic subsets: 1) long-range directional memory of individual hyphae and 2) inducement of branching by physical obstruction. Third, stochastic simulations using experimentally measured parameters showed that this strategy maximizes both survival and biomass homogeneity in microconfined networks and produces optimal results only when both algorithms are synergistically used. This study suggests that even simple microorganisms have developed adequate strategies to solve nontrivial geometrical problems.

  10. Microbridge structures for uniform interval control of flowing droplets in microfluidic networks

    OpenAIRE

    Lee, Do-Hyun; Lee, Wonhye; Um, Eujin; Park, Je-Kyun

    2011-01-01

    Precise temporal control of microfluidic droplets such as synchronization and combinatorial pairing of droplets is required to achieve a variety range of chemical and biochemical reactions inside microfluidic networks. Here, we present a facile and robust microfluidic platform enabling uniform interval control of flowing droplets for the precise temporal synchronization and pairing of picoliter droplets with a reagent. By incorporating microbridge structures interconnecting the droplet-carryi...

  11. Microfabrication of cylindrical microfluidic channel networks for microvascular research.

    Science.gov (United States)

    Huang, Zhouchun; Li, Xiang; Martins-Green, Manuela; Liu, Yuxin

    2012-10-01

    Current methods for formation of microvascular channel scaffolds are limited with non-circular channel cross-sections, complicated fabrication, and less flexibility in microchannel network design. To address current limitations in the creation of engineered microvascular channels with complex three-dimensional (3-D) geometries in the shape of microvessels, we have developed a reproducible, cost-effective, and flexible micromanufacturing process combined with photolithographic reflowable photoresist and soft lithography techniques to fabricate cylindrical microchannel and networks. A positive reflowable photoresist AZ P4620 was used to fabricate a master microchannel mold with semi-circular cross-sections. By the alignment and bonding of two polydimethylsiloxane (PDMS) microchannels replicated from the master mold together, a cylindrical microchannel or microchannel network was created. Further examination of the channel dimensions and surface profiles at different branching levels showed that the shape of the microfluidic channel was well approximated by a semi-circular surface, and a multi-level, multi-depth channel network was created. In addition, a computational fluidic dynamics (CFD) model was used to simulate shear flows and corresponding pressure distributions inside of the microchannel and channel network based on the dimensions of the fabricated channels. The fabricated multi-depth cylindrical microchannel network can provide platforms for the investigation of microvascular cells growing inside of cylindrical channels under shear flows and lumen pressures, and work as scaffolds for the investigation of morphogenesis and tubulogenesis.

  12. Design of pressure-driven microfluidic networks using electric circuit analogy.

    Science.gov (United States)

    Oh, Kwang W; Lee, Kangsun; Ahn, Byungwook; Furlani, Edward P

    2012-02-07

    This article reviews the application of electric circuit methods for the analysis of pressure-driven microfluidic networks with an emphasis on concentration- and flow-dependent systems. The application of circuit methods to microfluidics is based on the analogous behaviour of hydraulic and electric circuits with correlations of pressure to voltage, volumetric flow rate to current, and hydraulic to electric resistance. Circuit analysis enables rapid predictions of pressure-driven laminar flow in microchannels and is very useful for designing complex microfluidic networks in advance of fabrication. This article provides a comprehensive overview of the physics of pressure-driven laminar flow, the formal analogy between electric and hydraulic circuits, applications of circuit theory to microfluidic network-based devices, recent development and applications of concentration- and flow-dependent microfluidic networks, and promising future applications. The lab-on-a-chip (LOC) and microfluidics community will gain insightful ideas and practical design strategies for developing unique microfluidic network-based devices to address a broad range of biological, chemical, pharmaceutical, and other scientific and technical challenges.

  13. Coding/Decoding and Reversibility of Droplet Trains in Microfluidic Networks

    National Research Council Canada - National Science Library

    Michael J. Fuerstman; Piotr Garstecki; George M. Whitesides

    2007-01-01

    .... The encoding/decoding device is a functional microfluidic system that requires droplets to navigate a network in a precise manner without the use of valves, switches, or other means of external control.

  14. Numerical design and optimization of hydraulic resistance and wall shear stress inside pressure-driven microfluidic networks.

    Science.gov (United States)

    Damiri, Hazem Salim; Bardaweel, Hamzeh Khalid

    2015-11-07

    Microfluidic networks represent the milestone of microfluidic devices. Recent advancements in microfluidic technologies mandate complex designs where both hydraulic resistance and pressure drop across the microfluidic network are minimized, while wall shear stress is precisely mapped throughout the network. In this work, a combination of theoretical and modeling techniques is used to construct a microfluidic network that operates under minimum hydraulic resistance and minimum pressure drop while constraining wall shear stress throughout the network. The results show that in order to minimize the hydraulic resistance and pressure drop throughout the network while maintaining constant wall shear stress throughout the network, geometric and shape conditions related to the compactness and aspect ratio of the parent and daughter branches must be followed. Also, results suggest that while a "local" minimum hydraulic resistance can be achieved for a geometry with an arbitrary aspect ratio, a "global" minimum hydraulic resistance occurs only when the aspect ratio of that geometry is set to unity. Thus, it is concluded that square and equilateral triangular cross-sectional area microfluidic networks have the least resistance compared to all rectangular and isosceles triangular cross-sectional microfluidic networks, respectively. Precise control over wall shear stress through the bifurcations of the microfluidic network is demonstrated in this work. Three multi-generation microfluidic network designs are considered. In these three designs, wall shear stress in the microfluidic network is successfully kept constant, increased in the daughter-branch direction, or decreased in the daughter-branch direction, respectively. For the multi-generation microfluidic network with constant wall shear stress, the design guidelines presented in this work result in identical profiles of wall shear stresses not only within a single generation but also through all the generations of the

  15. Fabrication of circular microfluidic network in enzymatically-crosslinked gelatin hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    He, Jiankang, E-mail: jiankanghe@mail.xjtu.edu.cn; Chen, Ruomeng; Lu, Yongjie; Zhan, Li; Liu, Yaxiong; Li, Dichen; Jin, Zhongmin

    2016-02-01

    It is a huge challenge to engineer vascular networks in vital organ tissue engineering. Although the incorporation of artificial microfluidic network into thick tissue-engineered constructs has shown great promise, most of the existing microfluidic strategies are limited to generate rectangle cross-sectional channels rather than circular vessels in soft hydrogels. Here we present a facile approach to fabricate branched microfluidic network with circular cross-sections in gelatin hydrogels by combining micromolding and enzymatically-crosslinking mechanism. Partially crosslinked hydrogel slides with predefined semi-circular channels were molded, assembled and in situ fully crosslinked to form a seamless and circular microfluidic network. The bonding strength of the resultant gelatin hydrogels was investigated. The morphology and the dimension of the resultant circular channels were characterized using scanning electron microscopy (SEM) and micro-computerized tomography (μCT). Computational fluid dynamic simulation shows that the fabrication error had little effect on the distribution of flow field but affected the maximum velocity in comparison with designed models. The microfluidic gelatin hydrogel facilitates the attachment and spreading of human umbilical endothelial cells (HUVECs) to form a uniform endothelialized layer around the circular channel surface, which successfully exhibited barrier functions. The presented method might provide a simple way to fabricate circular microfluidic networks in biologically-relevant hydrogels to advance various applications of in vitro tissue models, organ-on-a-chip systems and tissue engineering. - Highlights: • A facile method was proposed to build a circular fluidic network in gelatin hydrogel. • The fluidic network is mechanically robust and supports physiological flow. • HUVECs formed endothelialized layer around the channel to express barrier function.

  16. A microfluidic platform for controlled biochemical stimulation of twin neuronal networks.

    Science.gov (United States)

    Biffi, Emilia; Piraino, Francesco; Pedrocchi, Alessandra; Fiore, Gianfranco B; Ferrigno, Giancarlo; Redaelli, Alberto; Menegon, Andrea; Rasponi, Marco

    2012-06-01

    Spatially and temporally resolved delivery of soluble factors is a key feature for pharmacological applications. In this framework, microfluidics coupled to multisite electrophysiology offers great advantages in neuropharmacology and toxicology. In this work, a microfluidic device for biochemical stimulation of neuronal networks was developed. A micro-chamber for cell culturing, previously developed and tested for long term neuronal growth by our group, was provided with a thin wall, which partially divided the cell culture region in two sub-compartments. The device was reversibly coupled to a flat micro electrode array and used to culture primary neurons in the same microenvironment. We demonstrated that the two fluidically connected compartments were able to originate two parallel neuronal networks with similar electrophysiological activity but functionally independent. Furthermore, the device allowed to connect the outlet port to a syringe pump and to transform the static culture chamber in a perfused one. At 14 days invitro, sub-networks were independently stimulated with a test molecule, tetrodotoxin, a neurotoxin known to block action potentials, by means of continuous delivery. Electrical activity recordings proved the ability of the device configuration to selectively stimulate each neuronal network individually. The proposed microfluidic approach represents an innovative methodology to perform biological, pharmacological, and electrophysiological experiments on neuronal networks. Indeed, it allows for controlled delivery of substances to cells, and it overcomes the limitations due to standard drug stimulation techniques. Finally, the twin network configuration reduces biological variability, which has important outcomes on pharmacological and drug screening.

  17. Microbridge structures for uniform interval control of flowing droplets in microfluidic networks.

    Science.gov (United States)

    Lee, Do-Hyun; Lee, Wonhye; Um, Eujin; Park, Je-Kyun

    2011-09-01

    Precise temporal control of microfluidic droplets such as synchronization and combinatorial pairing of droplets is required to achieve a variety range of chemical and biochemical reactions inside microfluidic networks. Here, we present a facile and robust microfluidic platform enabling uniform interval control of flowing droplets for the precise temporal synchronization and pairing of picoliter droplets with a reagent. By incorporating microbridge structures interconnecting the droplet-carrying channel and the flow control channel, a fluidic pressure drop was derived between the two fluidic channels via the microbridge structures, reordering flowing droplets with a defined uniform interval. Through the adjustment of the control oil flow rate, the droplet intervals were flexibly and precisely adjustable. With this mechanism of droplet spacing, the gelation of the alginate droplets as well as control of the droplet interval was simultaneously achieved by additional control oil flow including calcified oleic acid. In addition, by parallel linking identical microfluidic modules with distinct sample inlet, controlled synchronization and pairing of two distinct droplets were demonstrated. This method is applicable to facilitate and develop many droplet-based microfluidic applications, including biological assay, combinatorial synthesis, and high-throughput screening.

  18. Development of a general method for obtaining the geometry of microfluidic networks

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Mohammad Sayed, E-mail: m.sayedrazavi@gmail.com; Salimpour, M. R. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shirani, Ebrahim [Department of Engineering, Foolad Institute of Technology, FooladShahr 84916-63763, Isfahan (Iran, Islamic Republic of)

    2014-01-15

    In the present study, a general method for geometry of fluidic networks is developed with emphasis on pressure-driven flows in the microfluidic applications. The design method is based on general features of network's geometry such as cross-sectional area and length of channels. Also, the method is applicable to various cross-sectional shapes such as circular, rectangular, triangular, and trapezoidal cross sections. Using constructal theory, the flow resistance, energy loss and performance of the network are optimized. Also, by this method, practical design strategies for the fabrication of microfluidic networks can be improved. The design method enables rapid prediction of fluid flow in the complex network of channels and is very useful for improving proper miniaturization and integration of microfluidic networks. Minimization of flow resistance of the network of channels leads to universal constants for consecutive cross-sectional areas and lengths. For a Y-shaped network, the optimal ratios of consecutive cross-section areas (A{sub i+1}/A{sub i}) and lengths (L{sub i+1}/L{sub i}) are obtained as A{sub i+1}/A{sub i} = 2{sup −2/3} and L{sub i+1}/L{sub i} = 2{sup −1/3}, respectively. It is shown that energy loss in the network is proportional to the volume of network. It is also seen when the number of channels is increased both the hydraulic resistance and the volume occupied by the network are increased in a similar manner. Furthermore, the method offers that fabrication of multi-depth and multi-width microchannels should be considered as an integral part of designing procedures. Finally, numerical simulations for the fluid flow in the network have been performed and results show very good agreement with analytic results.

  19. A microfluidic platform with a flow-balanced fluidic network for osteoarthritis diagnosis

    Science.gov (United States)

    Kim, Kangil; Park, Yoo Min; Yoon, Hyun C.; Yang, Sang Sik

    2013-05-01

    Osteoarthritis (OA) is one of the most common human diseases, and the occurrence of OA is likely to increase with the increase of population ages. The diagnosis of OA is based on patientrelevant measures, structural measures, and measurement of biomarkers that are released through joint metabolism. Traditionally, radiography or magnetic resonance imaging (MRI) is used to diagnose OA and predict its course. However, diagnostic imaging in OA provides only indirect information on pathology and treatment response. A sensing of OA based on the detection of biomarkers insignificantly improves the accuracy and sensitivity of diagnosis and reduces the cost compared with that of radiography or MRI. In our former study, we proposed microfluidic platform to detect biomarker of OA. But the platform can detect only one biomarker because it has one microfluidic channel. In this report, we proposes microfluidic platform that can detect several biomarkers. The proposed platform has three layers. The bottom layer has gold patterns on a Si substrate for optical sensing. The middle layer and top layer were fabricated by polydimethysiloxane (PDMS) using soft-lithography. The middle layer has four channels connecting top layer to bottom layer. The top layer consists of one sample injection inlet, and four antibody injection inlets. To this end, we designed a flow-balanced microfluidic network using analogy between electric and hydraulic systems. Also, the designed microfluidic network was confirmed by finite element model (FEM) analysis using COMSOL FEMLAB. To verify the efficiency of fabricated platform, the optical sensing test was performed to detect biomarker of OA using fluorescence microscope. We used cartilage oligomeric matrix protein (COMP) as biomarker because it reflects specific changes in joint tissues. The platform successfully detected various concentration of COMP (0, 100, 500, 1000 ng/ml) at each chamber. The effectiveness of the microfluidic platform was verified

  20. Generation of tunable and pulsatile concentration gradients via microfluidic network

    KAUST Repository

    Zhou, Bingpu

    2014-06-04

    We demonstrate a compact Polydimethylsiloxane microfluidic chip which can quickly generate ten different chemical concentrations simultaneously. The concentration magnitude of each branch can be flexibly regulated based on the flow rate ratios of the two injecting streams. The temporal/pulsatile concentration gradients are achieved by integrating on-chip pneumatic actuated valves controlled by the external signals. The temporal concentration gradients can also be tuned precisely by varying applied frequency and duty cycle of the trigger signal. It is believed that such microdevice will be potentially used for some application areas of producing stable chemical gradients as well as allowing fast, pulsatile gradient transformation in seconds.

  1. Blood Perfusion in Microfluidic Models of Pulmonary Capillary Networks: Role of Geometry and Hematocrit

    Science.gov (United States)

    Stauber, Hagit; Waisman, Dan; Sznitman, Josue; Technion-IIT Team; Department of Neonatology Carmel Medical Center; Faculty of Medicine-Technion IIT Collaboration

    2015-11-01

    Microfluidic platforms are increasingly used to study blood microflows at true physiological scale due to their ability to overcome manufacturing obstacle of complex anatomical morphologies, such as the organ-specific architectures of the microcirculation. In the present work, we utilize microfluidic platforms to devise in vitro models of the underlying pulmonary capillary networks (PCN), where capillary lengths and diameters are similar to the size of RBCs (~ 5-10 μm). To better understand flow characteristics and dispersion of red blood cells (RBCs) in PCNs, we have designed microfluidic models of alveolar capillary beds inspired by the seminal ``sheet flow'' model of Fung and Sobin (1969). Our microfluidic PCNs feature confined arrays of staggered pillars with diameters of ~ 5,7 and 10 μm, mimicking the dense structure of pulmonary capillary meshes. The devices are perfused with suspensions of RBCs at varying hematocrit levels under different flow rates. Whole-field velocity patterns using micro-PIV and single-cell tracking using PTV are obtained with fluorescently-labelled RBCs and discussed. Our experiments deliver a real-scale quantitative description of RBC perfusion characteristics across the pulmonary capillary microcirculation.

  2. System-level network simulation for robust centrifugal-microfluidic lab-on-a-chip systems.

    Science.gov (United States)

    Schwarz, I; Zehnle, S; Hutzenlaub, T; Zengerle, R; Paust, N

    2016-05-10

    Centrifugal microfluidics shows a clear trend towards a higher degree of integration and parallelization. This trend leads to an increase in the number and density of integrated microfluidic unit operations. The fact that all unit operations are processed by the same common spin protocol turns higher integration into higher complexity. To allow for efficient development anyhow, we introduce advanced lumped models for network simulations in centrifugal microfluidics. These models consider the interplay of centrifugal and Euler pressures, viscous dissipation, capillary pressures and pneumatic pressures. The simulations are fast and simple to set up and allow for the precise prediction of flow rates as well as switching and valving events. During development, channel and chamber geometry variations due to manufacturing tolerances can be taken into account as well as pipetting errors, variations of contact angles, compliant chamber walls and temperature variations in the processing device. As an example of considering these parameters during development, we demonstrate simulation based robustness analysis for pneumatic siphon valving in centrifugal microfluidics. Subsequently, the influence of liquid properties on pumping and valving is studied for four liquids relevant for biochemical analysis, namely, water (large surface tension), blood plasma (large contact angle hysteresis), ethanol/water (highly wetting) and glycerine/water (highly viscous). In a second example, we derive a spin protocol to attain a constant flow rate under varying pressure conditions. Both examples show excellent agreement with experimental validations.

  3. Design of parallel microfluidic gradient-generating networks for studying cellular response to chemical stimuli

    Institute of Scientific and Technical Information of China (English)

    Lihui WANG; Dayu LIU; Bo WANG; Jie SUN; Lianhong LI

    2008-01-01

    A microfluidic chip featuring laminar flow-based parallel gradient-generating networks was designed and fabricated. The microchip contains 5 gradient genera-tors and 30 cell chambers where the resulting concentra-tion gradients of drugs are delivered to stimulate on-chip cultured cells. The microfluidics exploits the advantage of lab-on-a-chip technology by integrating the generation of drug concentration gradients and a series of cell opera-tions including seeding, culture, stimulation and staining into a chip. The microfluidic network was patterned on a glass wafer, which was further bonded to a PDMS film. A series of weir structures were fabricated on the cell culture reservoir to facilitate cell positioning and seeding. Cell injection and fluid delivery were controlled by a syringe pump. Steady parallel concentration gradients were gen-erated by flowing two fluids in each network. Over time observation shows that the microchip was suitable for cell seeding and culture. The microchip described above was applied in studying the role of reduced glutathione (GSH) in mediating chemotherapy sensitivity of MCF-7 cells. MCF-7 cells were treated with concentration gradients of As2O3 and N-acetyl cysteine (NAC) for GSH modu-lation, followed by exposure to adriamycin. GSH levels were down-regulated upon As203 treatment and up-regu-lated upon NAC treatment. Suppression of intracellular GSH by treatment with As2O3 has been shown to increase sensitivity to adriamycin. Conversely, elevation of intra-cellular GSH by treatment with NAC leads to increased drug resistance. The integrated microfluidic chip is able to perform multiparametric pharmacological profiling with easy operation, and thus holds great potential for extra-polation to the cell based high-content drug screening.

  4. Red Blood Cell Dispersion in Morphologically-Inspired Microfluidic Models of Alveolar Capillary Networks

    Science.gov (United States)

    Stauber, Hagit; Fishler, Rami; Waisman, Dan; Sznitman, Josue

    2014-11-01

    Microfluidics is frequently used to study blood flow characteristics in microcapillary networks and investigate transport properties of red blood cells (RBC). To date, most of microfluidic studies have not focused on the specific morphology of alveolar capillary networks (ACN), with characteristic length scales of ~ 5 μm, known to give rise to organ-specific blood flow characteristics. To better understand flow characteristics and dispersion of RBCs in ACNs, we have designed morphologically-inspired microfluidic models of alveolar capillary beds at a real scale. We fabricate lab-on-chip devices featuring confined staggered pillar arrays with diameters of ~ 10 μm, representative of the dense ACN capillary meshes. Devices are supplied by an external reservoir containing whole blood at various hematocrit levels, to mimic RBC perfusion (Re < 0.01) within alveolar capillaries. Whole-field velocity patterns are imaged (PIV) and RBC motion is tracked using particle tracking velocimetry (PTV) from which dispersion coefficients are extracted. Our efforts are aimed at delivering a real-scale quantitative description of the pulmonary ACN microcirculation.

  5. Flow control using audio tones in resonant microfluidic networks: towards cell-phone controlled lab-on-a-chip devices.

    Science.gov (United States)

    Phillips, Reid H; Jain, Rahil; Browning, Yoni; Shah, Rachana; Kauffman, Peter; Dinh, Doan; Lutz, Barry R

    2016-08-16

    Fluid control remains a challenge in development of portable lab-on-a-chip devices. Here, we show that microfluidic networks driven by single-frequency audio tones create resonant oscillating flow that is predicted by equivalent electrical circuit models. We fabricated microfluidic devices with fluidic resistors (R), inductors (L), and capacitors (C) to create RLC networks with band-pass resonance in the audible frequency range available on portable audio devices. Microfluidic devices were fabricated from laser-cut adhesive plastic, and a "buzzer" was glued to a diaphragm (capacitor) to integrate the actuator on the device. The AC flowrate magnitude was measured by imaging oscillation of bead tracers to allow direct comparison to the RLC circuit model across the frequency range. We present a systematic build-up from single-channel systems to multi-channel (3-channel) networks, and show that RLC circuit models predict complex frequency-dependent interactions within multi-channel networks. Finally, we show that adding flow rectifying valves to the network creates pumps that can be driven by amplified and non-amplified audio tones from common audio devices (iPod and iPhone). This work shows that RLC circuit models predict resonant flow responses in multi-channel fluidic networks as a step towards microfluidic devices controlled by audio tones.

  6. Microfluidic Dye Lasers

    DEFF Research Database (Denmark)

    Kristensen, Anders; Balslev, Søren; Gersborg-Hansen, Morten

    2006-01-01

    A technology for miniaturized, polymer based lasers, suitable for integration with planar waveguides and microfluidic networks is presented. The microfluidic dye laser device consists of a microfluidic channel with an embedded optical resonator. The devices are fabricated in a thin polymer film...

  7. Acoustofluidics 1: Governing equations in microfluidics

    DEFF Research Database (Denmark)

    Bruus, Henrik

    2011-01-01

    Governing equations for microfluidics and basic flow solutions are presented. Equivalent circuit modeling for determining flow rates in microfluidic networks is introduced.......Governing equations for microfluidics and basic flow solutions are presented. Equivalent circuit modeling for determining flow rates in microfluidic networks is introduced....

  8. Frequency tuning allows flow direction control in microfluidic networks with passive features.

    Science.gov (United States)

    Jain, Rahil; Lutz, Barry

    2017-05-02

    Frequency tuning has emerged as an attractive alternative to conventional pumping techniques in microfluidics. Oscillating (AC) flow driven through a passive valve can be rectified to create steady (DC) flow, and tuning the excitation frequency to the characteristic (resonance) frequency of the underlying microfluidic network allows control of flow magnitude using simple hardware, such as an on-chip piezo buzzer. In this paper, we report that frequency tuning can also be used to control the direction (forward or backward) of the rectified DC flow in a single device. Initially, we observed that certain devices provided DC flow in the "forward" direction expected from previous work with a similar valve geometry, and the maximum DC flow occurred at the same frequency as a prominent peak in the AC flow magnitude, as expected. However, devices of a slightly different geometry provided the DC flow in the opposite direction and at a frequency well below the peak AC flow. Using an equivalent electrical circuit model, we found that the "forward" DC flow occurred at the series resonance frequency (with large AC flow peak), while the "backward" DC flow occurred at a less obvious parallel resonance (a valley in AC flow magnitude). We also observed that the DC flow occurred only when there was a measurable differential in the AC flow magnitude across the valve, and the DC flow direction was from the channel with large AC flow magnitude to that with small AC flow magnitude. Using these observations and the AC flow predictions from the equivalent circuit model, we designed a device with an AC flowrate frequency profile that was expected to allow the DC flow in opposite directions at two distinct frequencies. The fabricated device showed the expected flow reversal at the expected frequencies. This approach expands the flow control toolkit to include both magnitude and direction control in frequency-tuned microfluidic pumps. The work also raises interesting questions about the

  9. A microfluidic investigation of gas exsolution in glass and shale fracture networks

    Science.gov (United States)

    Porter, M. L.; Jimenez-Martinez, J.; Harrison, A.; Currier, R.; Viswanathan, H. S.

    2016-12-01

    Microfluidic investigations of pore-scale fluid flow and transport phenomena has steadily increased in recent years. In these investigations fluid flow is restricted to two-dimensions allowing for real-time visualization and quantification of complex flow and reactive transport behavior, which is difficult to obtain in other experimental systems. In this work, we describe a unique high pressure (up to 10.3 MPa) and temperature (up to 80 °C) microfluidics experimental system that allows us to investigate fluid flow and transport in geo-material (e.g., shale, Portland cement, etc.) micromodels. The use of geo-material micromodels allows us to better represent fluid-rock interactions including wettability, chemical reactivity, and nano-scale porosity at conditions representative of natural subsurface environments. Here, we present experimental results in fracture systems with applications to hydrocarbon mobility in fractured rocks. Complex fracture network patterns are derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in the different materials. We discuss results from two-phase gas (CO2 and N2) injection experiments designed to enhance oil recovery. In these experiments gas was injected into micromodels saturated with oil and allowed to soak for approximately 12 hours at elevated pressures. The pressure in the system was then decreased to atmospheric, causing the gas to expand and/or dissolve out of solution, subsequently mobilizing the oil. In addition to the experimental results, we present a relatively simple model designed to quantify the amount of oil mobilized as a function of decreasing system pressure. We will show comparisons between the experiments and model, and discuss the potential use of the model in field-scale reservoir simulations.

  10. Between giant oscillations and uniform distribution of droplets -- the role of varying lumen of channels in microfluidic networks

    OpenAIRE

    Cybulski, Olgierd; Jakiela, Slawomir; Garstecki, Piotr

    2015-01-01

    The simplest microfluidic network (a loop) comprises two parallel channels with a common inlet and a common outlet. Recent studies, that assumed constant cross-section of the channels along their length, have shown that the sequence of droplets entering left (L) or right (R) arm of the loop can present either a uniform distribution of choices (e.g. RLRLRL...) or long sequences of repeated choices (RRR...LLL), with all the intermediate permutations being dynamically equivalent and virtually eq...

  11. Integrated Microfluidic Reactors.

    Science.gov (United States)

    Lin, Wei-Yu; Wang, Yanju; Wang, Shutao; Tseng, Hsian-Rong

    2009-12-01

    Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides. These proof-of-principle demonstrations validate the feasibility and set a solid foundation for exploring a broad application of the integrated microfluidic system.

  12. Microfluidic Investigation of Oil Mobilization in Shale Fracture Networks at Reservoir Conditions

    Science.gov (United States)

    Porter, M. L.; Jimenez-Martinez, J.; Carey, J. W.; Viswanathan, H. S.

    2015-12-01

    Investigations of pore-scale fluid flow and transport phenomena using engineered micromodels has steadily increased in recent years. In these investigations fluid flow is restricted to two-dimensions allowing for real time visualization and quantification of complex flow and reactive transport behavior, which is difficult to obtain in other experimental systems. One drawback to these studies is the use of engineered materials that do not faithfully represent the rock properties (e.g., porosity, wettability, roughness, etc.) encountered in subsurface formations. In this work, we describe a unique high pressure (up to 1500 psi) and temperature (up to 80 °C) microfluidics experimental system in which we investigate fluid flow and transport in geo-material (e.g., shale, Portland cement, etc.) micromodels. The use of geo-material micromodels allows us to better represent fluid-rock interactions including wettability, chemical reactivity, and nano-scale porosity at conditions representative of natural subsurface environments. Here, we present experimental results in fracture systems with applications to hydrocarbon mobility in hydraulically fractured shale. Complex fracture network patterns are derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in the different materials. We discuss results from two-phase huff-and-puff experiments involving N2 and n-Decane, as well as three-phase displacement experiments involving supercritical CO2, brine, and n-Decane.

  13. A network-flow based valve-switching aware binding algorithm for flow-based microfluidic biochips

    DEFF Research Database (Denmark)

    Tseng, Kai-Han; You, Sheng-Chi; Minhass, Wajid Hassan

    2013-01-01

    -flow based resource binding algorithm based on breadth-first search (BFS) and minimum cost maximum flow (MCMF) in architectural-level synthesis. The experimental results show that our methodology not only makes significant reduction of valve-switching activities but also diminishes the application completion......Designs of flow-based microfluidic biochips are receiving much attention recently because they replace conventional biological automation paradigm and are able to integrate different biochemical analysis functions on a chip. However, as the design complexity increases, a flow-based microfluidic...... biochip needs more chip-integrated micro-valves, i.e., the basic unit of fluid-handling functionality, to manipulate the fluid flow for biochemical applications. Moreover, frequent switching of micro-valves results in decreased reliability. To minimize the valve-switching activities, we develop a network...

  14. Promise of a microfluidic research network in South Africa: establishment of the base with the CSIR

    CSIR Research Space (South Africa)

    Land, K

    2008-11-01

    Full Text Available The CSIR is developing a new technology, broadly referred to as microfluidics, which deals with the behaviour, precise control and manipulation of fluids - with applications in areas such as micro fuel cells, disease detection, chemical...

  15. Chemical sensing and imaging in microfluidic pore network structures relevant to natural carbon cycling and industrial carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Zhang, Changyong; Wilkins, Michael J.; Warner, Marvin G.; Anheier, Norman C.; Suter, Jonathan D.; Kelly, Ryan T.; Oostrom, Martinus

    2013-06-11

    Energy and climate change represent significant factors in global security. Atmospheric carbon dioxide levels, while global in scope, are influenced by pore-scale phenomena in the subsurface. We are developing tools to visualize and investigate processes in pore network microfluidic structures with transparent covers as representations of normally-opaque porous media. In situ fluorescent oxygen sensing methods and fluorescent cellulosic materials are being used to investigate processes related to terrestrial carbon cycling involving cellulytic respiring microorganisms. These structures also enable visualization of water displacement from pore spaces by hydrophobic fluids, including carbon dioxide, in studies related to carbon sequestration.

  16. Between giant oscillations and uniform distribution of droplets: The role of varying lumen of channels in microfluidic networks.

    Science.gov (United States)

    Cybulski, Olgierd; Jakiela, Slawomir; Garstecki, Piotr

    2015-12-01

    The simplest microfluidic network (a loop) comprises two parallel channels with a common inlet and a common outlet. Recent studies that assumed a constant cross section of the channels along their length have shown that the sequence of droplets entering the left (L) or right (R) arm of the loop can present either a uniform distribution of choices (e.g., RLRLRL...) or long sequences of repeated choices (RRR...LLL), with all the intermediate permutations being dynamically equivalent and virtually equally probable to be observed. We use experiments and computer simulations to show that even small variation of the cross section along channels completely shifts the dynamics either into the strong preference for highly grouped patterns (RRR...LLL) that generate system-size oscillations in flow or just the opposite-to patterns that distribute the droplets homogeneously between the arms of the loop. We also show the importance of noise in the process of self-organization of the spatiotemporal patterns of droplets. Our results provide guidelines for rational design of systems that reproducibly produce either grouped or homogeneous sequences of droplets flowing in microfluidic networks.

  17. Phaseguides as tunable passive microvalves for liquid routing in complex microfluidic networks

    NARCIS (Netherlands)

    Yildirim, Ender; Trietsch, Sebastiaan J.; Joore, Jos; Berg, van den Albert; Hankemeier, Thomas; Vulto, Paul

    2014-01-01

    A microfluidic passive valving platform is introduced that has full control over the stability of each valve. The concept is based on phaseguides, which are small ridges at the bottom of a channel acting as pinning barriers. It is shown that the angle between the phaseguide and the channel sidewall

  18. Generation of arbitrary monotonic concentration profiles by a serial dilution microfluidic network composed of microchannels with a high fluidic-resistance ratio.

    Science.gov (United States)

    Hattori, Koji; Sugiura, Shinji; Kanamori, Toshiyuki

    2009-06-21

    This paper reports a serial dilution microfluidic network composed of microchannels with a high fluidic-resistance ratio for generating linear concentration profiles as well as logarithmic concentration profiles spanning 3 and 6 orders of magnitude. The microfluidic networks were composed of thin fluidic-resistance microchannels with 160 to 730 microm(2) cross-sectional areas and thick diffusion-mixing microchannels with 3,600 to 17,000 microm(2) cross-sectional areas, and were fabricated from polydimethylsiloxane by multilayer photolithography and replica molding. We proposed a design algorithm of the microfluidic network for an arbitrary monotonic concentration profile by means of a hydrodynamic calculation. Because of the high fluidic-resistance ratio of the fluidic-resistance microchannels to the diffusion-mixing microchannels, appropriate geometry and dimensions of the fluidic-resistance microchannels allowed us to obtain desired concentration profiles. The fabricated microfluidic network was compact, occupying a 8 x 18 to 21.0 x 13.5 mm(2) area on the microchip. Both the linear and the logarithmic concentration profiles were successfully generated with the error less than 15% for the linear concentration profile, 22% and 35% for the logarithmic concentration profiles of 3 and 6 orders of magnitude, respectively. The generated linear concentration profiles of the small molecule, calcein, were independent of the flow rate within the range of 0.009 to 0.23 microL/min. The concentration profiles of the large molecules, dextrans, depended on the flow rate and molecular weight. The required residence time of large molecules in the diffusion-mixing microchannel was correlated with dimensionless diffusion time, Fick number, and was discussed based on the scaling law. These compact, stable serial dilution microfluidic networks are expected to be applied to various integrated on-chip analyses.

  19. Chemical communication and dynamics of droplet emulsions in networks of Belousov-Zhabotinsky micro-oscillators produced by microfluidics.

    Science.gov (United States)

    Torbensen, Kristian; Rossi, Federico; Ristori, Sandra; Abou-Hassan, Ali

    2017-03-29

    Chemical communication leading to synchronization and collective behaviour of dynamic elements, such as cell colonies, is a widespread phenomenon with biological, physical and chemical importance. Such synchronization between elements proceeds via chemical communication by emmision, interdiffusion and reception of specific messenger molecules. On a lab scale, these phenomena can be modeled by encapsulating an oscillating chemical reaction, which serves as a signal (information) sender/receiver element, inside microcompartments such as droplet emulsions, liposomes and polymersomes. Droplets can thus be regarded as single units, able to generate chemical messengers that diffuse in the environment and hence can interact with other compartments. The Belousov-Zhabotinsky (BZ) reaction is a well-known chemical oscillator largely used as a model for complex nonlinear phenomena, including chemical, physical and biological examples. When the BZ-reaction is encapsulated inside microcompartments, its chemical intermediates can serve as messengers by diffusing among different microcompartments, to trigger specific reactions leading to a collective behavior between the elements. The geometry and constitution of the diffusion pathways play an important role in governing the collective behaviour of the system. In this context, microfluidics is not only a versatile tool for mastering the encapsulation process of the BZ-reaction in monodisperse microcompartments, but also for creating geometries and networks with well defined boundaries. The individual compartments can be engineered with selected properties using different surfactants in the case of simple emulsions, or with specific membrane properties in the case of liposomes. Furthermore, it enables the arrangement of these microcompartments in various geometric configurations, where the diffusive coupling pathways between individual compartments are both spatially and chemically well-defined. In this tutorial paper, we review a

  20. Microfluidics made of yarns and knots: from fundamental properties to simple networks and operations.

    Science.gov (United States)

    Safavieh, Roozbeh; Zhou, Gina Z; Juncker, David

    2011-08-07

    We present and characterize cotton yarn and knots as building blocks for making microfluidic circuits from the bottom up. The yarn used is made up of 200-300 fibres, each with a lumen. Liquid applied at the extremity of the yarn spontaneously wets the yarn, and the wetted length increases linearly over time in untreated yarn, but progresses according to a square root relationship as described by Washburn's equation upon plasma activation of the yarn. Knots are proposed for combining, mixing and splitting streams of fluids. Interestingly, the topology of the knot controls the mixing ratio of two inlet streams into two outlet yarns, and thus the ratio can be adjusted by choosing a specific knot. The flow resistance of a knot is shown to depend on the force used to tighten it and the flow resistance rapidly increases for single-stranded knots, but remains low for double-stranded knots. Finally, a serial dilutor is made with a web made of yarns and double-stranded overhand knots. These results suggest that yarn and knots may be used to build low cost microfluidic circuits.

  1. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  2. A Microfluidic Pore Network Approach to Investigate Water Transport in Fuel Cell Porous Transport Layers

    CERN Document Server

    Bazylak, A; Markicevic, B; Sinton, D; Djilali, N

    2008-01-01

    Pore network modelling has traditionally been used to study displacement processes in idealized porous media related to geological flows, with applications ranging from groundwater hydrology to enhanced oil recovery. Very recently, pore network modelling has been applied to model the gas diffusion layer (GDL) of a polymer electrolyte membrane (PEM) fuel cell. Discrete pore network models have the potential to elucidate transport phenomena in the GDL with high computational efficiency, in contrast to continuum or molecular dynamics modelling that require extensive computational resources. However, the challenge in studying the GDL with pore network modelling lies in defining the network parameters that accurately describe the porous media as well as the conditions of fluid invasion that represent realistic transport processes. In this work, we discuss the first stage of developing and validating a GDL-representative pore network model. We begin with a two-dimensional pore network model with a single mobile pha...

  3. Microfluidic Production of Multiple Emulsions

    Directory of Open Access Journals (Sweden)

    Goran T. Vladisavljević

    2017-03-01

    Full Text Available Microfluidic devices are promising tools for the production of monodispersed tuneable complex emulsions. This review highlights the advantages of microfluidics for the fabrication of emulsions and presents an overview of the microfluidic emulsification methods including two-step and single-step methods for the fabrication of high-order multiple emulsions (double, triple, quadruple and quintuple and emulsions with multiple and/or multi-distinct inner cores. The microfluidic methods for the formation of multiple emulsion drops with ultra-thin middle phase, multi-compartment jets, and Janus and ternary drops composed of two or three distinct surface regions are also presented. Different configurations of microfluidic drop makers are covered, such as co-flow, T-junctions and flow focusing (both planar and three-dimensional (3D. Furthermore, surface modifications of microfluidic channels and different modes of droplet generation are summarized. Non-confined microfluidic geometries used for buoyancy-driven drop generation and membrane integrated microfluidics are also discussed. The review includes parallelization and drop splitting strategies for scaling up microfluidic emulsification. The productivity of a single drop maker is typically <1 mL/h; thus, more than 1000 drop makers are needed to achieve commercially relevant droplet throughputs of >1 L/h, which requires combining drop makers into twodimensional (2D and 3D assemblies fed from a single set of inlet ports through a network of distribution and collection channels.

  4. The use of artificial neural networks for optimizing polydispersity index (PDI) in nanoprecipitation process of acetaminophen in microfluidic devices.

    Science.gov (United States)

    Aghajani, Mahdi; Shahverdi, Ahmad Reza; Amani, Amir

    2012-12-01

    Artificial neural networks (ANNs) were used in this study to determine factors that control the polydispersity index (PDI) in an acetaminophen nanosuspension which was prepared using nanoprecipitation in microfluidic devices. The PDI of prepared formulations was measured by dynamic light scattering. Afterwards, the ANNs were applied to model the data. Four independent variables, namely, surfactant concentration, solvent temperature, and flow rate of solvent and antisolvent were considered as input variables, and the PDI of acetaminophen nanosuspension was taken as the output variable. The response surfaces, generated as 3D graphs after modeling, were used to survey the interactions happening between the input variables and the output variable. Comparison of the response surfaces indicated that the antisolvent flow rate and the solvent temperature have reverse effect on the PDI, whereas solvent flow rate has direct relation with PDI. Also, the effect of the concentration of the surfactant on the PDI was found to be indirect and less influential. Overall, it was found that minimum PDI may be obtained at high values of antisolvent flow rate and solvent temperature, while the solvent flow rate should be kept to a minimum.

  5. Between giant oscillations and uniform distribution of droplets -- the role of varying lumen of channels in microfluidic networks

    CERN Document Server

    Cybulski, Olgierd; Garstecki, Piotr

    2015-01-01

    The simplest microfluidic network (a loop) comprises two parallel channels with a common inlet and a common outlet. Recent studies, that assumed constant cross-section of the channels along their length, have shown that the sequence of droplets entering left (L) or right (R) arm of the loop can present either a uniform distribution of choices (e.g. RLRLRL...) or long sequences of repeated choices (RRR...LLL), with all the intermediate permutations being dynamically equivalent and virtually equally probable to be observed. We use experiments and computer simulations to show that even small variation of the cross-section along channels completely shifts the dynamics either into the strong preference for highly grouped patterns (RRR...LLL) that generate system-size oscillations in flow, or just the opposite - to patterns that distribute the droplets homogeneously between the arms of the loop. We also show the importance of noise in the process of self-organization of the spatio-temporal patterns of droplets. Our...

  6. Stimulated Raman scattering microscopy by Nyquist modulation of a two-branch ultrafast fiber source.

    Science.gov (United States)

    Riek, Claudius; Kocher, Claudius; Zirak, Peyman; Kölbl, Christoph; Fimpel, Peter; Leitenstorfer, Alfred; Zumbusch, Andreas; Brida, Daniele

    2016-08-15

    A highly stable setup for stimulated Raman scattering (SRS) microscopy is presented. It is based on a two-branch femtosecond Er:fiber laser operating at a 40 MHz repetition rate. One of the outputs is directly modulated at the Nyquist frequency with an integrated electro-optic modulator (EOM). This compact source combines a jitter-free pulse synchronization with a broad tunability and allows for shot-noise limited SRS detection. The performance of the SRS microscope is illustrated with measurements on samples from material science and cell biology.

  7. Inconsistency measurement between two branches of LiNbO3 integrated optic Y-junction

    Science.gov (United States)

    Li, Chuang; Yuan, Yonggui; Yang, Jun; Yu, Zhangjun; Peng, Feng; Wu, Bing; Zhang, Yu; Yuan, Libo; Hua, Yong; Shu, Ping

    2016-06-01

    We investigate the inconsistency of the polarization related performance between two branches of a packaged LiNbO3 integrated optic Y-junction. An optical path tracking method is proposed to simplify the description of polarization light transmission behavior in packaged Y-junction. By developing a simple but practical fiber test system based on white light interferometry, the interferograms representing different branches of Y-junction are detected and distinguished accurately. The inconsistencies of performance including not only conventional parameters such as polarization extinction ratio of LiNbO3 chip and crosstalk at the joint points between polarization-maintaining pigtails and chip, but also birefringence of LiNbO3 chip and power ratio of Y-junction are obtained with only one-time measurement. It is analyzed theoretically and verified experimentally for complete parameters of a packaged Y-junction. Besides, the static and dynamic measurement results reveal that performance inconsistency for both branches of Y-junction can be effectively evaluated with high accuracy. The inconsistency investigation is highly beneficial in real-time monitoring the inconsistency between two branches of Y-junction and to filtrate qualified Y-junctions.

  8. Ultrasensitive detection of dopamine using a carbon nanotube network microfluidic flow electrode.

    Science.gov (United States)

    Sansuk, Siriwat; Bitziou, Eleni; Joseph, Maxim B; Covington, James A; Boutelle, Martyn G; Unwin, Patrick R; Macpherson, Julie V

    2013-01-02

    The electrochemical measurement of dopamine (DA), in phosphate buffer solution (pH 7.4), with a limit of detection (LOD) of ∼5 pM in 50 μL (∼ 250 attomol) is achieved using a band electrode comprised of a sparse network of pristine single-walled carbon nanotubes (SWNTs), which covers dopamine (DA), reported herein, is significantly lower than previous reports using FIA-electrochemical detection. Furthermore, the SWNT electrodes can be used as grown, i.e., they do not require chemical modification or cleanup. The extremely low background signals of the SWNT electrodes, as a consequence of the sparse surface coverage and the low intrinsic capacitance of the SWNTs, means that no signal processing is required to measure the low currents for DA oxidation at trace levels. DA detection in artificial cerebral fluid is also possible with a LOD of ∼50 pM in 50 μL (∼2.5 fmol).

  9. Design of Dual-Band Two-Branch-Line Couplers with Arbitrary Coupling Coefficients in Bands

    Directory of Open Access Journals (Sweden)

    I. Prudyus

    2014-12-01

    Full Text Available A new approach to design dual-band two-branch couplers with arbitrary coupling coefficients at two operating frequency bands is proposed in this article. The method is based on the usage of equivalent subcircuits input reactances of the even-mode and odd-mode excitations. The exact design formulas for three options of the dual-band coupler with different location and number of stubs are received. These formulas permit to obtain the different variants for each structure in order to select the physically realizable solution and can be used in broad range of frequency ratio and power division ratio. For verification, three different dual-band couplers, which are operating at 2.4/3.9 GHz with different coupling coefficients (one with 3/6 dB, and 10/3 dB two others are designed, simulated, fabricated and tested. The measured results are in good agreement with the simulated ones.

  10. A New Two-Branch Amplification Architecture and its Application with Various Modulated Signals

    Institute of Scientific and Technical Information of China (English)

    W. Hamdane; A. B. Kouki; F. Gagnon

    2011-01-01

    This paper proposes a new two-branch amplification architecture that combines baseband signal decomposition with RF front-end optimization. In the proposed architecture, the filtered modulated signals are separated into two components that are then amplified independently and combined to regenerate an amplified version of the original signal. A branch with an efficient amplifier transmits a low-varying envelope signal that contains the main part of the information. Another branch amplifies the residual portion of the signal. The baseband decomposition and parameters of the RF part are optimized to find the configuration that gives the best power efficiency and linearity. For M-ary quadrature amplitude modulation (M-QAM) signals, this technique is limited in terms of power efficiency. However, for filtered continuous phase modulation (CPM) signals, especially for minimum shift keying (MSK) and Gaussian MSK (GMSK) signals, high power efficiency can be achieved with no significant impact on the overall linearity. The results show that this technique gives better performance than the single-ended ctass-B amplifier.

  11. Two branches of the lupeol synthase gene in the molecular evolution of plant oxidosqualene cyclases.

    Science.gov (United States)

    Shibuya, M; Zhang, H; Endo, A; Shishikura, K; Kushiro, T; Ebizuka, Y

    1999-11-01

    Two new triterpene synthase cDNAs, named as OEW and TRW, were cloned from olive leaves (Olea europaea) and from dandelion roots (Taraxacum officinale), respectively, by the PCR method with primers designed from the conserved sequences found in the known oxidosqualene cyclases. Their ORFs consisted of 2274 bp nucleotides and coded for 758 amino acid long polypeptides. They shared high sequence identity (78%) to each other, while they showed only about 60% identities to the known triterpene synthases LUPI (lupeol synthase clone from Arabidopsis thaliana) and PNY (beta-amyrin synthase clone from Panax ginseng) at amino acid level. To determine the enzyme functions of the translates, they were expressed in an ERG7 deficient yeast mutant. Accumulation of lupeol in the cells of yeast transformants proved both of these clones code for lupeol synthase proteins. An EST (expression sequence tag) clone isolated from Medicago truncatula roots as a homologue of cycloartenol synthase gene, exhibits high sequence identity (75-77%) to these two lupeol synthase cDNAs, suggesting it to be another lupeol synthase clone. Comparatively low identity (approximately 57%) of LUP1 from Arabidopsis thaliana to either one of these clones leaves LUP1 as a distinct clone among lupeol synthases. From these sequence comparisons, now we propose that two branches of lupeol synthase gene have been generated in higher plants during the course of evolution.

  12. Theoretical microfluidics

    DEFF Research Database (Denmark)

    Bruus, Henrik

    in complexity, a proper theoretical understanding becomes increasingly important. The basic idea of the book is to provide a self-contained formulation of the theoretical framework of microfluidics, and at the same time give physical motivation and examples from lab-on-a-chip technology. After three chapters...

  13. Theoretical microfluidics

    DEFF Research Database (Denmark)

    Bruus, Henrik

    , complex flow patterns and acousto-fluidics, as well as the new fields of opto- and nano-fluidics. Throughout the book simple models with analytical solutions are presented to provide the student with a thorough physical understanding of order of magnitudes and various selected microfluidic phenomena...

  14. The Two Branches of the Recirculation of Atlantic Water in Fram Strait

    Science.gov (United States)

    von Appen, Wilken-Jon; Schauer, Ursula; Hattermann, Tore; Albretsen, Jon

    2016-04-01

    The Fram Strait between Greenland and Svalbard is one of the two gateways by which warm Atlantic Water enters the Arctic Ocean providing oceanic heat. The West Spitsbergen Current advects the warm water northward in the eastern Fram Strait. However, only some of this water stays in the boundary current and enters the Arctic Ocean. Another part leaves the boundary current and flows westward across Fram Strait before turning southward in the East Greenland Current. This recirculation of Atlantic Water corresponds with the ice edge in Fram Strait and the two likely depend on each other. Here we present results from a high resolution regional numerical model that shows the recirculation to consist of two branches. The northern branch depends on eddy fluxes while the southern branch exhibits less high frequency variability. We also present a compilation of different observational data in the center of Fram Strait around 0°EW that give insight into the structure of the southern recirculation branch near the ice edge. A glider section resolves the small horizontal scale over which the geostrophic flow occurs. Several meridional CTD sections capture the differences and similarities between different summers. Moorings and Argo floats provide information in winter as well. These observations are compared to the representation of the recirculation in the numerical model. We show that the southern recirculation occurs over a small horizontal distance of about 20km in the vicinity of 79°N and is significantly stronger in winter than in summer. While there is cold freshwater at the surface north of the front, the temperature down to 500m is much higher in the recirculation than further south.

  15. Microfluidic fabrication of plasmonic microcapsules

    NARCIS (Netherlands)

    Wang, J.; Jin, M.L.; Eijkel, J.C.T.; Berg, van den A.; Zhou, G.F.; Shui, L.L.

    2016-01-01

    This paper presents the plasmonic microcapsules with well-ordered nanoparticles embedded in polymer network fabricated by using a microfluidic device. The well-ordered nanoparticle arrays on the microcapsule form high-density uniform “hot-spots” with a deposited metal film, on which the localized su

  16. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  17. Microfluidics: a new cosset for neurobiology.

    Science.gov (United States)

    Wang, Jinyi; Ren, Li; Li, Li; Liu, Wenming; Zhou, Jing; Yu, Wenhao; Tong, Denwen; Chen, Shulin

    2009-03-07

    Recently, microfluidic systems have shown great potential in the study of molecular and cellular biology. With its excellent properties, such as miniaturization, integration and automation, to name just a few, microfluidics creates new opportunities for the spatial and temporal control of cell growth and environmental stimuli in vitro. In the field of neuroscience, microfluidic devices offer precise control of the microenvironment surrounding individual cells, and the delivery of biochemical or physical cues to neural networks or single neurons. The intent of this review is to outline recent advances in microfluidic-based applications in neurobiology, with emphasis on neuron culture, neuron manipulation, neural stem cell differentiation, neuropharmacology, neuroelectrophysiology, and neuron biosensors. It also aims to stimulate development of microfluidic-based applications in neurobiology by involving scientists from various disciplines, especially neurobiology and microtechnology.

  18. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  19. Microfluidic platform for reproducible self-assembly of chemically communicating droplet networks with predesigned number and type of the communicating compartments.

    Science.gov (United States)

    Guzowski, Jan; Gizynski, Konrad; Gorecki, Jerzy; Garstecki, Piotr

    2016-02-21

    We report a microfluidic system for individually tailored generation and incubation of core-shell liquid structures with multiple cores that chemically communicate with each other via lipid membranes. We encapsulate an oscillating reaction-diffusion Belousov-Zhabotinsky (BZ) medium inside the aqueous droplets and study the propagation of chemical wave-fronts through the membranes. We further encapsulate the sets of interconnected BZ-droplets inside oil-lipid shells in order to i) chemically isolate the structures and ii) confine them via tunable capillary forces which leads to self-assembly of predesigned topologies. We observe that doublets (pairs) of droplets encapsulated in the shell exhibit oscillation patterns that evolve in time. We collect statistical data from tens of doublets all created under precisely controlled, almost identical conditions from which we conclude that the different types of transitions between the patterns depend on the relative volumes of the droplets within a chemically coupled pair. With this we show that the volume of the compartment is an important control parameter in designing chemical networks, a feature previously appreciated only by theory. Our system not only allows for new insights into the dynamics of geometrically complex and interacting chemical systems but is also suitable for generating autonomous chemically interconnected microstructures with possible future use, e.g., as smart biosensors or drug-release capsules.

  20. Microfluidic fabrication of plasmonic microcapsules

    OpenAIRE

    Wang, J.; Jin, M. L.; Eijkel, J.C.T.; Berg, van den, A.E.; Zhou, G.F.; Shui, L.L.

    2016-01-01

    This paper presents the plasmonic microcapsules with well-ordered nanoparticles embedded in polymer network fabricated by using a microfluidic device. The well-ordered nanoparticle arrays on the microcapsule form high-density uniform “hot-spots” with a deposited metal film, on which the localized surface plasmon resonance effect is obtained. These plasmonic microcapsules can be engineered and modified by nanoparticle size and the metal film thickness. Repeatable Surfaced-Enhanced Raman Scatte...

  1. Performance of an integrated microoptical system for fluorescence detection in microfluidic systems

    NARCIS (Netherlands)

    Roulet, Jean-Christophe; Völkel, Reinhard; Herzig, Hans Peter; Verpoorte, Elisabeth; De Rooij, Nico F.; Dändliker, René

    2002-01-01

    This article presents a new integrated microfluidic/microoptic device designed for basic biochemical analysis. The microfluidic network is Wet-etched in a Borofloat 33 (Pyrex) glass wafer and sealed by means of a second wafer. Unlike other similar microfluidic systems, elements of the detection syst

  2. Microfluidic sieve valves

    Science.gov (United States)

    Quake, Stephen R; Marcus, Joshua S; Hansen, Carl L

    2015-01-13

    Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.

  3. Microfluidic single sperm analysis

    NARCIS (Netherlands)

    Wagenaar, de Bjorn

    2016-01-01

    Microfluidic technology has been occasionally used for in vitro analysis and separation of cells. The small dimensions of microfluidic chips are very suitable to study cells on the single cell level rather than in whole populations. Also sperm cells have been studied and manipulated using microfluid

  4. Multi-layer microfluidic glass chips for microanalytical applications

    NARCIS (Netherlands)

    Daridon, Antoine; Fascio, Valia; Lichtenberg, Jan; Wütrich, Rolf; Langen, Hans; Verpoorte, Elisabeth; De Rooij, Nico F.

    2001-01-01

    A new, versatile architecture is presented for microfluidic devices made entirely from glass, for use with reagents which would prove highly corrosive for silicon. Chips consist of three layers of glass wafers bonded together by fusion bonding. On the inside wafer faces a network of microfluidic cha

  5. Microfluidic neurite guidance to study structure-function relationships in topologically-complex population-based neural networks

    Science.gov (United States)

    Honegger, Thibault; Thielen, Moritz I.; Feizi, Soheil; Sanjana, Neville E.; Voldman, Joel

    2016-06-01

    The central nervous system is a dense, layered, 3D interconnected network of populations of neurons, and thus recapitulating that complexity for in vitro CNS models requires methods that can create defined topologically-complex neuronal networks. Several three-dimensional patterning approaches have been developed but none have demonstrated the ability to control the connections between populations of neurons. Here we report a method using AC electrokinetic forces that can guide, accelerate, slow down and push up neurites in un-modified collagen scaffolds. We present a means to create in vitro neural networks of arbitrary complexity by using such forces to create 3D intersections of primary neuronal populations that are plated in a 2D plane. We report for the first time in vitro basic brain motifs that have been previously observed in vivo and show that their functional network is highly decorrelated to their structure. This platform can provide building blocks to reproduce in vitro the complexity of neural circuits and provide a minimalistic environment to study the structure-function relationship of the brain circuitry.

  6. Microfluidics-Based PCR for Fusion Transcript Detection.

    Science.gov (United States)

    Chen, Hui

    2016-01-01

    The microfluidic technology allows the production of network of submillimeter-size fluidic channels and reservoirs in a variety of material systems. The microfluidic-based polymerase chain reaction (PCR) allows automated multiplexing of multiple samples and multiple assays simultaneously within a network of microfluidic channels and chambers that are co-ordinated in controlled fashion by the valves. The individual PCR reaction is performed in nanoliter volume, which allows testing on samples with limited DNA and RNA. The microfluidics devices are used in various types of PCR such as digital PCR and single molecular emulsion PCR for genotyping, gene expression, and miRNA expression. In this chapter, the use of a microfluidics-based PCR for simultaneous screening of 14 known fusion transcripts in patients with leukemia is described.

  7. Microfluidic CODES: a scalable multiplexed electronic sensor for orthogonal detection of particles in microfluidic channels.

    Science.gov (United States)

    Liu, Ruxiu; Wang, Ningquan; Kamili, Farhan; Sarioglu, A Fatih

    2016-04-21

    Numerous biophysical and biochemical assays rely on spatial manipulation of particles/cells as they are processed on lab-on-a-chip devices. Analysis of spatially distributed particles on these devices typically requires microscopy negating the cost and size advantages of microfluidic assays. In this paper, we introduce a scalable electronic sensor technology, called microfluidic CODES, that utilizes resistive pulse sensing to orthogonally detect particles in multiple microfluidic channels from a single electrical output. Combining the techniques from telecommunications and microfluidics, we route three coplanar electrodes on a glass substrate to create multiple Coulter counters producing distinct orthogonal digital codes when they detect particles. We specifically design a digital code set using the mathematical principles of Code Division Multiple Access (CDMA) telecommunication networks and can decode signals from different microfluidic channels with >90% accuracy through computation even if these signals overlap. As a proof of principle, we use this technology to detect human ovarian cancer cells in four different microfluidic channels fabricated using soft lithography. Microfluidic CODES offers a simple, all-electronic interface that is well suited to create integrated, low-cost lab-on-a-chip devices for cell- or particle-based assays in resource-limited settings.

  8. Fractal flow patterns in hydrophobic microfluidic pore networks: experimental modeling of two-phase flow in porous electrodes

    CERN Document Server

    Berejnov, Viatcheslav; Sinton, David; Djilali, Ned

    2009-01-01

    Experimental two-phase invasion percolation flow patterns were observed in hydrophobic micro-porous networks designed to model fuel cell specific porous media. In order to mimic the operational conditions encountered in the porous electrodes of polymer electrolyte membrane fuel cells (PEMFCs), micro-porous networks were fabricated with corresponding microchannel size distributions. The inlet channels were invaded homogeneously with flow rates corresponding to fuel cell current densities of 1.0 to 0.1 A/cm2 (Ca 10e-7-10e-8). A variety of fractal breakthrough patterns were observed and analyzed to quantify flooding density and geometrical diversity in terms of the total saturation, St, local saturations, s, and fractal dimension, D. It was found that St increases monotonically during the invasion process until the breakthrough point is reached, and s profiles indicate the dynamic distribution of the liquid phase during the process. Fractal analysis confirmed that the experiments fall within the flow regime of i...

  9. Development & Characterization of Multifunctional Microfluidic Materials

    Science.gov (United States)

    Ucar, Ahmet Burak

    The field of microfluidics has been mostly investigated for miniaturized lab on a chip devices for analytical and clinical applications. However, there is an emerging class of "smart" microfluidic materials, combining microfluidics with soft polymers to yield new functionalities. The best inspiration for such materials found in nature is skin, whose functions are maintained and controlled by a vascular "microfluidic" network. We report here the development and characterization of a few new classes of microfluidic materials. First, we introduced microfluidic materials that can change their stiffness on demand. These materials were based on an engineered microchannel network embedded into a matrix of polydimethylsiloxane (PDMS), whose channels were filled with a liquid photoresist (SU- 8). The elastomer filled with the photoresist was initially soft. The materials were shaped into a desired geometry and then exposed to UV-light. Once photocured, the material preserved the defined shape and it could be bent, twisted or stretched with a very high recoverable strain. As soon as the external force was removed the material returned back to its predefined shape. Thus, the polymerized SU-8 acted as the 'endoskeleton' of the microfluidic network, which drastically increased the composite's elastic and bending moduli. Second, we demonstrated a class of simple and versatile soft microfluidic materials that can be turned optically transparent or colored on demand. These materials were made in the form of flexible sheets containing a microchannel network embedded in PDMS, similar to the photocurable materials. However, this time the channels were filled with a glycerolwater mixture, whose refractive index was matched with that of the PDMS matrix. By pumping such dye solutions into the channel network and consecutively replacing the medium, we showed that we can control the material's color and light transmittance in the visible and near-infrared regions, which can be used for

  10. Parallel imaging microfluidic cytometer.

    Science.gov (United States)

    Ehrlich, Daniel J; McKenna, Brian K; Evans, James G; Belkina, Anna C; Denis, Gerald V; Sherr, David H; Cheung, Man Ching

    2011-01-01

    By adding an additional degree of freedom from multichannel flow, the parallel microfluidic cytometer (PMC) combines some of the best features of fluorescence-activated flow cytometry (FCM) and microscope-based high-content screening (HCS). The PMC (i) lends itself to fast processing of large numbers of samples, (ii) adds a 1D imaging capability for intracellular localization assays (HCS), (iii) has a high rare-cell sensitivity, and (iv) has an unusual capability for time-synchronized sampling. An inability to practically handle large sample numbers has restricted applications of conventional flow cytometers and microscopes in combinatorial cell assays, network biology, and drug discovery. The PMC promises to relieve a bottleneck in these previously constrained applications. The PMC may also be a powerful tool for finding rare primary cells in the clinic. The multichannel architecture of current PMC prototypes allows 384 unique samples for a cell-based screen to be read out in ∼6-10 min, about 30 times the speed of most current FCM systems. In 1D intracellular imaging, the PMC can obtain protein localization using HCS marker strategies at many times for the sample throughput of charge-coupled device (CCD)-based microscopes or CCD-based single-channel flow cytometers. The PMC also permits the signal integration time to be varied over a larger range than is practical in conventional flow cytometers. The signal-to-noise advantages are useful, for example, in counting rare positive cells in the most difficult early stages of genome-wide screening. We review the status of parallel microfluidic cytometry and discuss some of the directions the new technology may take.

  11. Valve Concepts for Microfluidic Cell Handling

    Directory of Open Access Journals (Sweden)

    M. Grabowski

    2010-01-01

    Full Text Available In this paper we present various pneumatically actuated microfluidic valves to enable user-defined fluid management within a microfluidic chip. To identify a feasible valve design, certain valve concepts are simulated in ANSYS to investigate the pressure dependent opening and closing characteristics of each design. The results are verified in a series of tests. Both the microfluidic layer and the pneumatic layer are realized by means of soft-lithographic techniques. In this way, a network of channels is fabricated in photoresist as a molding master. By casting these masters with PDMS (polydimethylsiloxane we get polymeric replicas containing the channel network. After a plasma-enhanced bonding process, the two layers are irreversibly bonded to each other. The bonding is tight for pressures up to 2 bar. The valves are integrated into a microfluidic cell handling system that is designed to manipulate cells in the presence of a liquid reagent (e.g. PEG – polyethylene glycol, for cell fusion. For this purpose a user-defined fluid management system is developed. The first test series with human cell lines show that the microfluidic chip is suitable for accumulating cells within a reaction chamber, where they can be flushed by a liquid medium.

  12. Commercialization of microfluidic devices.

    Science.gov (United States)

    Volpatti, Lisa R; Yetisen, Ali K

    2014-07-01

    Microfluidic devices offer automation and high-throughput screening, and operate at low volumes of consumables. Although microfluidics has the potential to reduce turnaround times and costs for analytical devices, particularly in medical, veterinary, and environmental sciences, this enabling technology has had limited diffusion into consumer products. This article analyzes the microfluidics market, identifies issues, and highlights successful commercialization strategies. Addressing niche markets and establishing compatibility with existing workflows will accelerate market penetration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Tunable Microfluidic Dye Laser

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter

    2003-01-01

    We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, but this principle only becomes practically applicable by the use of microfluidic mixing...

  14. Porous Microfluidic Devices - Fabrication adn Applications

    NARCIS (Netherlands)

    de Jong, J.; Geerken, M.J.; Lammertink, Rob G.H.; Wessling, Matthias

    2007-01-01

    The major part of microfluidic devices nowadays consists of a dense material that defines the fluidic structure. A generic fabrication method enabling the production of completely porous micro devices with user-defined channel networks is developed. The channel walls can be used as a (selective) bar

  15. Unconventional microfluidics: expanding the discipline.

    Science.gov (United States)

    Nawaz, Ahmad Ahsan; Mao, Xiaole; Stratton, Zackary S; Huang, Tony Jun

    2013-04-21

    Since its inception, the discipline of microfluidics has been harnessed for innovations in the biomedicine/chemistry fields-and to great effect. This success has had the natural side-effect of stereotyping microfluidics as a platform for medical diagnostics and miniaturized lab processes. But microfluidics has more to offer. And very recently, some researchers have successfully applied microfluidics to fields outside its traditional domains. In this Focus article, we highlight notable examples of such "unconventional" microfluidics applications (e.g., robotics, electronics). It is our hope that these early successes in unconventional microfluidics prompt further creativity, and inspire readers to expand the microfluidics discipline.

  16. Microfluidics and microbial engineering.

    Science.gov (United States)

    Kou, Songzi; Cheng, Danhui; Sun, Fei; Hsing, I-Ming

    2016-02-01

    The combination of microbial engineering and microfluidics is synergistic in nature. For example, microfluidics is benefiting from the outcome of microbial engineering and many reported point-of-care microfluidic devices employ engineered microbes as functional parts for the microsystems. In addition, microbial engineering is facilitated by various microfluidic techniques, due to their inherent strength in high-throughput screening and miniaturization. In this review article, we firstly examine the applications of engineered microbes for toxicity detection, biosensing, and motion generation in microfluidic platforms. Secondly, we look into how microfluidic technologies facilitate the upstream and downstream processes of microbial engineering, including DNA recombination, transformation, target microbe selection, mutant characterization, and microbial function analysis. Thirdly, we highlight an emerging concept in microbial engineering, namely, microbial consortium engineering, where the behavior of a multicultural microbial community rather than that of a single cell/species is delineated. Integrating the disciplines of microfluidics and microbial engineering opens up many new opportunities, for example in diagnostics, engineering of microbial motors, development of portable devices for genetics, high throughput characterization of genetic mutants, isolation and identification of rare/unculturable microbial species, single-cell analysis with high spatio-temporal resolution, and exploration of natural microbial communities.

  17. Nanomaterials meet microfluidics.

    Science.gov (United States)

    Pumera, Martin

    2011-05-28

    Nanomaterials and lab-on-a-chip platforms have undergone enormous development during the past decade. Here, we present an overview of how microfluidics benefited from the use of nanomaterials for the enhanced separation and detection of analytes. We also discuss how nanomaterials benefit from microfluidics in terms of synthesis and in terms of the simulation of environments for nanomotors and nanorobots. In our opinion, the "marriage" of nanomaterials and microfluidics is highly beneficial and is expected to solve vital challenges in related fields.

  18. Multi-layer microfluidic glass chips for microanalytical applications

    OpenAIRE

    Daridon, Antoine; Fascio, Valia; Lichtenberg, Jan; Wütrich, Rolf; Langen, Hans; Verpoorte, Elisabeth; De Rooij, Nicolaas F

    2010-01-01

    A new, versatile architecture is presented for microfluidic devices made entirely from glass, for use with reagents which would prove highly corrosive for silicon. Chips consist of three layers of glass wafers bonded together by fusion bonding. On the inside wafer faces a network of microfluidic channels is created by photolithography and wet chemical etching. Low dead-volume fluidic connections between the layers are fabricated by spark-assisted etching (SAE), a computer numerical controlled...

  19. Punch Card Programmable Microfluidics

    CERN Document Server

    Korir, George

    2014-01-01

    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes a series of operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series ...

  20. Cell manipulation in microfluidics.

    Science.gov (United States)

    Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

    2013-06-01

    Recent advances in the lab-on-a-chip field in association with nano/microfluidics have been made for new applications and functionalities to the fields of molecular biology, genetic analysis and proteomics, enabling the expansion of the cell biology field. Specifically, microfluidics has provided promising tools for enhancing cell biological research, since it has the ability to precisely control the cellular environment, to easily mimic heterogeneous cellular environment by multiplexing, and to analyze sub-cellular information by high-contents screening assays at the single-cell level. Various cell manipulation techniques in microfluidics have been developed in accordance with specific objectives and applications. In this review, we examine the latest achievements of cell manipulation techniques in microfluidics by categorizing externally applied forces for manipulation: (i) optical, (ii) magnetic, (iii) electrical, (iv) mechanical and (v) other manipulations. We furthermore focus on history where the manipulation techniques originate and also discuss future perspectives with key examples where available.

  1. Microfluidics in inorganic chemistry.

    Science.gov (United States)

    Abou-Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

    2010-08-23

    The application of microfluidics in chemistry has gained significant importance in the recent years. Miniaturized chemistry platforms provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. The advantages of microfluidics have been clearly established in the field of analytical and bioanalytical sciences and in the field of organic synthesis. It is less true in the field of inorganic chemistry and materials science; however in inorganic chemistry it has mostly been used for the separation and selective extraction of metal ions. Microfluidics has been used in materials science mainly for the improvement of nanoparticle synthesis, namely metal, metal oxide, and semiconductor nanoparticles. Microfluidic devices can also be used for the formulation of more advanced and sophisticated inorganic materials or hybrids.

  2. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng; Sui, Guodong; Elizarov, Arkadij; Kolb, Hartmuth C.; Huang, Jiang; Heath, James R.; Phelps, Michael E.; Quake, Stephen R.; Tseng, Hsian-rong; Wyatt, Paul; Daridon, Antoine

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  3. Microfluidic Bead Suspension Hopper

    OpenAIRE

    Price, Alexander K.; MacConnell, Andrew B.; Paegel, Brian M.

    2014-01-01

    Many high-throughput analytical platforms, from next-generation DNA sequencing to drug discovery, rely on beads as carriers of molecular diversity. Microfluidic systems are ideally suited to handle and analyze such bead libraries with high precision and at minute volume scales; however, the challenge of introducing bead suspensions into devices before they sediment usually confounds microfluidic handling and analysis. We developed a bead suspension hopper that exploits sedimentation to load b...

  4. Punch Card Programmable Microfluidics

    OpenAIRE

    George Korir; Manu Prakash

    2014-01-01

    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external component...

  5. Surface acoustic wave microfluidics.

    Science.gov (United States)

    Ding, Xiaoyun; Li, Peng; Lin, Sz-Chin Steven; Stratton, Zackary S; Nama, Nitesh; Guo, Feng; Slotcavage, Daniel; Mao, Xiaole; Shi, Jinjie; Costanzo, Francesco; Huang, Tony Jun

    2013-09-21

    The recent introduction of surface acoustic wave (SAW) technology onto lab-on-a-chip platforms has opened a new frontier in microfluidics. The advantages provided by such SAW microfluidics are numerous: simple fabrication, high biocompatibility, fast fluid actuation, versatility, compact and inexpensive devices and accessories, contact-free particle manipulation, and compatibility with other microfluidic components. We believe that these advantages enable SAW microfluidics to play a significant role in a variety of applications in biology, chemistry, engineering and medicine. In this review article, we discuss the theory underpinning SAWs and their interactions with particles and the contacting fluids in which they are suspended. We then review the SAW-enabled microfluidic devices demonstrated to date, starting with devices that accomplish fluid mixing and transport through the use of travelling SAW; we follow that by reviewing the more recent innovations achieved with standing SAW that enable such actions as particle/cell focusing, sorting and patterning. Finally, we look forward and appraise where the discipline of SAW microfluidics could go next.

  6. MEMS in microfluidic channels.

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, Carol Iris Hill; Okandan, Murat; Michalske, Terry A.; Sounart, Thomas L.; Matzke, Carolyn M.

    2004-03-01

    Microelectromechanical systems (MEMS) comprise a new class of devices that include various forms of sensors and actuators. Recent studies have shown that microscale cantilever structures are able to detect a wide range of chemicals, biomolecules or even single bacterial cells. In this approach, cantilever deflection replaces optical fluorescence detection thereby eliminating complex chemical tagging steps that are difficult to achieve with chip-based architectures. A key challenge to utilizing this new detection scheme is the incorporation of functionalized MEMS structures within complex microfluidic channel architectures. The ability to accomplish this integration is currently limited by the processing approaches used to seal lids on pre-etched microfluidic channels. This report describes Sandia's first construction of MEMS instrumented microfluidic chips, which were fabricated by combining our leading capabilities in MEMS processing with our low-temperature photolithographic method for fabricating microfluidic channels. We have explored in-situ cantilevers and other similar passive MEMS devices as a new approach to directly sense fluid transport, and have successfully monitored local flow rates and viscosities within microfluidic channels. Actuated MEMS structures have also been incorporated into microfluidic channels, and the electrical requirements for actuation in liquids have been quantified with an elegant theory. Electrostatic actuation in water has been accomplished, and a novel technique for monitoring local electrical conductivities has been invented.

  7. Monolayer-functionalized microfluidics devices for optical sensing of acidity

    NARCIS (Netherlands)

    Mela, P.; Onclin, S.; Goedbloed, M.H.; Levi, S.; Garcia-Parajo, M.F.; Hulst, van N.F.; Ravoo, B.J.; Reinhoudt, D.N.; Berg, van den A.

    2005-01-01

    This paper describes the integration of opto-chemosensors in microfluidics networks. Our technique exploits the internal surface of the network as a platform to build a sensing system by coating the surface with a self-assembled monolayer and subsequently binding a fluorescent sensing molecule to th

  8. Punch card programmable microfluidics.

    Science.gov (United States)

    Korir, George; Prakash, Manu

    2015-01-01

    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word "PUNCHCARD MICROFLUIDICS" using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world.

  9. Punch card programmable microfluidics.

    Directory of Open Access Journals (Sweden)

    George Korir

    Full Text Available Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word "PUNCHCARD MICROFLUIDICS" using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world.

  10. Discrete elements for 3D microfluidics.

    Science.gov (United States)

    Bhargava, Krisna C; Thompson, Bryant; Malmstadt, Noah

    2014-10-21

    Microfluidic systems are rapidly becoming commonplace tools for high-precision materials synthesis, biochemical sample preparation, and biophysical analysis. Typically, microfluidic systems are constructed in monolithic form by means of microfabrication and, increasingly, by additive techniques. These methods restrict the design and assembly of truly complex systems by placing unnecessary emphasis on complete functional integration of operational elements in a planar environment. Here, we present a solution based on discrete elements that liberates designers to build large-scale microfluidic systems in three dimensions that are modular, diverse, and predictable by simple network analysis techniques. We develop a sample library of standardized components and connectors manufactured using stereolithography. We predict and validate the flow characteristics of these individual components to design and construct a tunable concentration gradient generator with a scalable number of parallel outputs. We show that these systems are rapidly reconfigurable by constructing three variations of a device for generating monodisperse microdroplets in two distinct size regimes and in a high-throughput mode by simple replacement of emulsifier subcircuits. Finally, we demonstrate the capability for active process monitoring by constructing an optical sensing element for detecting water droplets in a fluorocarbon stream and quantifying their size and frequency. By moving away from large-scale integration toward standardized discrete elements, we demonstrate the potential to reduce the practice of designing and assembling complex 3D microfluidic circuits to a methodology comparable to that found in the electronics industry.

  11. Microfluidic parallel circuit for measurement of hydraulic resistance.

    Science.gov (United States)

    Choi, Sungyoung; Lee, Myung Gwon; Park, Je-Kyun

    2010-08-31

    We present a microfluidic parallel circuit that directly compares the test channel of an unknown hydraulic resistance with the reference channel with a known resistance, thereby measuring the unknown resistance without any measurement setup, such as standard pressure gauges. Many of microfluidic applications require the precise transport of fluid along a channel network with complex patterns. Therefore, it is important to accurately characterize and measure the hydraulic resistance of each channel segment, and determines whether the device principle works well. However, there is no fluidic device that includes features, such as the ability to diagnose microfluidic problems by measuring the hydraulic resistance of a microfluidic component in microscales. To address the above need, we demonstrate a simple strategy to measure an unknown hydraulic resistance, by characterizing the hydraulic resistance of microchannels with different widths and defining an equivalent linear channel of a microchannel with repeated patterns of a sudden contraction and expansion.

  12. [Application of microfluidics in aquatic environmental pollution analysis].

    Science.gov (United States)

    Wang, Hu; Wei, Jun-Feng; Zheng, Guo-Xia

    2014-04-01

    Recently, a new type of chip technology, microfluidics, has received global attention for its rapid analysis speed, low reagent consumption, small size and simple operation, etc. Based on a micro-channel network and supported by a Micro-Electro-Mechanic System (MEMS), this technology integrates all the functions of a laboratory into one small piece of chip, which is called "lab on the chip". This paper presented a brief introduction about microfluidics and its representative developments. Future prospects in the aspects of instrument miniaturization, system integration, chip materials, and detection techniques, as well as the implementation of microfluidics in aquatic environmental pollutant analysis were thoroughly discussed. Some problems faced now were put forward. With the rapid progress in the microfluidics, a universal low-cost microchip capable of high speed multi-channel detection and integrated with many kinds of detection methods would be the research focus in the future.

  13. Liquid metal enabled microfluidics.

    Science.gov (United States)

    Khoshmanesh, Khashayar; Tang, Shi-Yang; Zhu, Jiu Yang; Schaefer, Samira; Mitchell, Arnan; Kalantar-Zadeh, Kourosh; Dickey, Michael D

    2017-03-14

    Several gallium-based liquid metal alloys are liquid at room temperature. As 'liquid', such alloys have a low viscosity and a high surface tension while as 'metal', they have high thermal and electrical conductivities, similar to mercury. However, unlike mercury, these liquid metal alloys have low toxicity and a negligible vapor pressure, rendering them much safer. In comparison to mercury, the distinguishing feature of these alloys is the rapid formation of a self-limiting atomically thin layer of gallium oxide over their surface when exposed to oxygen. This oxide layer changes many physical and chemical properties of gallium alloys, including their interfacial and rheological properties, which can be employed and modulated for various applications in microfluidics. Injecting liquid metal into microfluidic structures has been extensively used to pattern and encapsulate highly deformable and reconfigurable electronic devices including electrodes, sensors, antennas, and interconnects. Likewise, the unique features of liquid metals have been employed for fabricating miniaturized microfluidic components including pumps, valves, heaters, and electrodes. In this review, we discuss liquid metal enabled microfluidic components, and highlight their desirable attributes including simple fabrication, facile integration, stretchability, reconfigurability, and low power consumption, with promising applications for highly integrated microfluidic systems.

  14. Pressure-driven microfluidic perfusion culture device for integrated dose-response assays.

    Science.gov (United States)

    Hattori, Koji; Sugiura, Shinji; Kanamori, Toshiyuki

    2013-12-01

    Cell-based assays are widely used in the various stages of drug discovery. Advances in microfluidic systems over the past two decades have enabled them to become a powerful tool for cell-based assays to achieve both reliability and high throughput. The interface between the micro-world and macro-world is important in industrial assay processes. Therefore, microfluidic cell-based assays using pressure-driven liquid handling are an ideal platform for integrated assays. The aim of this article is to review recent advancements in microfluidic cell-based assays focusing on a pressure-driven perfusion culture device. Here, we review the development of microfluidic cell-based assay devices and discuss the techniques involved in designing a microfluidic network, device fabrication, liquid and cell manipulation, and detection schemes for pressure-driven perfusion culture devices. Finally, we describe recent progress in semiautomatic and reliable pressure-driven microfluidic cell-based assays.

  15. Microfluidic Flame Barrier

    Science.gov (United States)

    Mungas, Gregory S. (Inventor); Fisher, David J. (Inventor); Mungas, Christopher (Inventor)

    2013-01-01

    Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

  16. Cell-based bioassays in microfluidic systems

    Science.gov (United States)

    Itle, Laura J.; Zguris, Jeanna C.; Pishko, Michael V.

    2004-12-01

    The development of cell-based bioassays for high throughput drug screening or the sensing of biotoxins is contingent on the development of whole cell sensors for specific changes in intracellular conditions and the integration of those systems into sample delivery devices. Here we show the feasibility of using a 5-(and-6)-carboxy SNARF-1, acetoxymethyl ester, acetate, a fluorescent dye capable of responding to changes in intracellular pH, as a detection method for the bacterial endotoxin, lipopolysaccharide. We used photolithography to entrap cells with this dye within poly(ethylene) glyocol diacrylate hydrogels in microfluidic channels. After 18 hours of exposure to lipopolysaccharide, we were able to see visible changes in the fluorescent pattern. This work shows the feasibility of using whole cell based biosensors within microfluidic networks to detect cellular changes in response to exogenous agents.

  17. Microfluidic technologies for studying synthetic circuits.

    Science.gov (United States)

    Lin, Benjamin; Levchenko, Andre

    2012-08-01

    Advances in synthetic biology have augmented the available toolkit of biomolecular modules, allowing engineering and manipulation of signaling in a variety of organisms, ranging in complexity from single bacteria and eukaryotic cells to multi-cellular systems. The richness of synthetic circuit outputs can be dramatically enhanced by sophisticated environmental control systems designed to precisely pattern spatial-temporally heterogeneous environmental stimuli controlling these circuits. Moreover, the performance of the synthetic modules and 'blocks' needed to assemble more complicated networks requires more complete characterization as a function of arbitrarily complex environmental inputs. Microfluidic technologies are poised to meet these needs through a variety of innovative designs capitalizing on the unique benefits of manipulating fluids on the micro-scales and nano-scales. This review discusses the utility of microfluidics for the study of synthetic circuits and highlights recent work in the area.

  18. Surfactants in microfluidics

    NARCIS (Netherlands)

    Michler, D.

    2015-01-01

    The rapid development of microfluidic techniques in the last two decades has revolutionized chemical and biological research. This technology has enabled scientists in a manifold of research fields to analyze and synthesize specimens with hither to unreached speed and precision. The number of applic

  19. Basic Microfluidics Theory

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith

    2015-01-01

    ,000 m−1, which is a huge difference and has a large impact on flow behavior. In this chapter the basic microfluidic theory will be presented, enabling the reader to gain a comprehensive understanding of how liquids behave at the microscale, enough to be able to engage in design of micro systems...

  20. Microfluidics for medical applications

    NARCIS (Netherlands)

    van den Berg, Albert; van den Berg, A.; Segerink, L.I.; Segerink, Loes Irene; Unknown, [Unknown

    2015-01-01

    Lab-on-a-chip devices for point of care diagnostics have been present in clinics for several years now. Alongside their continual development, research is underway to bring the organs and tissue on-a-chip to the patient, amongst other medical applications of microfluidics. This book provides the

  1. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...

  2. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  3. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

  4. Microfluidics: an enabling screening technology for enhanced oil recovery (EOR).

    Science.gov (United States)

    Lifton, Victor A

    2016-05-21

    Oil production is a critical industrial process that affects the entire world population and any improvements in its efficiency while reducing its environmental impact are of utmost societal importance. The paper reviews recent applications of microfluidics and microtechnology to study processes of oil extraction and recovery. It shows that microfluidic devices can be useful tools in investigation and visualization of such processes used in the oil & gas industry as fluid propagation, flooding, fracturing, emulsification and many others. Critical macro-scale processes that define oil extraction and recovery are controlled by the micro-scale processes based on wetting, adhesion, surface tension, colloids and other concepts of microfluidics. A growing number of research efforts demonstrates that microfluidics is becoming, albeit slowly, an accepted methodology in this area. We propose several areas of development where implementation of microfluidics may bring about deeper understanding and hence better control over the processes of oil recovery based on fluid propagation, droplet generation, wettability control. Studies of processes such as hydraulic fracturing, sand particle propagation in porous networks, high throughput screening of chemicals (for example, emulsifiers and surfactants) in microfluidic devices that simulate oil reservoirs are proposed to improve our understanding of these complicated physico-chemical systems. We also discuss why methods of additive manufacturing (3D printing) should be evaluated for quick prototyping and modification of the three-dimensional structures replicating natural oil-bearing rock formations for studies accessible to a wider audience of researchers.

  5. Magnetic digital microfluidics - a review.

    Science.gov (United States)

    Zhang, Yi; Nguyen, Nam-Trung

    2017-03-14

    A digital microfluidic platform manipulates droplets on an open surface. Magnetic digital microfluidics utilizes magnetic forces for actuation and offers unique advantages compared to other digital microfluidic platforms. First, the magnetic particles used in magnetic digital microfluidics have multiple functions. In addition to serving as actuators, they also provide a functional solid substrate for molecule binding, which enables a wide range of applications in molecular diagnostics and immunodiagnostics. Second, magnetic digital microfluidics can be manually operated in a "power-free" manner, which allows for operation in low-resource environments for point-of-care diagnostics where even batteries are considered a luxury item. This review covers research areas related to magnetic digital microfluidics. This paper first summarizes the current development of magnetic digital microfluidics. Various methods of droplet manipulation using magnetic forces are discussed, ranging from conventional magnetic particle-based actuation to the recent development of ferrofluids and magnetic liquid marbles. This paper also discusses several new approaches that use magnetically controlled flexible substrates for droplet manipulation. In addition, we emphasize applications of magnetic digital microfluidics in biosensing and medical diagnostics, and identify the current limitations of magnetic digital microfluidics. We provide a perspective on possible solutions to close these gaps. Finally, the paper discusses the future improvement of magnetic digital microfluidics to explore potential new research directions.

  6. PREFACE: Nano- and microfluidics Nano- and microfluidics

    Science.gov (United States)

    Jacobs, Karin

    2011-05-01

    The field of nano- and microfluidics emerged at the end of the 1990s parallel to the demand for smaller and smaller containers and channels for chemical, biochemical and medical applications such as blood and DNS analysis [1], gene sequencing or proteomics [2, 3]. Since then, new journals and conferences have been launched and meanwhile, about two decades later, a variety of microfluidic applications are on the market. Briefly, 'the small flow becomes mainstream' [4]. Nevertheless, research in nano- and microfluidics is more than downsizing the spatial dimensions. For liquids on the nanoscale, surface and interface phenomena grow in importance and may even dominate the behavior in some systems. The studies collected in this special issue all concentrate on these type of systems and were part ot the priority programme SPP1164 'Nano- and Microfluidics' of the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG). The priority programme was initiated in 2002 by Hendrik Kuhlmann and myself and was launched in 2004. Friction between a moving liquid and a solid wall may, for instance, play an important role so that the usual assumption of a no-slip boundary condition is no longer valid. Likewise, the dynamic deformations of soft objects like polymers, vesicles or capsules in flow arise from the subtle interplay between the (visco-)elasticity of the object and the viscous stresses in the surrounding fluid and, potentially, the presence of structures confining the flow like channels. Consequently, new theories were developed ( see articles in this issue by Münch and Wagner, Falk and Mecke, Bonthuis et al, Finken et al, Almenar and Rauscher, Straube) and experiments were set up to unambiguously demonstrate deviations from bulk, or 'macro', behavior (see articles in this issue by Wolff et al, Vinogradova and Belyaev, Hahn et al, Seemann et al, Grüner and Huber, Müller-Buschbaum et al, Gutsche et al, Braunmüller et al, Laube et al, Brücker, Nottebrock et al

  7. Highly Stretchable and Transparent Microfluidic Strain Sensors for Monitoring Human Body Motions.

    Science.gov (United States)

    Yoon, Sun Geun; Koo, Hyung-Jun; Chang, Suk Tai

    2015-12-16

    We report a new class of simple microfluidic strain sensors with high stretchability, transparency, sensitivity, and long-term stability with no considerable hysteresis and a fast response to various deformations by combining the merits of microfluidic techniques and ionic liquids. The high optical transparency of the strain sensors was achieved by introducing refractive-index matched ionic liquids into microfluidic networks or channels embedded in an elastomeric matrix. The microfluidic strain sensors offer the outstanding sensor performance under a variety of deformations induced by stretching, bending, pressing, and twisting of the microfluidic strain sensors. The principle of our microfluidic strain sensor is explained by a theoretical model based on the elastic channel deformation. In order to demonstrate its capability of practical usage, the simple-structured microfluidic strain sensors were performed onto a finger, wrist, and arm. The highly stretchable and transparent microfluidic strain sensors were successfully applied as potential platforms for distinctively monitoring a wide range of human body motions in real time. Our novel microfluidic strain sensors show great promise for making future stretchable electronic devices.

  8. Droplet microfluidics based microseparation systems.

    Science.gov (United States)

    Xiao, Zhiliang; Niu, Menglei; Zhang, Bo

    2012-06-01

    Lab on a chip (LOC) technology is a promising miniaturization approach. The feature that it significantly reduced sample consumption makes great sense in analytical and bioanalytical chemistry. Since the start of LOC technology, much attention has been focused on continuous flow microfluidic systems. At the turn of the century, droplet microfluidics, which was also termed segmented flow microfluidics, was introduced. Droplet microfluidics employs two immiscible phases to form discrete droplets, which are ideal vessels with confined volume, restricted dispersion, limited cross-contamination, and high surface area. Due to these unique features, droplet microfluidics proves to be a versatile tool in microscale sample handling. This article reviews the utility of droplet microfluidics in microanalytical systems with an emphasize on separation science, including sample encapsulation at ultra-small volume, compartmentalization of separation bands, isolation of droplet contents, and related detection techniques.

  9. System-level simulation of liquid filling in microfluidic chips.

    Science.gov (United States)

    Song, Hongjun; Wang, Yi; Pant, Kapil

    2011-06-01

    Liquid filling in microfluidic channels is a complex process that depends on a variety of geometric, operating, and material parameters such as microchannel geometry, flow velocity∕pressure, liquid surface tension, and contact angle of channel surface. Accurate analysis of the filling process can provide key insights into the filling time, air bubble trapping, and dead zone formation, and help evaluate trade-offs among the various design parameters and lead to optimal chip design. However, efficient modeling of liquid filling in complex microfluidic networks continues to be a significant challenge. High-fidelity computational methods, such as the volume of fluid method, are prohibitively expensive from a computational standpoint. Analytical models, on the other hand, are primarily applicable to idealized geometries and, hence, are unable to accurately capture chip level behavior of complex microfluidic systems. This paper presents a parametrized dynamic model for the system-level analysis of liquid filling in three-dimensional (3D) microfluidic networks. In our approach, a complex microfluidic network is deconstructed into a set of commonly used components, such as reservoirs, microchannels, and junctions. The components are then assembled according to their spatial layout and operating rationale to achieve a rapid system-level model. A dynamic model based on the transient momentum equation is developed to track the liquid front in the microchannels. The principle of mass conservation at the junction is used to link the fluidic parameters in the microchannels emanating from the junction. Assembly of these component models yields a set of differential and algebraic equations, which upon integration provides temporal information of the liquid filling process, particularly liquid front propagation (i.e., the arrival time). The models are used to simulate the transient liquid filling process in a variety of microfluidic constructs and in a multiplexer, representing a

  10. Methods of making microfluidic devices

    KAUST Repository

    Buttner, Ulrich

    2017-06-01

    Microfluidics has advanced in terms of designs and structures, however, fabrication methods are either time consuming or expensive to produce, in terms of the facilities and equipment needed. A fast and economically viable method is provided to allow, for example, research groups to have access to microfluidic fabrication. Unlike most fabrication methods, a method is provided to fabricate a microfluidic device in one step. In an embodiment, a resolution of 50 micrometers was achieved by using maskless high-resolution digital light projection (MDLP). Bonding and channel fabrication of complex or simple structures can be rapidly incorporated to fabricate the microfluidic devices.

  11. Microfluidic bubble logic.

    Science.gov (United States)

    Prakash, Manu; Gershenfeld, Neil

    2007-02-09

    We demonstrate universal computation in an all-fluidic two-phase microfluidic system. Nonlinearity is introduced into an otherwise linear, reversible, low-Reynolds number flow via bubble-to-bubble hydrodynamic interactions. A bubble traveling in a channel represents a bit, providing us with the capability to simultaneously transport materials and perform logical control operations. We demonstrate bubble logic AND/OR/NOT gates, a toggle flip-flop, a ripple counter, timing restoration, a ring oscillator, and an electro-bubble modulator. These show the nonlinearity, gain, bistability, synchronization, cascadability, feedback, and programmability required for scalable universal computation. With increasing complexity in large-scale microfluidic processors, bubble logic provides an on-chip process control mechanism integrating chemistry and computation.

  12. Microfluidic colloid filtration

    Science.gov (United States)

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

    2016-03-01

    Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level.

  13. The Microfluidic Jukebox

    Science.gov (United States)

    Tan, Say Hwa; Maes, Florine; Semin, Benoît; Vrignon, Jérémy; Baret, Jean-Christophe

    2014-04-01

    Music is a form of art interweaving people of all walks of life. Through subtle changes in frequencies, a succession of musical notes forms a melody which is capable of mesmerizing the minds of people. With the advances in technology, we are now able to generate music electronically without relying solely on physical instruments. Here, we demonstrate a musical interpretation of droplet-based microfluidics as a form of novel electronic musical instruments. Using the interplay of electric field and hydrodynamics in microfluidic devices, well controlled frequency patterns corresponding to musical tracks are generated in real time. This high-speed modulation of droplet frequency (and therefore of droplet sizes) may also provide solutions that reconciles high-throughput droplet production and the control of individual droplet at production which is needed for many biochemical or material synthesis applications.

  14. Microfluidic redox battery.

    Science.gov (United States)

    Lee, Jin Wook; Goulet, Marc-Antoni; Kjeang, Erik

    2013-07-01

    A miniaturized microfluidic battery is proposed, which is the first membraneless redox battery demonstrated to date. This unique concept capitalizes on dual-pass flow-through porous electrodes combined with stratified, co-laminar flow to generate electrical power on-chip. The fluidic design is symmetric to allow for both charging and discharging operations in forward, reverse, and recirculation modes. The proof-of-concept device fabricated using low-cost materials integrated in a microfluidic chip is shown to produce competitive power levels when operated on a vanadium redox electrolyte. A complete charge/discharge cycle is performed to demonstrate its operation as a rechargeable battery, which is an important step towards providing sustainable power to lab-on-a-chip and microelectronic applications.

  15. Droplet based microfluidics.

    Science.gov (United States)

    Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan

    2012-01-01

    Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.

  16. Droplet based microfluidics

    Science.gov (United States)

    Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan

    2012-01-01

    Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.

  17. Microfluidic desalination. Capacitive deionization on chip for microfluidic sample preparation

    NARCIS (Netherlands)

    Roelofs, Susan Helena

    2015-01-01

    The main aim of the work described in this thesis is to implement the desalination technique capacitive deionization (CDI) on a microfluidic chip to improve the reproducibility in the analysis of biological samples for drug development. Secondly, microfluidic CDI allows for the in situ study of ion

  18. Microfluidic vascular channels in gels using commercial 3D printers

    Science.gov (United States)

    Selvaganapathy, P. Ravi; Attalla, Rana

    2016-03-01

    This paper details the development of a three dimensional (3D) printing system with a modified microfluidic printhead used for the generation of complex vascular tissue scaffolds. The print-head features an integrated coaxial nozzle that allows the fabrication of hollow, calcium-polymerized alginate tubes that can easily be patterned using 3Dbioprinting techniques. This microfluidic design allows the incorporation of a wide range of scaffold materials as well as biological constituents such as cells, growth factors, and ECM material. With this setup, gel constructs with embedded arrays of hollow channels can be created and used as a potential substitute for blood vessel networks.

  19. Path to Low Cost Microfluidics

    CERN Document Server

    Govyadinov, Alexander N; Kornilovitch, Pavel; Markel, David

    2016-01-01

    The paper describes a novel concept for a low cost microfluidic platform utilizing materials and processes used in low cost thermal inkjet printing. The concept re-purposes the jetting elements to create pumps, mixers, and valves all necessary components for the transport of fluids in a broad range of microfluidic applications.

  20. Microfluidic devices for biological applications

    CSIR Research Space (South Africa)

    Potgieter, S

    2010-01-01

    Full Text Available , faster reaction times and process-specific designs. A microfluidic system typically consists of a series of channels with components like pumps, valves and actuators to control the flow of fluids. One of the applications being worked on is a microfluidic...

  1. Centrifugal microfluidics for biomedical applications.

    Science.gov (United States)

    Gorkin, Robert; Park, Jiwoon; Siegrist, Jonathan; Amasia, Mary; Lee, Beom Seok; Park, Jong-Myeon; Kim, Jintae; Kim, Hanshin; Madou, Marc; Cho, Yoon-Kyoung

    2010-07-21

    The centrifugal microfluidic platform has been a focus of academic and industrial research efforts for almost 40 years. Primarily targeting biomedical applications, a range of assays have been adapted on the system; however, the platform has found limited commercial success as a research or clinical tool. Nonetheless, new developments in centrifugal microfluidic technologies have the potential to establish wide-spread utilization of the platform. This paper presents an in-depth review of the centrifugal microfluidic platform, while highlighting recent progress in the field and outlining the potential for future applications. An overview of centrifugal microfluidic technologies is presented, including descriptions of advantages of the platform as a microfluidic handling system and the principles behind centrifugal fluidic manipulation. The paper also discusses a history of significant centrifugal microfluidic platform developments with an explanation of the evolution of the platform as it pertains to academia and industry. Lastly, we review the few centrifugal microfluidic-based sample-to-answer analysis systems shown to date and examine the challenges to be tackled before the centrifugal platform can be more broadly accepted as a new diagnostic platform. In particular, fully integrated, easy to operate, inexpensive and accurate microfluidic tools in the area of in vitro nucleic acid diagnostics are discussed.

  2. Active matter logic for autonomous microfluidics

    Science.gov (United States)

    Woodhouse, Francis G.; Dunkel, Jörn

    2017-04-01

    Chemically or optically powered active matter plays an increasingly important role in materials design, but its computational potential has yet to be explored systematically. The competition between energy consumption and dissipation imposes stringent physical constraints on the information transport in active flow networks, facilitating global optimization strategies that are not well understood. Here, we combine insights from recent microbial experiments with concepts from lattice-field theory and non-equilibrium statistical mechanics to introduce a generic theoretical framework for active matter logic. Highlighting conceptual differences with classical and quantum computation, we demonstrate how the inherent non-locality of incompressible active flow networks can be utilized to construct universal logical operations, Fredkin gates and memory storage in set-reset latches through the synchronized self-organization of many individual network components. Our work lays the conceptual foundation for developing autonomous microfluidic transport devices driven by bacterial fluids, active liquid crystals or chemically engineered motile colloids.

  3. RNA-protein binding kinetics in an automated microfluidic reactor.

    Science.gov (United States)

    Ridgeway, William K; Seitaridou, Effrosyni; Phillips, Rob; Williamson, James R

    2009-11-01

    Microfluidic chips can automate biochemical assays on the nanoliter scale, which is of considerable utility for RNA-protein binding reactions that would otherwise require large quantities of proteins. Unfortunately, complex reactions involving multiple reactants cannot be prepared in current microfluidic mixer designs, nor is investigation of long-time scale reactions possible. Here, a microfluidic 'Riboreactor' has been designed and constructed to facilitate the study of kinetics of RNA-protein complex formation over long time scales. With computer automation, the reactor can prepare binding reactions from any combination of eight reagents, and is optimized to monitor long reaction times. By integrating a two-photon microscope into the microfluidic platform, 5-nl reactions can be observed for longer than 1000 s with single-molecule sensitivity and negligible photobleaching. Using the Riboreactor, RNA-protein binding reactions with a fragment of the bacterial 30S ribosome were prepared in a fully automated fashion and binding rates were consistent with rates obtained from conventional assays. The microfluidic chip successfully combines automation, low sample consumption, ultra-sensitive fluorescence detection and a high degree of reproducibility. The chip should be able to probe complex reaction networks describing the assembly of large multicomponent RNPs such as the ribosome.

  4. MICROFLUIDIC COMPONENT CAPABLE OF SELF-SEALING

    DEFF Research Database (Denmark)

    2009-01-01

    A microfluidic component (100) for building a microfluidic system is provided. The microfluidic component (100) can be mounted on a microf luidic breadboard (202) in a manner that allows it to be connected to other microfluidic components (204, 206) without the requirement of additional devices....... The microfluidic component (100) comprises at least one flexible tube piece (102) for transporting a fluid. The microfluidic component (100) also comprises means for applying and maintaining pressure (104) between the flexible tube piece (102) and a tube piece (208, 210) housed in another microfluidic component...

  5. Rapid, low-cost prototyping of centrifugal microfluidic devices for effective implementation of various microfluidic operations

    CSIR Research Space (South Africa)

    Hugo, S

    2013-10-01

    Full Text Available The work presented here details the implementation of a centrifugal microfluidic platform – the first of its kind in South Africa – as a foundation for the development of various microfluidic operations. Microfluidic systems enable the precise...

  6. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  7. Rapid manufacturing for microfluidics

    CSIR Research Space (South Africa)

    Land, K

    2012-10-01

    Full Text Available . Microfluidics is at the forefront of developing solutions for drug discovery, diagnostics (from glucose tests to malaria and TB testing) and environmental diagnostics (E-coli monitoring of drinking water). In order to quickly implement new designs, a rapid... stream_source_info Land_2012.pdf.txt stream_content_type text/plain stream_size 2089 Content-Encoding ISO-8859-1 stream_name Land_2012.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Rapid manufacturing...

  8. Microfluidic Cell Culture Device

    Science.gov (United States)

    Takayama, Shuichi (Inventor); Cabrera, Lourdes Marcella (Inventor); Heo, Yun Seok (Inventor); Smith, Gary Daniel (Inventor)

    2014-01-01

    Microfluidic devices for cell culturing and methods for using the same are disclosed. One device includes a substrate and membrane. The substrate includes a reservoir in fluid communication with a passage. A bio-compatible fluid may be added to the reservoir and passage. The reservoir is configured to receive and retain at least a portion of a cell mass. The membrane acts as a barrier to evaporation of the bio-compatible fluid from the passage. A cover fluid may be added to cover the bio-compatible fluid to prevent evaporation of the bio-compatible fluid.

  9. Spatial manipulation with microfluidics

    Directory of Open Access Journals (Sweden)

    Benjamin eLin

    2015-04-01

    Full Text Available Biochemical gradients convey information through space, time, and concentration, and are ultimately capable of spatially resolving distinct cellular phenotypes, such as differentiation, proliferation, and migration. How these gradients develop, evolve, and function during development, homeostasis, and various disease states is a subject of intense interest across a variety of disciplines. Microfluidic technologies have become essential tools for investigating gradient sensing in vitro due to their ability to precisely manipulate fluids on demand in well controlled environments at cellular length scales. This minireview will highlight their utility for studying gradient sensing along with relevant applications to biology.

  10. Microfluidic Radiometal Labeling Systems for Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, D E; Kenis, P J. A.

    2011-12-29

    In a typical labeling procedure with radiometals, such as Cu-64 and Ga-68; a very large (~ 100-fold) excess of the non-radioactive reactant (precursor) is used to promote rapid and efficient incorporation of the radioisotope into the PET imaging agent. In order to achieve high specific activities, careful control of reaction conditions and extensive chromatographic purifications are required in order to separate the labeled compounds from the cold precursors. Here we propose a microfluidic approach to overcome these problems, and achieve high specific activities in a more convenient, semi-automated fashion and faster time frame. Microfluidic reactors, consisting of a network of micron-sized channels (typical dimensions in the range 10 - 300¼m), filters, separation columns, electrodes and reaction loops/chambers etched onto a solid substrate, are now emerging as an extremely useful technology for the intensification and miniaturization of chemical processes. The ability to manipulate, process and analyze reagent concentrations and reaction interfaces in both space and time within the channel network of a microreactor provides the fine level of reaction control that is desirable in PET radiochemistry practice. These factors can bring radiometal labeling, specifically the preparation of radio-labeled biomolecules such as antibodies, much closer to their theoretical maximum specific activities.

  11. Electro-Microfluidic Packaging

    Science.gov (United States)

    Benavides, G. L.; Galambos, P. C.

    2002-06-01

    There are many examples of electro-microfluidic products that require cost effective packaging solutions. Industry has responded to a demand for products such as drop ejectors, chemical sensors, and biological sensors. Drop ejectors have consumer applications such as ink jet printing and scientific applications such as patterning self-assembled monolayers or ejecting picoliters of expensive analytes/reagents for chemical analysis. Drop ejectors can be used to perform chemical analysis, combinatorial chemistry, drug manufacture, drug discovery, drug delivery, and DNA sequencing. Chemical and biological micro-sensors can sniff the ambient environment for traces of dangerous materials such as explosives, toxins, or pathogens. Other biological sensors can be used to improve world health by providing timely diagnostics and applying corrective measures to the human body. Electro-microfluidic packaging can easily represent over fifty percent of the product cost and, as with Integrated Circuits (IC), the industry should evolve to standard packaging solutions. Standard packaging schemes will minimize cost and bring products to market sooner.

  12. Microfluidic fuel cells and batteries

    CERN Document Server

    Kjeang, Erik

    2014-01-01

    Microfluidic fuel cells and batteries represent a special type of electrochemical power generators that can be miniaturized and integrated in a microfluidic chip. Summarizing the initial ten years of research and development in this emerging field, this SpringerBrief is the first book dedicated to microfluidic fuel cell and battery technology for electrochemical energy conversion and storage. Written at a critical juncture, where strategically applied research is urgently required to seize impending technology opportunities for commercial, analytical, and educational utility, the intention is

  13. Three-dimensional paper microfluidic devices assembled using the principles of origami.

    Science.gov (United States)

    Liu, Hong; Crooks, Richard M

    2011-11-01

    We report a method, based on the principles of origami (paper folding), for fabricating three-dimensional (3-D) paper microfluidic devices. The entire 3-D device is fabricated on a single sheet of flat paper in a single photolithographic step. It is assembled by simply folding the paper by hand. Following analysis, the device can be unfolded to reveal each layer. The applicability of the device to chemical analysis is demonstrated by colorimetric and fluorescence assays using multilayer microfluidic networks.

  14. Using a microfluidic device for high-content analysis of cell signaling.

    Science.gov (United States)

    Cheong, Raymond; Wang, Chiaochun Joanne; Levchenko, Andre

    2009-06-16

    Quantitative analysis and understanding of signaling networks require measurements of the location and activities of key proteins over time, at the level of single cells, in response to various perturbations. Microfluidic devices enable such analyses to be conducted in a high-throughput and in a highly controlled manner. We describe in detail how to design and use a microfluidic device to perform such information-rich experiments.

  15. Microfluidic Multichannel Flow Cytometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a "Microfluidic Multichannel Flow Cytometer." Several novel concepts are integrated to produce the final design, which is compatible with...

  16. Whole-Teflon microfluidic chips

    National Research Council Canada - National Science Library

    Kangning Ren; Wen Dai; Jianhua Zhou; Jing Su; Hongkai Wu

    2011-01-01

    .... In this work, we present a convenient strategy for fabricating whole-Teflon microfluidic chips with integrated valves that show outstanding inertness to various chemicals and extreme resistance against all solvents...

  17. Single cell microfluidics for systems oncology

    Science.gov (United States)

    Fan, Rong

    2012-02-01

    The singular term ``cancer'' is never one kind of disease, but deceivingly encompasses a large number of heterogeneous disease states, which makes it impossible to completely treat cancer using a generic approach. Rather systems approaches are urgently required to assess cancer heterogeneity, stratify patients and enable the most effective, individualized treatment. The heterogeneity of tumors at the single cell level is reflected by the hierarchical complexity of the tumor microenvironment. To identify all the cellular components, including both tumor and infiltrating immune cells, and to delineate the associated cell-to-cell signaling network that dictates tumor initiation, progression and metastasis, we developed a single cell microfluidics chip that can analyze a panel of proteins that are potentially associated inter-cellular signaling network in tumor microenvironment from hundreds of single cells in parallel. This platform integrates two advanced technologies -- microfluidic single cell handling and ultra-high density protein array. This device was first tested for highly multiplexed profiling of secreted proteins including tumor-immune signaling molecules from monocytic leukemia cells. We observed profound cellular heterogeneity with all functional phenotypes quantitatively identified. Correlation analysis further indicated the existence of an intercellular cytokine network in which TNFα-induced secondary signaling cascades further increased functional cellular diversity. It was also exploited to evaluate polyfunctionality of tumor antigen-specific T cells from melanoma patients being treated with adoptive T cell transfer immunotherapy. This platform could be further extended to analyze both solid tumor cells (e.g. human lung carcinoma cells) and infiltrating immune cells (e.g. macrophages) so as to enable systems analysis of the complex tumor microenvironment from small amounts of clinical specimens, e.g. skinny needle biopsies. Thus, it could potentially

  18. Perspective: microfluidic applications in microbiology.

    Science.gov (United States)

    Saleh-Lakha, Saleema; Trevors, Jack T

    2010-07-01

    The application of microfluidics technology to microbiology research is an excellent platform for the analysis of microorganisms and their nucleic acids. This technology combines engineering, physics, chemistry, biology and computing to control the devices. In this perspective we discuss how microfluidics can be applied to microbiological research and used in diagnostic applications. We also summarize advantages and limitations of this technology, as well as highlight some recent microbiological applications.

  19. Microfluidics - Sorting particles with light

    DEFF Research Database (Denmark)

    Glückstad, J.

    2004-01-01

    Microfluidic systems have great potential to perform complex chemical and biological processing and analysis on a single disposable chip. That goal is now a step closer with the demonstration of an efficient all-optical particle sorter.......Microfluidic systems have great potential to perform complex chemical and biological processing and analysis on a single disposable chip. That goal is now a step closer with the demonstration of an efficient all-optical particle sorter....

  20. Passive microfluidic array card and reader

    Science.gov (United States)

    Dugan, Lawrence Christopher [Modesto, CA; Coleman, Matthew A [Oakland, CA

    2011-08-09

    A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.

  1. Microfluidic Mechanics and Applications: a Review

    Directory of Open Access Journals (Sweden)

    Sandeep Arya

    2014-01-01

    Full Text Available Microfluidics involves the transportation, splitting and mixing of minute fluids to perform several chemical and biological reactions including drug screening, heating, cooling or dissolution of reagents. Efforts have been made to develop different microfluidic devices, droplets and valves that can stop and resume flow of liquids inside a microchannel. This paper provides the review related to the theory and mechanics of microfluidic devices and fluid flow. Different materials and techniques for fabricating microfluidic devices are discussed. Subsequently, the microfluidic components that are responsible for successful micrfluidic device formation are presented. Finally, recent applications related to the microfluidics are highlighted.

  2. Spiral microfluidic nanoparticle separators

    Science.gov (United States)

    Bhagat, Ali Asgar S.; Kuntaegowdanahalli, Sathyakumar S.; Dionysiou, Dionysios D.; Papautsky, Ian

    2008-02-01

    Nanoparticles have potential applications in many areas such as consumer products, health care, electronics, energy and other industries. As the use of nanoparticles in manufacturing increases, we anticipate a growing need to detect and measure particles of nanometer scale dimensions in fluids to control emissions of possible toxic nanoparticles. At present most particle separation techniques are based on membrane assisted filtering schemes. Unfortunately their efficiency is limited by the membrane pore size, making them inefficient for separating a wide range of sizes. In this paper, we propose a passive spiral microfluidic geometry for momentum-based particle separations. The proposed design is versatile and is capable of separating particulate mixtures over a wide dynamic range and we expect it will enable a variety of environmental, medical, or manufacturing applications that involve rapid separation of nanoparticles in real-world samples with a wide range of particle components.

  3. Interplay between materials and microfluidics

    Science.gov (United States)

    Hou, Xu; Zhang, Yu Shrike; Santiago, Grissel Trujillo-De; Alvarez, Mario Moisés; Ribas, João; Jonas, Steven J.; Weiss, Paul S.; Andrews, Anne M.; Aizenberg, Joanna; Khademhosseini, Ali

    2017-04-01

    Developments in the field of microfluidics have triggered technological revolutions in many disciplines, including chemical synthesis, electronics, diagnostics, single-cell analysis, micro- and nanofabrication, and pharmaceutics. In many of these areas, rapid growth is driven by the increasing synergy between fundamental materials development and new microfluidic capabilities. In this Review, we critically evaluate both how recent advances in materials fabrication have expanded the frontiers of microfluidic platforms and how the improved microfluidic capabilities are, in turn, furthering materials design. We discuss how various inorganic and organic materials enable the fabrication of systems with advanced mechanical, optical, chemical, electrical and biointerfacial properties — in particular, when these materials are combined into new hybrids and modular configurations. The increasing sophistication of microfluidic techniques has also expanded the range of resources available for the fabrication of new materials, including particles and fibres with specific functionalities, 3D (bio)printed composites and organoids. Together, these advances lead to complex, multifunctional systems, which have many interesting potential applications, especially in the biomedical and bioengineering domains. Future exploration of the interactions between materials science and microfluidics will continue to enrich the diversity of applications across engineering as well as the physical and biomedical sciences.

  4. Digital Microfluidics Sample Analyzer

    Science.gov (United States)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.

    2010-01-01

    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  5. A hybrid microfluidic-vacuum device for direct interfacing with conventional cell culture methods.

    Science.gov (United States)

    Chung, Bong Geun; Park, Jeong Won; Hu, Jia Sheng; Huang, Carlos; Monuki, Edwin S; Jeon, Noo Li

    2007-09-20

    Microfluidics is an enabling technology with a number of advantages over traditional tissue culture methods when precise control of cellular microenvironment is required. However, there are a number of practical and technical limitations that impede wider implementation in routine biomedical research. Specialized equipment and protocols required for fabrication and setting up microfluidic experiments present hurdles for routine use by most biology laboratories. We have developed and validated a novel microfluidic device that can directly interface with conventional tissue culture methods to generate and maintain controlled soluble environments in a Petri dish. It incorporates separate sets of fluidic channels and vacuum networks on a single device that allows reversible application of microfluidic gradients onto wet cell culture surfaces. Stable, precise concentration gradients of soluble factors were generated using simple microfluidic channels that were attached to a perfusion system. We successfully demonstrated real-time optical live/dead cell imaging of neural stem cells exposed to a hydrogen peroxide gradient and chemotaxis of metastatic breast cancer cells in a growth factor gradient. This paper describes the design and application of a versatile microfluidic device that can directly interface with conventional cell culture methods. This platform provides a simple yet versatile tool for incorporating the advantages of a microfluidic approach to biological assays without changing established tissue culture protocols.

  6. A practical guide to microfluidic perfusion culture of adherent mammalian cells.

    Science.gov (United States)

    Kim, Lily; Toh, Yi-Chin; Voldman, Joel; Yu, Hanry

    2007-06-01

    Culturing cells at microscales allows control over microenvironmental cues, such as cell-cell and cell-matrix interactions; the potential to scale experiments; the use of small culture volumes; and the ability to integrate with microsystem technologies for on-chip experimentation. Microfluidic perfusion culture in particular allows controlled delivery and removal of soluble biochemical molecules in the extracellular microenvironment, and controlled application of mechanical forces exerted via fluid flow. There are many challenges to designing and operating a robust microfluidic perfusion culture system for routine culture of adherent mammalian cells. The current literature on microfluidic perfusion culture treats microfluidic design, device fabrication, cell culture, and micro-assays independently. Here we systematically present and discuss important design considerations in the context of the entire microfluidic perfusion culture system. These design considerations include the choice of materials, culture configurations, microfluidic network fabrication and micro-assays. We also present technical issues such as sterilization; seeding cells in both 2D and 3D configurations; and operating the system under optimized mass transport and shear stress conditions, free of air-bubbles. The integrative and systematic treatment of the microfluidic system design and fabrication, cell culture, and micro-assays provides novices with an effective starting point to build and operate a robust microfludic perfusion culture system for various applications.

  7. A hybrid microfluidic-vacuum device for direct interfacing with conventional cell culture methods

    Directory of Open Access Journals (Sweden)

    Monuki Edwin S

    2007-09-01

    Full Text Available Abstract Background Microfluidics is an enabling technology with a number of advantages over traditional tissue culture methods when precise control of cellular microenvironment is required. However, there are a number of practical and technical limitations that impede wider implementation in routine biomedical research. Specialized equipment and protocols required for fabrication and setting up microfluidic experiments present hurdles for routine use by most biology laboratories. Results We have developed and validated a novel microfluidic device that can directly interface with conventional tissue culture methods to generate and maintain controlled soluble environments in a Petri dish. It incorporates separate sets of fluidic channels and vacuum networks on a single device that allows reversible application of microfluidic gradients onto wet cell culture surfaces. Stable, precise concentration gradients of soluble factors were generated using simple microfluidic channels that were attached to a perfusion system. We successfully demonstrated real-time optical live/dead cell imaging of neural stem cells exposed to a hydrogen peroxide gradient and chemotaxis of metastatic breast cancer cells in a growth factor gradient. Conclusion This paper describes the design and application of a versatile microfluidic device that can directly interface with conventional cell culture methods. This platform provides a simple yet versatile tool for incorporating the advantages of a microfluidic approach to biological assays without changing established tissue culture protocols.

  8. Electrorheological fluid-actuated microfluidic pump

    Science.gov (United States)

    Liu, Liyu; Chen, Xiaoqing; Niu, Xize; Wen, Weijia; Sheng, Ping

    2006-08-01

    The authors report the design and implementation of an electrorheological (ER) fluid-actuated microfluidic pump, with programmable digital control. Our microfluidic pump has a multilayered structure fabricated on polydimethylsiloxane by soft-lithographic technique. The ER microfluidic pump exhibits good performance at high pumping frequencies and uniform liquid flow characteristics. It can be easily integrated with other microfluidic components. The programmable control also gives the device flexibility in its operations.

  9. Computational Fluid Dynamics at work - Design and Optimization of Microfluidic Applications

    DEFF Research Database (Denmark)

    Krühne, Ulrich; Bodla, Vijaya Krishna; Møllenbach, Jacob

    2012-01-01

    Computational Fluid Dynamics (CFD) is presented as a powerful tool to support design and optimization of microfluidic reactors. This is demonstrated by means of three case studies. First a three-dimensional scaffold for tissue engineering purposes is investigated using a combination of CFD...... and a simple biological model. The result is a suggestion of an improved geometry design. In the second case study a microfluidic cartridge of a novel automated in vitro fertilization device is presented, where the CFD model has supported the fluidic design of the microfluidic network in which the stem cells...... are grown. In the last case study a biocatalytic microfluidic reactor design is presented in which the material characteristics of substrates and products of the catalytic reaction can be investigated. As model system the transaminase catalyzed formation of methylbenzylamine (MBA) from acetophenone...

  10. Microfluidic devices for cell cultivation and proliferation

    OpenAIRE

    Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

    2013-01-01

    Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell cul...

  11. Microfluidic stretchable RF electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2010-12-07

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  12. Vibration Induced Microfluidic Atomization

    Science.gov (United States)

    Yeo, Leslie; Qi, Aisha; Friend, James

    2008-11-01

    We demonstrate rapid generation of micron aerosol droplets in a microfluidic device in which a fluid drop is exposed to surface vibration as it sits atop a piezoelectric substrate. Little, however, is understood about the processes by which these droplets form due to the complex hydrodynamic processes that occur across widely varying length and time scales. Through experiments, scaling theory and numerical modelling, we elucidate the interfacial destabilization mechanisms that lead to droplet formation. Droplets form due to the axisymmetric break-up of cylindrical liquid jets ejected as a consequence of interfacial destabilization. Their 10 μm size correlates with the jet radius and the instability wavelength, both determined from a viscous-capillary dominant force balance and confirmed through a numerical solution. With the exception of drops that spread into thin films with thicknesses on the order of the boundary layer dimension, the free surface is always observed to vibrate at the capillary-viscous resonance frequency despite the surface vibration frequency being several orders larger. This is contrary to common assumptions used in deriving subharmonic models resulting in a Mathieu equation, which has commonly led to spurious predictions in the droplet size.

  13. Microfluidic tools toward industrial biotechnology.

    Science.gov (United States)

    Oliveira, Aline F; Pessoa, Amanda C S N; Bastos, Reinaldo G; de la Torre, Lucimara G

    2016-11-01

    Microfluidics is a technology that operates with small amounts of fluids and makes possible the investigation of cells, enzymes, and biomolecules and encapsulation of biocatalysts in a greater variety of conditions than permitted using conventional methods. This review discusses technological possibilities that can be applied in the field of industrial biotechnology, presenting the principal definitions and fundamental aspects of microfluidic parameters to better understand advanced approaches. Specifically, concentration gradient generators, droplet-based microfluidics, and microbioreactors are explored as useful tools that can contribute to industrial biotechnology. These tools present potential applications, inclusive as commercial platforms to optimizing in bioprocesses development as screening cells, encapsulating biocatalysts, and determining critical kinetic parameters. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1372-1389, 2016. © 2016 American Institute of Chemical Engineers.

  14. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    This Ph.D. thesis presents theory, modeling, design, fabrication, experiments and results for microfluidic magnetic separators. A model for magnetic bead movement in a microfluidic channel is presented, and the limits of the model are discussed. The effective magnetic field gradient is defined...... for fabrication of silicon based systems. This fabrication scheme is explained, and it is shown how, it is applied with variations for several designs of magnetic separators. An experimental setup for magnetic separation experiments has been developed. It has been coupled with an image analysis program....... It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside...

  15. Microfluidic Technologies for Synthetic Biology

    Directory of Open Access Journals (Sweden)

    Sung Kuk Lee

    2011-06-01

    Full Text Available Microfluidic technologies have shown powerful abilities for reducing cost, time, and labor, and at the same time, for increasing accuracy, throughput, and performance in the analysis of biological and biochemical samples compared with the conventional, macroscale instruments. Synthetic biology is an emerging field of biology and has drawn much attraction due to its potential to create novel, functional biological parts and systems for special purposes. Since it is believed that the development of synthetic biology can be accelerated through the use of microfluidic technology, in this review work we focus our discussion on the latest microfluidic technologies that can provide unprecedented means in synthetic biology for dynamic profiling of gene expression/regulation with high resolution, highly sensitive on-chip and off-chip detection of metabolites, and whole-cell analysis.

  16. Applications of microfluidics in quantitative biology.

    Science.gov (United States)

    Bai, Yang; Gao, Meng; Wen, Lingling; He, Caiyun; Chen, Yuan; Liu, Chenli; Fu, Xiongfei; Huang, Shuqiang

    2017-10-04

    Quantitative biology is dedicated to taking advantage of quantitative reasoning and advanced engineering technologies to make biology more predictable. Microfluidics, as an emerging technique, provides new approaches to precisely control fluidic conditions on small scales and collect data in high-throughput and quantitative manners. In this review, we present the relevant applications of microfluidics to quantitative biology based on two major categories (channel-based microfluidics and droplet-based microfluidics), and their typical features. We also envision some other microfluidic techniques that may not be employed in quantitative biology right now, but have great potential in the near future. This article is protected by copyright. All rights reserved.

  17. Microfluidic 3D Helix Mixers

    Directory of Open Access Journals (Sweden)

    Georgette B. Salieb-Beugelaar

    2016-10-01

    Full Text Available Polymeric microfluidic systems are well suited for miniaturized devices with complex functionality, and rapid prototyping methods for 3D microfluidic structures are increasingly used. Mixing at the microscale and performing chemical reactions at the microscale are important applications of such systems and we therefore explored feasibility, mixing characteristics and the ability to control a chemical reaction in helical 3D channels produced by the emerging thread template method. Mixing at the microscale is challenging because channel size reduction for improving solute diffusion comes at the price of a reduced Reynolds number that induces a strictly laminar flow regime and abolishes turbulence that would be desired for improved mixing. Microfluidic 3D helix mixers were rapidly prototyped in polydimethylsiloxane (PDMS using low-surface energy polymeric threads, twisted to form 2-channel and 3-channel helices. Structure and flow characteristics were assessed experimentally by microscopy, hydraulic measurements and chromogenic reaction, and were modeled by computational fluid dynamics. We found that helical 3D microfluidic systems produced by thread templating allow rapid prototyping, can be used for mixing and for controlled chemical reaction with two or three reaction partners at the microscale. Compared to the conventional T-shaped microfluidic system used as a control device, enhanced mixing and faster chemical reaction was found to occur due to the combination of diffusive mixing in small channels and flow folding due to the 3D helix shape. Thus, microfluidic 3D helix mixers can be rapidly prototyped using the thread template method and are an attractive and competitive method for fluid mixing and chemical reactions at the microscale.

  18. Fluid control in microfluidic devices using a fluid conveyance extension and an absorbent microfluidic flow modulator.

    Science.gov (United States)

    Yuen, Po Ki

    2013-05-07

    This article presents a simple method for controlling fluid in microfluidic devices without the need for valves or pumps. A fluid conveyance extension is fluidly coupled to the enclosed outlet chamber of a microfluidic device. After a fluid is introduced into the microfluidic device and saturates the fluid conveyance extension, a fluid flow in the microfluidic device is generated by contacting an absorbent microfluidic flow modulator with the fluid conveyance extension to absorb the fluid from the fluid conveyance extension through capillary action. Since the fluid in the microfluidic device is fluidly coupled with the fluid conveyance extension and the fluid conveyance extension is fluidly coupled with the absorbent microfluidic flow modulator, the absorption rate of the absorbent microfluidic flow modulator, which is the rate at which the absorbent microfluidic flow modulator absorbs fluid, matches the fluid flow rate in the microfluidic device. Thus, the fluid flow rate in the microfluidic device is set by the absorption rate of the absorbent microfluidic flow modulator. Sheath flow and fluid switching applications are demonstrated using this simple fluid control method without the need for valves or pumps. Also, the ability to control the fluid flow rate in the microfluidic device is demonstrated using absorbent microfluidic flow modulators with various absorbent characteristics and dimensions.

  19. Microfluidic device for drug delivery

    Science.gov (United States)

    Beebe, David J. (Inventor); MacDonald, Michael J. (Inventor); Eddington, David T. (Inventor); Mensing, Glennys A. (Inventor)

    2010-01-01

    A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual.

  20. Microfluidic devices for droplet injection

    Science.gov (United States)

    Aubrecht, Donald; Akartuna, Ilke; Weitz, David

    2012-02-01

    As picoliter-scale reaction vessels, microfluidic water-in-oil emulsions have found application for high-throughput, large-sample number analyses. Often, the biological or chemical system under investigation needs to be encapsulated into droplets to prevent cross contamination prior to the introduction of reaction reagents. Previous techniques of picoinjection or droplet synchronization and merging enable the addition of reagents to individual droplets, but present limitations on what can be added to each droplet. We present microfluidic devices that couple the strengths of picoinjection and droplet merging, allowing us to selectively add precise volume to our droplet reactions.

  1. Rapid laser prototyping of valves for microfluidic autonomous systems

    Science.gov (United States)

    Mohammed, M. I.; Abraham, E.; Y Desmulliez, M. P.

    2013-03-01

    Capillary forces in microfluidics provide a simple yet elegant means to direct liquids through flow channel networks. The ability to manipulate the flow in a truly automated manner has proven more problematic. The majority of valves require some form of flow control devices, which are manually, mechanically or electrically driven. Most demonstrated capillary systems have been manufactured by photolithography, which, despite its high precision and repeatability, can be labour intensive, requires a clean room environment and the use of fixed photomasks, limiting thereby the agility of the manufacturing process to readily examine alternative designs. In this paper, we describe a robust and rapid CO2 laser manufacturing process and demonstrate a range of capillary-driven microfluidic valve structures embedded within a microfluidic network. The manufacturing process described allows for advanced control and manipulation of fluids such that flow can be halted, triggered and delayed based on simple geometrical alterations to a given microchannel. The rapid prototyping methodology has been employed with PMMA substrates and a complete device has been created, ready for use, within 2-3 h. We believe that this agile manufacturing process can be applied to produce a range of complex autonomous fluidic platforms and allows subsequent designs to be rapidly explored.

  2. Digital microfluidics: A promising technique for biochemical applications

    Science.gov (United States)

    Wang, He; Chen, Liguo; Sun, Lining

    2017-07-01

    Digital microfluidics (DMF) is a versatile microfluidics technology that has significant application potential in the areas of automation and miniaturization. In DMF, discrete droplets containing samples and reagents are controlled to implement a series of operations via electrowetting-on-dielectric. This process works by applying electrical potentials to an array of electrodes coated with a hydrophobic dielectric layer. Unlike microchannels, DMF facilitates precise control over multiple reaction processes without using complex pump, microvalve, and tubing networks. DMF also presents other distinct features, such as portability, less sample consumption, shorter chemical reaction time, flexibility, and easier combination with other technology types. Due to its unique advantages, DMF has been applied to a broad range of fields (e.g., chemistry, biology, medicine, and environment). This study reviews the basic principles of droplet actuation, configuration design, and fabrication of the DMF device, as well as discusses the latest progress in DMF from the biochemistry perspective.

  3. Radio frequency feedback method for parallelized droplet microfluidics

    KAUST Repository

    Conchouso Gonzalez, David

    2016-12-19

    This paper reports on a radio frequency micro-strip T-resonator that is integrated to a parallel droplet microfluidic system. The T-resonator works as a feedback system to monitor uniform droplet production and to detect, in real-time, any malfunctions due to channel fouling or clogging. Emulsions at different W/O flow-rate ratios are generated in a microfluidic device containing 8 parallelized generators. These emulsions are then guided towards the RF sensor, which is then read using a Network Analyzer to obtain the frequency response of the system. The proposed T-resonator shows frequency shifts of 45MHz for only 5% change in the emulsion\\'s water in oil content. These shifts can then be used as a feedback system to trigger alarms and notify production and quality control engineers about problems in the droplet generation process.

  4. Controlled Cavitation in Microfluidic Systems

    NARCIS (Netherlands)

    Zwaan, Ed; le Gac, Severine; Tsuji, Kinko; Ohl, C.D.

    2007-01-01

    We report on cavitation in confined microscopic environments which are commonly called microfluidic or lab-on-a-chip systems. The cavitation bubble is created by focusing a pulsed laser into these structures filled with a lght-absorbing liquid. At hte center of a 20 mu m thick and 1 mm wide channel,

  5. Membranes and microfluidics: a review

    NARCIS (Netherlands)

    de Jong, J.; Lammertink, Rob G.H.; Wessling, Matthias

    2006-01-01

    The integration of mass transport control by means of membrane functionality into microfluidic devices has shown substantial growth over the last 10 years. Many different examples of mass transport control have been reported, demonstrating the versatile use of membranes. This review provides an

  6. Microfluidic technology for PET radiochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gillies, J.M. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom)]. E-mail: jgillies@picr.man.ac.uk; Prenant, C. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom); School of Chemical Engineering and Analytical Sciences, University of Manchester, P.O. Box 88, Manchester, M60 1QD (United Kingdom); Chimon, G.N. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom); School of Chemical Engineering and Analytical Sciences, University of Manchester, P.O. Box 88, Manchester, M60 1QD (United Kingdom); Smethurst, G.J. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom); Dekker, B.A. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom); Zweit, J. [Cancer Research-UK/University of Manchester Radiochemical Targeting and Imaging Group, Paterson Institute for Cancer Research, Manchester, M20 4BX (United Kingdom); School of Chemical Engineering and Analytical Sciences, University of Manchester, P.O. Box 88, Manchester, M60 1QD (United Kingdom)

    2006-03-15

    This paper describes the first application of a microfabricated reaction system to positron emission tomography (PET) radiochemistry. We have applied microfluidic technology to synthesise PET radiopharmaceuticals using {sup 18}F and {sup 124}I as labels for fluorodeoxyglucose (FDG) and Annexin-V, respectively. These reactions involved established methods of nucleophilic substitution on a mannose triflate precursor and direct iodination of the protein using iodogen as an oxidant. This has demonstrated a proof of principle of using microfluidic technology to radiochemical reactions involving low and high molecular weight compounds. Using microfluidic reactions, [{sup 18}F]FDG was synthesised with a 50% incorporation of the available F-18 radioactivity in a very short time of 4 s. The radiolabelling efficiency of {sup 124}I Annexin-V was 40% after 1 min reaction time. Chromatographic analysis showed that such reaction yields are comparable to conventional methods, but in a much shorter time. The yields can be further improved with more optimisation of the microfluidic device itself and its fluid mixing profiles. This demonstrates the potential for this technology to have an impact on rapid and simpler radiopharmaceutical synthesis using short and medium half-life radionuclides.

  7. Microfluidic Liquid-Liquid Contactors

    Energy Technology Data Exchange (ETDEWEB)

    Mcculloch, Quinn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-25

    This report describes progress made on the microfluidic contactor. A model was developed to predict its failure, a surrogate chemical system was selected to demonstrate mass transfer, and an all-optical system has been invented and implemented to monitor carryover and flowrates.

  8. Mixing in a Microfluid Device

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Deryabin, Mikhail

    Mixing of fluids in microchannels cannot rely on turbulence since the flow takes place at extremly low Reynolds numbers. Various active and passive devices have been developed to induce mixing in microfluid flow devices. We describe here a model of an active mixer where a transverse periodic flow...

  9. Topology optimization of microfluidic mixers

    DEFF Research Database (Denmark)

    Andreasen, Casper Schousboe; Gersborg, Allan Roulund; Sigmund, Ole

    2009-01-01

    This paper demonstrates the application of the topology optimization method as a general and systematic approach for microfluidic mixer design. The mixing process is modeled as convection dominated transport in low Reynolds number incompressible flow. The mixer performance is maximized by altering...

  10. Preprogrammed capillarity to passively control system-level sequential and parallel microfluidic flows.

    Science.gov (United States)

    Kim, Sung-Jin; Paczesny, Sophie; Takayama, Shuichi; Kurabayashi, Katsuo

    2013-06-01

    In microfluidics, capillarity-driven solution flow is often beneficial, owing to its inherently spontaneous motion. However, it is commonly perceived that, in an integrated microfluidic system, the passive capillarity control alone can hardly achieve well-controlled sequential and parallel flow of multiple solutions. Despite this common notion, we hereby demonstrate system-level sequential and parallel microfluidic flow processing by fully passive capillarity-driven control. After manual loading of solutions with a pipette, a network of microfluidic channels passively regulates the flow timing of the multiple solution menisci in a sequential and synchronous manner. Also, use of auxiliary channels and preprogramming of inlet-well meniscus pressure and channel fluidic conductance allow for controlling the flow direction of multiple solutions in our microfluidic system. With those components orchestrated in a single device chip, we show preprogrammed flow control of 10 solutions. The demonstrated system-level flow control proves capillarity as a useful means even for sophisticated microfluidic processing without any actively controlled valves and pumps.

  11. Comparison of static and microfluidic protease assays using modified bioluminescence resonance energy transfer chemistry.

    Directory of Open Access Journals (Sweden)

    Nan Wu

    Full Text Available BACKGROUND: Fluorescence and bioluminescence resonance energy transfer (F/BRET are two forms of Förster resonance energy transfer, which can be used for optical transduction of biosensors. BRET has several advantages over fluorescence-based technologies because it does not require an external light source. There would be benefits in combining BRET transduction with microfluidics but the low luminance of BRET has made this challenging until now. METHODOLOGY: We used a thrombin bioprobe based on a form of BRET (BRET(H, which uses the BRET(1 substrate, native coelenterazine, with the typical BRET(2 donor and acceptor proteins linked by a thrombin target peptide. The microfluidic assay was carried out in a Y-shaped microfluidic network. The dependence of the BRET(H ratio on the measurement location, flow rate and bioprobe concentration was quantified. Results were compared with the same bioprobe in a static microwell plate assay. PRINCIPAL FINDINGS: The BRET(H thrombin bioprobe has a lower limit of detection (LOD than previously reported for the equivalent BRET(1-based version but it is substantially brighter than the BRET(2 version. The normalised BRET(H ratio of the bioprobe changed 32% following complete cleavage by thrombin and 31% in the microfluidic format. The LOD for thrombin in the microfluidic format was 27 pM, compared with an LOD of 310 pM, using the same bioprobe in a static microwell assay, and two orders of magnitude lower than reported for other microfluidic chip-based protease assays. CONCLUSIONS: These data demonstrate that BRET based microfluidic assays are feasible and that BRET(H provides a useful test bed for optimising BRET-based microfluidics. This approach may be convenient for a wide range of applications requiring sensitive detection and/or quantification of chemical or biological analytes.

  12. Lab-on-chip system combining a microfluidic-ELISA with an array of amorphous silicon photosensors for the detection of celiac disease epitopes

    National Research Council Canada - National Science Library

    Francesca Costantini; Cristiana Sberna; Giulia Petrucci; Cesare Manetti; Giampiero de Cesare; Augusto Nascetti; Domenico Caputo

    2015-01-01

    This work presents a lab-on-chip system, which combines a glass-polydimethilsiloxane microfluidic network and an array of amorphous silicon photosensors for the diagnosis and follow-up of Celiac disease...

  13. Integrated microfluidic systems for DNA analysis.

    Science.gov (United States)

    Njoroge, Samuel K; Chen, Hui-Wen; Witek, Małgorzata A; Soper, Steven A

    2011-01-01

    The potential utility of genome-related research in terms of evolving basic discoveries in biology has generated widespread use of DNA diagnostics and DNA forensics and driven the accelerated development of fully integrated microfluidic systems for genome processing. To produce a microsystem with favorable performance characteristics for genetic-based analyses, several key operational elements must be strategically chosen, including device substrate material, temperature control, fluidic control, and reaction product readout. As a matter of definition, a microdevice is a chip that performs a single processing step, for example microchip electrophoresis. Several microdevices can be integrated to a single wafer, or combined on a control board as separate devices to form a microsystem. A microsystem is defined as a chip composed of at least two microdevices. Among the many documented analytical microdevices, those focused on the ability to perform the polymerase chain reaction (PCR) have been reported extensively due to the importance of this processing step in most genetic-based assays. Other microdevices that have been detailed in the literature include those for solid-phase extractions, microchip electrophoresis, and devices composed of DNA microarrays used for interrogating DNA primary structure. Great progress has also been made in the areas of chip fabrication, bonding and sealing to enclose fluidic networks, evaluation of different chip substrate materials, surface chemistries, and the architecture of reaction conduits for basic processing steps such as mixing. Other important elements that have been developed to realize functional systems include miniaturized readout formats comprising optical or electrochemical transduction and interconnect technologies. These discoveries have led to the development of fully autonomous and functional integrated systems for genome processing that can supply "sample in/answer out" capabilities. In this chapter, we focus on

  14. A microfluidic D-subminiature connector.

    Science.gov (United States)

    Scott, Adina; Au, Anthony K; Vinckenbosch, Elise; Folch, Albert

    2013-06-07

    Standardized, affordable, user-friendly world-to-chip interfaces represent one of the major barriers to the adoption of microfluidics. We present a connector system for plug-and-play interfacing of microfluidic devices to multiple input and output lines. The male connectors are based on existing standardized housings from electronics that are inexpensive and widely available. The female connectors are fabricated using familiar replica molding techniques that can easily be adopted by microfluidic developers.

  15. [Recent development of microfluidic diagnostic technologies].

    Science.gov (United States)

    Li, Haifang; Zhang, Qianyun; Lin, Jin-Ming

    2011-04-01

    Microfluidic devices exhibit a great promising development in clinical diagnosis and disease screening due to their advantages of precise controlling of fluid flow, requirement of miniamount sample, rapid reaction speed and convenient integration. In this paper, the improvements of microfluidic diagnostic technologies in recent years are reviewed. The applications and developments of on-chip disease marker detection, microfluidic cell selection and cell drug metabolism, and diagnostic micro-devices are discussed.

  16. Dynamics of Microvalve Operations in Integrated Microfluidics

    OpenAIRE

    Alan T. H. Lau; Hon Ming Yip; Kathy C. C. Ng; Xin Cui; Lam, Raymond H. W.

    2014-01-01

    Pneumatic microvalves are widely used key components for automating liquid manipulation and flow control in microfluidics for more than one decade. Due to their robust operations and the ease of fabrication, tremendous microfluidic systems have been developed with the multiple microvalves for higher throughput and extended functionalities. Therefore, operation performance of the microvalves in the integrated microfluidic devices is crucial to the related applications, in fields such as micro-...

  17. Bio-microfluidics: biomaterials and biomimetic designs.

    Science.gov (United States)

    Domachuk, Peter; Tsioris, Konstantinos; Omenetto, Fiorenzo G; Kaplan, David L

    2010-01-12

    Bio-microfluidics applies biomaterials and biologically inspired structural designs (biomimetics) to microfluidic devices. Microfluidics, the techniques for constraining fluids on the micrometer and sub-micrometer scale, offer applications ranging from lab-on-a-chip to optofluidics. Despite this wealth of applications, the design of typical microfluidic devices imparts relatively simple, laminar behavior on fluids and is realized using materials and techniques from silicon planar fabrication. On the other hand, highly complex microfluidic behavior is commonplace in nature, where fluids with nonlinear rheology flow through chaotic vasculature composed from a range of biopolymers. In this Review, the current state of bio-microfluidic materials, designs and applications are examined. Biopolymers enable bio-microfluidic devices with versatile functionalization chemistries, flexibility in fabrication, and biocompatibility in vitro and in vivo. Polymeric materials such as alginate, collagen, chitosan, and silk are being explored as bulk and film materials for bio-microfluidics. Hydrogels offer options for mechanically functional devices for microfluidic systems such as self-regulating valves, microlens arrays and drug release systems, vital for integrated bio-microfluidic devices. These devices including growth factor gradients to study cell responses, blood analysis, biomimetic capillary designs, and blood vessel tissue culture systems, as some recent examples of inroads in the field that should lead the way in a new generation of microfluidic devices for bio-related needs and applications. Perhaps one of the most intriguing directions for the future will be fully implantable microfluidic devices that will also integrate with existing vasculature and slowly degrade to fully recapitulate native tissue structure and function, yet serve critical interim functions, such as tissue maintenance, drug release, mechanical support, and cell delivery.

  18. Microfluidics for optics and quantitative cell biology

    OpenAIRE

    Campbell, James Kyle

    2008-01-01

    Microfluidics is a quickly expanding field with numerous applications. The advent of rapid-prototyping and soft- lithography allow for easy and inexpensive fabrication of microfluidic devices. Fluid manipulation on the microscale allows for new functionalities of devices and components not available on the macroscale. Fluid flows on the microscale are laminar with chemical mixing defined strictly by diffusion allowing us to design microfluidic devices with precise control of fluid flow and ch...

  19. Advances in microfluidics for environmental analysis.

    Science.gov (United States)

    Jokerst, Jana C; Emory, Jason M; Henry, Charles S

    2012-01-07

    During the past few years, a growing number of groups have recognized the utility of microfluidic devices for environmental analysis. Microfluidic devices offer a number of advantages and in many respects are ideally suited to environmental analyses. Challenges faced in environmental monitoring, including the ability to handle complex and highly variable sample matrices, lead to continued growth and research. Additionally, the need to operate for days to months in the field requires further development of robust, integrated microfluidic systems. This review examines recently published literature on the applications of microfluidic systems for environmental analysis and provides insight in the future direction of the field.

  20. Integrated lenses in polystyrene microfluidic devices

    KAUST Repository

    Fan, Yiqiang

    2013-04-01

    This paper reports a new method for integrating microlenses into microfluidic devices for improved observation. Two demonstration microfluidic devices were provided which were fabricated using this new technique. The integrated microlenses were fabricated using a free-surface thermo-compression molding method on a polystyrene (PS) sheet which was then bonded on top of microfluidic channels as a cover plate, with the convex microlenses providing a magnified image of the channel for the easier observation of the flow in the microchannels. This approach for fabricating the integrated microlens in microfluidic devices is rapid, low cost and without the requirement of cleanroom facilities. © 2013 IEEE.

  1. Electrokinetically driven microfluidic chips with surface-modified chambers for heterogeneous immunoassays

    NARCIS (Netherlands)

    Dodge, A.; Fluri, K.; Verpoorte, E.; De Rooij, N.F.

    2001-01-01

    This article presents the first example of a microfluidic chip for heterogeneous bioassays using a locally immobilized biospecitic layer and operated electrokinetically. The reaction chamber has picoliter dimensions and is integrated into a network of microchannels etched in glass. The high affinity

  2. The microfluidic Kelvin water dropper

    CERN Document Server

    Marin, Alvaro G; García-Sánchez, Pablo; Shui, Lingling; Xie, Yanbo; Fontelos, Marco A; Eijkel, Jan C T; Berg, Albert van den; Lohse, Detlef

    2013-01-01

    The so-called "Kelvin water dropper" is a simple experiment demonstrating the spontaneous appearance of induced free charge in droplets emitted through a tube. As Lord Kelvin explained, water droplets spontaneously acquire a net charge during detachment from a faucet due to the presence of electrical fields in their surrounding created by any metallic object. In his experiment, two streams of droplets are allowed to drip from separated nozzles into separated buckets, which are at the same time interconnected through the dripping needles. In this paper we build a microfluidic water dropper and demonstrate that the droplets get charged and break-up due to electrohydrodynamic instabilities. A comparison with recent simulations shows the dependence of the acquired charge in the droplets on different parameters of the system. The phenomenon opens a door to cheap and accessible transformation of pneumatic pressure into electrical energy and to an enhanced control in microfluidic and biophysical manipulation of caps...

  3. High-grade optical polydimethylsiloxane for microfluidic applications.

    Science.gov (United States)

    Lovchik, Robert Dean; Wolf, Heiko; Delamarche, Emmanuel

    2011-12-01

    Commercially available polydimethylsiloxane (PDMS) elastomers, such as Sylgard 184® are widely used in soft lithography and for microfluidic applications. These PDMS elastomers contain fillers to enhance their mechanical stability. The reinforcing fillers, often sub-micrometer small SiO(2) particles, tend to aggregate, swell with water, and thereby become cognoscible in a way that can strongly interfere with the visualization of micro-scale events taking place next to PDMS structures. As PDMS microfluidics are often used for studying cells and micro-/nanoparticles and for creating/handling nanodroplets, it has become highly desirable to employ a PDMS having high optical quality and that allows microscopy observation without artifacts. Here, we present a PDMS formulation that is free of fillers and has sufficiently low viscosity to perform a filtration step of the mixed prepolymers before curing. By molding a bi-layer microfluidic network (MFN), composed of a thin filler-free PDMS layer and a thicker Sylgard 184® backing layer, PDMS MFNs featuring both high optical quality and mechanical stability, can be fabricated.

  4. Thermally driven microfluidic pumping via reversible shape memory polymers

    Science.gov (United States)

    Robertson, J. M.; Rodriguez, R. X.; Holmes, L. R., Jr.; Mather, P. T.; Wetzel, E. D.

    2016-08-01

    The need exists for autonomous microfluidic pumping systems that utilize environmental cues to transport fluid within a network of channels for such purposes as heat distribution, self-healing, or optical reconfiguration. Here, we report on reversible thermally driven microfluidic pumping enabled by two-way shape memory polymers. After developing a suitable shape memory polymer (SMP) through variation in the crosslink density, thin and flexible microfluidic devices were constructed by lamination of plastic films with channels defined by laser-cutting of double-sided adhesive film. SMP blisters integrated into the devices provide thermally driven pumping, while opposing elastic blisters are used to generate backpressure for reversible operation. Thermal cycling of the device was found to drive reversible fluid flow: upon heating to 60 °C, the SMP rapidly contracted to fill the surface channels with a transparent fluid, and upon cooling to 8 °C the flow reversed and the channel re-filled with black ink. Combined with a metallized backing layer, this device results in refection of incident light at high temperatures and absorption of light (at the portions covered with channels) at low temperatures. We discuss power-free, autonomous applications ranging from thermal regulation of structures to thermal indication via color change.

  5. Acoustically-driven microfluidic systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A W; Benett, W J; Tarte, L R

    2000-06-23

    We have demonstrated a non-contact method of concentrating and mixing particles in a plastic microfluidic chamber employing acoustic radiation pressure. A flaw cell package has also been designed that integrates liquid sample interconnects, electrical contacts and a removable sample chamber. Experiments were performed on 1, 3, 6, and 10 {micro}m polystyrene beads. Increased antibody binding to a solid-phase substrate was observed in the presence of acoustic mixing due to improve mass transport.

  6. Optical detection in microfluidic systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter

    2009-01-01

    Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent...... to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest....

  7. Whole-Teflon microfluidic chips.

    Science.gov (United States)

    Ren, Kangning; Dai, Wen; Zhou, Jianhua; Su, Jing; Wu, Hongkai

    2011-05-17

    Although microfluidics has shown exciting potential, its broad applications are significantly limited by drawbacks of the materials used to make them. In this work, we present a convenient strategy for fabricating whole-Teflon microfluidic chips with integrated valves that show outstanding inertness to various chemicals and extreme resistance against all solvents. Compared with other microfluidic materials [e.g., poly(dimethylsiloxane) (PDMS)] the whole-Teflon chip has a few more advantages, such as no absorption of small molecules, little adsorption of biomolecules onto channel walls, and no leaching of residue molecules from the material bulk into the solution in the channel. Various biological cells have been cultured in the whole-Teflon channel. Adherent cells can attach to the channel bottom, spread, and proliferate well in the channels (with similar proliferation rate to the cells in PDMS channels with the same dimensions). The moderately good gas permeability of the Teflon materials makes it suitable to culture cells inside the microchannels for a long time.

  8. Microfluidic Devices for Blood Fractionation

    Directory of Open Access Journals (Sweden)

    Chwee Teck Lim

    2011-07-01

    Full Text Available Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate blood into its individual components has innumerable applications in both clinical diagnosis and biological research. Yet, processing blood is not trivial. In the past decade, a flurry of new microfluidic based technologies has emerged to address this compelling problem. Microfluidics is an attractive solution for this application leveraging its numerous advantages to process clinical blood samples. This paper reviews the various microfluidic approaches realized to successfully fractionate one or more blood components. Techniques to separate plasma from hematologic cellular components as well as isolating blood cells of interest including certain rare cells are discussed. Comparisons based on common separation metrics including efficiency (sensitivity, purity (selectivity, and throughput will be presented. Finally, we will provide insights into the challenges associated with blood-based separation systems towards realizing true point-of-care (POC devices and provide future perspectives.

  9. Ionic current devices-Recent progress in the merging of electronic, microfluidic, and biomimetic structures.

    Science.gov (United States)

    Koo, Hyung-Jun; Velev, Orlin D

    2013-05-09

    We review the recent progress in the emerging area of devices and circuits operating on the basis of ionic currents. These devices operate at the intersection of electrochemistry, electronics, and microfluidics, and their potential applications are inspired by essential biological processes such as neural transmission. Ionic current rectification has been demonstrated in diode-like devices containing electrolyte solutions, hydrogel, or hydrated nanofilms. More complex functions have been realized in ionic current based transistors, solar cells, and switching memory devices. Microfluidic channels and networks-an intrinsic component of the ionic devices-could play the role of wires and circuits in conventional electronics.

  10. Materials for microfluidic chip fabrication.

    Science.gov (United States)

    Ren, Kangning; Zhou, Jianhua; Wu, Hongkai

    2013-11-19

    Through manipulating fluids using microfabricated channel and chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials. This Account generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of

  11. Integrating Electronics and Microfluidics on Paper.

    Science.gov (United States)

    Hamedi, Mahiar M; Ainla, Alar; Güder, Firat; Christodouleas, Dionysios C; Fernández-Abedul, M Teresa; Whitesides, George M

    2016-07-01

    Paper microfluidics and printed electronics have developed independently, and are incompatible in many aspects. Monolithic integration of microfluidics and electronics on paper is demonstrated. This integration makes it possible to print 2D and 3D fluidic, electrofluidic, and electrical components on paper, and to fabricate devices using them.

  12. Principles, Techniques, and Applications of Tissue Microfluidics

    Science.gov (United States)

    Wade, Lawrence A.; Kartalov, Emil P.; Shibata, Darryl; Taylor, Clive

    2011-01-01

    The principle of tissue microfluidics and its resultant techniques has been applied to cell analysis. Building microfluidics to suit a particular tissue sample would allow the rapid, reliable, inexpensive, highly parallelized, selective extraction of chosen regions of tissue for purposes of further biochemical analysis. Furthermore, the applicability of the techniques ranges beyond the described pathology application. For example, they would also allow the posing and successful answering of new sets of questions in many areas of fundamental research. The proposed integration of microfluidic techniques and tissue slice samples is called "tissue microfluidics" because it molds the microfluidic architectures in accordance with each particular structure of each specific tissue sample. Thus, microfluidics can be built around the tissues, following the tissue structure, or alternatively, the microfluidics can be adapted to the specific geometry of particular tissues. By contrast, the traditional approach is that microfluidic devices are structured in accordance with engineering considerations, while the biological components in applied devices are forced to comply with these engineering presets.

  13. Cell Culture Microfluidic Biochips: Experimental Throughput Maximization

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan

    2011-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory, integrating all necessary functionalities on-chip in order to perform biochemical applications. Researchers have started to propose computer-aided design tools for the synthesis of such biochips. Our focus...... metaheuristic for experimental design generation for the cell culture microfluidic biochips, and we have evaluated our approach using multiple experimental setups....

  14. Modular microfluidic system for biological sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

    2015-09-29

    A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

  15. A microfluidic method to study demulsification kinetics

    NARCIS (Netherlands)

    Krebs, T.; Schroën, C.G.P.H.; Boom, R.M.

    2012-01-01

    We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing h

  16. Principles, Techniques, and Applications of Tissue Microfluidics

    Science.gov (United States)

    Wade, Lawrence A.; Kartalov, Emil P.; Shibata, Darryl; Taylor, Clive

    2011-01-01

    The principle of tissue microfluidics and its resultant techniques has been applied to cell analysis. Building microfluidics to suit a particular tissue sample would allow the rapid, reliable, inexpensive, highly parallelized, selective extraction of chosen regions of tissue for purposes of further biochemical analysis. Furthermore, the applicability of the techniques ranges beyond the described pathology application. For example, they would also allow the posing and successful answering of new sets of questions in many areas of fundamental research. The proposed integration of microfluidic techniques and tissue slice samples is called tissue microfluidics because it molds the microfluidic architectures in accordance with each particular structure of each specific tissue sample. Thus, microfluidics can be built around the tissues, following the tissue structure, or alternatively, the microfluidics can be adapted to the specific geometry of particular tissues. By contrast, the traditional approach is that microfluidic devices are structured in accordance with engineering considerations, while the biological components in applied devices are forced to comply with these engineering presets. The proposed principles represent a paradigm shift in microfluidic technology in three important ways: Microfluidic devices are to be directly integrated with, onto, or around tissue samples, in contrast to the conventional method of off-chip sample extraction followed by sample insertion in microfluidic devices. Architectural and operational principles of microfluidic devices are to be subordinated to suit specific tissue structure and needs, in contrast to the conventional method of building devices according to fluidic function alone and without regard to tissue structure. Sample acquisition from tissue is to be performed on-chip and is to be integrated with the diagnostic measurement within the same device, in contrast to the conventional method of off-chip sample prep and

  17. Passive microfluidic control of two merging streams by capillarity and relative flow resistance.

    Science.gov (United States)

    Kim, Sung-Jin; Lim, Yong Taik; Yang, Haesik; Shin, Yong Beom; Kim, Kyuwon; Lee, Dae-Sik; Park, Se Ho; Kim, Youn Tae

    2005-10-01

    In the progress of microfluidic devices, a simple and precise control of multiple streams has been essential for complex microfluidic networks. Consequently, microfluidic devices, which have a simple structure, typically use external energy sources to control the multiple streams. Here, we propose a pure passive scheme that uses capillarity without using external force or external regulation to control the merging of two streams and even to regulate their volumetric flow rate (VFR). We accomplish this process by controlling the geometry of two inlets and a junction, and by regulating the hydrophilicity of a substrate. Additionally, we use the relative flow resistance to control the VFR ratio of the merged two streams. Our results will significantly simplify the control of multiple streams without sacrificing precision.

  18. Electrorheological fluid and its applications in microfluidics.

    Science.gov (United States)

    Wang, Limu; Gong, Xiuqing; Wen, Weijia

    2011-01-01

    Microfluidics is a low-cost technique for fast-diagnosis and microsynthesis. Within a decade it might become the foundation of point-of-care and lab-on-a-chip applications. With microfluidic chips, high-throughput sample screening and information processing are made possible. The picoliter droplet runs in microfluidic chips are ideal miniaturized vessels for microdetection and microsynthesis. Meanwhile, individual manipulation of microdroplets remains a challenge: the shortcomings in automatic, reliable, and scalable methods for logic control prevent further integration of microfluidic applications. The giant electrorheological fluid (GERF), which is a kind of "smart" colloid, has tunable viscosity under the influence of external electric field. Therefore, GERF is introduced as the active controlling medium, with real-time response in on-chip fluid control. This review article introduces the working principles and fabrication methods of different types of electrorheological fluid, and extensively describes the strategies of GERF-assisted microfluidic controlling schemes.

  19. Manipulation of microfluidic droplets by electrorheological fluid

    KAUST Repository

    Zhang, Menying

    2009-09-01

    Microfluidics, especially droplet microfluidics, attracts more and more researchers from diverse fields, because it requires fewer materials and less time, produces less waste and has the potential of highly integrated and computer-controlled reaction processes for chemistry and biology. Electrorheological fluid, especially giant electrorheological fluid (GERF), which is considered as a kind of smart material, has been applied to the microfluidic systems to achieve active and precise control of fluid by electrical signal. In this review article, we will introduce recent results of microfluidic droplet manipulation, GERF and some pertinent achievements by introducing GERF into microfluidic system: digital generation, manipulation of "smart droplets" and droplet manipulation by GERF. Once it is combined with real-time detection, integrated chip with multiple functions can be realized. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.

  20. Microfluidic desalination techniques and their potential applications.

    Science.gov (United States)

    Roelofs, S H; van den Berg, A; Odijk, M

    2015-09-07

    In this review we discuss recent developments in the emerging research field of miniaturized desalination. Traditionally desalination is performed to convert salt water into potable water and research is focused on improving performance of large-scale desalination plants. Microfluidic desalination offers several new opportunities in comparison to macro-scale desalination, such as providing a platform to increase fundamental knowledge of ion transport on the nano- and microfluidic scale and new microfluidic sample preparation methods. This approach has also lead to the development of new desalination techniques, based on micro/nanofluidic ion-transport phenomena, which are potential candidates for up-scaling to (portable) drinking water devices. This review assesses microfluidic desalination techniques on their applications and is meant to contribute to further implementation of microfluidic desalination techniques in the lab-on-chip community.

  1. Microfluidics for food, agriculture and biosystems industries.

    Science.gov (United States)

    Neethirajan, Suresh; Kobayashi, Isao; Nakajima, Mitsutoshi; Wu, Dan; Nandagopal, Saravanan; Lin, Francis

    2011-05-07

    Microfluidics, a rapidly emerging enabling technology has the potential to revolutionize food, agriculture and biosystems industries. Examples of potential applications of microfluidics in food industry include nano-particle encapsulation of fish oil, monitoring pathogens and toxins in food and water supplies, micro-nano-filtration for improving food quality, detection of antibiotics in dairy food products, and generation of novel food structures. In addition, microfluidics enables applications in agriculture and animal sciences such as nutrients monitoring and plant cells sorting for improving crop quality and production, effective delivery of biopesticides, simplified in vitro fertilization for animal breeding, animal health monitoring, vaccination and therapeutics. Lastly, microfluidics provides new approaches for bioenergy research. This paper synthesizes information of selected microfluidics-based applications for food, agriculture and biosystems industries. © The Royal Society of Chemistry 2011

  2. Manipulation of microfluidic droplets by electrorheological fluid.

    Science.gov (United States)

    Zhang, Menying; Gong, Xiuqing; Wen, Weijia

    2009-09-01

    Microfluidics, especially droplet microfluidics, attracts more and more researchers from diverse fields, because it requires fewer materials and less time, produces less waste and has the potential of highly integrated and computer-controlled reaction processes for chemistry and biology. Electrorheological fluid, especially giant electrorheological fluid (GERF), which is considered as a kind of smart material, has been applied to the microfluidic systems to achieve active and precise control of fluid by electrical signal. In this review article, we will introduce recent results of microfluidic droplet manipulation, GERF and some pertinent achievements by introducing GERF into microfluidic system: digital generation, manipulation of "smart droplets" and droplet manipulation by GERF. Once it is combined with real-time detection, integrated chip with multiple functions can be realized.

  3. Research of Dielectric Breakdown Microfluidic Sampling Chip

    Directory of Open Access Journals (Sweden)

    Feng Jiang

    2013-01-01

    Full Text Available Microfluidic chip is mainly driven electrically by external electrode and array electrode, but there are certain disadvantages in both of ways, which affect the promotion and application of microfluidic technology. This paper discusses a scheme that uses the conductive solution in a microchannel made by PDMS, replacing electrodes and the way of dielectric breakdown to achieve microfluidic chip driver. It could reduce the driving voltage and simplify the chip production process. To prove the feasibility of this method, we produced a microfluidic chip used in PDMS material with the lithography technology and experimented it. The results showed that using the dielectric breakdown to achieve microfluidic chip driver is feasible, and it has certain application prospect.

  4. Fuel cell-powered microfluidic platform for lab-on-a-chip applications.

    Science.gov (United States)

    Esquivel, Juan Pablo; Castellarnau, Marc; Senn, Tobias; Löchel, Bernd; Samitier, Josep; Sabaté, Neus

    2012-01-07

    The achievement of a higher degree of integration of components--especially micropumps and power sources--is a challenge currently being pursued to obtain portable and totally autonomous microfluidic devices. This paper presents the integration of a micro direct methanol fuel cell (μDMFC) in a microfluidic platform as a smart solution to provide both electrical and pumping power to a Lab-on-a-Chip system. In this system the electric power produced by the fuel cell is available to enable most of the functionalites required by the microfluidic chip, while the generated CO(2) from the electrochemical reaction produces a pressure capable of pumping a liquid volume through a microchannel. The control of the fuel cell operating conditions allows regulation of the flow rate of a liquid sample through a microfluidic network. The relation between sample flow rate and the current generated by the fuel cell is practically linear, achieving values in the range of 4-18 μL min(-1) while having an available power between 1-4 mW. This permits adjusting the desired flow rate for a given application by controlling the fuel cell output conditions and foresees a fully autonomous analytical Lab-on-a-Chip in which the same device would provide the electrical power to a detection module and at the same time use the CO(2) pumping action to flow the required analytes through a particular microfluidic design.

  5. Multilayer microfluidic systems with indium-tin-oxide microelectrodes for studying biological cells

    Science.gov (United States)

    Wu, Hsiang-Chiu; Lyau, Jia-Bo; Lin, Min-Hsuan; Chuang, Yung-Jen; Chen, Hsin

    2017-07-01

    Contemporary semiconductor and micromachining technologies have been exploited to develop lab-on-a-chip microsystems, which enable parallel and efficient experiments in molecular and cellular biology. In these microlab systems, microfluidics play an important role for automatic transportation or immobilization of cells and bio-molecules, as well as for separation or mixing of different chemical reagents. However, seldom microlab systems allow both morphology and electrophysiology of biological cells to be studied in situ. This kind of study is important, for example, for understanding how neuronal networks grow in response to environmental stimuli. To fulfill this application need, this paper investigates the possibility of fabricating multi-layer photoresists as microfluidic systems directly above a glass substrate with indium-tin-oxide (ITO) electrodes. The microfluidic channels are designed to guide and trap biological cells on top of ITO electrodes, through which the electrical activities of cells can be recorded or elicited. As both the microfluidic system and ITO electrodes are transparent, the cellular morphology is observable easily during electrophysiological studies. Two fabrication processes are proposed and compared. One defines the structure and curing depth of each photoresist layer simply by controlling the exposure time in lithography, while the other further utilizes a sacrificial layer to defines the structure of the bottom layer. The fabricated microfluidic system is proved bio-compatible and able to trap blood cells or neurons. Therefore, the proposed microsystem will be useful for studying cultured cells efficiently in applications such as drug-screening.

  6. Successes and future outlook for microfluidics-based cardiovascular drug discovery.

    Science.gov (United States)

    Skommer, Joanna; Wlodkowic, Donald

    2015-03-01

    The greatest advantage of using microfluidics as a platform for the assessment of cardiovascular drug action is its ability to finely regulate fluid flow conditions, including flow rate, shear stress and pulsatile flow. At the same time, microfluidics provide means for modifying the vessel geometry (bifurcations, stenoses, complex networks), the type of surface of the vessel walls, and for patterning cells in 3D tissue-like architecture, including generation of lumen walls lined with cells and heart-on-a-chip structures for mimicking ventricular cardiomyocyte physiology. In addition, owing to the small volume of required specimens, microfluidics is ideally suited to clinical situations whereby monitoring of drug dosing or efficacy needs to be coupled with minimal phlebotomy-related drug loss. In this review, the authors highlight potential applications for the currently existing and emerging technologies and offer several suggestions on how to close the development cycle of microfluidic devices for cardiovascular drug discovery. The ultimate goal in microfluidics research for drug discovery is to develop 'human-on-a-chip' systems, whereby several organ cultures, including the vasculature and the heart, can mimic complex interactions between the organs and body systems. This would provide in vivo-like pharmacokinetics and pharmacodynamics for drug ADMET assessment. At present, however, the great variety of available designs does not go hand in hand with their use by the pharmaceutical community.

  7. Kinetic ELISA in Microfluidic Channels

    Directory of Open Access Journals (Sweden)

    Debashis Dutta

    2011-06-01

    Full Text Available In this article, we describe the kinetic ELISA of Blue Tongue and Epizootic Hemorrhagic Disease viral antibodies in microfluidic channels by monitoring the rate of generation of the enzyme reaction product under static conditions. It has been shown that this format of the immunoassay allows very reliable quantitation of the target species using inexpensive glass microchips and a standard epifluorescence microscope system coupled to a CCD camera. For the viral antibodies assayed here, the limit of detection (LOD for the analyte concentration in our microchips was established to be 3–5 times lower than that obtained on commercial microwell plates using a fiftieth of the sample volume and less than a third of the incubation time. Our analyses further show that when compared to the end-point ELISA format, the kinetic mode of this assay yields an improvement in the LOD by over an order of magnitude in microfluidic devices. This benefit is primarily realized as the observed variation in the background fluorescence (signal at the start of the enzyme reaction period was significantly larger than that in the rate of signal generation upon repeating these assays in different microchannels/microchips. Because the kinetic ELISA results depend only on the latter quantity, the noise level in them was substantially lower compared to that in its end-point counterpart in which the absolute fluorescence measurements are of greater significance. While a similar benefit was also recorded through implementation of kinetic ELISAs on the microwell platform, the improvement in LOD registered in that system was not as significant as was observed in the case of microfluidic assays.

  8. Microfluidics and microscale transport processes

    CERN Document Server

    Chakraborty, Suman

    2012-01-01

    With an intense focus on micro- and nanotechnology from a fluidic perspective, this book details the research activities in key directions on both the theoretical and experimental fronts. As part of the IIT Kharagpur Research Monograph series, the text discusses topics such as capillary transport in microchannels, fluid friction and heat transfer in microchannels, electrokinetics, and interfacial transport in nanochannels. It also covers nanoparticle transport in colloidal suspensions, bubble generation in microfluidic channels, micro-heat pipe, the lattice Boltzmann method for phase changing

  9. Microfluidics and the life sciences.

    Science.gov (United States)

    Becker, Holger; Gärtner, Claudia

    2012-01-01

    The field of microfluidics, often also referred to as "Lab-on-a-Chip" has made significant progress in the last 15 years and is an essential tool in the development of new products and protocols in the life sciences. This article provides a broad overview on the developments on the academic as well as the commercial side. Fabrication technologies for polymer-based devices are presented and a strategy for the development of complex integrated devices is discussed, together with an example on the use of these devices in pathogen detection.

  10. Simplified prototyping of perfusable polystyrene microfluidics

    Science.gov (United States)

    Tran, Reginald; Ahn, Byungwook; R. Myers, David; Qiu, Yongzhi; Sakurai, Yumiko; Moot, Robert; Mihevc, Emma; Trent Spencer, H.; Doering, Christopher; A. Lam, Wilbur

    2014-01-01

    Cell culture in microfluidic systems has primarily been conducted in devices comprised of polydimethylsiloxane (PDMS) or other elastomers. As polystyrene (PS) is the most characterized and commonly used substrate material for cell culture, microfluidic cell culture would ideally be conducted in PS-based microsystems that also enable tight control of perfusion and hydrodynamic conditions, which are especially important for culture of vascular cell types. Here, we report a simple method to prototype perfusable PS microfluidics for endothelial cell culture under flow that can be fabricated using standard lithography and wet laboratory equipment to enable stable perfusion at shear stresses up to 300 dyn/cm2 and pumping pressures up to 26 kPa for at least 100 h. This technique can also be extended to fabricate perfusable hybrid PS-PDMS microfluidics of which one application is for increased efficiency of viral transduction in non-adherent suspension cells by leveraging the high surface area to volume ratio of microfluidics and adhesion molecules that are optimized for PS substrates. These biologically compatible microfluidic devices can be made more accessible to biological-based laboratories through the outsourcing of lithography to various available microfluidic foundries. PMID:25379106

  11. Enzymatic Reactions in Microfluidic Devices

    Science.gov (United States)

    Ristenpart, W. D.; Wan, J.; Stone, H. A.

    2008-11-01

    We establish simple scaling laws for enzymatic reactions in microfluidic devices, and we demonstrate that kinetic parameters obtained conventionally using multiple stop-flow experiments may instead be extracted from a single microfluidic experiment. Introduction of an enzyme and substrate species in different arms of a Y-shaped channel allows the two species to diffuse across the parallel streamlines and to begin reacting. Measurements of the product concentration versus distance down the channel provide information about the kinetics of the reaction. In the limit where the enzyme is much larger (and thus less diffusive) than the substrate, we show that near the entrance the total amount of product (P) formed varies as a power law in the distance x down the channel. For reactions that follow standard Michaelis-Menten kinetics, the power law takes the form P˜(Vmax/Km) x^5/2, where Vmax and Km are the maximum reaction rate and Michaelis constant respectively. If a large excess of substrate is used, then Km is identified by measuring Vmax far downstream where the different species are completely mixed by diffusion. Numerical simulations and experiments using the bioluminescent reaction between luciferase and ATP as a model system are both shown to accord with the model. We discuss the implications for significant savings in the amount of time and enzyme required for determination of kinetic parameters.

  12. The microfluidic Kelvin water dropper.

    Science.gov (United States)

    Marín, Álvaro G; van Hoeve, Wim; García-Sánchez, Pablo; Shui, Lingling; Xie, Yanbo; Fontelos, Marco A; Eijkel, Jan C T; van den Berg, Albert; Lohse, Detlef

    2013-12-07

    The so-called "Kelvin water dropper" is a simple experiment demonstrating the spontaneous appearance of induced free charge in droplets emitted through a tube. As Lord Kelvin explained, water droplets spontaneously acquire a net charge during detachment from a faucet due to the presence of electrical fields in their surroundings created by any metallic object. In his experiment, two streams of droplets are allowed to drip from separate nozzles into separate buckets, which are, at the same time, interconnected through the dripping needles. In this paper, we build a microfluidic water dropper and demonstrate that the droplets get charged and break up due to electrohydrodynamic instabilities. A comparison with recent simulations shows the dependence of the acquired charge in the droplets on different parameters of the system. The phenomenon opens a door to cheap and accessible transformation of pneumatic pressure into electrical energy and to an enhanced control in microfluidic and biophysical manipulation of capsules, cells and droplets via self-induced charging of the elements.

  13. Microfluidic Systems for Pathogen Sensing: A Review

    Directory of Open Access Journals (Sweden)

    Peter Ertl

    2009-06-01

    Full Text Available Rapid pathogen sensing remains a pressing issue today since conventional identification methodsare tedious, cost intensive and time consuming, typically requiring from 48 to 72 h. In turn, chip based technologies, such as microarrays and microfluidic biochips, offer real alternatives capable of filling this technological gap. In particular microfluidic biochips make the development of fast, sensitive and portable diagnostic tools possible, thus promising rapid and accurate detection of a variety of pathogens. This paper will provide a broad overview of the novel achievements in the field of pathogen sensing by focusing on methods and devices that compliment microfluidics.

  14. Analogy among microfluidics, micromechanics, and microelectronics.

    Science.gov (United States)

    Li, Sheng-Shian; Cheng, Chao-Min

    2013-10-07

    We wish to illuminate the analogous link between microfluidic-based devices, and the already established pairing of micromechanics and microelectronics to create a triangular/three-way scientific relationship as a means of interlinking familial disciplines and accomplishing two primary goals: (1) to facilitate the modeling of multidisciplinary domains; and, (2) to enable us to co-simulate the entire system within a compact circuit simulator (e.g., Cadence or SPICE). A microfluidic channel-like structure embedded in a micro-electro-mechanical resonator via our proposed CMOS-MEMS technology is used to illustrate the connections among microfluidics, micromechanics, and microelectronics.

  15. Microfluidic systems for pathogen sensing: a review.

    Science.gov (United States)

    Mairhofer, Jürgen; Roppert, Kriemhilt; Ertl, Peter

    2009-01-01

    Rapid pathogen sensing remains a pressing issue today since conventional identification methodsare tedious, cost intensive and time consuming, typically requiring from 48 to 72 h. In turn, chip based technologies, such as microarrays and microfluidic biochips, offer real alternatives capable of filling this technological gap. In particular microfluidic biochips make the development of fast, sensitive and portable diagnostic tools possible, thus promising rapid and accurate detection of a variety of pathogens. This paper will provide a broad overview of the novel achievements in the field of pathogen sensing by focusing on methods and devices that compliment microfluidics.

  16. Shielding Electric Fields to Prevent Coalescence of Emulsions in Microfluidic Channels Using a 3D Metallic Coil

    Directory of Open Access Journals (Sweden)

    Jingmei Li

    2015-09-01

    Full Text Available In microfluidics, electric fields are widely used to assist the generation and the manipulation of droplets or jets. However, uncontrolled electric field can disrupt the operation of an integrated microfluidic system, for instance, through undesired coalescence of droplets, undesired changes in the wettability of the channel wall or unexpected death of cells. Therefore, an approach to control the distribution of electric fields inside microfluidic channels is needed. Inspired by the electro-magnetic shielding effect in electrical and radiation systems, we demonstrate the shielding of electric fields by incorporating 3D metallic coils in microfluidic devices. Using the degree of coalescence of emulsion drops as an indicator, we have shown that electric fields decrease dramatically in micro-channels surrounded by these conductive metallic coils both experimentally and numerically. Our work illustrates an approach to distribute electric fields in integrated microfluidic networks by selectively installing metallic coils or electrodes, and represents a significant step towards large-scale electro-microfluidic systems.

  17. Functionalized poly(ethylene glycol) diacrylate microgels by microfluidics: In situ peptide encapsulation for in serum selective protein detection.

    Science.gov (United States)

    Celetti, Giorgia; Natale, Concetta Di; Causa, Filippo; Battista, Edmondo; Netti, Paolo A

    2016-09-01

    Polymeric microparticles represent a robustly platform for the detection of clinically relevant analytes in biological samples; they can be functionalized encapsulating a multiple types of biologics entities, enhancing their applications as a new class of colloid materials. Microfluidic offers a versatile platform for the synthesis of monodisperse and engineered microparticles. In this work, we report microfluidic synthesis of novel polymeric microparticles endowed with specific peptide due to its superior specificity for target binding in complex media. A peptide sequence was efficiently encapsulated into the polymeric network and protein binding occurred with high affinity (KD 0.1-0.4μM). Fluidic dynamics simulation was performed to optimize the production conditions for monodisperse and stable functionalized microgels. The results demonstrate the easy and fast realization, in a single step, of functionalized monodisperse microgels using droplet-microfluidic technique, and how the inclusion of the peptide within polymeric network improve both the affinity and the specificity of protein capture.

  18. Genetic interaction mapping with microfluidic-based single cell sequencing

    Science.gov (United States)

    Haliburton, John R.; Shao, Wenjun; Deutschbauer, Adam; Arkin, Adam; Abate, Adam R.

    2017-01-01

    Genetic interaction mapping is useful for understanding the molecular basis of cellular decision making, but elucidating interactions genome-wide is challenging due to the massive number of gene combinations that must be tested. Here, we demonstrate a simple approach to thoroughly map genetic interactions in bacteria using microfluidic-based single cell sequencing. Using single cell PCR in droplets, we link distinct genetic information into single DNA sequences that can be decoded by next generation sequencing. Our approach is scalable and theoretically enables the pooling of entire interaction libraries to interrogate multiple pairwise genetic interactions in a single culture. The speed, ease, and low-cost of our approach makes genetic interaction mapping viable for routine characterization, allowing the interaction network to be used as a universal read out for a variety of biology experiments, and for the elucidation of interaction networks in non-model organisms. PMID:28170417

  19. Microfluidic Tools for Protein Crystallography

    Science.gov (United States)

    Abdallah, Bahige G.

    X-ray crystallography is the most widely used method to determine the structure of proteins, providing an understanding of their functions in all aspects of life to advance applications in fields such as drug development and renewable energy. New techniques, namely serial femtosecond crystallography (SFX), have unlocked the ability to unravel the structures of complex proteins with vital biological functions. A key step and major bottleneck of structure determination is protein crystallization, which is very arduous due to the complexity of proteins and their natural environments. Furthermore, crystal characteristics govern data quality, thus need to be optimized to attain the most accurate reconstruction of the protein structure. Crystal size is one such characteristic in which narrowed distributions with a small modal size can significantly reduce the amount of protein needed for SFX. A novel microfluidic sorting platform was developed to isolate viable ~200 nm -- ~600 nm photosystem I (PSI) membrane protein crystals from ~200 nm -- ~20 ?m crystal samples using dielectrophoresis, as confirmed by fluorescence microscopy, second-order nonlinear imaging of chiral crystals (SONICC), and dynamic light scattering. The platform was scaled-up to rapidly provide 100s of microliters of sorted crystals necessary for SFX, in which similar crystal size distributions were attained. Transmission electron microscopy was used to view the PSI crystal lattice, which remained well-ordered postsorting, and SFX diffraction data was obtained, confirming a high-quality, viable crystal sample. Simulations indicated sorted samples provided accurate, complete SFX datasets with 3500-fold less protein than unsorted samples. Microfluidic devices were also developed for versatile, rapid protein crystallization screening using nanovolumes of sample. Concentration gradients of protein and precipitant were generated to crystallize PSI, phycocyanin, and lysozyme using modified counterdiffusion

  20. Overview of the microfluidic diagnostics commercial landscape.

    Science.gov (United States)

    Kim, Lily

    2013-01-01

    Since its birth in the late 1980s, the field of microfluidics has continued to mature, with a growing number of companies pursuing diagnostic applications. In 2009 the worldwide in vitro diagnostics market was estimated at >$40 billion USD, and microfluidic diagnostics are poised to reap a significant part of this market across a range of areas including laboratory diagnostics, point-of-care diagnostics, cancer diagnostics, and others. The potential economic advantages of microfluidics are numerous and compelling: lower reagent and/or sample volumes, lower equipment costs, improved portability, increased automation, and increased measurement speed. All of these factors may help put more information in the hands of doctors and patients sooner, enabling earlier disease detection and more tailored, effective treatments. This chapter reviews the microfluidic diagnostics commercial landscape and discusses potential commercialization challenges and opportunities.

  1. Microfluidic Analytical Separator for Proteomics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SHOT proposes an innovative microfluidic device designed to effect a 2-dimensional resolution of a mixture of proteins based on isoelectric point (pI) and molecular...

  2. Microfluidic Analytical Separator for Proteomics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a microfluidic device designed to effect a 2-dimensional resolution of a mixture of proteins based on isoelectric point (pI) and molecular...

  3. 3D-printed microfluidic devices.

    Science.gov (United States)

    Amin, Reza; Knowlton, Stephanie; Hart, Alexander; Yenilmez, Bekir; Ghaderinezhad, Fariba; Katebifar, Sara; Messina, Michael; Khademhosseini, Ali; Tasoglu, Savas

    2016-06-20

    Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices.

  4. Multiplex single particle analysis in microfluidics.

    Science.gov (United States)

    Dannhauser, D; Romeo, G; Causa, F; De Santo, I; Netti, P A

    2014-10-21

    A straightforward way to measure separated micrometric sized particles in microfluidic flow is reported. The light scattering profile (LSP) of each single particle is fully characterized by using a CMOS-camera based small angle light scattering (SALS) apparatus, ranging from 2° up to 30°. To ensure controlled particle passage through the incident laser, a viscoelastic 3D alignment effect by viscoelastic induced particle migration has been implemented in a simple and cost-effective microfluidic device. Different polystyrene particle sizes are measured in microfluidic flows and the obtained scattering signatures are matched with the Lorenz-Mie based scattering theory. The results confirm the possibility of using this apparatus for real multiplex particle analyses in microfluidic particle flows.

  5. A microfluidic device for studying cell signaling with multiple inputs and adjustable amplitudes and frequencies

    Science.gov (United States)

    Ningsih, Zubaidah; Chon, James W. M.; Clayton, Andrew H. A.

    2013-12-01

    Cell function is largely controlled by an intricate web of macromolecular interactions called signaling networks. It is known that the type and the intensity (concentration) of stimulus affect cell behavior. However, the temporal aspect of the stimulus is not yet fully understood. Moreover, the process of distinguishing between two stimuli by a cell is still not clear. A microfluidic device enables the delivery of a precise and exact stimulus to the cell due to the laminar flow established inside its micro-channel. The slow stream delivers a constant stimulus which is adjustable according to the experiment set up. Moreover, with controllable inputs, microfluidic facilitates the stimuli delivery according to a certain pattern with adjustable amplitude, frequency and phase. Several designs of PDMS microfluidic device has been produced in this project via photolithography and soft lithography processes. To characterize the microfluidic performance, two experiments has been conducted. First, by comparing the fluorescence intensity and the lifetime of fluorescein in the present of KI, mixing extent between two inputs was observed using Frequency Lifetime Imaging Microscopy (FLIM). Furthermore, the input-output relationship of fluorescein concentration delivered was also drawn to characterize the amplitude, frequency and phase of the inputs. Second experiment involved the cell culturing inside microfluidic. Using NG108-15 cells, proliferation and differentiation were observed based on the cell number and cell physiological changes. Our results demonstrate that hurdle design gives 86% mixing of fluorescein and buffer. Relationship between inputoutput fluorescein concentrations delivered has also been demonstrated and cells were successfully cultured inside the microfluidic.

  6. Biocompatible "click" wafer bonding for microfluidic devices

    OpenAIRE

    Saharil, Farizah; Carlborg, Carl Fredrik; Haraldsson, Tommy; van der Wijngaart, Wouter

    2012-01-01

    We introduce a novel dry wafer bonding concept designed for permanent attachment of micromolded polymer structures to surface functionalized silicon substrates. The method, designed for simultaneous fabrication of many lab-on-chip devices, utilizes a chemically reactive polymer microfluidic structure, which rapidly bonds to a functionalized substrate via "click" chemistry reactions. The microfluidic structure consists of an off-stoichiometry thiol-ene (OSTE) polymer with a very high density o...

  7. Paper based microfluidic devices for environmental diagnostics

    CSIR Research Space (South Africa)

    Govindasamy, K

    2012-09-01

    Full Text Available such as elevated temperatures and mechanical stresses. Paper based microfluidic chips are patterned with micron sized hydrophobic barriers which penetrate the paper?s cross section. These barriers guide the capillary movement of fluids through the cellulose... visual or electrochemical signal, indicating whether the analyte is present in the sample. Although based on a similar operational principal as lateral flow technologies (such as home pregnancy tests), paper based microfluidics seeks to offer a more...

  8. Microfluidic Sample Preparation for Immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S; Benett, W; Bettencourt, K; Chang, J; Fisher, K; Hamilton, J; Krulevitch, P; Park, C; Stockton, C; Tarte, L; Wang, A; Wilson, T

    2001-08-09

    Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. to support detection instruments, they are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. They are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Many of these fluidic functions are accomplished with acoustic radiation pressure or dielectrophoresis. They are integrating these technologies into packaged systems with pumps and valves to control fluid flow through the fluidic circuit.

  9. Surface Sensitive Microfluidic Optomechanical Sensors

    CERN Document Server

    Kim, Kyu Hyun

    2014-01-01

    The microfluidic optomechanical resonator (uFOMR) based on a thin-walled glass capillary supports high Q-factor (>1000) mechanical modes in the presence of liquids. In this Letter, the sensitivity of the uFOMR to the surface change is studied by layer-by-layer removal of SiO2 molecules from the uFOMR inner surface using various concentrations of hydrofluoric acid solutions. A frequency downshift is observed with a sensitivity of 1.2 Hz/(pg/mm2), which translates to a surface density detection limit of 83 pg/mm2. This work opens a door to using the optomechanical mode for detection and characterization of molecules present near the resonator surface.

  10. Sampling by Fluidics and Microfluidics

    Directory of Open Access Journals (Sweden)

    V. Tesař

    2002-01-01

    Full Text Available Selecting one from several available fluid samples is a procedure often performed especially in chemical engineering. It is usually done by an array of valves sequentially opened and closed. Not generally known is an advantageous alternative: fluidic sampling units without moving parts. In the absence of complete pipe closure, cross-contamination between samples cannot be ruled out. This is eliminated by arranging for small protective flows that clear the cavities and remove any contaminated fluid. Although this complicates the overall circuit layout, fluidic sampling units with these "guard" flows were successfully built and tested. Recent interest in microchemistry leads to additional problems due very low operating Reynolds numbers. This necessitated the design of microfluidic sampling units based on new operating principles.

  11. Microfluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Black, Bryan; Ordonez, Simon; Mondal, Argha; Jain, Ankur; Mohanty, Samarendra

    2014-10-01

    The precision of axonal pathfinding and the accurate formation of functional neural circuitry are crucial for an organism during development as well as during adult central and peripheral nerve regeneration. While chemical cues are believed to be primarily responsible for axonal pathfinding, we hypothesize that forces due to localized fluid flow may directly affect neuronal guidance during early organ development. Here, we report direct evidence of fluid flow influencing axonal migration, producing turning angles of up to 90°. Microfluidic flow simulations indicate that an axon may experience significant bending force due to cross-flow, which may contribute to the observed axonal turning. This method of flow-based guidance was successfully used to fasciculate one advancing axon onto another, showcasing the potential of this technique to be used for the formation of in vitro neuronal circuits.

  12. A Review of Biomedical Centrifugal Microfluidic Platforms

    Directory of Open Access Journals (Sweden)

    Minghui Tang

    2016-02-01

    Full Text Available Centrifugal microfluidic or lab-on-a-disc platforms have many advantages over other microfluidic systems. These advantages include a minimal amount of instrumentation, the efficient removal of any disturbing bubbles or residual volumes, and inherently available density-based sample transportation and separation. Centrifugal microfluidic devices applied to biomedical analysis and point-of-care diagnostics have been extensively promoted recently. This paper presents an up-to-date overview of these devices. The development of biomedical centrifugal microfluidic platforms essentially covers two categories: (i unit operations that perform specific functionalities, and (ii systems that aim to address certain biomedical applications. With the aim to provide a comprehensive representation of current development in this field, this review summarizes progress in both categories. The advanced unit operations implemented for biological processing include mixing, valving, switching, metering and sequential loading. Depending on the type of sample to be used in the system, biomedical applications are classified into four groups: nucleic acid analysis, blood analysis, immunoassays, and other biomedical applications. Our overview of advanced unit operations also includes the basic concepts and mechanisms involved in centrifugal microfluidics, while on the other hand an outline on reported applications clarifies how an assembly of unit operations enables efficient implementation of various types of complex assays. Lastly, challenges and potential for future development of biomedical centrifugal microfluidic devices are discussed.

  13. Microfluidic Devices in Advanced Caenorhabditis elegans Research

    Directory of Open Access Journals (Sweden)

    Muniesh Muthaiyan Shanmugam

    2016-08-01

    Full Text Available The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.

  14. Dynamics of Microvalve Operations in Integrated Microfluidics

    Directory of Open Access Journals (Sweden)

    Alan T. H. Lau

    2014-02-01

    Full Text Available Pneumatic microvalves are widely used key components for automating liquid manipulation and flow control in microfluidics for more than one decade. Due to their robust operations and the ease of fabrication, tremendous microfluidic systems have been developed with the multiple microvalves for higher throughput and extended functionalities. Therefore, operation performance of the microvalves in the integrated microfluidic devices is crucial to the related applications, in fields such as micro-flows, cell analyses, drug discovery, and physical/chemical detections. It has been reported that operation performance of the microvalves are highly sensitive to the device configuration and pressurization scheme. This implies the further development of integrated microfluidics with a larger number of the valves may suffer the problems of undetermined microvalve behaviors during operations, which can become an unavoidable hurdle in the device design and optimization processes. Herein, we characterize responses of the individual microvalves for different operation configurations, e.g., membrane thicknesses and driving pressures. We investigate also the effects in microfluidics integrated with the more valves, through experiments, modeling and simulations. We show that dynamics of the microvalves is indeed influenced by the configurations, levels of design complexity and positions in the devices. Overall, taken dynamics of the microvalve responses into considerations, this work provides insights and guidelines for better designs of integrated microfluidics for the future applications requiring higher throughput and improved operation performance.

  15. Predicting Droplet Formation on Centrifugal Microfluidic Platforms

    Science.gov (United States)

    Moebius, Jacob Alfred

    Centrifugal microfluidics is a widely known research tool for biological sample and water quality analysis. Currently, the standard equipment used for such diagnostic applications include slow, bulky machines controlled by multiple operators. These machines can be condensed into a smaller, faster benchtop sample-to-answer system. Sample processing is an important step taken to extract, isolate, and convert biological factors, such as nucleic acids or proteins, from a raw sample to an analyzable solution. Volume definition is one such step. The focus of this thesis is the development of a model predicting monodispersed droplet formation and the application of droplets as a technique for volume definition. First, a background of droplet microfluidic platforms is presented, along with current biological analysis technologies and the advantages of integrating such technologies onto microfluidic platforms. Second, background and theories of centrifugal microfluidics is given, followed by theories relevant to droplet emulsions. Third, fabrication techniques for centrifugal microfluidic designs are discussed. Finally, the development of a model for predicting droplet formation on the centrifugal microfluidic platform are presented for the rest of the thesis. Predicting droplet formation analytically based on the volumetric flow rates of the continuous and dispersed phases, the ratios of these two flow rates, and the interfacial tension between the continuous and dispersed phases presented many challenges, which will be discussed in this work. Experimental validation was completed using continuous phase solutions of different interfacial tensions. To conclude, prospective applications are discussed with expected challenges.

  16. Microfluidic dielectrophoretic sorter using gel vertical electrodes

    Science.gov (United States)

    Luo, Jason; Nelson, Edward L.; Li, G. P.; Bachman, Mark

    2014-01-01

    We report the development and results of a two-step method for sorting cells and small particles in a microfluidic device. This approach uses a single microfluidic channel that has (1) a microfabricated sieve which efficiently focuses particles into a thin stream, followed by (2) a dielectrophoresis (DEP) section consisting of electrodes along the channel walls for efficient continuous sorting based on dielectric properties of the particles. For our demonstration, the device was constructed of polydimethylsiloxane, bonded to a glass surface, and conductive agarose gel electrodes. Gold traces were used to make electrical connections to the conductive gel. The device had several novel features that aided performance of the sorting. These included a sieving structure that performed continuous displacement of particles into a single stream within the microfluidic channel (improving the performance of downstream DEP, and avoiding the need for additional focusing flow inlets), and DEP electrodes that were the full height of the microfluidic walls (“vertical electrodes”), allowing for improved formation and control of electric field gradients in the microfluidic device. The device was used to sort polymer particles and HeLa cells, demonstrating that this unique combination provides improved capability for continuous DEP sorting of particles in a microfluidic device. PMID:24926390

  17. Microfluidic microwell and microcapillary biochips

    Science.gov (United States)

    Minot, Michael J.; Stowe, David W.; Detarando, Michael A.; Krans, Joseph A.; Kass, Jason L.

    2006-02-01

    Utilizing nanotechnology, proprietary chemistry, and microfluidics, innovative firms are developing biochips and instrument systems that enable high-speed automated biomedical sequencing. Incom Inc. presents development results on five novel biochip technologies based on FiberOptic MicroSlide and microcapillary technology. FiberOptic MicroSlides are fiber optic interrogated (FOI) biochips made up of millions of fused optical fibers, and are uniquely suited as a platform for microarray applications. FiberOptic MicroSlides (henceforth referred to as "MicroSlides" or "slides" in this paper) act as a 'zero thickness substrate' transmitting optical signals from top to bottom without spreading, so that fluorescent or luminescent activity on the surface or within a well can be directly coupled to a CCD device without additional optics. In contrast to bulk optics, the slides are compact and have excellent light-gathering power. They are an alternative to conventional microscope slides for applications involving moderate-resolution bottom viewing (inverted microscopy). The surface of the MicroSlides can be etched or patterned with a permanent polymer to form microwell arrays, or microfluidic structures suitable for genomic and proteomic analysis, cell migration studies and other applications. Low-cost microcapillary array plates have also been developed. These plates act as microscopic test tubes, which enable picoliter reactions to be detected, counted and analyzed. Progress in developing large area (300 mm X 300 mm) arrays with up to 100 million capillaries, and diameter / length aspect ratios up to 10,000: 1 is presented. Results demonstrate negligible optical cross talk between capillaries, resulting in improved signal-to-noise ratios while minimizing false hits.

  18. Microfluidic-optical integrated CMOS compatible devices for label-free biochemical sensing

    Science.gov (United States)

    Blanco, F. J.; Agirregabiria, M.; Berganzo, J.; Mayora, K.; Elizalde, J.; Calle, A.; Dominguez, C.; Lechuga, L. M.

    2006-05-01

    The fabrication, characterization and packaging of novel microfluidic-optical integrated biosensors for label-free biochemical detection is presented in this paper. The integrated device consists of a three-dimensional embedded microchannel network fabricated using enhanced CMOS compatible SU-8 multilevel polymer technology on top of a wafer containing Mach-Zehnder Interferometer (MZI) nanophotonic biosensor devices. PMMA housing provides connection to the macro-world and ensures robust leakage-free flow operation of the devices. This macro-microfluidic module can operate at pressure drops up to 1000 kPa. Fluid flow experiments have been performed in order to demonstrate the robustness of our microfluidic devices. The devices have been designed to operate under continuous flow. Steady-state flow rates ranging from 1 to 100 µl min-1 at pressure drops ranging from 10 to 500 kPa were measured in the laminar flow regime. Experimental results are in good agreement with laminar flow theory. The first interferometric sensing measurements are presented in order to demonstrate the functionality of these novel integrated devices for lab-on-a-chip and label-free biosensing applications. A bulk refractive index detection limit of 3.8 × 10-6 was obtained, close to the minimum detected up to now by label-free biosensor devices without microfluidic integration. As far as we know, this is the first time that a label-free biosensor device is integrated within a microfluidic network using a wafer-level CMOS compatible process technology.

  19. Rapid microfluidic thermal cycler for nucleic acid amplification

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Neil Reginald; Vafai, Kambiz

    2015-10-27

    A system for thermal cycling a material to be thermal cycled including a microfluidic heat exchanger; a porous medium in the microfluidic heat exchanger; a microfluidic thermal cycling chamber containing the material to be thermal cycled, the microfluidic thermal cycling chamber operatively connected to the microfluidic heat exchanger; a working fluid at first temperature; a first system for transmitting the working fluid at first temperature to the microfluidic heat exchanger; a working fluid at a second temperature, a second system for transmitting the working fluid at second temperature to the microfluidic heat exchanger; a pump for flowing the working fluid at the first temperature from the first system to the microfluidic heat exchanger and through the porous medium; and flowing the working fluid at the second temperature from the second system to the heat exchanger and through the porous medium.

  20. Operation placement for application-specific digital microfluidic biochips

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2013-01-01

    Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate onchip all the necessary functions for biochemical analysis using microfluidics. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as ......, such that the application completion time is minimized. The proposed algorithm has been evaluated using several benchmarks.......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate onchip all the necessary functions for biochemical analysis using microfluidics. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow......, but as discrete droplets on an array of electrodes. Microfluidic operations, such as transport, mixing, split, are performed on this array by routing the corresponding droplets on a series of electrodes. Researchers have proposed several approaches for the synthesis of digital microfluidic biochips. All previous...

  1. Microfluidic assay without blocking for rapid HIV screening and confirmation.

    Science.gov (United States)

    Song, Lusheng; Zhang, Yi; Wang, Wenjun; Ma, Liying; Liu, Yong; Hao, Yanlin; Shao, Yiming; Zhang, Wei; Jiang, Xingyu

    2012-08-01

    The essential step for HIV spreading limitation is the screening tests. However, there are multiple disadvantages in current screening assays which need further confirmation test. Herein we developed a rapid HIV assay combining screening and confirmation test by using the microfluidic network assay. Meanwhile, the assay is accelerated by bypassing the step of blocking. We call this method as microfluidic assay without blocking (MAWB). Both the limit of detection and reagent incubation time of MAWB are determined by screening of one model protein pair: ovalbumin and its antibody. The assay time is accelerated about 25% while the limit of detection (LOD) is well kept. Formatting the method in for both HIV screening (testing 8 HIV-related samples) and confirmation (assaying 6 kinds of HIV antibodies of each sample) within 30 min was successful. Fast HIV screening and confirmation of 20 plasma samples were also demonstrated by this method. MAWB improved the assay speed while keeping the LOD of conventional ELISA. Meanwhile, both the accuracy and throughput of MAWB were well improved, which made it an excellent candidate for a quick HIV test for both screening and confirmation. Methods like this one will find wide applications in clinical diagnosis and biochemical analysis based on the interactions between pairs of molecules.

  2. Tissue Equivalents Based on Cell-Seeded Biodegradable Microfluidic Constructs

    Directory of Open Access Journals (Sweden)

    Sarah L. Tao

    2010-03-01

    Full Text Available One of the principal challenges in the field of tissue engineering and regenerative medicine is the formation of functional microvascular networks capable of sustaining tissue constructs. Complex tissues and vital organs require a means to support oxygen and nutrient transport during the development of constructs both prior to and after host integration, and current approaches have not demonstrated robust solutions to this challenge. Here, we present a technology platform encompassing the design, construction, cell seeding and functional evaluation of tissue equivalents for wound healing and other clinical applications. These tissue equivalents are comprised of biodegradable microfluidic scaffolds lined with microvascular cells and designed to replicate microenvironmental cues necessary to generate and sustain cell populations to replace dermal and/or epidermal tissues lost due to trauma or disease. Initial results demonstrate that these biodegradable microfluidic devices promote cell adherence and support basic cell functions. These systems represent a promising pathway towards highly integrated three-dimensional engineered tissue constructs for a wide range of clinical applications.

  3. Microfluidic chip containing porous gradient for chemotaxis study

    Science.gov (United States)

    Al-Abboodi, Aswan; Tjeung, Ricky; Doran, Pauline; Yeo, Leslie; Friend, James; Chan, Peggy

    2011-12-01

    We have developed a new porous gradient microfluidic device based on in situ Gtn-HPA/CMC-Tyr hydrogel that comprises gelatin hydroxyphenylpropionic acid (Gtn-HPA) conjugate and carboxymethyl cellulose tyramine (CMC-Tyr) conjugate. The device is fabricated using a soft lithographic technique, in which microstructures were patterned on a thin layer of polydimethylsiloxane (PDMS) using a polymeric mold. Human fibrosarcoma cells (HT1080) were employed as invasive cancer cell model. Porosity gradients were generated by flowing pore etching fluid in the gradient generator network. Results suggested that spatial control of the porosity can be obtained, which mimics the 3-dimensional microenvironment in vivo for cell-based screening applications including real time chemotaxis, cytotoxicity, and continuous drug-response monitoring. A chemoattractant gradient is then generated and cell migration is monitored in real time using fluorescence microscopy. The viability of cells was evaluated using calcien AM stain. Herein, we successfully monitored the chemotactic responses of cancer cells, confirmed the validity of using in situ porous hydrogels as a construction material for a microchemotaxis device, and demonstrated the potential of the hydrogel with tunable porosity based microfluidic device in biological experiments. This device will also be practical in controlling the chemical and mechanical properties of the surroundings during the formation of tissue engineered constructs.

  4. Microfluidics: an enabling technology for the life sciences

    OpenAIRE

    Zengerle, Roland; Koltay, P.; Ducrée, Jens

    2004-01-01

    During the last year we have investigated existing and future markets, products and technologies for microfluidics in the life sciences. Within this paper we present some of the findings and discuss a major trend identified within this project: the development of microfluidic platforms for flexible design of application specific integrated microfluidic systems. We discuss two platforms in detail which are currently under development in our lab: microfluidics on a rotating CD ("Lab-CD") as wel...

  5. Demonstration of an integrated electroactive polymer actuator on a microfluidic electrophoresis device.

    Science.gov (United States)

    Price, Alexander K; Anderson, Kristen M; Culbertson, Christopher T

    2009-07-21

    The construction of microfluidic devices from siloxane-based polymers is widely reported in the current literature. While the use of these materials is primarily due to their rapid and facile fabrication, low cost and robustness, they also have the ability to function as smart materials. This feature, however, has not been commonly exploited in conjunction with their fluid-handling capabilities. Siloxanes are considered smart materials because their shapes can be modified in the presence of an electric field. The energy in the electric field can be transduced into mechanical energy and directly coupled with a microfabricated channel network in order to affect or initiate the movement of fluids. Here, we present a novel microfluidic device into which an electroactive polymer (EAP) actuation unit is integrated. The EAP actuation unit features a microfluidic channel placed above a patterned electrode. The patterned electrode is insulated from the channel by an EAP layer that is composed of PDMS. When a potential is applied across the EAP layer, it changes shape, which also changes the volume of the microfluidic channel above it. With this proof-of-concept device we demonstrated the ability to inject plugs of sample on a standard electrophoresis cross chip solely by changing the magnitude of the electric field between the channel and the electrode. Using an EAP actuation unit, the size of the injection plugs can be varied as a function of the electric field, the active area of the EAP actuation unit and the softness of the EAP.

  6. Manually operatable on-chip bistable pneumatic microstructures for microfluidic manipulations.

    Science.gov (United States)

    Chen, Arnold; Pan, Tingrui

    2014-09-07

    Bistable microvalves are of particular interest because of their distinct nature of requiring energy consumption only during the transition between the open and closed states. This characteristic can be highly advantageous in reducing the number of external inputs and the complexity of control circuitries since microfluidic devices as contemporary lab-on-a-chip platforms are transferring from research settings to low-resource environments with high integrability and a small form factor. In this paper, we first present manually operatable, on-chip bistable pneumatic microstructures (BPMs) for microfluidic manipulation. The structural design and operation of the BPM devices can be readily integrated into any pneumatically powered microfluidic network consisting of pneumatic and fluidic channels. It is mainly composed of a vacuum activation chamber (VAC) and a pressure release chamber (PRC), of which users have direct control through finger pressing to switch either to the bistable vacuum state (VS) or the atmospheric state (AS). We have integrated multiple BPM devices into a 4-to-1 microfluidic multiplexor to demonstrate on-chip digital flow switching from different sources. Furthermore, we have shown its clinical relevance in a point-of-care diagnostic chip that processes blood samples to identify the distinct blood types (A/B/O) on-chip.

  7. Graphene nano-ink biosensor arrays on a microfluidic paper for multiplexed detection of metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Labroo, Pratima; Cui, Yue, E-mail: yue.cui@usu.edu

    2014-02-01

    Graphical abstract: - Highlights: • We report graphene-ink biosensor arrays on a microfluidic paper for metabolites. • The device is able to detect multiple metabolites sensitively and rapidly. • The device fabrication process is simple and inexpensive. - Abstract: The development of a miniaturized and low-cost platform for the highly sensitive, selective and rapid detection of multiplexed metabolites is of great interest for healthcare, pharmaceuticals, food science, and environmental monitoring. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with extraordinary electrical sensing capability. Microfluidic paper with printing technique is a low cost matrix. Here, we demonstrated the development of graphene-ink based biosensor arrays on a microfluidic paper for the multiplexed detection of different metabolites, such as glucose, lactate, xanthine and cholesterol. Our results show that the graphene biosensor arrays can detect multiple metabolites on a microfluidic paper sensitively, rapidly and simultaneously. The device exhibits a fast measuring time of less than 2 min, a low detection limit of 0.3 μM, and a dynamic detection range of 0.3–15 μM. The process is simple and inexpensive to operate and requires a low consumption of sample volume. We anticipate that these results could open exciting opportunities for a variety of applications.

  8. Material Biocompatibility for PCR Microfluidic Chips

    KAUST Repository

    Kodzius, Rimantas

    2010-04-23

    As part of the current miniaturization trend, biological reactions and processes are being adapted to microfluidics devices. PCR is the primary method employed in DNA amplification, its miniaturization is central to efforts to develop portable devices for diagnostics and testing purposes. A problem is the PCR-inhibitory effect due to interaction between PCR reagents and the surrounding environment, which effect is increased in high-surface-are-to-volume ration microfluidics. In this study, we evaluated the biocompatibility of various common materials employed in the fabrication of microfluidic chips, including silicon, several kinds of silicon oxide, glasses, plastics, wax, and adhesives. Two-temperature PCR was performed with these materials to determine their PCR-inhibitory effect. In most of the cases, addition of bovine serum albumin effectively improved the reaction yield. We also studied the individual PCR components from the standpoint of adsorption. Most of the materials did not inhibit the DNA, whereas they did show noticeable interaction with the DNA polymerase. Our test, instead of using microfluidic devices, can be easily conducted in common PCR tubes using a standard bench thermocycler. Our data supports an overview of the means by which the materials most bio-friendly to microfluidics can be selected.

  9. Mechanically activated artificial cell by using microfluidics.

    Science.gov (United States)

    Ho, Kenneth K Y; Lee, Lap Man; Liu, Allen P

    2016-01-01

    All living organisms sense mechanical forces. Engineering mechanosensitive artificial cell through bottom-up in vitro reconstitution offers a way to understand how mixtures of macromolecules assemble and organize into a complex system that responds to forces. We use stable double emulsion droplets (aqueous/oil/aqueous) to prototype mechanosensitive artificial cells. In order to demonstrate mechanosensation in artificial cells, we develop a novel microfluidic device that is capable of trapping double emulsions into designated chambers, followed by compression and aspiration in a parallel manner. The microfluidic device is fabricated using multilayer soft lithography technology, and consists of a control layer and a deformable flow channel. Deflections of the PDMS membrane above the main microfluidic flow channels and trapping chamber array are independently regulated pneumatically by two sets of integrated microfluidic valves. We successfully compress and aspirate the double emulsions, which result in transient increase and permanent decrease in oil thickness, respectively. Finally, we demonstrate the influx of calcium ions as a response of our mechanically activated artificial cell through thinning of oil. The development of a microfluidic device to mechanically activate artificial cells creates new opportunities in force-activated synthetic biology.

  10. Mechanically activated artificial cell by using microfluidics

    Science.gov (United States)

    Ho, Kenneth K. Y.; Lee, Lap Man; Liu, Allen P.

    2016-09-01

    All living organisms sense mechanical forces. Engineering mechanosensitive artificial cell through bottom-up in vitro reconstitution offers a way to understand how mixtures of macromolecules assemble and organize into a complex system that responds to forces. We use stable double emulsion droplets (aqueous/oil/aqueous) to prototype mechanosensitive artificial cells. In order to demonstrate mechanosensation in artificial cells, we develop a novel microfluidic device that is capable of trapping double emulsions into designated chambers, followed by compression and aspiration in a parallel manner. The microfluidic device is fabricated using multilayer soft lithography technology, and consists of a control layer and a deformable flow channel. Deflections of the PDMS membrane above the main microfluidic flow channels and trapping chamber array are independently regulated pneumatically by two sets of integrated microfluidic valves. We successfully compress and aspirate the double emulsions, which result in transient increase and permanent decrease in oil thickness, respectively. Finally, we demonstrate the influx of calcium ions as a response of our mechanically activated artificial cell through thinning of oil. The development of a microfluidic device to mechanically activate artificial cells creates new opportunities in force-activated synthetic biology.

  11. Mechanically activated artificial cell by using microfluidics

    Science.gov (United States)

    Ho, Kenneth K. Y.; Lee, Lap Man; Liu, Allen P.

    2016-01-01

    All living organisms sense mechanical forces. Engineering mechanosensitive artificial cell through bottom-up in vitro reconstitution offers a way to understand how mixtures of macromolecules assemble and organize into a complex system that responds to forces. We use stable double emulsion droplets (aqueous/oil/aqueous) to prototype mechanosensitive artificial cells. In order to demonstrate mechanosensation in artificial cells, we develop a novel microfluidic device that is capable of trapping double emulsions into designated chambers, followed by compression and aspiration in a parallel manner. The microfluidic device is fabricated using multilayer soft lithography technology, and consists of a control layer and a deformable flow channel. Deflections of the PDMS membrane above the main microfluidic flow channels and trapping chamber array are independently regulated pneumatically by two sets of integrated microfluidic valves. We successfully compress and aspirate the double emulsions, which result in transient increase and permanent decrease in oil thickness, respectively. Finally, we demonstrate the influx of calcium ions as a response of our mechanically activated artificial cell through thinning of oil. The development of a microfluidic device to mechanically activate artificial cells creates new opportunities in force-activated synthetic biology. PMID:27610921

  12. Rapid wasted-free microfluidic fabrication based on ink-jet approach for microfluidic sensing applications

    Science.gov (United States)

    Jarujareet, Ungkarn; Amarit, Rattasart; Sumriddetchkajorn, Sarun

    2016-11-01

    Realizing that current microfluidic chip fabrication techniques are time consuming and labor intensive as well as always have material leftover after chip fabrication, this research work proposes an innovative approach for rapid microfluidic chip production. The key idea relies on a combination of a widely-used inkjet printing method and a heat-based polymer curing technique with an electronic-mechanical control, thus eliminating the need of masking and molds compared to typical microfluidic fabrication processes. In addition, as the appropriate amount of polymer is utilized during printing, there is much less amount of material wasted. Our inkjet-based microfluidic printer can print out the desired microfluidic chip pattern directly onto a heated glass surface, where the printed polymer is suddenly cured. Our proof-of-concept demonstration for widely-used single-flow channel, Y-junction, and T-junction microfluidic chips shows that the whole microfluidic chip fabrication process requires only 3 steps with a fabrication time of 6 minutes.

  13. Microfluidic mixing using contactless dielectrophoresis.

    Science.gov (United States)

    Salmanzadeh, Alireza; Shafiee, Hadi; Davalos, Rafael V; Stremler, Mark A

    2011-09-01

    The first experimental evidence of mixing enhancement in a microfluidic system using contactless dielectrophoresis (cDEP) is presented in this work. Pressure-driven flow of deionized water containing 0.5 μm beads was mixed in various chamber geometries by imposing a dielectrophoresis (DEP) force on the beads. In cDEP the electrodes are not in direct contact with the fluid sample but are instead capacitively coupled to the mixing chamber through thin dielectric barriers, which eliminates many of the problems encountered with standard DEP. Four system designs with rectangular and circular mixing chambers were fabricated in PDMS. Mixing tests were conducted for flow rates from 0.005 to 1 mL/h subject to an alternating current signal range of 0-300 V at 100-600 kHz. When the time scales of the bulk fluid motion and the DEP motion were commensurate, rapid mixing was observed. The rectangular mixing chambers were found to be more efficient than the circular chambers. This approach shows potential for mixing low diffusivity biological samples, which is a very challenging problem in laminar flows at small scales.

  14. Surfactant adsorption kinetics in microfluidics

    Science.gov (United States)

    Riechers, Birte; Maes, Florine; Akoury, Elias; Semin, Benoît; Gruner, Philipp; Baret, Jean-Christophe

    2016-10-01

    Emulsions are metastable dispersions. Their lifetimes are directly related to the dynamics of surfactants. We design a microfluidic method to measure the kinetics of adsorption of surfactants to the droplet interface, a key process involved in foaming, emulsification, and droplet coarsening. The method is based on the pH decay in the droplet as a direct measurement of the adsorption of a carboxylic acid surfactant to the interface. From the kinetic measurement of the bulk equilibration of the pH, we fully determine the adsorption process of the surfactant. The small droplet size and the convection during the droplet flow ensure that the transport of surfactant through the bulk is not limiting the kinetics of adsorption. To validate our measurements, we show that the adsorption process determines the timescale required to stabilize droplets against coalescence, and we show that the interface should be covered at more than 90% to prevent coalescence. We therefore quantitatively link the process of adsorption/desorption, the stabilization of emulsions, and the kinetics of solute partitioning—here through ion exchange—unraveling the timescales governing these processes. Our method can be further generalized to other surfactants, including nonionic surfactants, by making use of fluorophore-surfactant interactions.

  15. The air-liquid flow in a microfluidic airway tree.

    Science.gov (United States)

    Song, Yu; Baudoin, Michael; Manneville, Paul; Baroud, Charles N

    2011-09-01

    Microfluidic techniques are employed to investigate air-liquid flows in the lung. A network of microchannels with five generations is made and used as a simplified model of a section of the pulmonary airway tree. Liquid plugs are injected into the network and pushed by a flow of air; they divide at every bifurcation until they reach the exits of the network. A resistance, associated with the presence of one plug in a given generation, is defined to establish a linear relation between the driving pressure and the total flow rate in the network. Based on this resistance, good predictions are obtained for the flow of two successive plugs in different generations. The total flow rate of a two-plug flow is found to depend not only on the driving pressure and lengths of the plugs, but also the initial distance between them. Furthermore, long range interactions between daughters of a dividing plug are observed and discussed, particularly when the plugs are flowing through the bifurcations. These interactions lead to different flow patterns for different forcing conditions: the flow develops symmetrically when subjected to constant pressure or high flow rate forcing, while a low flow rate driving yields an asymmetric flow.

  16. Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

    Science.gov (United States)

    Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

    2009-01-01

    Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

  17. Design and Testing of Digital Microfluidic Biochips

    CERN Document Server

    Zhao, Yang

    2013-01-01

    This book provides a comprehensive methodology for automated design, test and diagnosis, and use of robust, low-cost, and manufacturable digital microfluidic systems. It focuses on the development of a comprehensive CAD optimization framework for digital microfluidic biochips that unifies different design problems. With the increase in system complexity and integration levels, biochip designers can utilize the design methods described in this book to evaluate different design alternatives, and carry out design-space exploration to obtain the best design point. Describes practical design automation tools that address different design problems (e.g., synthesis, droplet routing, control-pin mapping, testing and diagnosis, and error recovery) in a unified manner; Applies test pattern generation and error-recovery techniques for digital microfluidics-based biochips; Uses real bioassays as evaluation examples, e.g., multiplexed in vitro human physiological fluids diagnostics, PCR, protein crystallization.  

  18. Bridging Flows: Microfluidic End‐User Solutions

    DEFF Research Database (Denmark)

    Sabourin, David

    . A second practical challenge users face stems from the peripheral equipment, e.g. pumps, required to drive microfluidic devices. This equipment is often costly and bulky and results in limitations and restrictions on microfluidic device operation, such as the number of channels or devices which can...... be actuated or microscopic observation. To address the above issues interconnection and pumping solutions were developed. Methods for creating multiple, aligned, parallel and planar interconnections well suited to microscopy are described. Both reusable, non‐integrated, and permanent, integrated...... interconnection solutions are presented. The construction of twelve and eight channel miniaturized, mechanically actuated peristaltic pumps is also described. The small footprint of the pumps allows their placement adjacent to microfluidic devices and on microscope stages. The reusable, non...

  19. Nanostructures for all-polymer microfluidic systems

    DEFF Research Database (Denmark)

    Matschuk, Maria; Bruus, Henrik; Larsen, Niels Bent

    2010-01-01

    We present a process for fabricating nanostructured surfaces with feature sizes down to at least 50 nm and aspect ratios of 1:1 by injection molding. We explored the effects of mold coatings and injection molding conditions on the final nanostructure quality. A plasma-polymerized fluorocarbon based...... antistiction coating was found to improve the replication fidelity (shape and depth) of nanoscale features substantially. Arrays of holes of 50 nm diameter/35 nm depth and 100 nm/100 nm diameter, respectively, were mass-produced in cyclic olefin copolymer (Topas 5013) by injection molding. Polymer microfluidic...... channel chip parts resulted from a separate injection molding process. The microfluidic chip part and the nanostructured chip part were successfully bonded to form a sealed microfluidic system using air plasma assisted thermal bonding....

  20. Microfluidics for research and applications in oncology.

    Science.gov (United States)

    Chaudhuri, Parthiv Kant; Ebrahimi Warkiani, Majid; Jing, Tengyang; Kenry; Lim, Chwee Teck

    2016-01-21

    Cancer is currently one of the top non-communicable human diseases, and continual research and developmental efforts are being made to better understand and manage this disease. More recently, with the improved understanding in cancer biology as well as the advancements made in microtechnology and rapid prototyping, microfluidics is increasingly being explored and even validated for use in the detection, diagnosis and treatment of cancer. With inherent advantages such as small sample volume, high sensitivity and fast processing time, microfluidics is well-positioned to serve as a promising platform for applications in oncology. In this review, we look at the recent advances in the use of microfluidics, from basic research such as understanding cancer cell phenotypes as well as metastatic behaviors to applications such as the detection, diagnosis, prognosis and drug screening. We then conclude with a future outlook on this promising technology.

  1. Temperature Sensing in Modular Microfluidic Architectures

    Directory of Open Access Journals (Sweden)

    Krisna C. Bhargava

    2016-01-01

    Full Text Available A discrete microfluidic element with integrated thermal sensor was fabricated and demonstrated as an effective probe for process monitoring and prototyping. Elements were constructed using stereolithography and market-available glass-bodied thermistors within the modular, standardized framework of previous discrete microfluidic elements demonstrated in the literature. Flow rate-dependent response due to sensor self-heating and microchannel heating and cooling was characterized and shown to be linear in typical laboratory conditions. An acid-base neutralization reaction was performed in a continuous flow setting to demonstrate applicability in process management: the ratio of solution flow rates was varied to locate the equivalence point in a titration, closely matching expected results. This element potentially enables complex, three-dimensional microfluidic architectures with real-time temperature feedback and flow rate sensing, without application specificity or restriction to planar channel routing formats.

  2. MEMS and microfluidics for diagnostics devices.

    Science.gov (United States)

    Rosen, Y; Gurman, P

    2010-06-01

    There are conditions in clinical medicine demanding critical therapeutic decisions. These conditions necessitate accuracy, rapidity, accessibility, cost-effectiveness and mobility. New technologies have been developed in order to address these challenges. Microfluidics and Micro Electro-Mechanical Systems are two of such technologies. Microfluidics, a discipline that involves processing fluids at the microscale in etched microchannels, is being used to build lab- on-a-chip systems to run chemical and biological assays. These systems are being transformed into handheld devices designed to be used at remote settings or at the bedside. MEMS are microscale electromechanical elements integrated in lab chip systems or used as individual components. MEMS based sensors represents a highly developed field with successful commercialized products currently being incorporated into vitro,ex vivo and in vivo devices. In the present paper several examples of microfluidic devices and MEMS sensors are introduced together with some current examples of commercialized products. Future challenges and trends will be discussed.

  3. Microfluidics for miniaturized laboratories on a chip.

    Science.gov (United States)

    Franke, Thomas A; Wixforth, Achim

    2008-10-24

    Microfluidic systems promise solutions for high throughput and highly specific analysis for biology, medicine and chemistry while consuming only tiny amounts of reactants and space. On these lab-on-a-chip platforms often multiple physical effects such as electrokinetic, acoustic or capillary phenomena from various disciplines are exploited to gain the optimal functionality. The fluidics on these small length scales differ significantly from our experience of the macroscopic world. In this Review we survey some of the approaches and techniques to handle minute amounts of fluid volumes in microfluidic systems with special focus on surface acoustic wave driven fluidics, a technique developed in our laboratory. Here, we outline the basics of this technique and demonstrate, for example, how acoustic mixing and fluid actuation is realized. Furthermore we discuss the interplay of different physical effects in microfluidic systems and illustrate their usefulness for several applications.

  4. 3D-Printed Microfluidic Automation

    Science.gov (United States)

    Au, Anthony K.; Bhattacharjee, Nirveek; Horowitz, Lisa F.; Chang, Tim C.; Folch, Albert

    2015-01-01

    Microfluidic automation – the automated routing, dispensing, mixing, and/or separation of fluids through microchannels – generally remains a slowly-spreading technology because device fabrication requires sophisticated facilities and the technology’s use demands expert operators. Integrating microfluidic automation in devices has involved specialized multi-layering and bonding approaches. Stereolithography is an assembly-free, 3D-printing technique that is emerging as an efficient alternative for rapid prototyping of biomedical devices. Here we describe fluidic valves and pumps that can be stereolithographically printed in optically-clear, biocompatible plastic and integrated within microfluidic devices at low cost. User-friendly fluid automation devices can be printed and used by non-engineers as replacement for costly robotic pipettors or tedious manual pipetting. Engineers can manipulate the designs as digital modules into new devices of expanded functionality. Printing these devices only requires the digital file and electronic access to a printer. PMID:25738695

  5. Thermophoresis of DNA determined by microfluidic fluorescence.

    Science.gov (United States)

    Duhr, S; Arduini, S; Braun, D

    2004-11-01

    We describe a microfluidic all-optical technique to measure the thermophoresis of molecules. Within micrometer-thick chambers, we heat aqueous solutions with a micrometer-sized focus of infrared light. The temperature increase of about 1 K is monitored with temperature-sensitive fluorescent dyes. We test the approach in measuring the thermophoresis of DNA. We image the concentration of DNA in a second fluorescence-color channel. DNA is depleted away from the heated spot. The profile of depletion is fitted by the thermophoretic theory to reveal the Soret coefficient. We evaluate the method with numerical 3D calculations of temperature profiles, drift, convection and thermophoretic depletion using finite element methods. The approach opens new ways to monitor thermophoresis at the single molecule level, near boundaries and in complex mixtures. The flexible microfluidic setting is a good step towards microfluidic applications of thermophoresis in biotechnology.

  6. Microfluidic serpentine antennas with designed mechanical tunability.

    Science.gov (United States)

    Huang, YongAn; Wang, Yezhou; Xiao, Lin; Liu, Huimin; Dong, Wentao; Yin, Zhouping

    2014-11-07

    This paper describes the design and characterization of microfluidic serpentine antennas with reversible stretchability and designed mechanical frequency modulation (FM). The microfluidic antennas are designed based on the Poisson's ratio of the elastomer in which the liquid alloy antenna is embedded, to controllably decrease, stabilize or increase its resonance frequency when being stretched. Finite element modelling was used in combination with experimental verification to investigate the effects of substrate dimensions and antenna aspect ratios on the FM sensitivity to uniaxial stretching. It could be designed within the range of -1.2 to 0.6 GHz per 100% stretch. When the aspect ratio of the serpentine antenna is between 1.0 and 1.5, the resonance frequency is stable under stretching, bending, and twisting. The presented microfluidic serpentine antenna design could be utilized in the field of wireless mobile communication for the design of wearable electronics, with a stable resonance frequency under dynamic applied strain up to 50%.

  7. 3D-printed microfluidic automation.

    Science.gov (United States)

    Au, Anthony K; Bhattacharjee, Nirveek; Horowitz, Lisa F; Chang, Tim C; Folch, Albert

    2015-04-21

    Microfluidic automation - the automated routing, dispensing, mixing, and/or separation of fluids through microchannels - generally remains a slowly-spreading technology because device fabrication requires sophisticated facilities and the technology's use demands expert operators. Integrating microfluidic automation in devices has involved specialized multi-layering and bonding approaches. Stereolithography is an assembly-free, 3D-printing technique that is emerging as an efficient alternative for rapid prototyping of biomedical devices. Here we describe fluidic valves and pumps that can be stereolithographically printed in optically-clear, biocompatible plastic and integrated within microfluidic devices at low cost. User-friendly fluid automation devices can be printed and used by non-engineers as replacement for costly robotic pipettors or tedious manual pipetting. Engineers can manipulate the designs as digital modules into new devices of expanded functionality. Printing these devices only requires the digital file and electronic access to a printer.

  8. Recent Advancements towards Full-Systems Microfluidics

    Directory of Open Access Journals (Sweden)

    Amine Miled

    2017-07-01

    Full Text Available Microfluidics is quickly becoming a key technology in an expanding range of fields, such as medical sciences, biosensing, bioactuation, chemical synthesis, and more. This is helping its transformation from a promising R&D tool to commercially viable technology. Fuelling this expansion is the intensified focus on automation and enhanced functionality through integration of complex electrical control, mechanical properties, in situ sensing and flow control. Here we highlight recent contributions to the Sensors Special Issue series called “Microfluidics-Based Microsystem Integration Research” under the following categories: (i Device fabrication to support complex functionality; (ii New methods for flow control and mixing; (iii Towards routine analysis and point of care applications; (iv In situ characterization; and (v Plug and play microfluidics.

  9. Planar microfluidics - liquid handling without walls

    CERN Document Server

    Rathgeber, A; Kutschera, H J; Wixforth, A

    2001-01-01

    The miniaturization and integration of electronic circuitry has not only made the enormous increase in performance of semiconductor devices possible but also spawned a myriad of new products and applications ranging from a cellular phone to a personal computer. Similarly, the miniaturization and integration of chemical and biological processes will revolutionize life sciences. Drug design and diagnostics in the genomic era require reliable and cost effective high throughput technologies which can be integrated and allow for a massive parallelization. Microfluidics is the core technology to realize such miniaturized laboratories with feature sizes on a submillimeter scale. Here, we report on a novel microfluidic technology meeting the basic requirements for a microfluidic processor analogous to those of its electronic counterpart: Cost effective production, modular design, high speed, scalability and programmability.

  10. Electroporation of cells in microfluidic droplets.

    Science.gov (United States)

    Zhan, Yihong; Wang, Jun; Bao, Ning; Lu, Chang

    2009-03-01

    Droplet-based microfluidics has raised a lot of interest recently due to its wide applications to screening biological/chemical assays with high throughput. Despite the advances on droplet-based assays involving cells, gene delivery methods that are compatible with the droplet platform have been lacking. In this report, we demonstrate a simple microfluidic device that encapsulates cells into aqueous droplets and then electroporates the encapsulated cells. The electroporation occurs when the cell-containing droplets (in oil) flow through a pair of microelectrodes with a constant voltage established in between. We investigate the parameters and characteristics of the electroporation. We demonstrate delivering enhanced green fluorescent protein (EGFP) plasmid into Chinese hamster ovary (CHO) cells. We envision the application of this technique to high-throughput functional genomics studies based on droplet microfluidics.

  11. A self-triggered picoinjector in microfluidics

    Science.gov (United States)

    Yang, Yiming; Liu, Songsheng; Jia, Chunping; Mao, Hongju; Jin, Qinghui; Zhao, Jianlong; Zhou, Hongbo

    2016-12-01

    Droplet-based microfluidics has recently emerged as a potential platform for studies of single-cell, directed evolution, and genetic sequencing. In droplet-based microfluidics, adding reagents into drops is one of the most important functions. In this paper, we develop a new self-triggered picoinjector to add controlled volumes of reagent into droplets at kilohertz rates. In the picoinjector, the reagent injecting is triggered by the coming droplet itself, without needing a droplet detection module. Meanwhile, the dosing volume can be precisely controlled. These features make the system more practical and reliable. We expect the new picoinjector will find important applications of droplet-based microfluidics in automated biological assay, directed evolution, enzyme assay, and so on.

  12. A microfluidic toolbox approach to CBRNE sensing

    Science.gov (United States)

    Gärtner, Claudia; Klemm, Richard; Hlawatsch, Nadine; Becker, Holger

    2012-06-01

    Microfluidics has proven to be a very effective technology for the identification of biological and chemical analytes in a CBRNE scenario. As it will be shown in the following, the required steps of those analytical processes are manifold making the development of an integrated microfluidic device a complicated project with a high level of technological risk, because all necessary analytical processes have to be implemented into a single device. The implementation is initiated by a dissection of the biochemical workflow into mandatory bio-analytical steps and the resulting protocol for each of those steps is translated into an appropriate design of a chip-based unit. In this report, examples for such chipbased functional modules are given. In addition, examples for a merging of positively tested modules into an integrated chip are shown and, finally, representatives for a smooth interaction between outer world, microfluidic chip, and chip driving instrument are presented.

  13. Microfluidic platforms for plant cells studies.

    Science.gov (United States)

    Sanati Nezhad, A

    2014-09-07

    Conventional methods of plant cell analysis rely on growing plant cells in soil pots or agarose plates, followed by screening the plant phenotypes in traditional greenhouses and growth chambers. These methods are usually costly, need a large number of experiments, suffer from low spatial resolution and disorderly growth behavior of plant cells, with lack of ability to locally and accurately manipulate the plant cells. Microfluidic platforms take advantage of miniaturization for handling small volume of liquids and providing a closed environment, with the purpose of in vitro single cell analysis and characterizing cell response to external cues. These platforms have shown their ability for high-throughput cellular analysis with increased accuracy of experiments, reduced cost and experimental times, versatility in design, ability for large-scale and combinatorial screening, and integration with other miniaturized sensors. Despite extensive research on animal cells within microfluidic environments for high-throughput sorting, manipulation and phenotyping studies, the application of microfluidics for plant cells studies has not been accomplished yet. Novel devices such as RootChip, RootArray, TipChip, and PlantChip developed for plant cells analysis, with high spatial resolution on a micrometer scale mimicking the internal microenvironment of plant cells, offering preliminary results on the capability of microfluidics to conquer the constraints of conventional methods. These devices have been used to study different aspects of plant cell biology such as gene expression, cell biomechanics, cellular mechanism of growth, cell division, and cells fusion. This review emphasizes the advantages of current microfluidic systems for plant science studies, and discusses future prospects of microfluidic platforms for characterizing plant cells response to diverse external cues.

  14. Single- and two-phase flow in microfluidic porous media analogs based on Voronoi tessellation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mengjie [Colorado School of Mines, Golden; Xiao, Feng [Colorado School of Mines, Golden; Johnson-Paben, Rebecca [Colorado School of Mines, Golden; Retterer, Scott T [ORNL; Yin, Xiaolong [Colorado School of Mines, Golden; Neeves, Keith B [ORNL

    2012-01-01

    The objective of this study was to create a microfluidic model of complex porous media for studying single and multiphase flows. Most experimental porous media models consist of periodic geometries that lend themselves to comparison with well-developed theoretical predictions. However, most real porous media such as geological formations and biological tissues contain a degree of randomness and complexity that is not adequately represented in periodic geometries. To design an experimental tool to study these complex geometries, we created microfluidic models of random homogeneous and heterogeneous networks based on Voronoi tessellations. These networks consisted of approximately 600 grains separated by a highly connected network of channels with an overall porosity of 0.11 0.20. We found that introducing heterogeneities in the form of large cavities within the network changed the permeability in a way that cannot be predicted by the classical porosity-permeability relationship known as the Kozeny equation. The values of permeability found in experiments were in excellent agreement with those calculated from three-dimensional lattice Boltzmann simulations. In two-phase flow experiments of oil displacement with water we found that the surface energy of channel walls determined the pattern of water invasion, while the network topology determined the residual oil saturation. These results suggest that complex network topologies lead to fluid flow behavior that is difficult to predict based solely on porosity. The microfluidic models developed in this study using a novel geometry generation algorithm based on Voronoi tessellation are a new experimental tool for studying fluid and solute transport problems within complex porous media.

  15. Integrated Microfluidic Sensor System with Magnetostrictive Resonators

    KAUST Repository

    Liang, Cai

    2011-12-08

    The present embodiments describe a method that integrates a magnetostrictive sensor with driving and detecting elements into a microfluidic chip to detect a chemical, biochemical or biomedical species. These embodiments may also measure the properties of a fluid such as viscosity, pH values. The whole system can be referred to lab-on-a-chip (LOC) or micro-total-analysis-systems (.mu.TAS). In particular, this present embodiments include three units, including a microfluidics unit, a magnetostrictive sensor, and driving/detecting elements. An analyzer may also be provided to analyze an electrical signal associated with a feature of a target specimen.

  16. Diffusion dynamics in microfluidic dye lasers

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Niels Asger

    2007-01-01

    We have investigated the bleaching dynamics that occur in opto-fluidic dye lasers, where the liquid laser dye in a channel is locally bleached due to optical pumping. Our studies suggest that for micro-fluidic devices, the dye bleaching may be compensated through diffusion of dye molecules alone....... By relying on diffusion rather than convection to generate the necessary dye replenishment, our observation potentially allows for a significant simplification of opto-fluidic dye laser device layouts, omitting the need for cumbersome and costly external fluidic handling or on-chip micro-fluidic pumping...

  17. Micro-Fluidic Device for Drug Delivery

    Science.gov (United States)

    Beebe, David J. (Inventor); MacDonald, Michael J. (Inventor); Eddington, David T. (Inventor); Mensing, Glennys A. (Inventor)

    2014-01-01

    A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual.

  18. Biocompatible "click" wafer bonding for microfluidic devices.

    Science.gov (United States)

    Saharil, Farizah; Carlborg, Carl Fredrik; Haraldsson, Tommy; van der Wijngaart, Wouter

    2012-09-07

    We introduce a novel dry wafer bonding concept designed for permanent attachment of micromolded polymer structures to surface functionalized silicon substrates. The method, designed for simultaneous fabrication of many lab-on-chip devices, utilizes a chemically reactive polymer microfluidic structure, which rapidly bonds to a functionalized substrate via"click" chemistry reactions. The microfluidic structure consists of an off-stoichiometry thiol-ene (OSTE) polymer with a very high density of surface bound thiol groups and the substrate is a silicon wafer that has been functionalized with common bio-linker molecules. We demonstrate here void free, and low temperature (silane functionalized silicon wafer.

  19. Recent Advances in Applications of Droplet Microfluidics

    Directory of Open Access Journals (Sweden)

    Wei-Lung Chou

    2015-09-01

    Full Text Available Droplet-based microfluidics is a colloidal and interfacial system that has rapidly progressed in the past decade because of the advantages of low fabrication costs, small sample volumes, reduced analysis durations, high-throughput analysis with exceptional sensitivity, enhanced operational flexibility, and facile automation. This technology has emerged as a new tool for many recently used applications in molecular detection, imaging, drug delivery, diagnostics, cell biology and other fields. Herein, we review recent applications of droplet microfluidics proposed since 2013.

  20. Physics and applications of microfluidics in biology.

    Science.gov (United States)

    Beebe, David J; Mensing, Glennys A; Walker, Glenn M

    2002-01-01

    Fluid flow at the microscale exhibits unique phenomena that can be leveraged to fabricate devices and components capable of performing functions useful for biological studies. The physics of importance to microfluidics are reviewed. Common methods of fabricating microfluidic devices and systems are described. Components, including valves, mixers, and pumps, capable of controlling fluid flow by utilizing the physics of the microscale are presented. Techniques for sensing flow characteristics are described and examples of devices and systems that perform bioanalysis are presented. The focus of this review is microscale phenomena and the use of the physics of the scale to create devices and systems that provide functionality useful to the life sciences.

  1. Microfluidic fuel cells for energy generation.

    Science.gov (United States)

    Safdar, M; Jänis, J; Sánchez, S

    2016-08-07

    Sustainable energy generation is of recent interest due to a growing energy demand across the globe and increasing environmental issues caused by conventional non-renewable means of power generation. In the context of microsystems, portable electronics and lab-on-a-chip based (bio)chemical sensors would essentially require fully integrated, reliable means of power generation. Microfluidic-based fuel cells can offer unique advantages compared to conventional fuel cells such as high surface area-to-volume ratio, ease of integration, cost effectiveness and portability. Here, we summarize recent developments which utilize the potential of microfluidic devices for energy generation.

  2. Microfluidic Assessment of Frying Oil Degradation

    Science.gov (United States)

    Liu, Mei; Xie, Shaorong; Ge, Ji; Xu, Zhensong; Wu, Zhizheng; Ru, Changhai; Luo, Jun; Sun, Yu

    2016-06-01

    Monitoring the quality of frying oil is important for the health of consumers. This paper reports a microfluidic technique for rapidly quantifying the degradation of frying oil. The microfluidic device generates monodispersed water-in-oil droplets and exploits viscosity and interfacial tension changes of frying oil samples over their frying/degradation process. The measured parameters were correlated to the total polar material percentage that is widely used in the food industry. The results reveal that the steady-state length of droplets can be used for unambiguously assessing frying oil quality degradation.

  3. Microfluidic chip-capillary electrophoresis devices

    CERN Document Server

    Fung, Ying Sing; Du, Fuying; Guo, Wenpeng; Ma, Tongmei; Nie, Zhou; Sun, Hui; Wu, Ruige; Zhao, Wenfeng

    2015-01-01

    Capillary electrophoresis (CE) and microfluidic chip (MC) devices are relatively mature technologies, but this book demonstrates how they can be integrated into a single, revolutionary device that can provide on-site analysis of samples when laboratory services are unavailable. By introducing the combination of CE and MC technology, Microfluidic Chip-Capillary Electrophoresis Devices broadens the scope of chemical analysis, particularly in the biomedical, food, and environmental sciences.The book gives an overview of the development of MC and CE technology as well as technology that now allows

  4. Recent developments in microfluidics-based chemotaxis studies.

    Science.gov (United States)

    Wu, Jiandong; Wu, Xun; Lin, Francis

    2013-07-07

    Microfluidic devices can better control cellular microenvironments compared to conventional cell migration assays. Over the past few years, microfluidics-based chemotaxis studies showed a rapid growth. New strategies were developed to explore cell migration in manipulated chemical gradients. In addition to expanding the use of microfluidic devices for a broader range of cell types, microfluidic devices were used to study cell migration and chemotaxis in complex environments. Furthermore, high-throughput microfluidic chemotaxis devices and integrated microfluidic chemotaxis systems were developed for medical and commercial applications. In this article, we review recent developments in microfluidics-based chemotaxis studies and discuss the new trends in this field observed over the past few years.

  5. Microfluidics and Raman microscopy: current applications and future challenges.

    Science.gov (United States)

    Chrimes, Adam F; Khoshmanesh, Khashayar; Stoddart, Paul R; Mitchell, Arnan; Kalantar-Zadeh, Kourosh

    2013-07-07

    Raman microscopy systems are becoming increasingly widespread and accessible for characterising chemical species. Microfluidic systems are also progressively finding their way into real world applications. Therefore, it is anticipated that the integration of Raman systems with microfluidics will become increasingly attractive and practical. This review aims to provide an overview of Raman microscopy-microfluidics integrated systems for researchers who are actively interested in utilising these tools. The fundamental principles and application strengths of Raman microscopy are discussed in the context of microfluidics. Various configurations of microfluidics that incorporate Raman microscopy methods are presented, with applications highlighted. Data analysis methods are discussed, with a focus on assisting the interpretation of Raman-microfluidics data from complex samples. Finally, possible future directions of Raman-microfluidic systems are presented.

  6. Microfluidics' great promise for Biology - Microfluidics as a new engine for the molecular sciences

    KAUST Repository

    Kodzius, Rimantas

    2010-06-04

    History of the Life Sciences Origins of life Discoveries and instrumentation The power of genetic variation Diagnostics based on DNA/ protein variation Genomic scanning providers DNA sequencing companies Microfluidics story Commercial products available P

  7. Monolithic multilayer microfluidics via sacrificial molding of 3D-printed isomalt†

    Science.gov (United States)

    Gelber, Matthew K.

    2015-01-01

    Here we demonstrate a method for creating multilayer or 3D microfluidics by casting a curable resin around a water-soluble, freestanding sacrificial mold. We use a purpose-built 3D printer to pattern self-supporting filaments of the sugar alcohol isomalt, which we then back-fill with a transparent epoxy resin. Dissolving the sacrificial mold leaves a network of cylindrical channels as well as input and output ports. We use this technique to fabricate a combinatorial mixer capable of producing 8 combinations of two fluids in ratios ranging from 1 : 100 to 100 : 1. This approach allows rapid iteration on microfluidic chip design and enables the use of geometry and materials not accessible using conventional soft lithography. The ability to precisely pattern round channels in all three dimensions in hard and soft media may prove enabling for many organ-on-chip systems. PMID:25671493

  8. Specific transport of target molecules by motor proteins in microfluidic channels.

    Science.gov (United States)

    Tarhan, Mehmet C; Yokokawa, Ryuji; Morin, Fabrice O; Fujita, Hiroyuki

    2013-06-03

    Direct transport powered by motor proteins can alleviate the challenges presented by miniaturization of microfluidic systems. There have been several recent attempts to build motor-protein-driven transport systems based on simple capturing or transport mechanisms. However, to achieve a multifunctional device for practical applications, a more complex sorting/transport system should be realized. Herein, the proof of concept of a sorting device employing selective capture of distinct target molecules and transport of the sorted molecules to different predefined directions is presented. By combining the bottom-up functionality of biological systems with the top-down handling capabilities of micro-electromechanical systems technology, highly selective molecular recognition and motor-protein-based transport is integrated in a microfluidic channel network.

  9. Microfluidic analogy of the wheatstone bridge for systematic investigations of electro-osmotic flows.

    Science.gov (United States)

    Plecis, Adrien; Chen, Yong

    2008-05-15

    A microfluidic analogy of the electric Wheatstone Bridge has been developed for electrokinetic study of miscellaneous liquid-solid interfaces. By using an optimized glass-PDMS-glass device technology, microfluidic channels with well-controlled surface properties can be fabricated, forming an "H" shaped fluidic network. After solving a set of linear equations, the electro-osmotic flow rate in the center channel can be deduced from indirect measurement of flow rates in the lateral channels. Experimentally, we demonstrate that the electro-osmotic mobility can be monitored every 30 s with accuracy better than 3% for a large dynamic range of electric fields. The results obtained with a borosilicate glass (D-263) and several standard biological buffers are also shown to illustrate the capability of this high throughput method.

  10. Monolithic multilayer microfluidics via sacrificial molding of 3D-printed isomalt.

    Science.gov (United States)

    Gelber, Matthew K; Bhargava, Rohit

    2015-04-07

    Here we demonstrate a method for creating multilayer or 3D microfluidics by casting a curable resin around a water-soluble, freestanding sacrificial mold. We use a purpose-built 3D printer to pattern self-supporting filaments of the sugar alcohol isomalt, which we then back-fill with a transparent epoxy resin. Dissolving the sacrificial mold leaves a network of cylindrical channels as well as input and output ports. We use this technique to fabricate a combinatorial mixer capable of producing 8 combinations of two fluids in ratios ranging from 1 : 100 to 100 : 1. This approach allows rapid iteration on microfluidic chip design and enables the use of geometry and materials not accessible using conventional soft lithography. The ability to precisely pattern round channels in all three dimensions in hard and soft media may prove enabling for many organ-on-chip systems.

  11. Inventions Utilizing Microfluidics and Colloidal Particles

    Science.gov (United States)

    Marr, David W.; Gong, Tieying; Oakey, John; Terray, Alexander V.; Wu, David T.

    2009-01-01

    Several related inventions pertain to families of devices that utilize microfluidics and/or colloidal particles to obtain useful physical effects. The families of devices can be summarized as follows: (1) Microfluidic pumps and/or valves wherein colloidal-size particles driven by electrical, magnetic, or optical fields serve as the principal moving parts that propel and/or direct the affected flows. (2) Devices that are similar to the aforementioned pumps and/or valves except that they are used to manipulate light instead of fluids. The colloidal particles in these devices are substantially constrained to move in a plane and are driven to spatially order them into arrays that function, variously, as waveguides, filters, or switches for optical signals. (3) Devices wherein the ultra-laminar nature of microfluidic flows is exploited to effect separation, sorting, or filtering of colloidal particles or biological cells in suspension. (4) Devices wherein a combination of confinement and applied electrical and/or optical fields forces the colloidal particles to become arranged into three-dimensional crystal lattices. Control of the colloidal crystalline structures could be exploited to control diffraction of light. (5) Microfluidic devices, incorporating fluid waveguides, wherein switching of flows among different paths would be accompanied by switching of optical signals.

  12. Microfluidic manipulation with artificial/bioinspired cilia

    NARCIS (Netherlands)

    den Toonder, Jaap M. J.; Onck, Patrick R.

    2013-01-01

    A recent development, inspired by nature, is the use of 'artificial cilia' to create pumping and/or mixing in microfluidic devices. Cilia are small hairs that can be found in biology and are used for (fluid) actuation and sensing. Microscopic actuators resembling cilia, actuated to move under the in

  13. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  14. Reaction and separation opportunities with microfluidic devices

    NARCIS (Netherlands)

    Kolfschoten, R.C.

    2011-01-01

    Microfluidic devices make precisely controlled processing of substances possible on a microliter level. The advantage is that, due to the small sizes, the driving forces for mass and heat transfer are high. The surface to volume ratios are also high, which can benefit many surface oriented processes

  15. Microfluidic desalination techniques and their potential applications

    NARCIS (Netherlands)

    Roelofs, Susan Helena; van den Berg, Albert; Odijk, Mathieu

    2015-01-01

    In this review we discuss recent developments in the emerging research field of miniaturized desalination. Traditionally desalination is performed to convert salt water into potable water and research is focused on improving performance of large-scale desalination plants. Microfluidic desalination

  16. Planar microcoil-based microfluidic NMR probes.

    NARCIS (Netherlands)

    Massin, C.; Vincent, F.; Homsy, A.; Ehrmann, K.; Boero, G.; Besse, P-A; Daridon, A.; Verpoorte, E.; de Rooij, N.F.; Popovic, R.S.

    2003-01-01

    Microfabricated small-volume NMR probes consisting of electroplated planar microcoils integrated on a glass substrate with etched microfluidic channels are fabricated and tested. 1H NMR spectra are acquired at 300 MHz with three different probes having observed sample volumes of respectively 30, 120

  17. Differential white cell count by centrifugal microfluidics.

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  18. Designing Polymeric Microfluidic Platforms for Biomedical Applications

    DEFF Research Database (Denmark)

    Vedarethinam, Indumathi

    Micro- and Nanotechnology have the potential to offer a smart solution for diagnostics and academia research with rapid, low cost, robust analysis systems to facilitate biological analyses. New, high throughput microfluidic platforms have the potential to surpass in performance the conventional a...

  19. Nucleic acid amplification using microfluidic systems.

    Science.gov (United States)

    Chang, Chen-Min; Chang, Wen-Hsin; Wang, Chih-Hung; Wang, Jung-Hao; Mai, John D; Lee, Gwo-Bin

    2013-04-07

    In the post-human-genome-project era, the development of molecular diagnostic techniques has advanced the frontiers of biomedical research. Nucleic-acid-based technology (NAT) plays an especially important role in molecular diagnosis. However, most research and clinical protocols still rely on the manual analysis of individual samples by skilled technicians which is a time-consuming and labor-intensive process. Recently, with advances in microfluidic designs, integrated micro total-analysis-systems have emerged to overcome the limitations of traditional detection assays. These microfluidic systems have the capability to rapidly perform experiments in parallel and with a high-throughput which allows a NAT analysis to be completed in a few hours or even a few minutes. These features have a significant beneficial influence on many aspects of traditional biological or biochemical research and this new technology is promising for improving molecular diagnosis. Thus, in the foreseeable future, microfluidic systems developed for molecular diagnosis using NAT will become an important tool in clinical diagnosis. One of the critical issues for NAT is nucleic acid amplification. In this review article, recent advances in nucleic acid amplification techniques using microfluidic systems will be reviewed. Different approaches for fast amplification of nucleic acids for molecular diagnosis will be highlighted.

  20. A microfluidic based optical particle detection method

    Science.gov (United States)

    Dou, James; Chen, Lu; Nayyar, Rakesh; Aitchison, Stewart

    2012-03-01

    An optical particle detection and analysis method is presented. This method combines the capillary microfluidics, integrated optics and novel image acquisition and analysis algorithms to form the basis of a portable or handheld cytometer instrument. Experimental results provided shows the testing results are closely matched with conventional flow cytometer data.

  1. Microfluidic distillation chip for methanol concentration detection.

    Science.gov (United States)

    Wang, Yao-Nan; Liu, Chan-Chiung; Yang, Ruey-Jen; Ju, Wei-Jhong; Fu, Lung-Ming

    2016-03-17

    An integrated microfluidic distillation system is proposed for separating a mixed ethanol-methanol-water solution into its constituent components. The microfluidic chip is fabricated using a CO2 laser system and comprises a serpentine channel, a boiling zone, a heating zone, and a cooled collection chamber filled with de-ionized (DI) water. In the proposed device, the ethanol-methanol-water solution is injected into the microfluidic chip and driven through the serpentine channel and into the collection chamber by means of a nitrogen carrier gas. Following the distillation process, the ethanol-methanol vapor flows into the collection chamber and condenses into the DI water. The resulting solution is removed from the collection tank and reacted with a mixed indicator. Finally, the methanol concentration is inversely derived from the absorbance measurements obtained using a spectrophotometer. The experimental results show the proposed microfluidic system achieves an average methanol distillation efficiency of 97%. The practicality of the proposed device is demonstrated by detecting the methanol concentrations of two commercial fruit wines. It is shown that the measured concentration values deviate by no more than 3% from those obtained using a conventional bench top system.

  2. Microfluidics for Antibiotic Susceptibility and Toxicity Testing

    Directory of Open Access Journals (Sweden)

    Jing Dai

    2016-10-01

    Full Text Available The recent emergence of antimicrobial resistance has become a major concern for worldwide policy makers as very few new antibiotics have been developed in the last twenty-five years. To prevent the death of millions of people worldwide, there is an urgent need for a cheap, fast and accurate set of tools and techniques that can help to discover and develop new antimicrobial drugs. In the past decade, microfluidic platforms have emerged as potential systems for conducting pharmacological studies. Recent studies have demonstrated that microfluidic platforms can perform rapid antibiotic susceptibility tests to evaluate antimicrobial drugs’ efficacy. In addition, the development of cell-on-a-chip and organ-on-a-chip platforms have enabled the early drug testing, providing more accurate insights into conventional cell cultures on the drug pharmacokinetics and toxicity, at the early and cheaper stage of drug development, i.e., prior to animal and human testing. In this review, we focus on the recent developments of microfluidic platforms for rapid antibiotics susceptibility testing, investigating bacterial persistence and non-growing but metabolically active (NGMA bacteria, evaluating antibiotic effectiveness on biofilms and combinatorial effect of antibiotics, as well as microfluidic platforms that can be used for in vitro antibiotic toxicity testing.

  3. Planar microcoil-based microfluidic NMR probes.

    NARCIS (Netherlands)

    Massin, C.; Vincent, F.; Homsy, A.; Ehrmann, K.; Boero, G.; Besse, P-A; Daridon, A.; Verpoorte, E.; de Rooij, N.F.; Popovic, R.S.

    2003-01-01

    Microfabricated small-volume NMR probes consisting of electroplated planar microcoils integrated on a glass substrate with etched microfluidic channels are fabricated and tested. 1H NMR spectra are acquired at 300 MHz with three different probes having observed sample volumes of respectively 30, 120

  4. Microfluidic desalination techniques and their potential applications

    NARCIS (Netherlands)

    Roelofs, S.H.; Berg, van den A.; Odijk, M.

    2015-01-01

    In this review we discuss recent developments in the emerging research field of miniaturized desalination. Traditionally desalination is performed to convert salt water into potable water and research is focused on improving performance of large-scale desalination plants. Microfluidic desalination o

  5. Microfluidic enzymatic biosensing systems: A review.

    Science.gov (United States)

    Mross, Stefan; Pierrat, Sebastien; Zimmermann, Tom; Kraft, Michael

    2015-08-15

    Microfluidic biosensing systems with enzyme-based detection have been extensively studied in the last years owing to features such as high specificity, a broad range of analytes and a high degree of automation. This review gives an overview of the most important factors associated with these systems. In the first part, frequently used immobilization protocols such as physisorption and covalent bonding and detection techniques such as amperometry and fluorescence measurements are discussed with respect to effort, lifetime and measurement range. The Michaelis-Menten model describing the kinetics of enzymatic reactions, the role of redox mediators and the limitations of the linear measurement range of enzymatic sensors are introduced. Several possibilities of extending the linear measurement range in microfluidic systems such as diffusion-limiting membranes and the flow injection setup are presented. Regarding the integration of enzymes into microfluidic systems during the fabrication process, the constraints imposed by the biomolecules due to the limited usage of high temperatures and solvents are addressed. In the second part, the most common forms of enzyme integration into microfluidic systems, i.e. in channels and on electrodes, on microparticles, on paper and thread and as injected enzyme solutions, are reviewed, focusing on fabrication, applications and performance.

  6. High content screening in microfluidic devices

    Science.gov (United States)

    Cheong, Raymond; Paliwal, Saurabh; Levchenko, Andre

    2011-01-01

    Importance of the field Miniaturization is key to advancing the state-of-the-art in high content screening (HCS), in order to enable dramatic cost savings through reduced usage of expensive biochemical reagents and to enable large-scale screening on primary cells. Microfluidic technology offers the potential to enable HCS to be performed with an unprecedented degree of miniaturization. Areas covered in this review This perspective highlights a real-world example from the authors’ work of HCS assays implemented in a highly miniaturized microfluidic format. Advantages of this technology are discussed, including cost savings, high throughput screening on primary cells, improved accuracy, the ability to study complex time-varying stimuli, and ease of automation, integration, and scaling. What the reader will gain The reader will understand the capabilities of a new microfluidics-based platform for HCS, and the advantages it provides over conventional plate-based HCS. Take home message Microfluidics technology will drive significant advancements and broader usage and applicability of HCS in drug discovery. PMID:21852997

  7. Design of microfluidic bioreactors using topology optimization

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Bruus, Henrik

    2007-01-01

    We address the design of optimal reactors for supporting biological cultures using the method of topology optimization. For some years this method have been used to design various optimal microfluidic devices.1-4 We apply this method to distribute optimally biologic cultures within a flow of nutr...

  8. Low pressure microfluidic-based DNA fragmentation

    NARCIS (Netherlands)

    Shui, Lingling; Sparreboom, Wouter; Bomer, Johan G.; Jin, Mingliang; Carlen, Edwin; van den Berg, Albert

    2011-01-01

    We report a low-pressure microfluidic deoxyribonucleic acid (DNA) fragmentation device based on a combination of me-chanical hydrodynamic shearing and low temperature sample heating. Conventional DNA fragmentation based on hydrody-namic shearing is capable of achieving fragment lengths (FL) < 10k bp

  9. Integrated multifunctional microfluidics for automated proteome analyses.

    Science.gov (United States)

    Osiri, John K; Shadpour, Hamed; Witek, Małgorzata A; Soper, Steven A

    2011-01-01

    Proteomics is a challenging field for realizing totally integrated microfluidic systems for complete proteome processing due to several considerations, including the sheer number of different protein types that exist within most proteomes, the large dynamic range associated with these various protein types, and the diverse chemical nature of the proteins comprising a typical proteome. For example, the human proteome is estimated to have >10(6) different components with a dynamic range of >10(10). The typical processing pipeline for proteomics involves the following steps: (1) selection and/or extraction of the particular proteins to be analyzed; (2) multidimensional separation; (3) proteolytic digestion of the protein sample; and (4) mass spectral identification of either intact proteins (top-down proteomics) or peptide fragments generated from proteolytic digestions (bottom-up proteomics). Although a number of intriguing microfluidic devices have been designed, fabricated and evaluated for carrying out the individual processing steps listed above, work toward building fully integrated microfluidic systems for protein analysis has yet to be realized. In this chapter, information will be provided on the nature of proteomic analysis in terms of the challenges associated with the sample type and the microfluidic devices that have been tested to carry out individual processing steps. These include devices such as those for multidimensional electrophoretic separations, solid-phase enzymatic digestions, and solid-phase extractions, all of which have used microfluidics as the functional platform for their implementation. This will be followed by an in-depth review of microfluidic systems, which are defined as units possessing two or more devices assembled into autonomous systems for proteome processing. In addition, information will be provided on the challenges involved in integrating processing steps into a functional system and the approaches adopted for device

  10. Mixing in polymeric microfluidic devices.

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, Peter Randall; Sun, Amy Cha-Tien; Davis, Robert H. (University of Colorado at Boulder, Boulder, CO); Brotherton, Christopher M. (University of Colorado at Boulder, Boulder, CO)

    2006-04-01

    This SAND report describes progress made during a Sandia National Laboratories sponsored graduate fellowship. The fellowship was funded through an LDRD proposal. The goal of this project is development and characterization of mixing strategies for polymeric microfluidic devices. The mixing strategies under investigation include electroosmotic flow focusing, hydrodynamic focusing, physical constrictions and porous polymer monoliths. For electroosmotic flow focusing, simulations were performed to determine the effect of electroosmotic flow in a microchannel with heterogeneous surface potential. The heterogeneous surface potential caused recirculations to form within the microchannel. These recirculations could then be used to restrict two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the mixing region surface potential to the average channel surface potential was made large in magnitude and negative in sign, and when the ratio of the characteristic convection time to the characteristic diffusion time was minimized. Based on these results, experiments were performed to evaluate the manipulation of surface potential using living-radical photopolymerization. The material chosen to manipulate typically exhibits a negative surface potential. Using living-radical surface grafting, a positive surface potential was produced using 2-(Dimethylamino)ethyl methacrylate and a neutral surface was produced using a poly(ethylene glycol) surface graft. Simulations investigating hydrodynamic focusing were also performed. For this technique, mixing is enhanced by using a tertiary fluid stream to constrict the two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the tertiary flow stream flow-rate to the mixing streams flow-rate was maximized. Also, like the electroosmotic focusing mixer, mixing was also maximized when the ratio of the characteristic convection time to the

  11. Structural and magnetic properties of two branches of the tripod-kagome-lattice family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb)

    Science.gov (United States)

    Dun, Z. L.; Trinh, J.; Lee, M.; Choi, E. S.; Li, K.; Hu, Y. F.; Wang, Y. X.; Blanc, N.; Ramirez, A. P.; Zhou, H. D.

    2017-03-01

    We present a systematic study of the structural and magnetic properties of two branches of the rare-earth tripod-kagome-lattice (TKL) family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb; here, we use abbreviation A-R, as in MgPr for Mg2Pr3Sb3O14 ), which complements our previously reported work on MgDy, MgGd, and MgEr [Z. L. Dun et al., Phys. Rev. Lett. 116, 157201 (2016), 10.1103/PhysRevLett.116.157201]. The present susceptibility (χdc, χac) and specific-heat measurements reveal various magnetic ground states, including the nonmagnetic singlet state for MgPr, ZnPr; long-range orderings (LROs) for MgGd, ZnGd, MgNd, ZnNd, and MgYb; a long-range magnetic charge ordered state for MgDy, ZnDy, and potentially for MgHo; possible spin-glass states for ZnEr, ZnHo; the absence of spin ordering down to 80 mK for MgEr, MgTb, ZnTb, and ZnYb compounds. The ground states observed here bear both similarities as well as striking differences from the states found in the parent pyrochlore systems. In particular, while the TKLs display a greater tendency towards LRO, the lack of LRO in MgHo, MgTb, and ZnTb can be viewed from the standpoint of a balance among spin-spin interactions, anisotropies, and non-Kramers nature of single-ion state. While substituting Zn for Mg changes the chemical pressure, and subtly modifies the interaction energies for compounds with larger R ions, this substitution introduces structural disorder and modifies the ground states for compounds with smaller R ions (Ho, Er, Yb).

  12. Interconnection blocks: a method for providing reusable, rapid, multiple, aligned and planar microfluidic interconnections

    DEFF Research Database (Denmark)

    Sabourin, David; Snakenborg, Detlef; Dufva, Hans Martin

    2009-01-01

    In this paper a method is presented for creating 'interconnection blocks' that are re-usable and provide multiple, aligned and planar microfluidic interconnections. Interconnection blocks made from polydimethylsiloxane allow rapid testing of microfluidic chips and unobstructed microfluidic...

  13. Microfluidic Extraction of Biomarkers using Water as Solvent

    Science.gov (United States)

    Amashukeli, Xenia; Manohara, Harish; Chattopadhyay, Goutam; Mehdi, Imran

    2009-01-01

    A proposed device, denoted a miniature microfluidic biomarker extractor (mu-EX), would extract trace amounts of chemicals of interest from samples, such as soils and rocks. Traditionally, such extractions are performed on a large scale with hazardous organic solvents; each solvent capable of dissolving only those molecules lying within narrow ranges of specific chemical and physical characteristics that notably include volatility, electric charge, and polarity. In contrast, in the mu-EX, extractions could be performed by use of small amounts (typically between 0.1 and 100 L) of water as a universal solvent. As a rule of thumb, in order to enable solvation and extraction of molecules, it is necessary to use solvents that have polarity sufficiently close to the polarity of the target molecules. The mu-EX would make selection of specific organic solvents unnecessary, because mu-EX would exploit a unique property of liquid water: the possibility of tuning its polarity to match the polarity of organic solvents appropriate for extraction of molecules of interest. The change of the permittivity of water would be achieved by exploiting interactions between the translational states of water molecules and an imposed electromagnetic field in the frequency range of 300 to 600 GHz. On a molecular level, these interactions would result in disruption of the three-dimensional hydrogen-bonding network among liquid-water molecules and subsequent solvation and hydrolysis of target molecules. The mu-EX is expected to be an efficient means of hydrolyzing chemical bonds in complex macromolecules as well and, thus, enabling analysis of the building blocks of these complex chemical systems. The mu-EX device would include a microfluidic channel, part of which would lie within a waveguide coupled to an electronically tuned source of broad-band electromagnetic radiation in the frequency range from 300 to 600 GHz (see figure). The part of the microfluidic channel lying in the waveguide would

  14. Microfluidics-based in vivo mimetic systems for the study of cellular biology.

    Science.gov (United States)

    Kim, Donghyuk; Wu, Xiaojie; Young, Ashlyn T; Haynes, Christy L

    2014-04-15

    The human body is a complex network of molecules, organelles, cells, tissues, and organs: an uncountable number of interactions and transformations interconnect all the system's components. In addition to these biochemical components, biophysical components, such as pressure, flow, and morphology, and the location of all of these interactions play an important role in the human body. Technical difficulties have frequently limited researchers from observing cellular biology as it occurs within the human body, but some state-of-the-art analytical techniques have revealed distinct cellular behaviors that occur only in the context of the interactions. These types of findings have inspired bioanalytical chemists to provide new tools to better understand these cellular behaviors and interactions. What blocks us from understanding critical biological interactions in the human body? Conventional approaches are often too naïve to provide realistic data and in vivo whole animal studies give complex results that may or may not be relevant for humans. Microfluidics offers an opportunity to bridge these two extremes: while these studies will not model the complexity of the in vivo human system, they can control the complexity so researchers can examine critical factors of interest carefully and quantitatively. In addition, the use of human cells, such as cells isolated from donated blood, captures human-relevant data and limits the use of animals in research. In addition, researchers can adapt these systems easily and cost-effectively to a variety of high-end signal transduction mechanisms, facilitating high-throughput studies that are also spatially, temporally, or chemically resolved. These strengths should allow microfluidic platforms to reveal critical parameters in the human body and provide insights that will help with the translation of pharmacological advances to clinical trials. In this Account, we describe selected microfluidic innovations within the last 5 years

  15. Manufacturing methods and applications of membranes in microfluidics.

    Science.gov (United States)

    Chen, Xueye; Shen, Jienan; Hu, Zengliang; Huo, Xuyao

    2016-12-01

    Applications of membranes in microfluidics solved many thorny problems for analytical chemistry and bioscience, so that the use of membranes in microfluidics has been a topic of growing interest. Many different examples have been reported, demonstrating the versatile use of membranes. This work reviews a lot of applications of membranes in microfluidics. Membranes in microfluidics for applications including chemical reagents detection, gas detection, drug screening, cell, protein, microreactor, electrokinetical fluid, pump and valve and fluid transport control and so on, have been analyzed and discussed. In addition, the definition and basic concepts of membranes are summed up. And the methods of manufacturing membranes in microfluidics are discussed. This paper will provide a helpful reference to researchers who want to study applications of membranes in microfluidics.

  16. A microfluidic multiplex proteomic immunoassay device for translational research

    OpenAIRE

    Cao, Jing; Seegmiller, Jesse; Hanson, Naomi Q; Zaun, Christopher; Li, Danni

    2015-01-01

    Objective Microfluidic technology has the potential to miniaturize and automate complex laboratory procedures. The objective of this study was to assess a microfluidic immunoassay device, Simple Plex, which simultaneously measured IL-1β, TNF-α, IL-6, and IL-10 in serum samples. This assessment is important to understanding the potentials of this microfluidic device as a valuable tool in translational research efforts. Methods We studied the operational characteristics of Simple Plex, and comp...

  17. Redundancy Optimization for Error Recovery in Digital Microfluidic Biochips

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2015-01-01

    Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets....... Researchers have proposed approaches for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application. During the execution...

  18. Digital microfluidic processing of mammalian embryos for vitrification.

    Directory of Open Access Journals (Sweden)

    Derek G Pyne

    Full Text Available Cryopreservation is a key technology in biology and clinical practice. This paper presents a digital microfluidic device that automates sample preparation for mammalian embryo vitrification. Individual micro droplets manipulated on the microfluidic device were used as micro-vessels to transport a single mouse embryo through a complete vitrification procedure. Advantages of this approach, compared to manual operation and channel-based microfluidic vitrification, include automated operation, cryoprotectant concentration gradient generation, and feasibility of loading and retrieval of embryos.

  19. Micro and nanotextured polymer fibers for open microfluidics

    OpenAIRE

    Yunusa, Muhammad

    2016-01-01

    Microfluidics is the science of controlling low volumes of fluids in a microchannel. It is used in diverse area of applications such as chemical and biological analysis. Benefits of microfluidics are fast analysis, short reaction times, and portability of device. Current fabrication techniques of lab-on-a-chip microfluidic devices are soft lithography and micromachining. However, these methods suffer from design limitations such as flexibility of product, high cost, integration of external co...

  20. Novel Polymer Microfluidics Technology for In Situ Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop a novel microfluidic device that combines rigid monolithic porous polymer based micro-capillary electrochromatography...

  1. Structure and fabrication details of an integrated modularized microfluidic system

    Directory of Open Access Journals (Sweden)

    Qingchang Tian

    2015-12-01

    Full Text Available This article contains schemes, original experimental data and figures for an integrated modularized microfluidic system described in “An integrated microfluidic system for bovine DNA purification and digital PCR detection [1]”. In this data article, we described the structure and fabrication of the integrated modularized microfluidic system. This microfluidic system was applied to isolate DNA from ovine tissue lysate and detect the bovine DNA with digital PCR (dPCR. The DNA extraction efficiency of the microdevice was compared with the efficiency of benchtop protocol.

  2. Recent Advances and Future Perspectives on Microfluidic Liquid Handling

    Directory of Open Access Journals (Sweden)

    Nam-Trung Nguyen

    2017-06-01

    Full Text Available The interdisciplinary research field of microfluidics has the potential to revolutionize current technologies that require the handling of a small amount of fluid, a fast response, low costs and automation. Microfluidic platforms that handle small amounts of liquid have been categorised as continuous-flow microfluidics and digital microfluidics. The first part of this paper discusses the recent advances of the two main and opposing applications of liquid handling in continuous-flow microfluidics: mixing and separation. Mixing and separation are essential steps in most lab-on-a-chip platforms, as sample preparation and detection are required for a variety of biological and chemical assays. The second part discusses the various digital microfluidic strategies, based on droplets and liquid marbles, for the manipulation of discrete microdroplets. More advanced digital microfluidic devices combining electrowetting with other techniques are also introduced. The applications of the emerging field of liquid-marble-based digital microfluidics are also highlighted. Finally, future perspectives on microfluidic liquid handling are discussed.

  3. Fundamentals of microfluidic cell culture in controlled microenvironments.

    Science.gov (United States)

    Young, Edmond W K; Beebe, David J

    2010-03-01

    Microfluidics has the potential to revolutionize the way we approach cell biology research. The dimensions of microfluidic channels are well suited to the physical scale of biological cells, and the many advantages of microfluidics make it an attractive platform for new techniques in biology. One of the key benefits of microfluidics for basic biology is the ability to control parameters of the cell microenvironment at relevant length and time scales. Considerable progress has been made in the design and use of novel microfluidic devices for culturing cells and for subsequent treatment and analysis. With the recent pace of scientific discovery, it is becoming increasingly important to evaluate existing tools and techniques, and to synthesize fundamental concepts that would further improve the efficiency of biological research at the microscale. This tutorial review integrates fundamental principles from cell biology and local microenvironments with cell culture techniques and concepts in microfluidics. Culturing cells in microscale environments requires knowledge of multiple disciplines including physics, biochemistry, and engineering. We discuss basic concepts related to the physical and biochemical microenvironments of the cell, physicochemical properties of that microenvironment, cell culture techniques, and practical knowledge of microfluidic device design and operation. We also discuss the most recent advances in microfluidic cell culture and their implications on the future of the field. The goal is to guide new and interested researchers to the important areas and challenges facing the scientific community as we strive toward full integration of microfluidics with biology.

  4. Fundamentals of microfluidic cell culture in controlled microenvironments†

    Science.gov (United States)

    Young, Edmond W. K.; Beebe, David J.

    2010-01-01

    Microfluidics has the potential to revolutionize the way we approach cell biology research. The dimensions of microfluidic channels are well suited to the physical scale of biological cells, and the many advantages of microfluidics make it an attractive platform for new techniques in biology. One of the key benefits of microfluidics for basic biology is the ability to control parameters of the cell microenvironment at relevant length and time scales. Considerable progress has been made in the design and use of novel microfluidic devices for culturing cells and for subsequent treatment and analysis. With the recent pace of scientific discovery, it is becoming increasingly important to evaluate existing tools and techniques, and to synthesize fundamental concepts that would further improve the efficiency of biological research at the microscale. This tutorial review integrates fundamental principles from cell biology and local microenvironments with cell culture techniques and concepts in microfluidics. Culturing cells in microscale environments requires knowledge of multiple disciplines including physics, biochemistry, and engineering. We discuss basic concepts related to the physical and biochemical microenvironments of the cell, physicochemical properties of that microenvironment, cell culture techniques, and practical knowledge of microfluidic device design and operation. We also discuss the most recent advances in microfluidic cell culture and their implications on the future of the field. The goal is to guide new and interested researchers to the important areas and challenges facing the scientific community as we strive toward full integration of microfluidics with biology. PMID:20179823

  5. Microfluidic methods for non-viral gene delivery.

    Science.gov (United States)

    Lai, Wing-Fu

    2015-01-01

    Microfluidics is a compelling technology that shows considerable promise in applications ranging from gene expression profiling to cell-based assays. Owing to its capacity to enable generation of single droplets and multiple droplet arrays with precisely controlled composition and a narrow size distribution, recently microfluidics has been exploited for delivery of genes. This article provides an overview of recent advances in microfluidic gene delivery, and speculates the prospects for further research. The objectives of this article are to illustrate the potential roles played by microfluidics in gene delivery research, and to shed new light on strategies to enhance the efficiency of gene therapy.

  6. Microfabrication and Applications of Opto-Microfluidic Sensors

    Directory of Open Access Journals (Sweden)

    Daiying Zhang

    2011-05-01

    Full Text Available A review of research activities on opto-microfluidic sensors carried out by the research groups in Canada is presented. After a brief introduction of this exciting research field, detailed discussion is focused on different techniques for the fabrication of opto-microfluidic sensors, and various applications of these devices for bioanalysis, chemical detection, and optical measurement. Our current research on femtosecond laser microfabrication of optofluidic devices is introduced and some experimental results are elaborated. The research on opto-microfluidics provides highly sensitive opto-microfluidic sensors for practical applications with significant advantages of portability, efficiency, sensitivity, versatility, and low cost.

  7. Hydrogel Droplet Microfluidics for High-Throughput Single Molecule/Cell Analysis.

    Science.gov (United States)

    Zhu, Zhi; Yang, Chaoyong James

    2017-01-17

    Heterogeneity among individual molecules and cells has posed significant challenges to traditional bulk assays, due to the assumption of average behavior, which would lose important biological information in heterogeneity and result in a misleading interpretation. Single molecule/cell analysis has become an important and emerging field in biological and biomedical research for insights into heterogeneity between large populations at high resolution. Compared with the ensemble bulk method, single molecule/cell analysis explores the information on time trajectories, conformational states, and interactions of individual molecules/cells, all key factors in the study of chemical and biological reaction pathways. Various powerful techniques have been developed for single molecule/cell analysis, including flow cytometry, atomic force microscopy, optical and magnetic tweezers, single-molecule fluorescence spectroscopy, and so forth. However, some of them have the low-throughput issue that has to analyze single molecules/cells one by one. Flow cytometry is a widely used high-throughput technique for single cell analysis but lacks the ability for intercellular interaction study and local environment control. Droplet microfluidics becomes attractive for single molecule/cell manipulation because single molecules/cells can be individually encased in monodisperse microdroplets, allowing high-throughput analysis and manipulation with precise control of the local environment. Moreover, hydrogels, cross-linked polymer networks that swell in the presence of water, have been introduced into droplet microfluidic systems as hydrogel droplet microfluidics. By replacing an aqueous phase with a monomer or polymer solution, hydrogel droplets can be generated on microfluidic chips for encapsulation of single molecules/cells according to the Poisson distribution. The sol-gel transition property endows the hydrogel droplets with new functionalities and diversified applications in single

  8. An easy-to-use microfluidic interconnection system to create quick and reversibly interfaced simple microfluidic devices

    DEFF Research Database (Denmark)

    Pfreundt, Andrea; Andersen, Karsten Brandt; Dimaki, Maria;

    2015-01-01

    The presented microfluidic interconnection system provides an alternative for the individual interfacing of simple microfluidic devices fabricated in polymers such as polymethylmethacrylate, polycarbonate and cyclic olefin polymer. A modification of the device inlet enables the direct attachment...... pressures above 250 psi and therefore supports applications with high flow rates or highly viscous fluids. The ease of incorporation, configuration, fabrication and use make this interconnection system ideal for the rapid prototyping of simple microfluidic devices or other integrated systems that require...

  9. Dry-Mass Sensing for Microfluidics

    CERN Document Server

    Müller, T; Knowles, T P J

    2014-01-01

    We present an approach for interfacing an electromechanical sensor with a microfluidic device for the accurate quantification of the dry mass of analytes within microchannels. We show that depositing solutes onto the active surface of a quartz crystal microbalance by means of an on-chip microfluidic spray nozzle and subsequent solvent removal provides the basis for the real-time determination of dry solute mass. Moreover, this detection scheme does not suffer from the decrease in the sensor quality factor and the viscous drag present if the measurement is performed in a liquid environment, yet allows solutions to be analysed. We demonstrate the sensitivity and reliability of our approach by controlled deposition of nanogram levels of salt and protein from a micrometer-sized channel.

  10. Microfluidic Pumping by Micromolar Salt Concentrations

    CERN Document Server

    Niu, Ran; Brown, Aidan T; Rempfer, Georg; Botin, Denis; Holm, Christian; Palberg, Thomas; de Graaf, Joost

    2016-01-01

    A colloidal ion-exchange-resin-based microfluidic pump is introduced and experimentally characterized. It operates in almost deionized water for periods exceeding 24h and effects fluid flows of um/s over hundreds of um. This fluid flow displays a far-field, power-law decay which is characteristic of two-dimensional (2D) flow when the system is strongly confined in the vertical direction, and of three-dimensional (3D) flow when the system is less confined. Using theory and numerical calculations we show that our observations are consistent with electroosmotic pumping driven by umol/L ionic impurities in the sample cell, revealing the surprising impact of trace amounts of charge carriers. In addition, we explain how the power-law decay of the fluid flow can be understood on the basis of the confinement imposed by the sample cell. These two insights should benefit the design of a new class of microfluidic pumps.

  11. Femtolitre chemistry assisted by microfluidic pen lithography.

    Science.gov (United States)

    Carbonell, Carlos; Stylianou, Kyriakos C; Hernando, Jordi; Evangelio, Emi; Barnett, Sarah A; Nettikadan, Saju; Imaz, Inhar; Maspoch, Daniel

    2013-01-01

    Chemical reactions at ultrasmall volumes are becoming increasingly necessary to study biological processes, to synthesize homogenous nanostructures and to perform high-throughput assays and combinatorial screening. Here we show that a femtolitre reaction can be realized on a surface by handling and mixing femtolitre volumes of reagents using a microfluidic stylus. This method, named microfluidic pen lithography, allows mixing reagents in isolated femtolitre droplets that can be used as reactors to conduct independent reactions and crystallization processes. This strategy overcomes the high-throughput limitations of vesicles and micelles and obviates the usually costly step of fabricating microdevices and wells. We anticipate that this process enables performing distinct reactions (acid-base, enzymatic recognition and metal-organic framework synthesis), creating multiplexed nanoscale metal-organic framework arrays, and screening combinatorial reactions to evaluate the crystallization of novel peptide-based materials.

  12. Research highlights: microfluidics meets big data.

    Science.gov (United States)

    Tseng, Peter; Weaver, Westbrook M; Masaeli, Mahdokht; Owsley, Keegan; Di Carlo, Dino

    2014-03-07

    In this issue we highlight a collection of recent work in which microfluidic parallelization and automation have been employed to address the increasing need for large amounts of quantitative data concerning cellular function--from correlating microRNA levels to protein expression, increasing the throughput and reducing the noise when studying protein dynamics in single-cells, and understanding how signal dynamics encodes information. The painstaking dissection of cellular pathways one protein at a time appears to be coming to an end, leading to more rapid discoveries which will inevitably translate to better cellular control--in producing useful gene products and treating disease at the individual cell level. From these studies it is also clear that development of large scale mutant or fusion libraries, automation of microscopy, image analysis, and data extraction will be key components as microfluidics contributes its strengths to aid systems biology moving forward.

  13. Cavity optomechanics on a microfluidic resonator

    CERN Document Server

    Kim, Kyu Hyun; Lee, Wonsuk; Liu, Jing; Tomes, Matthew; Fan, Xudong; Carmon, Tal

    2012-01-01

    Light pressure is known to excite or cool vibrations in microresonators for sensing quantum-optomechanical effects and we now show that it can be explored for investigations with liquids. Currently, optical resonances are utilized to detect analytes in liquids. However, optomechanical oscillations have never been excited when devices were immersed in liquid. This is because replacing the surrounding air with water inherently increases the acoustical impedance and the associated acoustical-radiation losses. Here we fabricate a hollow optomechanical bubble resonator with water inside, and use light pressure to excite 8 MHz - 140 MHz vibrations with 1 mW optical-threshold power and >2000 mechanical Q, constituting the first time that any microfluidic system is optomechanically actuated. Bridging between optomechanics and microfluidics will enable recently developed capillaries and on-chip bubbles to vibrate via optical excitation; and allow optomechanics with non-solid material phases including bio-analytes, sup...

  14. Microfluidic Scintillation Detectors for High Energy Physics

    CERN Document Server

    Maoddi, Pietro; Mapelli, Alessandro

    This thesis deals with the development and study of microfluidic scintillation detectors, a technology of recent introduction for the detection of high energy particles. Most of the interest for such devices comes from the use of a liquid scintillator, which entails the possibility of changing the active material in the detector, leading to increased radiation resistance. A first part of the thesis focuses on the work performed in terms of design and modelling studies of novel prototype devices, hinting to new possibilities and applications. In this framework, the simulations performed to validate selected designs and the main technological choices made in view of their fabrication are addressed. The second part of this thesis deals with the microfabrication of several prototype devices. Two different materials were studied for the manufacturing of microfluidic scintillation detectors, namely the SU-8 photosensitive epoxy and monocrystalline silicon. For what concerns the former, an original fabrication appro...

  15. Droplet Manipulations in Two Phase Flow Microfluidics

    Directory of Open Access Journals (Sweden)

    Arjen M. Pit

    2015-11-01

    Full Text Available Even though droplet microfluidics has been developed since the early 1980s, the number of applications that have resulted in commercial products is still relatively small. This is partly due to an ongoing maturation and integration of existing methods, but possibly also because of the emergence of new techniques, whose potential has not been fully realized. This review summarizes the currently existing techniques for manipulating droplets in two-phase flow microfluidics. Specifically, very recent developments like the use of acoustic waves, magnetic fields, surface energy wells, and electrostatic traps and rails are discussed. The physical principles are explained, and (potential advantages and drawbacks of different methods in the sense of versatility, flexibility, tunability and durability are discussed, where possible, per technique and per droplet operation: generation, transport, sorting, coalescence and splitting.

  16. Chemical control of Vorticella bioactuator using microfluidics.

    Science.gov (United States)

    Nagai, Moeto; Ryu, Sangjin; Thorsen, Todd; Matsudaira, Paul; Fujita, Hiroyuki

    2010-06-21

    In this report, we demonstrate a microfluidic platform to control the stalk contraction and extension of Vorticella convallaria by changing concentration of Ca2+ with pneumatically-actuated elastomeric microvalves. Habitation, extraction and control of V. convallaria were carried out in a PDMS-based microfluidic device. By treating the cells with the permeant saponin, external actuation of cell-anchoring stalk between an extended and contracted state was achieved by cyclic exposure of the cells to a Ca2+ buffer (10(-6) M) and a rinse buffer containing EGTA as a chelation agent. When solutions were switched, the stalk contracted and extended responding to the ambient Ca2+ concentration change. The length of the stalk changed between 20 and 60 microm, resulting in a working distance of about 40 microm.

  17. Nanoplasmonic and Microfluidic Devices for Biological Sensing

    KAUST Repository

    Perozziello, G.

    2017-02-16

    In this chapter we report about recent advances on the development and application of 2D and 3D plasmonic nanostructures used for sensing of biological samples by Raman spectroscopy at unprecedented resolution of analysis. Besides, we explain how the integration of these nanodevices in a microfluidic apparatus can simplify the analysis of biological samples. In the first part we introduce and motivate the convenience of using nanoplasmonic enhancers and Raman spectroscopy for biological sensing, describing the phenomena and the current approaches to fabricate nanoplasmonic structures. In the second part, we explain how specific multi-element devices produce the optimal enhancement of the Raman scattering. We report cases where biological sensing of DNA was performed at few molecules level with nanometer spatial resolutions. Finally, we show an example of microfluidic device integrating plasmonic nanodevices to sort and drive biological samples, like living cells, towards the optical probe in order to obtain optimal conditions of analysis.

  18. Bonding PMMA microfluidics using commercial microwave ovens

    Science.gov (United States)

    Toossi, A.; Moghadas, H.; Daneshmand, M.; Sameoto, D.

    2015-08-01

    In this paper, a novel low-cost, rapid substrate-bonding technique is successfully applied to polymethyl methacrylate (PMMA) microfluidics bonding for the first time. This technique uses a thin intermediate metallic microwave susceptor layer at the interface of the bonding site (microchannels) which produces localized heating required for bonding during microwave irradiation. The metallic susceptor pattern is designed using a multiphysics simulation model developed in ANSYS Multiphysics software (high-frequency structural simulation (HFSS) coupled with ANSYS-Thermal). In our experiments, the required microwave energy for bonding is delivered using a relatively inexpensive, widely accessible commercial microwave oven. Using this technique, simple PMMA microfluidics prototypes are successfully bonded and sealed in less than 35 seconds with a minimum measured bond strength of 1.375 MPa.

  19. Tuning particle focusing in inertial microfluidic devices

    Science.gov (United States)

    Hood, Kaitlyn; Kahkeshani, Soroush; di Carlo, Dino; Roper, Marcus

    2014-11-01

    Particles in microfluidic devices at finite Reynolds number are subject to two forces: (i) inertial focusing and (ii) particle-particle interactions. Although microfluidic chips exploit these forces to manipulate particles for particle/cell sorting and high throughput flow cytometry, the forces are not understood well enough to allow rational design of devices that can tune and attenuate particle focusing. We present a mathematical model addressing both inertial focusing and particle interactions, and we apply our model to various channel geometries to determine the balance of forces. In addition, we present experimental data that illustrate the accuracy of our model. We will address the following questions: Why do high aspect ratio channels favor two equilibrium positions? Why do particle chains form?

  20. A microfluidic chip for ICPMS sample introduction.

    Science.gov (United States)

    Verboket, Pascal E; Borovinskaya, Olga; Meyer, Nicole; Günther, Detlef; Dittrich, Petra S

    2015-03-05

    This protocol discusses the fabrication and usage of a disposable low cost microfluidic chip as sample introduction system for inductively coupled plasma mass spectrometry (ICPMS). The chip produces monodisperse aqueous sample droplets in perfluorohexane (PFH). Size and frequency of the aqueous droplets can be varied in the range of 40 to 60 µm and from 90 to 7,000 Hz, respectively. The droplets are ejected from the chip with a second flow of PFH and remain intact during the ejection. A custom-built desolvation system removes the PFH and transports the droplets into the ICPMS. Here, very stable signals with a narrow intensity distribution can be measured, showing the monodispersity of the droplets. We show that the introduction system can be used to quantitatively determine iron in single bovine red blood cells. In the future, the capabilities of the introduction device can easily be extended by the integration of additional microfluidic modules.

  1. Plasmonic nanoshell synthesis in microfluidic composite foams.

    Science.gov (United States)

    Duraiswamy, Suhanya; Khan, Saif A

    2010-09-01

    The availability of robust, scalable, and automated nanoparticle manufacturing processes is crucial for the viability of emerging nanotechnologies. Metallic nanoparticles of diverse shape and composition are commonly manufactured by solution-phase colloidal chemistry methods, where rapid reaction kinetics and physical processes such as mixing are inextricably coupled, and scale-up often poses insurmountable problems. Here we present the first continuous flow process to synthesize thin gold "nanoshells" and "nanoislands" on colloidal silica surfaces, which are nanoparticle motifs of considerable interest in plasmonics-based applications. We assemble an ordered, flowing composite foam lattice in a simple microfluidic device, where the lattice cells are alternately aqueous drops containing reagents for nanoparticle synthesis or gas bubbles. Microfluidic foam generation enables precisely controlled reagent dispensing and mixing, and the ordered foam structure facilitates compartmentalized nanoparticle growth. This is a general method for aqueous colloidal synthesis, enabling continuous, inherently digital, scalable, and automated production processes for plasmonic nanomaterials.

  2. Femtolitre chemistry assisted by microfluidic pen lithography

    Science.gov (United States)

    Carbonell, Carlos; Stylianou, Kyriakos C.; Hernando, Jordi; Evangelio, Emi; Barnett, Sarah A.; Nettikadan, Saju; Imaz, Inhar; Maspoch, Daniel

    2013-01-01

    Chemical reactions at ultrasmall volumes are becoming increasingly necessary to study biological processes, to synthesize homogenous nanostructures and to perform high-throughput assays and combinatorial screening. Here we show that a femtolitre reaction can be realized on a surface by handling and mixing femtolitre volumes of reagents using a microfluidic stylus. This method, named microfluidic pen lithography, allows mixing reagents in isolated femtolitre droplets that can be used as reactors to conduct independent reactions and crystallization processes. This strategy overcomes the high-throughput limitations of vesicles and micelles and obviates the usually costly step of fabricating microdevices and wells. We anticipate that this process enables performing distinct reactions (acid-base, enzymatic recognition and metal-organic framework synthesis), creating multiplexed nanoscale metal-organic framework arrays, and screening combinatorial reactions to evaluate the crystallization of novel peptide-based materials. PMID:23863998

  3. 3D Printed Multimaterial Microfluidic Valve

    Science.gov (United States)

    Patrick, William G.; Sharma, Sunanda; Kong, David S.; Oxman, Neri

    2016-01-01

    We present a novel 3D printed multimaterial microfluidic proportional valve. The microfluidic valve is a fundamental primitive that enables the development of programmable, automated devices for controlling fluids in a precise manner. We discuss valve characterization results, as well as exploratory design variations in channel width, membrane thickness, and membrane stiffness. Compared to previous single material 3D printed valves that are stiff, these printed valves constrain fluidic deformation spatially, through combinations of stiff and flexible materials, to enable intricate geometries in an actuated, functionally graded device. Research presented marks a shift towards 3D printing multi-property programmable fluidic devices in a single step, in which integrated multimaterial valves can be used to control complex fluidic reactions for a variety of applications, including DNA assembly and analysis, continuous sampling and sensing, and soft robotics. PMID:27525809

  4. Electrodes for Microfluidic Integrated Optoelectronic Tweezers

    Directory of Open Access Journals (Sweden)

    Kuo-Wei Huang

    2011-01-01

    Full Text Available We report on two types of electrodes that enable the integration of optoelectronic tweezers (OETs with multilayer poly(dimethylsilane- (PDMS- based microfluidic devices. Both types of electrodes, Au-mesh and single-walled carbon nanotube- (SWNT- embedded PDMS thin film, are optically transparent, electrically conductive, and can be mechanically deformed and provide interfaces to form strong covalent bonding between an OET device and PDMS through standard oxygen plasma treatment. Au-mesh electrodes provide high electrical conductivity and high transparency but are lack of flexibility and allow only small deformation. On the other hand, SWNT-embedded PDMS thin film electrodes provide not only electrical conductivity but also optical transparency and can undergo large mechanical deformation repeatedly without failure. This enables, for the first time, microfluidic integrated OET with on-chip valve and pump functions, which is a critical step for OET-based platforms to conduct more complex and multistep biological and biochemical analyses.

  5. Microfluidic electroporation for cellular analysis and delivery.

    Science.gov (United States)

    Geng, Tao; Lu, Chang

    2013-10-01

    Electroporation is a simple yet powerful technique for breaching the cell membrane barrier. The applications of electroporation can be generally divided into two categories: the release of intracellular proteins, nucleic acids and other metabolites for analysis and the delivery of exogenous reagents such as genes, drugs and nanoparticles with therapeutic purposes or for cellular manipulation. In this review, we go over the basic physics associated with cell electroporation and highlight recent technological advances on microfluidic platforms for conducting electroporation. Within the context of its working mechanism, we summarize the accumulated knowledge on how the parameters of electroporation affect its performance for various tasks. We discuss various strategies and designs for conducting electroporation at the microscale and then focus on analysis of intracellular contents and delivery of exogenous agents as two major applications of the technique. Finally, an outlook for future applications of microfluidic electroporation in increasingly diverse utilities is presented.

  6. Cell Culture Microfluidic Biochips: Experimental Throughput Maximization

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan

    2011-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory, integrating all necessary functionalities on-chip in order to perform biochemical applications. Researchers have started to propose computer-aided design tools for the synthesis of such biochips. Our foc...... metaheuristic for experimental design generation for the cell culture microfluidic biochips, and we have evaluated our approach using multiple experimental setups....... in this paper is on the optimization of how a biochemical application is performed on a biochip. In this paper, we consider cell culture biochips, where several cell colonies are exposed to soluble compounds and monitored in real-time to determine the right combination of factors that leads to the desired...

  7. A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing.

    Science.gov (United States)

    Habhab, Mohammed-Baker; Ismail, Tania; Lo, Joe Fujiou

    2016-11-23

    Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.

  8. A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing

    Directory of Open Access Journals (Sweden)

    Mohammed-Baker Habhab

    2016-11-01

    Full Text Available Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.

  9. Synthesis of worm and chain-like nanoparticles by a microfluidic reactor process

    Science.gov (United States)

    Song, Yujun; Sun, Qiangqiang; Zhang, Tao; Jin, Pengyun; Han, Li

    2010-09-01

    We demonstrate a room temperature microfluidic reactor (MFR) process for the synthesis of worm-like and chain-like shaped metallic nanoparticles (NPs). These high aspect ratio NPs are in geometrically metastable states, which can be further transformed into ellipsoidal, spherical, or short rod-like species with enhanced crystallinity after their solutions are stirred for several hours and/or undergo sonication for more than half an hour, evidenced by their transmission electron microscope (TEM) images, selected area electron diffraction (SAED), and X-ray Diffraction (XRD). Analysis on the relative stronger shape control ability by the microfluidic process than by the batch process suggests that the attachment and merging of pre-formed nanoclusters along the flow orientation in the microchannel slits may be the main reason for the formation of non-spherical shaped NPs. The result indicates that the room temperature microfluidic process has the potential to assemble primary nanoclusters into two-dimension architectures (i.e., chain-like networks).

  10. Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control.

    Science.gov (United States)

    Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

    2016-01-01

    Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature.

  11. Tailoring microfluidic systems for organ-like cell culture applications using multiphysics simulations

    Science.gov (United States)

    Hagmeyer, Britta; Schütte, Julia; Böttger, Jan; Gebhardt, Rolf; Stelzle, Martin

    2013-03-01

    Replacing animal testing with in vitro cocultures of human cells is a long-term goal in pre-clinical drug tests used to gain reliable insight into drug-induced cell toxicity. However, current state-of-the-art 2D or 3D cell cultures aiming at mimicking human organs in vitro still lack organ-like morphology and perfusion and thus organ-like functions. To this end, microfluidic systems enable construction of cell culture devices which can be designed to more closely resemble the smallest functional unit of organs. Multiphysics simulations represent a powerful tool to study the various relevant physical phenomena and their impact on functionality inside microfluidic structures. This is particularly useful as it allows for assessment of system functions already during the design stage prior to actual chip fabrication. In the HepaChip®, dielectrophoretic forces are used to assemble human hepatocytes and human endothelial cells in liver sinusoid-like structures. Numerical simulations of flow distribution, shear stress, electrical fields and heat dissipation inside the cell assembly chambers as well as surface wetting and surface tension effects during filling of the microchannel network supported the design of this human-liver-on-chip microfluidic system for cell culture applications. Based on the device design resulting thereof, a prototype chip was injection-moulded in COP (cyclic olefin polymer). Functional hepatocyte and endothelial cell cocultures were established inside the HepaChip® showing excellent metabolic and secretory performance.

  12. A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing

    Science.gov (United States)

    Habhab, Mohammed-Baker; Ismail, Tania; Lo, Joe Fujiou

    2016-01-01

    Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications. PMID:27886051

  13. Fluid delivery manifolds and microfluidic systems

    Energy Technology Data Exchange (ETDEWEB)

    Renzi, Ronald F.; Sommer, Gregory J.; Singh, Anup K.; Hatch, Anson V.; Claudnic, Mark R.; Wang, Ying-Chih; Van de Vreugde, James L.

    2017-02-28

    Embodiments of fluid distribution manifolds, cartridges, and microfluidic systems are described herein. Fluid distribution manifolds may include an insert member and a manifold base and may define a substantially closed channel within the manifold when the insert member is press-fit into the base. Cartridges described herein may allow for simultaneous electrical and fluidic interconnection with an electrical multiplex board and may be held in place using magnetic attraction.

  14. Discrete elements for 3D microfluidics

    OpenAIRE

    Krisna C. Bhargava; Thompson, Bryant; Malmstadt, Noah

    2014-01-01

    Microfluidic systems promise to improve the analysis and synthesis of materials, biological or otherwise, by lowering the required volume of fluid samples, offering a tightly controlled fluid-handling environment, and simultaneously integrating various chemical processes. To build these systems, designers depend on microfabrication techniques that restrict them to arranging their designs in two dimensions and completely fabricating their design in a single step. This study introduces modular,...

  15. Biofunctionalization of PDMS-based microfluidic systems

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Bergoi Ibarlucea, Cesar Fernández-Sánchez, Stefanie Demming, Stephanus Büttgenbach & Andreu Llobera ### Abstract Three simple approaches for the selective immobilization of biomolecules on the surface of poly(dimethylsiloxane) (PDMS) microfluidic systems that do not require any specific instrumentation, are described and compared. They are based in the introduction of hydroxyl groups on the PDMS surface by direct adsorption of either polyethylene glycol (PEG) or polyvinyl...

  16. Algorithm for a Microfluidic Assembly Line

    OpenAIRE

    Schneider, Tobias M.; Mandre, Shreyas; Brenner, Michael P.

    2011-01-01

    Microfluidic technology has revolutionized the control of flows at small scales giving rise to new possibilities for assembling complex structures on the microscale. We analyze different possible algorithms for assembling arbitrary structures, and demonstrate that a sequential assembly algorithm can manufacture arbitrary 3D structures from identical constituents. We illustrate the algorithm by showing that a modified Hele-Shaw cell with 7 controlled flowrates can be designed to construct the ...

  17. Fluid control structures in microfluidic devices

    Energy Technology Data Exchange (ETDEWEB)

    Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

    2017-05-09

    Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

  18. Membrane-less microfiltration using inertial microfluidics

    OpenAIRE

    Majid Ebrahimi Warkiani; Andy Kah Ping Tay; Guofeng Guan; Jongyoon Han

    2015-01-01

    Microfiltration is a ubiquitous and often crucial part of many industrial processes, including biopharmaceutical manufacturing. Yet, all existing filtration systems suffer from the issue of membrane clogging, which fundamentally limits the efficiency and reliability of the filtration process. Herein, we report the development of a membrane-less microfiltration system by massively parallelizing inertial microfluidics to achieve a macroscopic volume processing rates (~ 500 mL/min). We demonstra...

  19. Predicting Droplet Formation on Centrifugal Microfluidic Platforms

    OpenAIRE

    Moebius, Jacob Alfred

    2015-01-01

    Centrifugal microfluidics is a widely known research tool for biological sample and water quality analysis. Currently, the standard equipment used for such diagnostic applications include slow, bulky machines controlled by multiple operators. These machines can be condensed into a smaller, faster benchtop sample-to-answer system.Sample processing is an important step taken to extract, isolate, and convert biological factors, such as nucleic acids or proteins, from a raw sample to an analyzabl...

  20. Note: Professional grade microfluidics fabricated simply

    Science.gov (United States)

    Mohammad, Anna; Davis, Mark; Aprelev, Alexey; Ferrone, Frank A.

    2016-10-01

    Microfluidics has found increasingly wide usage in the research and teaching laboratory, but setting up a facility for its production has typically required either significant capital expense or sacrifice of quality. We present an approach to produce devices, without a clean room, using LEDs and spin-coaters, and plasma bonded using a commercial microwave oven. Submicron features can be readily reproduced with good fidelity.

  1. Enabling Microfluidics: From Clean Rooms to Makerspaces

    Science.gov (United States)

    2016-09-30

    e.g. detection , electric manipulation, inlets/outlets) 129 [31]. For example, Lafluer et al. used 3D-printed and paper substrates to develop an...preparation, sample analysis, and optical detection methods can be 272 designed synonymously in the same space for a potentially instrument-free sample-to...287 drug screening, sepsis diagnostics, and ultra-rare cell types), new innovations in microfluidics 288 have obviated some of the need for the

  2. Multiplexed microfluidic approach for nucleic acid enrichment

    Energy Technology Data Exchange (ETDEWEB)

    VanderNoot, Victoria A.; Langevin, Stanley Alan; Bent, Zachary; Renzi, Ronald F.; Ferko, Scott M.; Van De Vreugde, James L.; Lane, Todd; Patel, Kamlesh; Branda, Steven

    2016-04-26

    A system for enhancing a nucleic acid sample may include a one pump, a denaturing chamber; a microfluidic hydroxyapatite chromatography device configured for performing hydroxyapatite chromatography on the nucleic acid sample, a sample collector, and tubing connecting the pump with the denaturing chamber, the hydroxyapatite chromatography device and the sample collector such that the pump may be used to move the nucleic acid sample from the denaturing chamber to the hydroxyapatite chromatography device and then to the sample collector.

  3. A metering rotary nanopump for microfluidic systems.

    Science.gov (United States)

    Darby, Scott G; Moore, Matthew R; Friedlander, Troy A; Schaffer, David K; Reiserer, Ron S; Wikswo, John P; Seale, Kevin T

    2010-12-07

    We describe the design, fabrication, and testing of a microfabricated metering rotary nanopump for the purpose of driving fluid flow in microfluidic devices. The miniature peristaltic pump is composed of a set of microfluidic channels wrapped in a helix around a central camshaft in which a non-cylindrical cam rotates. The cam compresses the helical channels to induce peristaltic flow as it is rotated. The polydimethylsiloxane (PDMS) nanopump design is able to produce intermittent delivery or removal of several nanolitres of fluid per revolution as well as consistent continuous flow rates ranging from as low as 15 nL min(-1) to above 1.0 µL min(-1). At back pressures encountered in typical microfluidic devices, the pump acts as a high impedance flow source. The durability, biocompatibility, ease of integration with soft-lithographic fabrication, the use of a simple rotary motor instead of multiple synchronized pneumatic or mechanical actuators, and the absence of power consumption or fluidic conductance in the resting state all contribute to a compact pump with a low cost of fabrication and versatile implementation. This suggests that the pump design may be useful for a wide variety of biological experiments and point of care devices.

  4. A Microfluidic Platform for Interfacial Electrophoretic Deposition

    Science.gov (United States)

    Joung, Young Soo; Moran, Jeffrey; Jones, Andrew; Bailey, Eric; Buie, Cullen

    2014-11-01

    Composite membranes of hydrogel and carbon nanotubes (CNTs) are fabricated using electrophoretic deposition (EPD) at the interface of two immiscible liquids in microfluidic channels. Microfluidic channels, which have two parallel electrodes at the walls, are used to create electric fields across the interface of oil and water continuously supplied into the channels. Depending on the Reynolds (Re) and Weber (We) numbers of oil and water, we observe different formations of the interface. Once we find the optimal Re and We to create a planar interface in the channel, we apply an electric field across the interface for EPD of CNTs and/or silver (Ag) nanorods dispersed in water. During EPD, particles migrate to the oil/water interface, where cross-linking of polymers is induced to form composite hydrogel membranes. Properties of the composite hydrogel films are controlled by electric fields, CNT concentrations, and both Re and We numbers, allowing for continuous production. This fabrication method is effective to create composite polymer membranes placed in microfluidic devices with tunable electrical, mechanical, and biological properties. Potential applications include fabrication of doped hydrogels for drug delivery, conductive hydrogels for biological sensing, and electron permeable membranes for water splitting and osmotic power generation.

  5. Microfluidic Biosensing Systems Using Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Franz Keplinger

    2013-09-01

    Full Text Available In recent years, there has been rapidly growing interest in developing hand held, sensitive and cost-effective on-chip biosensing systems that directly translate the presence of certain bioanalytes (e.g., biomolecules, cells and viruses into an electronic signal. The impressive and rapid progress in micro- and nanotechnology as well as in biotechnology enables the integration of a variety of analytical functions in a single chip. All necessary sample handling and analysis steps are then performed within the chip. Microfluidic systems for biomedical analysis usually consist of a set of units, which guarantees the manipulation, detection and recognition of bioanalytes in a reliable and flexible manner. Additionally, the use of magnetic fields for performing the aforementioned tasks has been steadily gaining interest. This is because magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the biosensing system. In combination with these applied magnetic fields, magnetic nanoparticles are utilized. Some of the merits of magnetic nanoparticles are the possibility of manipulating them inside microfluidic channels by utilizing high gradient magnetic fields, their detection by integrated magnetic microsensors, and their flexibility due to functionalization by means of surface modification and specific binding. Their multi-functionality is what makes them ideal candidates as the active component in miniaturized on-chip biosensing systems. In this review, focus will be given to the type of biosening systems that use microfluidics in combination with magnetoresistive sensors and detect the presence of bioanalyte tagged with magnetic nanoparticles.

  6. Microfluidics in flow cytometry and related techniques.

    Science.gov (United States)

    Béné, M C

    2017-05-01

    Technological advances in laboratory automation are now well understood and applied as they considerably improved the speed and robustness of haematological laboratory data, in the companion fields of blood analyzers and flow cytometry. Still rather confidential is the field of microfluidics, mostly confined so far to academic settings and research laboratories. The literature in the field of microfluidics is growing and applications in hematology range from cell counting to flow cytometry, cell sorting, or ex vivo testing. A literature search allows to identify many innovative solutions developed to master the specific physics of fluid movements in microchips. Miniaturization also dwells on findings that have emerged from different areas such as electronics and nanoengineering. This review proposes an overview of the major principles guiding developments in microfluidics and describes a necessarily limited and nonexhaustive series of specific applications. Readers are strongly encouraged to consult the documents referred to in the references section to learn more about this world knocking at our door and possibly liable to revolutionize our profession of hematology biologists in a not so far future. © 2017 John Wiley & Sons Ltd.

  7. Microfluidic biosensing systems using magnetic nanoparticles.

    Science.gov (United States)

    Giouroudi, Ioanna; Keplinger, Franz

    2013-09-09

    In recent years, there has been rapidly growing interest in developing hand held, sensitive and cost-effective on-chip biosensing systems that directly translate the presence of certain bioanalytes (e.g., biomolecules, cells and viruses) into an electronic signal. The impressive and rapid progress in micro- and nanotechnology as well as in biotechnology enables the integration of a variety of analytical functions in a single chip. All necessary sample handling and analysis steps are then performed within the chip. Microfluidic systems for biomedical analysis usually consist of a set of units, which guarantees the manipulation, detection and recognition of bioanalytes in a reliable and flexible manner. Additionally, the use of magnetic fields for performing the aforementioned tasks has been steadily gaining interest. This is because magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the biosensing system. In combination with these applied magnetic fields, magnetic nanoparticles are utilized. Some of the merits of magnetic nanoparticles are the possibility of manipulating them inside microfluidic channels by utilizing high gradient magnetic fields, their detection by integrated magnetic microsensors, and their flexibility due to functionalization by means of surface modification and specific binding. Their multi-functionality is what makes them ideal candidates as the active component in miniaturized on-chip biosensing systems. In this review, focus will be given to the type of biosening systems that use microfluidics in combination with magnetoresistive sensors and detect the presence of bioanalyte tagged with magnetic nanoparticles.

  8. Microfluidics for Positron Emission Tomography Probe Development

    Directory of Open Access Journals (Sweden)

    Ming-Wei Wang

    2010-07-01

    Full Text Available Owing to increased needs for positron emission tomography (PET, high demands for a wide variety of radiolabeled compounds will have to be met by exploiting novel radiochemistry and engineering technologies to improve the production and development of PET probes. The application of microfluidic reactors to perform radiosyntheses is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional labeling systems. Microfluidics-based radiochemistry can lead to the use of smaller quantities of precursors, accelerated reaction rates, and easier purification processes with greater yield and higher specific activity of desired probes. Several proof-of-principle examples along with the basics of device architecture and operation and the potential limitations of each design are discussed. Along with the concept of radioisotope distribution from centralized cyclotron facilities to individual imaging centers and laboratories (“decentralized model”, an easy-to-use, stand-alone, flexible, fully automated, radiochemical microfluidic platform can provide simpler and more cost-effective procedures for molecular imaging using PET.

  9. 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.

  10. Logic control of microfluidics with smart colloid

    KAUST Repository

    Wang, Limu

    2010-01-01

    We report the successful realization of a microfluidic chip with switching and corresponding inverting functionalities. The chips are identical logic control components incorporating a type of smart colloid, giant electrorheological fluid (GERF), which possesses reversible characteristics via a liquid-solid phase transition under external electric field. Two pairs of electrodes embedded on the sides of two microfluidic channels serve as signal input and output, respectively. One, located in the GERF micro-channel is used to control the flow status of GERF, while another one in the ither micro-fluidic channel is used to detect the signal generated with a passing-by droplet (defined as a signal droplet). Switching of the GERF from the suspended state (off-state) to the flowing state (on-state) or vice versa in the micro-channel is controlled by the appearance of signal droplets whenever they pass through the detection electrode. The output on-off signals can be easily demonstrated, clearly matching with GERF flow status. Our results show that such a logic switch is also a logic IF gate, while its inverter functions as a NOT gate. © The Royal Society of Chemistry 2010.

  11. Micromagnetic-microfluidic blood cleansing device.

    Science.gov (United States)

    Yung, Chong Wing; Fiering, Jason; Mueller, Andrew J; Ingber, Donald E

    2009-05-07

    Sepsis is a lethal disease caused by a systemic microbial infection that spreads via the bloodstream to overwhelm the body's defenses. Current therapeutic approaches are often suboptimal, in part, because they do not fully eliminate the pathogen, and hence the source of deadly toxins. Here we describe an extracorporeal blood cleansing device to selectively remove pathogens from contaminated blood and thereby enhance the patient's response to antibiotic therapy. Immunomagnetic microbeads were modified to create magnetic opsonins that were used to cleanse flowing human whole blood of Candida albicans fungi, a leading cause of sepsis-related deaths. The micromagnetic-microfluidic blood cleansing device generates magnetic field gradients across vertically stacked channels to enable continuous and high throughput separation of fungi from flowing whole blood. A multiplexed version of the device containing four parallel channels achieved over 80% clearance of fungi from contaminated blood at a flow rate of 20 mL/h in a single pass, a rate 1000 times faster than a previously described prototype micromagnetic-microfluidic cell separation system. These results provide the first proof-of-principle that a multiplexed micromagnetic-microfluidic separation system can be used to cleanse pathogens from flowing human blood at a rate and separation efficiency that is relevant for clinical applications.

  12. Capture of DNA in microfluidic channel using magnetic beads: increasing capture efficiency with integrated microfluidic mixer

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Dufva, Hans Martin; Hansen, Mikkel Fougt

    2007-01-01

    We have studied the hybridization of target DNA in solution with probe DNA on magnetic beads immobilized on the channel sidewalls in a magnetic bead separator. The hybridization is carried out under a liquid flow and is diffusion limited. Two systems are compared: one with a straight microfluidic...... channel and one with an integrated staggered herringbone mixer. Fluorescence microscopy studies show that the hybridization is much more efficient in the system with the integrated mixer. The results, which are discussed in terms of a simple model, are relevant for any diffusion-limited reaction taking...... place on the surface in a microfluidic system....

  13. Pulsatile microfluidics as an analytical tool for determining the dynamic characteristics of microfluidic systems

    DEFF Research Database (Denmark)

    Vedel, Søren; Olesen, Laurits Højgaard; Bruus, Henrik

    2010-01-01

    An understanding of all fluid dynamic time scales is needed to fully understand and hence exploit the capabilities of fluid flow in microfluidic systems. We propose the use of harmonically oscillating microfluidics as an analytical tool for the deduction of these time scales. Furthermore, we...... suggest the use of system-level equivalent circuit theory as an adequate theory of the behavior of the system. A novel pressure source capable of operation in the desired frequency range is presented for this generic analysis. As a proof of concept, we study the fairly complex system of water...

  14. Microfluidic geometric metering-based multi-reagent mixture generator for robust live cell screening array.

    Science.gov (United States)

    Wang, Han; Kim, Jeongyun; Jayaraman, Arul; Han, Arum

    2014-12-01

    Microfluidic live cell arrays with integrated concentration gradient or mixture generators have been utilized in screening cellular responses to various biomolecular cues. Microfluidic network-based gradient generators that can create concentration gradients by repeatedly splitting and mixing different solutions using networks of serpentine channels are commonly used. However, in this method the generation of concentration gradients relies on the continuous flow of sample solutions at optimized flow rates, which poses challenges in maintaining the pressure and flow stability throughout the entire assay period. Here we present a microfluidic live cell screening array with an on-demand multi-reagent mixture generator where the mixing ratios, thus generated concentrations, are hard-wired into the chip itself through a geometric metering method. This platform showed significantly improved robustness and repeatability in generating concentration gradients of fluorescent dyes (average coefficient of variance C.V. = 9 %) compared to the conventional network-based gradient generators (average C.V. = 21 %). In studying the concentration dependent effects of the environmental toxicant 3-methylcholanthrene (3MC) on the activation of cytochrome P450 1A1 (Cyp 1A1) enzyme in H4IIE rat hepatoma cells, statistical variation of the Cyp 1A1 response was significantly lower (C.V. = 5 %) when using the developed mixture generator compared to that using the conventional gradient generator (C.V. = 12 %). Reduction in reagent consumption by 12-times was also achieved. This robust, accurate, and scalable multi-reagent mixture generator integrated with a cell culture array as a live cell assay platform can be readily implemented into various screening applications where repeatability, robustness, and low reagent consumptions over long periods of assay time are of importance.

  15. Microfluidic platform for neurotransmitter sensing based on cyclic voltammetry and dielectrophoresis for in vitro experiments.

    Science.gov (United States)

    Mathault, Jessy; Zamprogno, Pauline; Greener, Jesse; Miled, Amine

    2015-08-01

    This paper presents a new microfluidic platform that can simultaneously measure and locally modulate neurotransmitter concentration in a neuron network. This work focuses on the development of a first prototype including a potentiostat and electrode functionalization to detect several neurotransmitter's simultaneously. We tested dopamine as proof of concept to validate functionality. The system is based on 320 bidirectional electrode array for dielectrophoretic manipulation and cyclic voltammetry. Each electrode is connected to a mechanical multiplexer in order to reduce noise interference and fully isolate the electrode. The multiplexing rate is 476 kHz and each electrode can drive a signal with an amplitude of 60 V pp for dielectrophoretic manipulation.

  16. Formation and Transport of Bubbles in Microfluidic Systems

    NARCIS (Netherlands)

    Van Steijn, V.

    2010-01-01

    Precise manipulation of minute volumes of fluids is at the heart of microfluidics and opens up an exciting route to miniaturize processes in the areas of chemistry, biology and medicine. An attractive way to transport small fluid samples through the channels of microfluidic devices is by enclosing t

  17. Screening of aptamers on microfluidic systems for clinical applications.

    Science.gov (United States)

    Weng, Chen-Hsun; Huang, Chao-Jyun; Lee, Gwo-Bin

    2012-01-01

    The use of microfluidic systems for screening of aptamers and their biomedical applications are reviewed in this paper. Aptamers with different nucleic acid sequences have been extensively studied and the results demonstrated a strong binding affinity to target molecules such that they can be used as promising candidate biomarkers for diagnosis and therapeutics. Recently, the aptamer screening protocol has been conducted with microfluidic-based devices. Furthermore, aptamer affinity screening by a microfluidic-based method has demonstrated remarkable advantages over competing traditional methods. In this paper, we first reviewed microfluidic systems which demonstrated efficient and rapid screening of a specific aptamer. Then, the clinical applications of screened aptamers, also performed by microfluidic systems, are further reviewed. These automated microfluidic systems can provide advantages over their conventional counterparts including more compactness, faster analysis, less sample/reagent consumption and automation. An aptamer-based compact microfluidic system for diagnosis may even lead to a point-of-care device. The use of microfluidic systems for aptamer screening and diagnosis is expected to continue growing in the near future and may make a substantial impact on biomedical applications.

  18. Screening of Aptamers on Microfluidic Systems for Clinical Applications

    Directory of Open Access Journals (Sweden)

    Gwo-Bin Lee

    2012-07-01

    Full Text Available The use of microfluidic systems for screening of aptamers and their biomedical applications are reviewed in this paper. Aptamers with different nucleic acid sequences have been extensively studied and the results demonstrated a strong binding affinity to target molecules such that they can be used as promising candidate biomarkers for diagnosis and therapeutics. Recently, the aptamer screening protocol has been conducted with microfluidic-based devices. Furthermore, aptamer affinity screening by a microfluidic-based method has demonstrated remarkable advantages over competing traditional methods. In this paper, we first reviewed microfluidic systems which demonstrated efficient and rapid screening of a specific aptamer. Then, the clinical applications of screened aptamers, also performed by microfluidic systems, are further reviewed. These automated microfluidic systems can provide advantages over their conventional counterparts including more compactness, faster analysis, less sample/reagent consumption and automation. An aptamer-based compact microfluidic system for diagnosis may even lead to a point-of-care device. The use of microfluidic systems for aptamer screening and diagnosis is expected to continue growing in the near future and may make a substantial impact on biomedical applications.

  19. Formation and Transport of Bubbles in Microfluidic Systems

    NARCIS (Netherlands)

    Van Steijn, V.

    2010-01-01

    Precise manipulation of minute volumes of fluids is at the heart of microfluidics and opens up an exciting route to miniaturize processes in the areas of chemistry, biology and medicine. An attractive way to transport small fluid samples through the channels of microfluidic devices is by enclosing

  20. A microfluidic device based on an evaporation-driven micropump

    NARCIS (Netherlands)

    Nie, C.; Frijns, A.J.H.; Mandamparambil, R.; Toonder, J.M.J. den

    2015-01-01

    In this paper we introduce a microfluidic device ultimately to be applied as a wearable sweat sensor. We show proof-of-principle of the microfluidic functions of the device, namely fluid collection and continuous fluid flow pumping. A filter-paper based layer, that eventually will form the interface

  1. A microfluidic device based on an evaporation-driven micropump

    NARCIS (Netherlands)

    Nie, C.; Frijns, A.J.H.; Mandamparambil, R.; Toonder, J.M.J. den

    2015-01-01

    In this paper we introduce a microfluidic device ultimately to be applied as a wearable sweat sensor. We show proof-of-principle of the microfluidic functions of the device, namely fluid collection and continuous fluid flow pumping. A filter-paper based layer, that eventually will form the interface

  2. Split and flow: reconfigurable capillary connection for digital microfluidic devices.

    Science.gov (United States)

    Lapierre, Florian; Harnois, Maxime; Coffinier, Yannick; Boukherroub, Rabah; Thomy, Vincent

    2014-09-21

    Supplying liquid to droplet-based microfluidic microsystems remains a delicate task facing the problems of coupling continuous to digital or macro- to microfluidic systems. Here, we take advantage of superhydrophobic microgrids to address this problem. Insertion of a capillary tube inside a microgrid aperture leads to a simple and reconfigurable droplet generation setup.

  3. Flow control in microfluidic chips : Material choice and smart design

    NARCIS (Netherlands)

    Debrauwer, P.; Emmelkamp, J.; Bolt, P.J.

    2009-01-01

    This paper describes a model and experiments to validate it for the design of bubble free chambers and channels in microfluidic chips. When handling liquids in a microfluidic chip problems may arise with entrapping air or liquid. These air and liquid bubbles deteriorate the efficiency of the process

  4. A microfluidic AFM cantilever based dispensing and aspiration platform

    NARCIS (Netherlands)

    Van Oorschot, R.; Perez Garza, H.H.; Derks, R.J.S.; Staufer, U.; Ghatkesar, M.K.

    2015-01-01

    We present the development of a microfluidic AFM (atomic force microscope) cantilever-based platform to enable the local dispensing and aspiration of liquid with volumes in the pico-to-femtoliter range. The platform consists of a basic AFM measurement system, microfluidic AFM chip, fluidic interface

  5. Optical manipulation with two beam traps in microfluidic polymer systems

    DEFF Research Database (Denmark)

    Khoury Arvelo, Maria; Matteucci, Marco; Sørensen, Kristian Tølbøl

    2015-01-01

    An optical trapping system with two opposing laser beams, also known as the optical stretcher, are naturally constructed inside a microfluidic lab-on-chip system. We present and compare two approaches to combine a simple microfluidic system with either waveguides directly written in the microflui...

  6. Using microfluidics to study programmed cell death: A new approach

    DEFF Research Database (Denmark)

    Mark, Christina; Zor, Kinga; Heiskanen, Arto

    This project focuses on applying microfluidic tissue culture for electrochemical or optical measurements during programmed cell death (PCD) in barley aleurone layer to increase understanding of the underlying mechanisms of PCD in plants. Microfluidic tissue culture enables in vitro experiments to...

  7. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  8. Microfluidic Diffusion Viscometer for Rapid Analysis of Complex Solutions.

    Science.gov (United States)

    Arosio, Paolo; Hu, Kevin; Aprile, Francesco A; Müller, Thomas; Knowles, Tuomas P J

    2016-04-05

    The viscosity of complex solutions is a physical property of central relevance for a large number of applications in material, biological, and biotechnological sciences. Here we demonstrate a microfluidic technology to measure the viscosity of solutions by following the advection and diffusion of tracer particles under steady-state flow. We validate our method with standard water-glycerol mixtures, and then we apply this microfluidic diffusion viscometer to measure the viscosity of protein solutions at high concentrations as well as of a crude cell lysate. Our approach exhibits a series of attractive features, including analysis time on the order of seconds and the consumption of a few μL of sample, as well as the possibility to readily integrate the microfluidic viscometer in other instrument platforms or modular microfluidic devices. These characteristics make microfluidic diffusion viscometry an attractive approach in automated processes in biotechnology and health-care sciences where fast measurements with limited amount of sample consumption are required.

  9. A microfluidic timer for timed valving and pumping in centrifugal microfluidics.

    Science.gov (United States)

    Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N

    2015-03-21

    Accurate timing of microfluidic operations is essential for the automation of complex laboratory workflows, in particular for the supply of sample and reagents. Here we present a new unit operation for timed valving and pumping in centrifugal microfluidics. It is based on temporary storage of pneumatic energy and time delayed sudden release of said energy. The timer is loaded at a relatively higher spinning frequency. The countdown is started by reducing to a relatively lower release frequency, at which the timer is released after a pre-defined delay time. We demonstrate timing for 1) the sequential release of 4 liquids at times of 2.7 s ± 0.2 s, 14.0 s ± 0.5 s, 43.4 s ± 1.0 s and 133.8 s ± 2.3 s, 2) timed valving of typical assay reagents (contact angles 36-78°, viscosities 0.9-5.6 mPa s) and 3) on demand valving of liquids from 4 inlet chambers in any user defined sequence controlled by the spinning protocol. The microfluidic timer is compatible to all wetting properties and viscosities of common assay reagents and does neither require assistive equipment, nor coatings. It can be monolithically integrated into a microfluidic test carrier and is compatible to scalable fabrication technologies such as thermoforming or injection molding.

  10. Pulsatile microfluidics as an analytical tool for determining the dynamic characteristics of microfluidic systems

    DEFF Research Database (Denmark)

    Vedel, Søren; Olesen, Laurits Højgaard; Bruus, Henrik

    2010-01-01

    -filled interconnected elastic microfluidic tubes containing a large, trapped air bubble and driven by a pulsatile pressure difference. We demonstrate good agreement between the system-level model and the experimental results, allowing us to determine the dynamic time scales of the system. However, the generic analysis...

  11. Reversible Control of Anisotropic Electrical Conductivity using Colloidal Microfluidic Networks

    Science.gov (United States)

    2007-04-17

    steady electrophoresis (EP), AC-electro- osmosis (ACEO), and dielectrophoresis (DEP) effects (explained in detail later in this report). Figure 2 shows...capacitance (compare Figs. 2i and 2a). At moderate forcing frequencies (~ 1 kHz) we observe onset of AC electro- osmosis (ACEO), which forms an impinging...resistance can also be seen to be fairly constant at high frequencies, with a value that is inversely proportional to the conductivity of the solution

  12. Biologically Inspired Electronic, Photovoltaic and Microfluidic Devices Based on Aqueous Soft Matter

    Science.gov (United States)

    Koo, Hyung Jun

    Hydrogels are a water-based soft material where three dimensional networks of hydrophilic polymer retain large amounts of water. We developed hydrogel based devices with new functionalities inspired by materials, structures and processes in nature. The advantages, such as softness, biocompatibility and high ionic conductivity, could enable hydrogels to be novel materials for biomimetic devices operated by ionic current. Moreover, microfluidic patterns are easily embedded in moldable hydrogels and allow for unique convective/diffusive transport mechanism in porous gel to be used for uniform delivery of reagent solution. We first developed and characterized a device with unidirectional ionic current flow across a SiO2/Gel junction, which showed highly efficient rectification of the ionic current by non-linear conductivity of SiO2 films. Addition of polyelectrolytes and salt to the gel layer significantly improved the performance of the new diode device because of the enhanced gel conductance. A soft matter based diode composed of hydrogel and liquid metal (eutectic gallium indium, EGaIn) was also presented. The ability to control the thickness, and thus resistivity, of an insulating oxide skin on the metal enables the current rectification. The effect of ionic conductivity and pH on the formation of the insulating oxide was investigated in a simple model system with liquid metal/electrolyte solution or hydrogel/Pt interfaces. Finally, we present a diode composed entirely of soft materials by replacing the platinum electrode with a second liquid metal electrode. A new type of hydrogel-based photovoltaic systems (HGPVs) was constructed. Two photosensitive ionized molecules embedded in aqueous gel served as photoactive species. The HGPVs showed performance comparable with or higher than those of some other biomimetic or ionic photovoltaic systems reported recently. We suggest a provisional mechanism of the device operation, based on a synergetic effect of the two dye

  13. Bistability in a simple fluid network due to viscosity contrast

    CERN Document Server

    Geddes, John B; Gardner, David; Carr, Russell T

    2009-01-01

    We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity--sucrose solution and water. Possible applications include bloodflow, microfluidics, and other network flows governed by similar principles.

  14. Microfluidic gene arrays for rapid genomic profiling

    Science.gov (United States)

    West, Jay A.; Hukari, Kyle W.; Hux, Gary A.; Shepodd, Timothy J.

    2004-12-01

    Genomic analysis tools have recently become an indispensable tool for the evaluation of gene expression in a variety of experiment protocols. Two of the main drawbacks to this technology are the labor and time intensive process for sample preparation and the relatively long times required for target/probe hybridization. In order to overcome these two technological barriers we have developed a microfluidic chip to perform on chip sample purification and labeling, integrated with a high density genearray. Sample purification was performed using a porous polymer monolithic material functionalized with an oligo dT nucleotide sequence for the isolation of high purity mRNA. These purified mRNA"s can then rapidly labeled using a covalent fluorescent molecule which forms a selective covalent bond at the N7 position of guanine residues. These labeled mRNA"s can then released from the polymer monolith to allow for direct hybridization with oligonucletide probes deposited in microfluidic channel. To allow for rapid target/probe hybridization high density microarray were printed in microchannels. The channels can accommodate array densities as high as 4000 probes. When oligonucleotide deposition is complete, these channels are sealed using a polymer film which forms a pressure tight seal to allow sample reagent flow to the arrayed probes. This process will allow for real time target to probe hybridization monitoring using a top mounted CCD fiber bundle combination. Using this process we have been able to perform a multi-step sample preparation to labeled target/probe hybridization in less than 30 minutes. These results demonstrate the capability to perform rapid genomic screening on a high density microfluidic microarray of oligonucleotides.

  15. Interfacial microfluidic transport on micropatterned superhydrophobic textile.

    Science.gov (United States)

    Xing, Siyuan; Jiang, Jia; Pan, Tingrui

    2013-05-21

    Textile-enabled interfacial microfluidics, utilizing fibrous hydrophilic yarns (e.g., cotton) to guide biological reagent flows, has been extended to various biochemical analyses recently. The restricted capillary-driving mechanism, however, persists as a major challenge for continuous and facilitated biofluidic transport. In this paper, we have first introduced a novel interfacial microfluidic transport principle to drive three-dimensional liquid flows on a micropatterned superhydrophobic textile (MST) platform in a more autonomous and controllable manner. Specifically, the MST system utilizes the surface tension-induced Laplace pressure to facilitate the liquid motion along the hydrophilic yarn, in addition to the capillarity present in the fibrous structure. The fabrication of MST is simply accomplished by stitching hydrophilic cotton yarn into a superhydrophobic fabric substrate (contact angle 140 ± 3°), from which well-controlled wetting patterns are established for interfacial microfluidic operations. The geometric configurations of the stitched micropatterns, e.g., the lengths and diameters of the yarn and bundled arrangement, can all influence the transport process, which is investigated both experimentally and theoretically. Two operation modes, discrete and continuous transport, are also presented in detail. In addition, the gravitational effect as well as the droplet removal process have been also considered and quantitatively analysed during the transport process. As a demonstration, an MST design has been implemented on an artificial skin surface to collect and remove sweat in a highly efficient and facilitated means. The results have illustrated that the novel interfacial transport on the textile platform can be potentially extended to a variety of biofluidic collection and removal applications.

  16. An automated Teflon microfluidic peptide synthesizer.

    Science.gov (United States)

    Zheng, Hui; Wang, Weizhi; Li, Xiaojun; Wang, Zihua; Hood, Leroy; Lausted, Christopher; Hu, Zhiyuan

    2013-09-07

    We present a microfluidic synthesizer made entirely of Teflon material for solid phase peptide synthesis (SPPS). Solvent-resistant perfluoroalkoxy (PFA) was used to construct chip-sized devices featuring multiple tri-layer pneumatic microvalves. Using these devices, model peptides were automatically synthesized and cleaved in situ in a continuous-flow manner. The total coupling and cleavage time was significantly reduced compared to conventional bulk reactors. The synthesis of a decapeptide, for instance, took less than 6 h using our device while it usually takes more than three days using conventional reactors.

  17. Scintillation particle detection based on microfluidics

    CERN Document Server

    Mapelli, A; Renaud, P; Gorini, B; Trivino, N Vico; Jiguet, S; Vandelli, W; Haguenauer, M

    2010-01-01

    A novel type of particle detector based on scintillation, with precise spatial resolution and high radiation hardness, is being studied. It consists of a single microfluidic channel filled with a liquid scintillator and is designed to define an array of scintillating waveguides each independently coupled to a photodetector. Prototype detectors built using an SU-8 epoxy resin have been tested with electrons from a radioactive source. The experimental results show a light yield compatible with the theoretical expectations and confirm the validity of the approach. (C) 2010 Elsevier B.V. All rights reserved.

  18. Microfluidic system for enhanced cardiac tissue formation

    Directory of Open Access Journals (Sweden)

    Busek Mathias

    2017-09-01

    Full Text Available Hereby a microfluidic system for cell cultivation is presented in which human pluripotent stem cell-derived cardiomyocytes were cultivated under perfusion. Besides micro-perfusion this system is also capable to produce well-defined oxygen contents, apply defined forces and has excellent imaging characteristics. Cardiomyocytes attach to the surface, start spontaneous beating and stay functional for up to 14 days under perfusion. The cell motion was subsequently analysed using an adapted video analysis script to calculate beating rate, beating direction and contraction or relaxation speed.

  19. Biocatalytic process development using microfluidic miniaturized systems

    DEFF Research Database (Denmark)

    Krühne, Ulrich; Heintz, Søren; Ringborg, Rolf Hoffmeyer

    2014-01-01

    The increasing interest in biocatalytic processes means there is a clear need for a new systematic development paradigm which encompasses both protein engineering and process engineering. This paper argues that through the use of a new microfluidic platform, data can be collected more rapidly...... and integrated with process modeling, can provide the basis for validating a reduced number of potential processes. The miniaturized platform should use a smaller reagent inventory and make better use of precious biocatalysts. The EC funded BIOINTENSE project will use ω-transaminase based synthesis of chiral...

  20. Active micromachines: Microfluidics powered by mesoscale turbulence

    CERN Document Server

    Thampi, Sumesh P; Shendruk, Tyler N; Golestanian, Ramin; Yeomans, Julia M

    2016-01-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterised by mesoscale turbulence, the emergence of chaotic flow structures. By immersing an ordered array of symmetric rotors in an active fluid, we introduce a microfluidic system that exploits spontaneous symmetry breaking in mesoscale turbulence to generate work. The lattice of rotors self-organises into a spin-state where neighbouring discs continuously rotate in permanent alternating directions due to combined hydrodynamic and elastic effects. Our virtual prototype demonstrates a new research direction for the design of micromachines powered by the nematohydrodynamic properties of active turbulence.

  1. A capillary valve for microfluidic systems.

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Eric B.; Kanouff, Michael P.; Rush, Brian M.

    2004-10-01

    Microfluidic systems are becoming increasingly complicated as the number of applications grows. The use of microfluidic systems for chemical and biological agent detection, for example, requires that a given sample be subjected to many process steps, which requires microvalves to control the position and transport of the sample. Each microfluidic application has its own specific valve requirements and this has precipitated the wide variety of valve designs reported in the literature. Each of these valve designs has its strengths and weaknesses. The strength of the valve design proposed here is its simplicity, which makes it easy to fabricate, easy to actuate, and easy to integrate with a microfluidic system. It can be applied to either gas phase or liquid phase systems. This novel design uses a secondary fluid to stop the flow of the primary fluid in the system. The secondary fluid must be chosen based on the type of flow that it must stop. A dielectric fluid must be used for a liquid phase flow driven by electroosmosis, and a liquid with a large surface tension should be used to stop a gas phase flow driven by a weak pressure differential. Experiments were carried out investigating certain critical functions of the design. These experiments verified that the secondary fluid can be reversibly moved between its 'valve opened' and 'valve closed' positions, where the secondary fluid remained as one contiguous piece during this transport process. The experiments also verified that when Fluorinert is used as the secondary fluid, the valve can break an electric circuit. It was found necessary to apply a hydrophobic coating to the microchannels to stop the primary fluid, an aqueous electrolyte, from wicking past the Fluorinert and short-circuiting the valve. A simple model was used to develop valve designs that could be closed using an electrokinetic pump, and re-opened by simply turning the pump off and allowing capillary forces to push the secondary

  2. How boundaries shape chemical delivery in microfluidics

    Science.gov (United States)

    Aminian, Manuchehr; Bernardi, Francesca; Camassa, Roberto; Harris, Daniel M.; McLaughlin, Richard M.

    2016-12-01

    Many microfluidic systems—including chemical reaction, sample analysis, separation, chemotaxis, and drug development and injection—require control and precision of solute transport. Although concentration levels are easily specified at injection, pressure-driven transport through channels is known to spread the initial distribution, resulting in reduced concentrations downstream. Here we document an unexpected phenomenon: The channel’s cross-sectional aspect ratio alone can control the shape of the concentration profile along the channel length. Thin channels (aspect ratio delivery, based only on the channel dimensions.

  3. Detection methods for centrifugal microfluidic platforms

    DEFF Research Database (Denmark)

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-01-01

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation......, have been developed and allow automation and integration of complex assay protocols in lab-on-a-disc systems. Besides liquid handling, the detection strategy for reading out the assay is crucial for developing a fully integrated system. In this review, we focus on biosensors and readout methods...

  4. DNA reaction networks: Providing a panoramic view

    Science.gov (United States)

    Wang, Fei; Fan, Chunhai

    2016-08-01

    A quantitative understanding of the functional landscape of a biochemical circuit can reveal the design rules required to optimize the circuit. Now, a high-throughput droplet-based microfluidic platform has been developed which enables high-resolution mapping of bifurcation diagrams for two nonlinear DNA networks.

  5. Hybrid CMOS / Microfluidic Systems for Cell Manipulation with Dielectrophoresis

    Science.gov (United States)

    Hunt, Tom; Issadore, David; Westervelt, Robert M.

    2007-03-01

    A hybrid CMOS/microfluidic chip combines the biocompatibility of microfluidics with the built-in logic, programmability, and sensitivity of CMOS integrated circuits (ICs)^1 We have designed a CMOS IC for moving individual cells using dielectrophoresis (DEP). The IC was built in a commercial foundry and we subsequently fabricated a microfluidic chamber on the top surface. The chip consists of a 1.4 by 2.8mm array of over 32,000 individually addressable 11x11 micron pixels. An RF voltage of 5V at 10MHz can be applied to each pixel with respect to the conductive lid of the microfluidic chamber, producing a localized electric field that can trap a cell. By shifting the location of energized pixels, the array can trap and move cells along programmable paths through the microfluidic chamber. We show the design, fabrication, and testing of the hybrid chip. Bringing together the biocompatibility of microfluidics and the power of CMOS chips, hybrid CMOS / microfluidic systems are an exciting technology for biomedical research. Thanks to NSEC NSF grant PHY-0117795 and the NCI MIT-Harvard CCNE. [1] H Lee, Y Liu, RM Westervelt, D Ham, IEEE JSSC 41, 6, pp. 1471-1480, 2006

  6. Microfluidic positioning of pollen grains in lab-on-a-chip for single cell analysis.

    Science.gov (United States)

    Ghanbari, Mahmood; Nezhad, Amir Sanati; Agudelo, Carlos G; Packirisamy, Muthukumaran; Geitmann, Anja

    2014-04-01

    A lab-on-a-chip device with a knot shaped microfluidic network is presented to enable trapping of single pollen grains at the entrances of a series of microchannels. This set-up serves to create identical growth conditions for serially arranged tip growing plant cells such as pollen tubes. The design consists of an inlet to introduce the pollen suspension into the chip, three outlets to evacuate excess medium or cells, a distribution chamber to guide the pollen grains toward the growth microchannels and a serial arrangement of microchannels with different geometries connected to the distribution chamber. These microchannels are to harbor the individual pollen tubes. Two different criteria were established to assess the efficiency and optimize the device: trapping probability and uniformity of fluid flow conditions within the microchannels. The performance of different geometries of the microfluidic network was numerically analyzed and experimentally tested. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Effect of high pressure microfluidization on the crystallization behavior of palm stearin - palm olein blends.

    Science.gov (United States)

    Han, Lijuan; Li, Lin; Li, Bing; Zhao, Lei; Liu, Guoqin; Liu, Xinqi; Wang, Xuede

    2014-04-24

    Moderate and high microfluidization pressures (60 and 120 MPa) and different treatment times (once and twice) were used to investigate the effect of high-pressure microfluidization (HPM) treatment on the crystallization behavior and physical properties of binary mixtures of palm stearin (PS) and palm olein (PO). The polarized light microscopy (PLM), texture analyzer, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques were applied to analyze the changes in crystal network structure, hardness, polymorphism and thermal property of the control and treated blends. PLM results showed that HPM caused significant reductions in maximum crystal diameter in all treated blends, and thus led to changes in the crystal network structure, and finally caused higher hardness in than the control blends. The XRD study demonstrated that HPM altered crystalline polymorphism. The HPM-treated blends showed a predominance of the more stable β' form, which is of more interest for food applications, while the control blend had more α- and β-form. This result was further confirmed by DSC observations. These changes in crystallization behavior indicated that HPM treatment was more likely to modify the crystallization processes and nucleation mechanisms.

  8. Effect of High Pressure Microfluidization on the Crystallization Behavior of Palm Stearin — Palm Olein Blends

    Directory of Open Access Journals (Sweden)

    Lijuan Han

    2014-04-01

    Full Text Available Moderate and high microfluidization pressures (60 and 120 MPa and different treatment times (once and twice were used to investigate the effect of high-pressure microfluidization (HPM treatment on the crystallization behavior and physical properties of binary mixtures of palm stearin (PS and palm olein (PO. The polarized light microscopy (PLM, texture analyzer, X-ray diffraction (XRD and differential scanning calorimetry (DSC techniques were applied to analyze the changes in crystal network structure, hardness, polymorphism and thermal property of the control and treated blends. PLM results showed that HPM caused significant reductions in maximum crystal diameter in all treated blends, and thus led to changes in the crystal network structure, and finally caused higher hardness in than the control blends. The XRD study demonstrated that HPM altered crystalline polymorphism. The HPM-treated blends showed a predominance of the more stable β' form, which is of more interest for food applications, while the control blend had more α- and β-form. This result was further confirmed by DSC observations. These changes in crystallization behavior indicated that HPM treatment was more likely to modify the crystallization processes and nucleation mechanisms.

  9. Non-Linear Electrohydrodynamics in Microfluidic Devices

    Directory of Open Access Journals (Sweden)

    Jun Zeng

    2011-03-01

    Full Text Available Since the inception of microfluidics, the electric force has been exploited as one of the leading mechanisms for driving and controlling the movement of the operating fluid and the charged suspensions. Electric force has an intrinsic advantage in miniaturized devices. Because the electrodes are placed over a small distance, from sub-millimeter to a few microns, a very high electric field is easy to obtain. The electric force can be highly localized as its strength rapidly decays away from the peak. This makes the electric force an ideal candidate for precise spatial control. The geometry and placement of the electrodes can be used to design electric fields of varying distributions, which can be readily realized by Micro-Electro-Mechanical Systems (MEMS fabrication methods. In this paper, we examine several electrically driven liquid handling operations. The emphasis is given to non-linear electrohydrodynamic effects. We discuss the theoretical treatment and related numerical methods. Modeling and simulations are used to unveil the associated electrohydrodynamic phenomena. The modeling based investigation is interwoven with examples of microfluidic devices to illustrate the applications.

  10. Integrated Microfluidics for Protein Modification Discovery*

    Science.gov (United States)

    Noach-Hirsh, Meirav; Nevenzal, Hadas; Glick, Yair; Chorni, Evelin; Avrahami, Dorit; Barbiro-Michaely, Efrat; Gerber, Doron; Tzur, Amit

    2015-01-01

    Protein post-translational modifications mediate dynamic cellular processes with broad implications in human disease pathogenesis. There is a large demand for high-throughput technologies supporting post-translational modifications research, and both mass spectrometry and protein arrays have been successfully utilized for this purpose. Protein arrays override the major limitation of target protein abundance inherently associated with MS analysis. This technology, however, is typically restricted to pre-purified proteins spotted in a fixed composition on chips with limited life-time and functionality. In addition, the chips are expensive and designed for a single use, making complex experiments cost-prohibitive. Combining microfluidics with in situ protein expression from a cDNA microarray addressed these limitations. Based on this approach, we introduce a modular integrated microfluidic platform for multiple post-translational modifications analysis of freshly synthesized protein arrays (IMPA). The system's potency, specificity and flexibility are demonstrated for tyrosine phosphorylation and ubiquitination in quasicellular environments. Unlimited by design and protein composition, and relying on minute amounts of biological material and cost-effective technology, this unique approach is applicable for a broad range of basic, biomedical and biomarker research. PMID:26276765

  11. Accelerating Yeast Prion Biology using Droplet Microfluidics

    Science.gov (United States)

    Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David

    2012-02-01

    Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

  12. Microfluidic Screening of Electric Fields for Electroporation

    Science.gov (United States)

    Garcia, Paulo A.; Ge, Zhifei; Moran, Jeffrey L.; Buie, Cullen R.

    2016-02-01

    Electroporation is commonly used to deliver molecules such as drugs, proteins, and/or DNA into cells, but the mechanism remains poorly understood. In this work a rapid microfluidic assay was developed to determine the critical electric field threshold required for inducing bacterial electroporation. The microfluidic device was designed to have a bilaterally converging channel to amplify the electric field to magnitudes sufficient to induce electroporation. The bacterial cells are introduced into the channel in the presence of SYTOX®, which fluorescently labels cells with compromised membranes. Upon delivery of an electric pulse, the cells fluoresce due to transmembrane influx of SYTOX® after disruption of the cell membranes. We calculate the critical electric field by capturing the location within the channel of the increase in fluorescence intensity after electroporation. Bacterial strains with industrial and therapeutic relevance such as Escherichia coli BL21 (3.65 ± 0.09 kV/cm), Corynebacterium glutamicum (5.20 ± 0.20 kV/cm), and Mycobacterium smegmatis (5.56 ± 0.08 kV/cm) have been successfully characterized. Determining the critical electric field for electroporation facilitates the development of electroporation protocols that minimize Joule heating and maximize cell viability. This assay will ultimately enable the genetic transformation of bacteria and archaea considered intractable and difficult-to-transfect, while facilitating fundamental genetic studies on numerous diverse microbes.

  13. Microfluidic chips for protein differential expression profiling.

    Science.gov (United States)

    Armenta, Jenny M; Dawoud, Abdulilah A; Lazar, Iulia M

    2009-04-01

    Biomarker discovery and screening using novel proteomic technologies is an area that is attracting increased attention in the biomedical community. Early detection of abnormal physiological conditions will be highly beneficial for diagnosing various diseases and increasing survivability rates. Clearly, progress in this area will depend on the development of fast, reliable, and highly sensitive and specific sample bioanalysis methods. Microfluidics has emerged as a technology that could become essential in proteomics research as it enables the integration of all sample preparation, separation, and detection steps, with the added benefit of enhanced sample throughput. The combination of these advantages with the sensitivity and capability of MS detection to deliver precise structural information makes microfluidics-MS a very competitive technology for biomarker discovery. The integration of LC microchip devices with MS detection, and specifically their applicability to biomarker screening applications in MCF-7 breast cancer cellular extracts is reported in this manuscript. Loading approximately 0.1-1 microg of crude protein extract tryptic digest on the chip has typically resulted in the reliable identification of approximately 40-100 proteins. The potential of an LC-ESI-MS chip for comparative proteomic analysis of isotopically labeled MCF-7 breast cancer cell extracts is explored for the first time.

  14. Integrated Microfluidics for Protein Modification Discovery.

    Science.gov (United States)

    Noach-Hirsh, Meirav; Nevenzal, Hadas; Glick, Yair; Chorni, Evelin; Avrahami, Dorit; Barbiro-Michaely, Efrat; Gerber, Doron; Tzur, Amit

    2015-10-01

    Protein post-translational modifications mediate dynamic cellular processes with broad implications in human disease pathogenesis. There is a large demand for high-throughput technologies supporting post-translational modifications research, and both mass spectrometry and protein arrays have been successfully utilized for this purpose. Protein arrays override the major limitation of target protein abundance inherently associated with MS analysis. This technology, however, is typically restricted to pre-purified proteins spotted in a fixed composition on chips with limited life-time and functionality. In addition, the chips are expensive and designed for a single use, making complex experiments cost-prohibitive. Combining microfluidics with in situ protein expression from a cDNA microarray addressed these limitations. Based on this approach, we introduce a modular integrated microfluidic platform for multiple post-translational modifications analysis of freshly synthesized protein arrays (IMPA). The system's potency, specificity and flexibility are demonstrated for tyrosine phosphorylation and ubiquitination in quasicellular environments. Unlimited by design and protein composition, and relying on minute amounts of biological material and cost-effective technology, this unique approach is applicable for a broad range of basic, biomedical and biomarker research.

  15. Microfluidics, Chromatography, and Atomic-Force Microscopy

    Science.gov (United States)

    Anderson, Mark

    2008-01-01

    A Raman-and-atomic-force microscope (RAFM) has been shown to be capable of performing several liquid-transfer and sensory functions essential for the operation of a microfluidic laboratory on a chip that would be used to perform rapid, sensitive chromatographic and spectro-chemical analyses of unprecedentedly small quantities of liquids. The most novel aspect of this development lies in the exploitation of capillary and shear effects at the atomic-force-microscope (AFM) tip to produce shear-driven flow of liquids along open microchannels of a microfluidic device. The RAFM can also be used to perform such functions as imaging liquids in microchannels; removing liquid samples from channels for very sensitive, tip-localized spectrochemical analyses; measuring a quantity of liquid adhering to the tip; and dip-pen deposition from a chromatographic device. A commercial Raman-spectroscopy system and a commercial AFM were integrated to make the RAFM so as to be able to perform simultaneous topographical AFM imaging and surface-enhanced Raman spectroscopy (SERS) at the AFM tip. The Raman-spectroscopy system includes a Raman microprobe attached to an optical microscope, the translation stage of which is modified to accommodate the AFM head. The Raman laser excitation beam, which is aimed at the AFM tip, has a wavelength of 785 nm and a diameter of about 5 m, and its power is adjustable up to 10 mW. The AFM is coated with gold to enable tip-localized SERS.

  16. Digital Microfluidic System with Vertical Functionality

    Directory of Open Access Journals (Sweden)

    Brian F. Bender

    2015-11-01

    Full Text Available Digital (droplet microfluidics (DµF is a powerful platform for automated lab-on-a-chip procedures, ranging from quantitative bioassays such as RT-qPCR to complete mammalian cell culturing. The simple MEMS processing protocols typically employed to fabricate DµF devices limit their functionality to two dimensions, and hence constrain the applications for which these devices can be used. This paper describes the integration of vertical functionality into a DµF platform by stacking two planar digital microfluidic devices, altering the electrode fabrication process, and incorporating channels for reversibly translating droplets between layers. Vertical droplet movement was modeled to advance the device design, and three applications that were previously unachievable using a conventional format are demonstrated: (1 solutions of calcium dichloride and sodium alginate were vertically mixed to produce a hydrogel with a radially symmetric gradient in crosslink density; (2 a calcium alginate hydrogel was formed within the through-well to create a particle sieve for filtering suspensions passed from one layer to the next; and (3 a cell spheroid formed using an on-chip hanging-drop was retrieved for use in downstream processing. The general capability of vertically delivering droplets between multiple stacked levels represents a processing innovation that increases DµF functionality and has many potential applications.

  17. Retinal synaptic regeneration via microfluidic guiding channels.

    Science.gov (United States)

    Su, Ping-Jung; Liu, Zongbin; Zhang, Kai; Han, Xin; Saito, Yuki; Xia, Xiaojun; Yokoi, Kenji; Shen, Haifa; Qin, Lidong

    2015-08-28

    In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demonstrated by administration of glycinergic factors. In addition, an image-based analytical method was used to quantify the synaptic connections and to assess the kinetics of synaptic regeneration. The rate of RSR decreased significantly below 100 μM of inhibitor glycine and then approached to a relatively constant level at higher concentrations. Furthermore, RSR was enhanced by chemical stimulation with potassium chloride. Collectively, the microfluidic synaptic regeneration chip provides a novel tool for high-throughput investigation of RSR at the cellular level and may be useful in quality control of retinal precursor cell transplantation.

  18. Microfluidic Fabrication of Conjugated Polymer Sensor Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Imsung; Song, Simon [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

  19. Microfluidic-chip platform for cell sorting

    Science.gov (United States)

    Malik, Sarul; Balyan, Prerna; Akhtar, J.; Agarwal, Ajay

    2016-04-01

    Cell sorting and separation are considered to be very crucial preparatory steps for numerous clinical diagnostics and therapeutics applications in cell biology research arena. Label free cell separation techniques acceptance rate has been increased to multifold by various research groups. Size based cell separation method focuses on the intrinsic properties of the cell which not only avoids clogging issues associated with mechanical and centrifugation filtration methods but also reduces the overall cost for the process. Consequentially flow based cell separation method for continuous flow has attracted the attention of millions. Due to the realization of structures close to particle size in micro dimensions, the microfluidic devices offer precise and rapid particle manipulation which ultimately leads to an extraordinary cell separation results. The proposed microfluidic device is fabricated to separate polystyrene beads of size 1 µm, 5 µm, 10 µm and 20 µm. The actual dimensions of blood corpuscles were kept in mind while deciding the particle size of polystyrene beads which are used as a model particles for study.

  20. Microfluidic Cell Cycle Analysis of Spread Cells by DAPI Staining

    OpenAIRE

    Jing Sun; Jiayu Zhang; Haibo Yang; Gongzhuo Wang; Yanzhao Li; Xuxin Zhang; Qidan Chen; Ming-Fei Lang

    2017-01-01

    Single-cell cell cycle analysis is an emerging technique that requires detailed exploration of the image analysis process. In this study, we established a microfluidic single-cell cell cycle analysis method that can analyze cells in small numbers and in situ on a microfluidic chip. In addition, factors that influenced the analysis were carefully investigated. U87 or HeLa cells were seeded and attached to microfluidic channels before measurement. Cell nucleic DNA was imaged by 4′-6-diamidino-2...

  1. Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells

    CERN Document Server

    Iliescu, Ciprian; Avram, Marioara; Xu, G; Avram, Andrei

    2008-01-01

    This paper presents a microfluidic device for magnetophoretic separation red blood cells from blood under contionous flow. The separation method consist of continous flow of a blood sample (diluted in PBS) through a microfluidic channel which presents on the bottom "dots" of feromagnetic layer. By appling a magnetic field perpendicular on the flowing direction, the feromagnetic "dots" generates a gradient of magnetic field which amplifies the magnetic force. As a result, the red blood cells are captured on the bottom of the microfluidic channel while the rest of the blood is collected at the outlet. Experimental results show that an average of 95 % of red blood cells are trapped in the device

  2. Digital Microfluidic Biochips: Recent Research and Emerging Challenges

    DEFF Research Database (Denmark)

    Ho, Tsung-Yi; Chakrabarty, Krishnendu; Pop, Paul

    2011-01-01

    Microfluidic biochips are replacing the conventional biochemical analyzers, and are able to integrate on-chip all the basic functions for biochemical analysis. The “digital” microfluidic biochips (DMFBs) are manipulating liquids not as a continuous flow, but as discrete droplets on a two......-dimensional array of electrodes. Basic microfluidic operations, such as mixing and dilution, are performed on the array, by routing the corresponding droplets on a series of electrodes. The challenges facing biochips are similar to those faced by microelectronics some decades ago. To meet the challenges...

  3. Reconfigurable microfluidic nanoparticle trapping using dielectrophoresis for chemical detection

    Science.gov (United States)

    Salemmilani, Reza; Piorek, Brian; Moskovits, Martin; Meinhart, Carl

    2016-11-01

    We report a microfluidic particle manipulation platform based on dielectrophoresis (DEP) to capture and release nanoscale particles cyclically via reconfigurable traps. DEP is routinely used in microfluidic devices for capturing and trapping cells and particles of various sizes, however the trapping of small nanoparticles by DEP is challenging due to the inverse relationship of the DEP force with particle size. The architecture we describe uses electrically insulating silica beads of micron scale in conjunction with DEP electrodes configured to manipulate nanoscale particles for microfluidic applications such as filtration and chemical detection. Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, United States.

  4. Microfluidic pneumatic logic circuits and digital pneumatic microprocessors for integrated microfluidic systems.

    Science.gov (United States)

    Rhee, Minsoung; Burns, Mark A

    2009-11-07

    We have developed pneumatic logic circuits and microprocessors built with microfluidic channels and valves in polydimethylsiloxane (PDMS). The pneumatic logic circuits perform various combinational and sequential logic calculations with binary pneumatic signals (atmosphere and vacuum), producing cascadable outputs based on Boolean operations. A complex microprocessor is constructed from combinations of various logic circuits and receives pneumatically encoded serial commands at a single input line. The device then decodes the temporal command sequence by spatial parallelization, computes necessary logic calculations between parallelized command bits, stores command information for signal transportation and maintenance, and finally executes the command for the target devices. Thus, such pneumatic microprocessors will function as a universal on-chip control platform to perform complex parallel operations for large-scale integrated microfluidic devices. To demonstrate the working principles, we have built 2-bit, 3-bit, 4-bit, and 8-bit microprocessors to control various target devices for applications such as four color dye mixing, and multiplexed channel fluidic control. By significantly reducing the need for external controllers, the digital pneumatic microprocessor can be used as a universal on-chip platform to autonomously manipulate microfluids in a high throughput manner.

  5. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  6. Ideal synchronizer for marked pairs in fork-join network

    CERN Document Server

    Vyshenski, S V; Dubenskaya, Yu Yu

    2008-01-01

    We introduce a new functional element (synchronizer for marked pairs) meant to join results of parallel processing in two-branch fork-join queueing network. Approximations for distribution of sojourn time at the synchronizer are derived along with a validity domain. Calculations are performed assuming that: arrivals to the network form a Poisson process, each branch operates like an M/M/N queueing system. It is shown that a mean quantity of jobs in the synchronizer is bounded below by the value, defined by parameters of the network (which contains the synchronizer) and does not depend upon performance and particular properties of the synchronizer.

  7. Characterization of Fluid Flow in Paper-Based Microfluidic Systems

    Science.gov (United States)

    Walji, Noosheen; MacDonald, Brendan

    2014-11-01

    Paper-based microfluidic devices have been presented as a viable low-cost alternative with the versatility to accommodate many applications in disease diagnosis and environmental monitoring. Current microfluidic designs focus on the use of silicone and PDMS structures, and several models have been developed to describe these systems; however, the design process for paper-based devices is hindered by a lack of prediction capability. In this work we simplify the complex underlying physics of the capillary-driven flow mechanism in a porous medium and generate a practical numerical model capable of predicting the flow behaviour. We present our key insights regarding the properties that dictate the behaviour of fluid wicking in paper-based microfluidic devices. We compare the results from our model to experiments and discuss the application of our model to design of paper-based microfluidic devices for arsenic detection in drinking water in Bangladesh.

  8. Isolation of cancer cells by "in situ" microfluidic biofunctionalization protocols

    DEFF Research Database (Denmark)

    De Vitis, Stefania; Matarise, Giuseppina; Pardeo, Francesca

    2014-01-01

    The aim of this work is the development of a microfluidic immunosensor for the immobilization of cancer cells and their separation from healthy cells by using "in situ" microfluidic biofunctionalization protocols. These protocols allow to link antibodies on microfluidic device surfaces and can...... for the isolation of cancer cells in heterogeneous blood samples by exploiting the binding of specific antibody to an adhesion protein (EpCAM), overexpressed on the tumor cell membranes. The presented biofunctionalization protocols can be performed right before running the experiment: this allows to have a flexible...... be used to study the interaction between cell membrane and biomolecules. Moreover they allow to perform analysis with high processing speed, small quantity of reagents and samples, short reaction times and low production costs. In this work the developed protocols were used in microfluidic devices...

  9. Microfluidic Assay to Quantify the Adhesion of Marine Bacteria

    National Research Council Canada - National Science Library

    Arpa-Sancet, M P; Christophis, C; Rosenhahn, A

    2012-01-01

    .... To determine the attachment strength of bacteria to coatings, a microfluidic adhesion assay has been developed which allows probing at which critical wall shear stress bacteria are removed from the surface...

  10. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  11. Microfluidic Cytometer for Complete Blood Count Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will fabricate and test microfluidic designs for a micro-electromechanical system based complete blood count (CBC) analysis in separate modules and integrate them...

  12. Synthesis of nanomaterials by continuous-flow microfluidics: A review

    CSIR Research Space (South Africa)

    Makgwane, PR

    2014-02-01

    Full Text Available -purpose batch reactor is masked with complications, on the other hand, the interface of nanomaterials synthesis processes and continuous-flow microfluidic chemistry has demonstrated relatively superior process performance over conventional technologies...

  13. Microfluidic cell chips for high-throughput drug screening.

    Science.gov (United States)

    Chi, Chun-Wei; Ahmed, Ah Rezwanuddin; Dereli-Korkut, Zeynep; Wang, Sihong

    2016-05-01

    The current state of screening methods for drug discovery is still riddled with several inefficiencies. Although some widely used high-throughput screening platforms may enhance the drug screening process, their cost and oversimplification of cell-drug interactions pose a translational difficulty. Microfluidic cell-chips resolve many issues found in conventional HTS technology, providing benefits such as reduced sample quantity and integration of 3D cell culture physically more representative of the physiological/pathological microenvironment. In this review, we introduce the advantages of microfluidic devices in drug screening, and outline the critical factors which influence device design, highlighting recent innovations and advances in the field including a summary of commercialization efforts on microfluidic cell chips. Future perspectives of microfluidic cell devices are also provided based on considerations of present technological limitations and translational barriers.

  14. Microfluidics for gametes, embryos, and embryonic stem cells.

    Science.gov (United States)

    Smith, G D; Swain, J E; Bormann, C L

    2011-01-01

    Microfluidics is a young but established field that holds significant potential for scientific discovery. The utility of microfluidics can improve our knowledge of basic biology as well as expand our understanding in specialized areas such as assisted reproduction and stem cell developmental biology. This review describes the technology of microfluidics and discusses applications within assisted reproduction technology and embryonic stem cell growth and directed differentiation. Development of an integrated microfluidic platform for assisted reproduction, which can manipulate gametes, embryos, embryonic stem cells, their culture environment, and incorporate biomarker analysis, could have a dramatic impact on the basic understanding of embryo/embryonic stem cell development, as well as provide significant improvements in current technologies used to treat infertility, preserve fertility, and derive therapeutic cells from stem cells.

  15. Opto-Microfluidic Immunosensors: From Colorimetric to Plasmonic

    Directory of Open Access Journals (Sweden)

    Jie-Long He

    2016-02-01

    Full Text Available Optical detection has long been the most popular technique in immunosensing. Recent developments in the synthesis of luminescent probes and the fabrication of novel nanostructures enable more sensitive and efficient optical detection, which can be miniaturized and integrated with microfluidics to realize compact lab-on-a-chip immunosensors. These immunosensors are portable, economical and automated, but their sensitivity is not compromised. This review focuses on the incorporation and implementation of optical detection and microfluidics in immunosensors; it introduces the working principles of each optical detection technique and how it can be exploited in immunosensing. The recent progress in various opto-microfluidic immunosensor designs is described. Instead of being comprehensive to include all opto-microfluidic platforms, the report centers on the designs that are promising for point-of-care immunosensing diagnostics, in which ease of use, stability and cost-effective fabrication are emphasized.

  16. Lithium Niobate Micromachining for the Fabrication of Microfluidic Droplet Generators

    Directory of Open Access Journals (Sweden)

    Giacomo Bettella

    2017-06-01

    Full Text Available In this paper, we present the first microfluidic junctions for droplet generation directly engraved on lithium niobate crystals by micromachining techniques, preparatory to a fully integrated opto-microfluidics lab-on-chip system. In particular, laser ablation technique and the mechanical micromachining technique are exploited to realise microfluidic channels in T- and cross junction configurations. The quality of both lateral and bottom surfaces of the channels are therefore compared together with a detailed study of their roughness measured by means of atomic force microscopy in order to evaluate the final performance achievable in an optofluidic device. Finally, the microfluidics performances of these water-in-oil droplets generators are investigated depending on these micromachining techniques, with particular focus on a wide range of droplet generation rates.

  17. Interface of nanocatalysis and microfluidic reactors for green chemistry methods

    CSIR Research Space (South Africa)

    Makgwane, PR

    2013-10-01

    Full Text Available The development of green catalytic methods for chemical synthesis and energy generation based on nanocoated catalyst microfluidic systems is a growing area of innovative research. The interface between heterogeneous catalysis and microchannel...

  18. Experimental and numerical studies of two-phase microfluidic flows

    CSIR Research Space (South Africa)

    Mbanjwa, MB

    2010-09-01

    Full Text Available Flow of immiscible fluids is important in microfluidics for applications such as generation of emulsions and vesicles, drug delivery capsules, cell encapsulation and chemical reactions. The behaviour of these flows differs from large scale flows...

  19. Cell mechanics through analysis of cell trajectories in microfluidic channel

    Science.gov (United States)

    Bowie, Samuel; Alexeev, Alexander; Sulchek, Todd

    The understanding of dynamic cell behavior can aid in research ranging from the mechanistic causes of diseases to the development of microfluidic devices for cancer detection. Through analysis of trajectories captured from video of the cells moving in a specially designed microfluidic device, insight into the dynamic viscoelastic nature of cells can be found. The microfluidic device distinguishes cells viscoelastic properties through the use of angled ridges causing a series of compressions, resulting in differences in trajectories based on cell stiffness. Trajectories of cell passing through the device are collected using image processing methods and data mining techniques are used to relate the trajectories to cell properties obtained from experiments. Furthermore, numerical simulation of the cell and microfluidic device are used to match the experimental results from the trajectory analysis. Combination of the modeling and experimental data help to uncover how changes in cellular structures result in changes in mechanical properties.

  20. Single-molecule emulsion PCR in microfluidic droplets.

    Science.gov (United States)

    Zhu, Zhi; Jenkins, Gareth; Zhang, Wenhua; Zhang, Mingxia; Guan, Zhichao; Yang, Chaoyong James

    2012-06-01

    The application of microfluidic droplet PCR for single-molecule amplification and analysis has recently been extensively studied. Microfluidic droplet technology has the advantages of compartmentalizing reactions into discrete volumes, performing highly parallel reactions in monodisperse droplets, reducing cross-contamination between droplets, eliminating PCR bias and nonspecific amplification, as well as enabling fast amplification with rapid thermocycling. Here, we have reviewed the important technical breakthroughs of microfluidic droplet PCR in the past five years and their applications to single-molecule amplification and analysis, such as high-throughput screening, next generation DNA sequencing, and quantitative detection of rare mutations. Although the utilization of microfluidic droplet single-molecule PCR is still in the early stages, its great potential has already been demonstrated and will provide novel solutions to today's biomedical engineering challenges in single-molecule amplification and analysis.

  1. Dynamic Interfacial Tension Measurements with Microfluidic Y-Junctions

    NARCIS (Netherlands)

    Steegmans, M.L.J.; Warmerdam, A.; Schroën, C.G.P.H.; Boom, R.M.

    2009-01-01

    Emulsification in microdevices (microfluidic emulsification) involves micrometer-sized droplets and fast interface expansion rates. In addition, droplets are formed in less than milliseconds, and therefore traditional tensiometric techniques cannot be used to quantify the actual interfacial tension.

  2. Collective waves in dense and confined microfluidic droplet arrays

    Science.gov (United States)

    Schiller, Ulf D.; Fleury, Jean-Baptiste; Seemann, Ralf; Gompper, Gerhard

    Excitation mechanisms for collective waves in confined dense one-dimensional microfluidic droplet arrays are investigated by experiments and computer simulations. We demonstrate that distinct modes can be excited by creating specific `defect' patterns in flowing droplet trains. Excited longitudinal modes exhibit a short-lived cascade of pairs of laterally displacing droplets. Transversely excited modes obey the dispersion relation of microfluidic phonons and induce a coupling between longitudinal and transverse modes, whose origin is the hydrodynamic interaction of the droplets with the confining walls. Moreover, we investigate the long-time behaviour of the oscillations and discuss possible mechanisms for the onset of instabilities. Our findings demonstrate that the collective dynamics of microfluidic droplet ensembles can be studied particularly well in dense and confined systems. Experimentally, the ability to control microfluidic droplets may allow to modulate the refractive index of optofluidic crystals which is a promising approach for the production of dynamically programmable metamaterials.

  3. Integration of microfluidics into the synthetic biology design flow.

    Science.gov (United States)

    Huang, Haiyao; Densmore, Douglas

    2014-09-21

    One goal of synthetic biology is to design and build genetic circuits in living cells for a range of applications. Major challenges in these efforts include increasing the scalability and robustness of engineered biological systems and streamlining and automating the synthetic biology workflow of specification-design-assembly-verification. We present here a summary of the advances in microfluidic technology, particularly microfluidic large scale integration, that can be used to address the challenges facing each step of the synthetic biology workflow. Microfluidic technologies allow precise control over the flow of biological content within microscale devices, and thus may provide more reliable and scalable construction of synthetic biological systems. The integration of microfluidics and synthetic biology has the capability to produce rapid prototyping platforms for characterization of genetic devices, testing of biotherapeutics, and development of biosensors.

  4. Novel Polymer Microfluidics Technology for In Situ Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop a new polymer based microfluidics technology for NASA planetary science applications. In particular, we will design, build and...

  5. Four Thruster Microfluidic Electrospray Propulsion (MEP) Cubesat Board Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cubesat Microfluidic Electrospray Propulsion (MEP) system module prototype will be designed, built and tested to demonstrate that a four MEP thruster system can...

  6. Compact and controlled microfluidic mixing and biological particle capture

    Science.gov (United States)

    Ballard, Matthew; Owen, Drew; Mills, Zachary Grant; Hesketh, Peter J.; Alexeev, Alexander

    2016-11-01

    We use three-dimensional simulations and experiments to develop a multifunctional microfluidic device that performs rapid and controllable microfluidic mixing and specific particle capture. Our device uses a compact microfluidic channel decorated with magnetic features. A rotating magnetic field precisely controls individual magnetic microbeads orbiting around the features, enabling effective continuous-flow mixing of fluid streams over a compact mixing region. We use computer simulations to elucidate the underlying physical mechanisms that lead to effective mixing and compare them with experimental mixing results. We study the effect of various system parameters on microfluidic mixing to design an efficient micromixer. We also experimentally and numerically demonstrate that orbiting microbeads can effectively capture particles transported by the fluid, which has major implications in pre-concentration and detection of biological particles including various cells and bacteria, with applications in areas such as point-of-care diagnostics, biohazard detection, and food safety. Support from NSF and USDA is gratefully acknowledged.

  7. Microfluidic Cytometer for Complete Blood Count Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — RMD proposes to develop a MEMS based complete blood count (CBC) instrument that can be used aboard a spacecraft. We will produce a microfluidic scale combination...

  8. Synthesis and Manipulation of Semiconductor Nanocrystals in Microfluidic Reactors

    OpenAIRE

    Chan, Emory Ming-Yue

    2006-01-01

    Microfluidic reactors are investigated as a mechanism to control the growth of semiconductor nanocrystals and characterize the structural evolution of colloidal quantum dots. Due to their short diffusion lengths, low thermal masses, and predictable fluid dynamics, microfluidic devices can be used to quickly and reproducibly alter reaction conditions such as concentration, temperature, and reaction time, while allowing for rapid reagent mixing and product characterization. These features ...

  9. Screening of Aptamers on Microfluidic Systems for Clinical Applications

    OpenAIRE

    Gwo-Bin Lee; Chao-Jyun Huang; Chen-Hsun Weng

    2012-01-01

    The use of microfluidic systems for screening of aptamers and their biomedical applications are reviewed in this paper. Aptamers with different nucleic acid sequences have been extensively studied and the results demonstrated a strong binding affinity to target molecules such that they can be used as promising candidate biomarkers for diagnosis and therapeutics. Recently, the aptamer screening protocol has been conducted with microfluidic-based devices. Furthermore, aptamer affinity screening...

  10. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    OpenAIRE

    Mauk, Michael G.; Changchun Liu; Jinzhao Song; Bau, Haim H.

    2015-01-01

    Microfluidic components and systems for rapid (<60 min), low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs) are described. A microfluidic point-of-care (POC) diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (poly...

  11. Disposable world-to-chip interface for digital microfluidics

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, R. Michael; Shah, Gaurav; Keng, Pei-Yuin

    2017-05-16

    The present disclosure sets forth incorporating microfluidic chips interfaces for use with digital microfluidic processes. Methods and devices according to the present disclosure utilize compact, integrated platforms that interface with a chip upstream and downstream of the reaction, as well as between intermediate reaction steps if needed. In some embodiments these interfaces are automated, including automation of a multiple reagent process. Various reagent delivery systems and methods are also disclosed.

  12. Microfluidics and Nanofluidics Handbook Fabrication, Implementation, and Applications

    CERN Document Server

    Mitra, Sushanta K

    2011-01-01

    The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Finite Volume Method for Num

  13. Enhancing Single Molecule Imaging in Optofluidics and Microfluidics

    OpenAIRE

    Vasdekis, Andreas E.; Laporte, Gregoire P.J.

    2011-01-01

    Microfluidics and optofluidics have revolutionized high-throughput analysis and chemical synthesis over the past decade. Single molecule imaging has witnessed similar growth, due to its capacity to reveal heterogeneities at high spatial and temporal resolutions. However, both resolution types are dependent on the signal to noise ratio (SNR) of the image. In this paper, we review how the SNR can be enhanced in optofluidics and microfluidics. Starting with optofluidics, we outline integrated ph...

  14. 1D photonic crystal sensor integrated in a microfluidic system

    DEFF Research Database (Denmark)

    Nunes, Pedro; Mortensen, Asger; Kutter, Jörg Peter

    2009-01-01

    A refractive index sensor was designed as a 1D resonator incorporated in a microfluidic channel, where aqueous solutions were injected. A sensitivity of 480 nm/RIU and a minimum difference of Deltan = 0.002 were determined.......A refractive index sensor was designed as a 1D resonator incorporated in a microfluidic channel, where aqueous solutions were injected. A sensitivity of 480 nm/RIU and a minimum difference of Deltan = 0.002 were determined....

  15. Direct digital manufacturing of autonomous centrifugal microfluidic device

    Science.gov (United States)

    Ukita, Yoshiaki; Takamura, Yuzuru; Utsumi, Yuichi

    2016-06-01

    This paper presents strategies that attempt to solve two key problems facing the commercialization of microfluidics: cost reduction in microfluidic chip manufacturing and microfluidic device driver development. To reduce the cost of microfluidic chip manufacturing, we propose to use of three-dimensional (3D) printers for direct digital manufacturing (DDM). An evaluation of 3D micro-scale structure printing using several 3D printers is reported, and some of the technical issues to be addressed in the future are suggested. To evaluate micro-scale printing, three types of 3D printers, with the ability to print structures on the scale of several hundred meters, were selected by first screening six 3D printers. Line and space patterns with line widths of 100-500 µm and an aspect ratio of one were printed and evaluated. The estimated critical dimension was around 200 µm. The manufacturing of a monolithic microfluidic chip with embedded channels was also demonstrated. Monolithic microfluidic chips with embedded microchannels having 500 × 500 and 250 × 250 µm2 cross sections and 2-20 mm lengths were printed, and the fidelity of the channel shape, residual supporting material, and flow of liquid water were evaluated. The liquid flow evaluation showed that liquid water could flow through all of the microchannels with the 500 × 500 µm2 cross section, whereas this was not possible through some of the channels with the 250 × 250 µm2 cross section because of the residual resin or supporting material. To reduce the device-driver cost, we propose to use of the centrifugal microfluidic concept. An autonomous microfluidic device that could implement sequential flow control under a steadily rotating condition was printed. Four-step flow injection under a steadily rotating condition at 1500 rpm was successfully demonstrated without any external triggering such as changing the rotational speed.

  16. "Microcanals" for micropipette access to single cells in microfluidic environments.

    Science.gov (United States)

    Hsu, Chia-Hsien; Chen, Chihchen; Folch, Albert

    2004-10-01

    We demonstrate the fabrication and operation of "microcanals"(i.e. open-air microfluidic channels without a roof), which enable micropipette manipulation and probing of cells within a microfluidic environment. The microcanal devices are fabricated in PDMS on glass substrates using a PDMS membrane transferring technique. Here we show patch-clamp electrophysiological recording and intracellular dye injection performed on cells seeded in microcanals.

  17. A Microfluidic Device for Spatiotemporal Delivery of Stimuli to Cells

    Directory of Open Access Journals (Sweden)

    Zubaidah Ningsih

    2015-03-01

    Full Text Available Living cells encounter many stimuli from the immediate environment. Receptors recognize these environmental cues and transduce signals to produce cell responses. The frequency of a signal is now emerging as an important factor determining cell responses. As a componentry system in understanding temporal stimulation, microfluidic devices allow the observation of cell behaviour under dynamic stimulation and controllable environment. In this paper we describe the design, construction and characterization of a microfluidic device suitable for cell stimulation studies.

  18. Droplet-based microfluidic method for synthesis of microparticles

    CSIR Research Space (South Africa)

    Mbanjwa, MB

    2012-10-01

    Full Text Available Droplet-based microfluidics has, in recent years, received increased attention as an important tool for performing numerous methods in modern day chemistry and biology such as the synthesis of hydrogel microparticles. Hydrogels have been used in many..., in recent years, received increased attention as an important tool for performing numerous methods in modern day chemistry and biology, such as synthesis of hydrogel microparticles. CONCLUSION AND OUTLOOK The droplet-based microfluidic method offers...

  19. Optical two-beam traps in microfluidic systems

    DEFF Research Database (Denmark)

    Berg-Sørensen, Kirstine

    2016-01-01

    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast...... written waveguides and in an injection molded polymer chip with grooves for optical fibers. (C) 2016 The Japan Society of Applied Physics....

  20. Microfluidics as a functional tool for cell mechanics.

    Science.gov (United States)

    Vanapalli, Siva A; Duits, Michel H G; Mugele, Frieder

    2009-01-05

    Living cells are a fascinating demonstration of nature's most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax-thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remodeling of the cytoskeleton. To understand this intricate coupling between mechanical properties, mechanical function and force-induced biochemical signaling requires tools that are capable of both controlling and manipulating the cell microenvironment and measuring the resulting mechanical response. In this review, the power of microfluidics as a functional tool for research in cell mechanics is highlighted. In particular, current literature is discussed to show that microfluidics powered by soft lithographic techniques offers the following capabilities that are of significance for understanding the mechanical behavior of cells: (i) Microfluidics enables the creation of in vitro models of physiological environments in which cell mechanics can be probed. (ii) Microfluidics is an excellent means to deliver physical cues that affect cell mechanics, such as cell shape, fluid flow, substrate topography, and stiffness. (iii) Microfluidics can also expose cells to chemical cues, such as growth factors and drugs, which alter their mechanical behavior. Moreover, these chemical cues can be delivered either at the whole cell or subcellular level. (iv) Microfluidic devices offer the possibility of measuring the intrinsic mechanical properties of cells in a high throughput fashion. (v) Finally, microfluidic methods provide exquisite control over drop size, generation, and manipulation. As a result, droplets are being increasingly used to control the physicochemical environment of cells and as biomimetic analogs of living cells. These powerful attributes of microfluidics should further stimulate novel means of investigating the link between physicochemical cues and the biomechanical

  1. Centrifugal microfluidic platforms: advanced unit operations and applications.

    Science.gov (United States)

    Strohmeier, O; Keller, M; Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N

    2015-10-01

    Centrifugal microfluidics has evolved into a mature technology. Several major diagnostic companies either have products on the market or are currently evaluating centrifugal microfluidics for product development. The fields of application are widespread and include clinical chemistry, immunodiagnostics and protein analysis, cell handling, molecular diagnostics, as well as food, water, and soil analysis. Nevertheless, new fluidic functions and applications that expand the possibilities of centrifugal microfluidics are being introduced at a high pace. In this review, we first present an up-to-date comprehensive overview of centrifugal microfluidic unit operations. Then, we introduce the term "process chain" to review how these unit operations can be combined for the automation of laboratory workflows. Such aggregation of basic functionalities enables efficient fluidic design at a higher level of integration. Furthermore, we analyze how novel, ground-breaking unit operations may foster the integration of more complex applications. Among these are the storage of pneumatic energy to realize complex switching sequences or to pump liquids radially inward, as well as the complete pre-storage and release of reagents. In this context, centrifugal microfluidics provides major advantages over other microfluidic actuation principles: the pulse-free inertial liquid propulsion provided by centrifugal microfluidics allows for closed fluidic systems that are free of any interfaces to external pumps. Processed volumes are easily scalable from nanoliters to milliliters. Volume forces can be adjusted by rotation and thus, even for very small volumes, surface forces may easily be overcome in the centrifugal gravity field which enables the efficient separation of nanoliter volumes from channels, chambers or sensor matrixes as well as the removal of any disturbing bubbles. In summary, centrifugal microfluidics takes advantage of a comprehensive set of fluidic unit operations such as

  2. Clear Castable Polyurethane Elastomer for Fabrication of Microfluidic Devices

    Science.gov (United States)

    Domansky, Karel; Leslie, Daniel C.; McKinney, James; Fraser, Jacob P.; Sliz, Josiah D.; Hamkins-Indik, Tiama; Hamilton, Geraldine A.; Bahinski, Anthony; Ingber, Donald E.

    2013-01-01

    Polydimethylsiloxane (PDMS) has numerous desirable properties for fabricating microfluidic devices, including optical transparency, flexibility, biocompatibility, and fabrication by casting; however, partitioning of small hydrophobic molecules into the bulk of PDMS hinders industrial acceptance of PDMS microfluidic devices for chemical processing and drug development applications. Here we describe an attractive alternative material that is similar to PDMS in terms of optical transparency, flexibility and castability, but that is also resistant to absorption of small hydrophobic molecules. PMID:23954953

  3. Microfluidic Impedance Flow Cytometry Enabling High-Throughput Single-Cell Electrical Property Characterization

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2015-04-01

    Full Text Available This article reviews recent developments in microfluidic impedance flow cytometry for high-throughput electrical property characterization of single cells. Four major perspectives of microfluidic impedance flow cytometry for single-cell characterization are included in this review: (1 early developments of microfluidic impedance flow cytometry for single-cell electrical property characterization; (2 microfluidic impedance flow cytometry with enhanced sensitivity; (3 microfluidic impedance and optical flow cytometry for single-cell analysis and (4 integrated point of care system based on microfluidic impedance flow cytometry. We examine the advantages and limitations of each technique and discuss future research opportunities from the perspectives of both technical innovation and clinical applications.

  4. Microfluidic impedance flow cytometry enabling high-throughput single-cell electrical property characterization.

    Science.gov (United States)

    Chen, Jian; Xue, Chengcheng; Zhao, Yang; Chen, Deyong; Wu, Min-Hsien; Wang, Junbo

    2015-04-29

    This article reviews recent developments in microfluidic impedance flow cytometry for high-throughput electrical property characterization of single cells. Four major perspectives of microfluidic impedance flow cytometry for single-cell characterization are included in this review: (1) early developments of microfluidic impedance flow cytometry for single-cell electrical property characterization; (2) microfluidic impedance flow cytometry with enhanced sensitivity; (3) microfluidic impedance and optical flow cytometry for single-cell analysis and (4) integrated point of care system based on microfluidic impedance flow cytometry. We examine the advantages and limitations of each technique and discuss future research opportunities from the perspectives of both technical innovation and clinical applications.

  5. Development of Droplet Microfluidics Enabling High-Throughput Single-Cell Analysis

    Directory of Open Access Journals (Sweden)

    Na Wen

    2016-07-01

    Full Text Available This article reviews recent developments in droplet microfluidics enabling high-throughput single-cell analysis. Five key aspects in this field are included in this review: (1 prototype demonstration of single-cell encapsulation in microfluidic droplets; (2 technical improvements of single-cell encapsulation in microfluidic droplets; (3 microfluidic droplets enabling single-cell proteomic analysis; (4 microfluidic droplets enabling single-cell genomic analysis; and (5 integrated microfluidic droplet systems enabling single-cell screening. We examine the advantages and limitations of each technique and discuss future research opportunities by focusing on key performances of throughput, multifunctionality, and absolute quantification.

  6. Droplet Microfluidics for Chip-Based Diagnostics

    Directory of Open Access Journals (Sweden)

    Karan V. I. S. Kaler

    2014-12-01

    Full Text Available Droplet microfluidics (DMF is a fluidic handling technology that enables precision control over dispensing and subsequent manipulation of droplets in the volume range of microliters to picoliters, on a micro-fabricated device. There are several different droplet actuation methods, all of which can generate external stimuli, to either actively or passively control the shape and positioning of fluidic droplets over patterned substrates. In this review article, we focus on the operation and utility of electro-actuation-based DMF devices, which utilize one or more micro-/nano-patterned substrates to facilitate electric field-based handling of chemical and/or biological samples. The underlying theory of DMF actuations, device fabrication methods and integration of optical and opto-electronic detectors is discussed in this review. Example applications of such electro-actuation-based DMF devices have also been included, illustrating the various actuation methods and their utility in conducting chip-based laboratory and clinical diagnostic assays.

  7. From Single Microparticles to Microfluidic Emulsification

    DEFF Research Database (Denmark)

    Kinoshita, K.; Ortiz, Elisa Parra; Hussein, Abdirazak

    2016-01-01

    level, the micropipette technique was used to form and characterize the encapsulation of Ibuprofen (Ibp) into poly(lactic-co-glycolic acid) (PLGA) microspheres from dichloromethane (DCM) solutions, measuring the loading capacity and solubility limits of Ibp in typical PLGA microspheres. Formed...... time of pure Ibp microspheres in the buffer or in detergent micelle solutions, as a function of the microsphere size and compare that to calculated dissolution times using the Epstein-Plesset (EP) model. Single, pure Ibp microparticles precipitated as liquid phase microdroplets that then gradually......) micelles was directly visualized microscopically for the first time by the micropipette technique, showing that such micellization could increase the solubility of Ibp from 4 to 80 mM at 100 mM SDS. We also introduce a particular microfluidic device that has recently been used to make PLGA microspheres...

  8. Digital Microfluidics for Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Beatriz Coelho

    2017-06-01

    Full Text Available Digital Microfluidics (DMF has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.

  9. Microfluidic Flow of Cholesteric Liquid Crystals

    CERN Document Server

    Wiese, Oliver; Henrich, Oliver

    2016-01-01

    We explore the rheology and flow-induced morphological changes of cholesteric liquid crystal patterns subject to Poiseuille flow within a slab geometry, and under different anchoring conditions at the wall. Our focus is particularly on the behaviour of Cholesteric Fingers of the first kind and of Blue Phase II. Depending on the applied pressure gradient, we observe a number of dynamic regimes with different rheological properties. Our results provide the first insight into the flow response of cholesteric phases with fully two- or three-dimensional director field patterns and normal and planar degenerate anchoring conditions as commonly realised in experiments. They are also of high relevance for a fundamental understanding of complex liquid crystals in confinement and an important step towards future microfluidic applications that are based on cholesteric liquid crystals.

  10. On the Quantification of Mixing in Microfluidics

    CERN Document Server

    Hashmi, Ali

    2016-01-01

    Methods for quantifying mixing in microfluidics have varied largely in the past, and various indices have been employed to represent the extent of mixing. Mixing between two or more colored liquids is usually quantified using simple mathematical functions operated over a sequence of images. The function, usually termed mixing indices, involves a measure of standard deviation. Here, we first review some mixing indices and then experimentally verify the index most representative of a mixing event. It is observed that the relative mixing index is not affected by the lighting conditions, unlike other known mixing indices. Based on this finding, the use of a relative mixing index is advocated for further use in the lab-on-a-chip community for quantifying mixing events.

  11. Reversible Dialysis in a Microfluidic Formulator.

    Science.gov (United States)

    Selimovic, Seila; Shim, Jung-Uk; Fraden, Seth

    2006-03-01

    In order to facilitate the screening of conditions for protein crystallization, we have been using the Microfluidic Formulator chip (Stephen Quake, PNAS Vol. 101, 40 ). This PDMS device allows us to mix up to 40 different reagents and protein solutions. We use this combinatorial approach along with a ``drop-on-demand'' method whereby we employ on-chip positive displacement pumps to form aqueous droplets containing protein and separate them by plugs of oil. Subsequently, the aqueous drops containing protein are guided by surface tension forces into storage chambers. To control the chemical potential of these sub-nanoliter protein samples, we fabricate reservoirs underneath the storage compartments. A thin PDMS membrane that is permeable to water, but not to protein or salt, separates the reservoirs from the storage chambers. Water can permeate into or out of the stored samples until the chemical potentials of the reservoir and the protein solution are equal leading to protein crystallization in some chambers.

  12. Fabrication of Microfluidic Fiber Chip Detection System

    Institute of Scientific and Technical Information of China (English)

    Bo Su; Da-fu Cui; Chang-chun Liu; Xing Chen

    2006-01-01

    The diameter of the excitation beam was decreased greatly by integrating the fiber on the microfluidic chip as light propagation medium. The coupling efficiency of the fiber was improved with optical fiber collimation device coupling beam.The chip was placed in the darkroom to avoid the interference of the external light. The cost of the instrument was decreased with a high brightness blue LED as excitation source; the performance of the system was valuated by the determination of FITC fluorescein with a minimum detectable concentration of 2.2×10-8 mol/L, the Signal-to-Noise Ratio (SNR) S/N=5. The correlation coefficient of the detection system within the range of 1.8 × 10-7 mol/L~ 4 × 10-5mol/L was 0.9972.

  13. Microfluidic flow of cholesteric liquid crystals.

    Science.gov (United States)

    Wiese, Oliver; Marenduzzo, Davide; Henrich, Oliver

    2016-11-16

    We explore the rheology and flow-induced morphological changes of cholesteric liquid crystal patterns subject to Poiseuille flow within a slab geometry, and under different anchoring conditions at the wall. Our focus is particularly on the behaviour of "Cholesteric Fingers of the first kind" and of Blue Phase II. Depending on the applied pressure gradient, we observe a number of dynamic regimes with different rheological properties. Our results provide the first insight into the flow response of cholesteric phases with fully two- or three-dimensional director field patterns and normal and planar degenerate anchoring conditions as commonly realised in experiments. They are also of high relevance for a fundamental understanding of complex liquid crystals in confinement and an important step towards future microfluidic applications that are based on cholesteric liquid crystals.

  14. Microfluidic immunomagnetic separation for enhanced bacterial detection

    DEFF Research Database (Denmark)

    Hoyland, James; Kunstmann-Olsen, Casper; Ahmed, Shakil

    A combined lab-on-a-chip approach combining immunomagnetic separation (IMS) and flow cytometry was developed for the enrichment and detection of salmonella contamination in food samples. Immunomagnetic beads were immobilized in chips consisting of long fractal meanders while contaminated samples...... to obtain maximum capturing efficiency. The effects of channel volume, path length and number of bends of microfluidic chip on IMS efficiency were also determined....... were flowed over them. After incubation the beads can be released for detection into the flow-cytometry chip. Immunomagnetic beads were prepared by using anti-Salmonella antibodies and magnetic beads (2.8μm). Both the synthesized and commercially available anti-Salmonella beads were used to capture...

  15. On the quantification of mixing in microfluidics.

    Science.gov (United States)

    Hashmi, Ali; Xu, Jie

    2014-10-01

    Methods for quantifying mixing in microfluidics have varied largely in the past, and various indices have been employed to represent the extent of mixing. Mixing between two or more colored liquids is usually quantified using simple mathematical functions operated over a sequence of images. The function, usually termed mixing indices, involves a measure of standard deviation. Here, we first review some mixing indices and then experimentally verify the index most representative of a mixing event. It is observed that the relative mixing index is not affected by the lighting conditions, unlike other known mixing indices. Based on this finding, the use of a relative mixing index is advocated for further use in the lab-on-a-chip community for quantifying mixing events. © 2014 Society for Laboratory Automation and Screening.

  16. Membrane-less microfiltration using inertial microfluidics.

    Science.gov (United States)

    Warkiani, Majid Ebrahimi; Tay, Andy Kah Ping; Guan, Guofeng; Han, Jongyoon

    2015-07-08

    Microfiltration is a ubiquitous and often crucial part of many industrial processes, including biopharmaceutical manufacturing. Yet, all existing filtration systems suffer from the issue of membrane clogging, which fundamentally limits the efficiency and reliability of the filtration process. Herein, we report the development of a membrane-less microfiltration system by massively parallelizing inertial microfluidics to achieve a macroscopic volume processing rates (~ 500 mL/min). We demonstrated the systems engineered for CHO (10-20 μm) and yeast (3-5 μm) cells filtration, which are two main cell types used for large-scale bioreactors. Our proposed system can replace existing filtration membrane and provide passive (no external force fields), continuous filtration, thus eliminating the need for membrane replacement. This platform has the desirable combinations of high throughput, low-cost, and scalability, making it compatible for a myriad of microfiltration applications and industrial purposes.

  17. Engineering particle morphology with microfluidic droplets

    Science.gov (United States)

    Kang, Zhanxiao; Kong, Tiantian; Lei, Leyan; Zhu, Pingan; Tian, Xiaowei; Wang, Liqiu

    2016-07-01

    The controlled generation of microparticles with non-spherical features is of increasing importance. Such particles are useful for fundamental studies in areas such as self-assembly, as well as biomedical applications from drug carriers to photonic devices. We propose a simple model that captures the dominating factors controlling the size and morphology of non-spherical particles from phase separated droplets. The validity of our model is verified by comparing the generated non-spherical microparticles by droplet microfluidics. This simple relationship between the dominating factors and the final morphologies enables the production of non-spherical particles with well-defined shapes and tightly-controlled dimensions for a variety of applications from drug delivery vehicles to structural materials.

  18. Microfluidic Lithography of Bioinspired Helical Micromotors.

    Science.gov (United States)

    Yu, Yunru; Shang, Luoran; Gao, Wei; Zhao, Ze; Wang, Huan; Zhao, Yuanjin

    2017-07-29

    Considerable efforts have been devoted to developing artificial micro/nanomotors that can convert energy into movement. A flow lithography integrated microfluidic spinning and spiraling system is developed for the continuous generation of bioinspired helical micromotors. Because the generation processes could be precisely tuned by adjusting the flow rates and the illuminating frequency, the length, diameter, and pitch of the helical micromotors were highly controllable. Benefiting from the fast online gelation and polymerization, the resultant helical micromotors could be imparted with Janus, triplex, and core-shell cross-sectional structures that have never been achieved by other methods. Owing to the spatially controlled encapsulation of functional nanoparticles in the microstructures, the helical micromotors can perform locomotion not only by magnetically actuated rotation or corkscrew motion but also through chemically powered catalytic reaction. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Digital Microfluidics: A New Paradigm for Radiochemistry

    Directory of Open Access Journals (Sweden)

    Pei Yuin Keng

    2015-12-01

    Full Text Available The emerging technology of digital microfluidics is opening up the possibility of performing radiochemistry at the microliter scale to produce tracers for positron emission tomography (PET labeled with fluorine-18 or other isotopes. Working at this volume scale not only reduces reagent costs but also improves specific activity (SA by reducing contamination by the stable isotope. This technology could provide a practical means to routinely prepare high-SA tracers for applications such as neuroimaging and could make it possible to routinely achieve high SA using synthesis strategies such as isotopic exchange. Reagent droplets are controlled electronically, providing high reliability, a compact control system, and flexibility for diverse syntheses with a single-chip design. The compact size may enable the development of a self-shielded synthesizer that does not require a hot cell. This article reviews the progress of this technology and its application to the synthesis of PET tracers.

  20. Douglas Weibel: using microfluidics for microbiology.

    Science.gov (United States)

    Brownlee, Christen

    2010-07-16

    The ubiquity of microorganisms is unparalleled in any other known organism. These creatures surround our outsides and colonize our insides, a fact that has been known for centuries. However, despite their prevalence and long study, many of their characteristics still remain largely unexplained, including how proteins organize within microbial cells and how microbes interact with each other and with their environments. Many of the techniques used to study microorganisms are nearly as old as the knowledge of microorganisms themselves. Seeking new ways to look at microbiology, Douglas Weibel, Ph.D., an assistant professor of biochemistry at the University of Wisconsin-Madison, turned to chemistry. He and his colleagues are using novel microfluidic methods to develop new ways to culture bacteria and small molecules to control the function of proteins in vivo. By combining chemistry with microbiology, Weibel and his team hope to shine new light on this old field.

  1. A microfluidic dialysis device for complex biological mixture SERS analysis

    KAUST Repository

    Perozziello, Gerardo

    2015-08-01

    In this paper, we present a microfluidic device fabricated with a simple and inexpensive process allowing rapid filtering of peptides from a complex mixture. The polymer microfluidic device can be used for sample preparation in biological applications. The device is fabricated by micromilling and solvent assisted bonding, in which a microdialysis membrane (cut-off of 12-14 kDa) is sandwiched in between an upper and a bottom microfluidic chamber. An external frame connects the microfluidic device to external tubes, microvalves and syringe pumps. Bonding strength and interface sealing are pneumatically tested. Microfluidic protocols are also described by using the presented device to filter a sample composed of specific peptides (MW 1553.73 Da, at a concentration of 1.0 ng/μl) derived from the BRCA1 protein, a tumor-suppressor molecule which plays a pivotal role in the development of breast cancer, and albumin (MW 66.5 kDa, at a concentration of 35 μg/μl), the most represented protein in human plasma. The filtered samples coming out from the microfluidic device were subsequently deposited on a SERS (surface enhanced Raman scattering) substrate for further analysis by Raman spectroscopy. By using this approach, we were able to sort the small peptides from the bigger and highly concentrated protein albumin and to detect them by using a label-free technique at a resolution down to 1.0 ng/μl.

  2. Microfluidics: A Groundbreaking Technology for PET Tracer Production?

    Directory of Open Access Journals (Sweden)

    Björn Wängler

    2013-07-01

    Full Text Available Application of microfluidics to Positron Emission Tomography (PET tracer synthesis has attracted increasing interest within the last decade. The technical advantages of microfluidics, in particular the high surface to volume ratio and resulting fast thermal heating and cooling rates of reagents can lead to reduced reaction times, increased synthesis yields and reduced by-products. In addition automated reaction optimization, reduced consumption of expensive reagents and a path towards a reduced system footprint have been successfully demonstrated. The processing of radioactivity levels required for routine production, use of microfluidic-produced PET tracer doses in preclinical and clinical imaging as well as feasibility studies on autoradiolytic decomposition have all given promising results. However, the number of microfluidic synthesizers utilized for commercial routine production of PET tracers is very limited. This study reviews the state of the art in microfluidic PET tracer synthesis, highlighting critical design aspects, strengths, weaknesses and presenting several characteristics of the diverse PET market space which are thought to have a significant impact on research, development and engineering of microfluidic devices in this field. Furthermore, the topics of batch- and single-dose production, cyclotron to quality control integration as well as centralized versus de-centralized market distribution models are addressed.

  3. Open-source, community-driven microfluidics with Metafluidics.

    Science.gov (United States)

    Kong, David S; Thorsen, Todd A; Babb, Jonathan; Wick, Scott T; Gam, Jeremy J; Weiss, Ron; Carr, Peter A

    2017-06-07

    Microfluidic devices have the potential to automate and miniaturize biological experiments, but open-source sharing of device designs has lagged behind sharing of other resources such as software. Synthetic biologists have used microfluidics for DNA assembly, cell-free expression, and cell culture, but a combination of expense, device complexity, and reliance on custom set-ups hampers their widespread adoption. We present Metafluidics, an open-source, community-driven repository that hosts digital design files, assembly specifications, and open-source software to enable users to build, configure, and operate a microfluidic device. We use Metafluidics to share designs and fabrication instructions for both a microfluidic ring-mixer device and a 32-channel tabletop microfluidic controller. This device and controller are applied to build genetic circuits using standard DNA assembly methods including ligation, Gateway, Gibson, and Golden Gate. Metafluidics is intended to enable a broad community of engineers, DIY enthusiasts, and other nontraditional participants with limited fabrication skills to contribute to microfluidic research.

  4. A microfluidic device with groove patterns for studying cellular behavior.

    Science.gov (United States)

    Chung, Bong Geun; Manbachi, Amir; Khademhosseini, Ali

    2007-01-01

    We describe a microfluidic device with microgrooved patterns for studying cellular behavior. This microfluidic platform consists of a top fluidic channel and a bottom microgrooved substrate. To fabricate the microgrooved channels, a top poly(dimethylsiloxane) (PDMS) mold containing the impression of the microfluidic channels was aligned and bonded to a microgrooved substrate. Using this device, mouse fibroblast cells were immobilized and patterned within microgrooved substrates (25, 50, 75, and 100 microm wide). To study apoptosis in a microfluidic device, media containing hydrogen peroxide, Annexin V, and propidium iodide was perfused into the fluidic channel for 2 hours. We found that cells exposed to the oxidative stress became apoptotic. These apoptotic cells were confirmed by Annexin V that bound to phosphatidylserine at the outer leaflet of the plasma membrane during the apoptosis process. Using this microfluidic device with microgrooved patterns, the apoptosis process was observed in real-time and analyzed by using an inverted microscope containing an incubation chamber (37 degrees C, 5% CO(2)). Therefore, this microfluidic device incorporated with microgrooved substrates could be useful for studying the cellular behavior and performing high-throughput drug screening.

  5. A gradient-generating microfluidic device for cell biology.

    Science.gov (United States)

    Chung, Bong Geun; Manbachi, Amir; Saadi, Wajeeh; Lin, Francis; Jeon, Noo Li; Khademhosseini, Ali

    2007-01-01

    The fabrication and operation of a gradient-generating microfluidic device for studying cellular behavior is described. A microfluidic platform is an enabling experimental tool, because it can precisely manipulate fluid flows, enable high-throughput experiments, and generate stable soluble concentration gradients. Compared to conventional gradient generators, poly(dimethylsiloxane) (PDMS)-based microfluidic devices can generate stable concentration gradients of growth factors with well-defined profiles. Here, we developed simple gradient-generating microfluidic devices with three separate inlets. Three microchannels combined into one microchannel to generate concentration gradients. The stability and shape of growth factor gradients were confirmed by fluorescein isothyiocyanate (FITC)-dextran with a molecular weight similar to epidermal growth factor (EGF). Using this microfluidic device, we demonstrated that fibroblasts exposed to concentration gradients of EGF migrated toward higher concentrations. The directional orientation of cell migration and motility of migrating cells were quantitatively assessed by cell tracking analysis. Thus, this gradient-generating microfluidic device might be useful for studying and analyzing the behavior of migrating cells.

  6. Collective oscillations and coupled modes in confined microfluidic droplet arrays

    Science.gov (United States)

    Schiller, Ulf D.; Fleury, Jean-Baptiste; Seemann, Ralf; Gompper, Gerhard

    Microfluidic droplets have a wide range of applications ranging from analytic assays in cellular biology to controlled mixing in chemical engineering. Ensembles of microfluidic droplets are interesting model systems for non-equilibrium many-body phenomena. When flowing in a microchannel, trains of droplets can form microfluidic crystals whose dynamics are governed by long-range hydrodynamic interactions and boundary effects. In this contribution, excitation mechanisms for collective waves in dense and confined microfluidic droplet arrays are investigated by experiments and computer simulations. We demonstrate that distinct modes can be excited by creating specific `defect' patterns in flowing droplet trains. While longitudinal modes exhibit a short-lived cascade of pairs of laterally displacing droplets, transversely excited modes form propagating waves that behave like microfluidic phonons. We show that the confinement induces a coupling between longitudinal and transverse modes. We also investigate the life time of the collective oscillations and discuss possible mechanisms for the onset of instabilities. Our results demonstrate that microfluidic phonons can exhibit effects beyond the linear theory, which can be studied particularly well in dense and confined systems. This work was supported by Deutsche Forschungsgemeinschaft under Grant No. SE 1118/4.

  7. Impact of Nutrient Restriction on the Structure of Listeria monocytogenes Biofilm Grown in a Microfluidic System

    Directory of Open Access Journals (Sweden)

    Tamazight Cherifi

    2017-05-01

    Full Text Available Biofilm formation by the pathogen Listeria monocytogenes is a major concern in food industries. The aim of this work was to elucidate the effect of nutrient limitation on both biofilm architecture and on the viability of the bacteria in microfluidic growth conditions. Biofilm formation by two L. monocytogenes strains was performed in a rich medium (BHI and in a 10-fold diluted BHI (BHI/10 at 30°C for 24 h by using both static conditions and the microfluidic system Bioflux. In dynamic conditions, biofilms grown in rich and poor medium showed significant differences as well in structure and in the resulting biovolume. In BHI/10, biofilm was organized in a knitted network where cells formed long chains, whereas in the rich medium, the observed structure was homogeneous cellular multilayers. Biofilm biovolume production in BHI/10 was significantly higher than in BHI in these dynamic conditions. Interestingly, biovolume of dead cells in biofilms formed under limited nutrient conditions (BHI/10 was significantly higher than in biofilms formed in the BHI medium. In the other hand, in static conditions, biofilm is organized in a multilayer cells and dispersed cells in a rich medium BHI and poor medium BHI/10 respectively. There was significantly more biomass in the rich medium compared to BHI/10 but no difference was noted in the dead/damaged subpopulation showing how L. monocytogenes biofilm could be affected by the growth conditions. This work demonstrated that nutrient concentration affects biofilm structure and the proportion of dead cells in biofilms under microfluidic condition. Our study also showed that limited nutrients play an important role in the structural stability of L. monocytogenes biofilm by enhancing cell death and liberating extracellular DNA.

  8. Mechanisms of mass transport during coalescence-induced microfluidic drop dilution

    Science.gov (United States)

    Wang, William S.; Vanapalli, Siva A.

    2016-10-01

    Confinement-guided coalescence of drops in microfluidic devices is an effective means to manipulate the composition of individual droplets. Recently, Sun et al. [Lab Chip 11, 3949 (2011), 10.1039/c1lc20709a] have shown that coalescence between a long moving plug and an array of parked droplets in a microfluidic network can be used to flexibly manipulate the composition of the static droplet arrays. However, the transport mechanisms underlying this complex dilution process have not been elucidated. In this study, we develop phenomenological models and perform particle-based numerical simulations to identify the key mass transfer mechanisms influencing the concentration profiles of drops during coalescence-induced drop dilution. Motivated by experimental observations, in the simulations we consider (i) advection within the moving plug, (ii) diffusion in the moving plug and parked droplets, (iii) fluid advection due to initiation of coalescence, and (iv) advection in the coalesced plug due to the continuous phase flowing through the gutters in noncircular microchannels. We find that the dilution process is dominated by diffusion, recirculation in the moving plug, and gutter-flow-induced advection, but is only weakly affected by coalescence-induced advection. We show that the control parameters regulating dilution can be divided into those influencing the duration of mass transfer (e.g., plug length and velocity) and those affecting the rate of mass transfer (e.g., diffusion and gutter-flow-induced advection). Finally, we demonstrate that our simulations are able to predict droplet concentration profiles in experiments. The results from this study will allow better design of drop dilution microfluidic devices. Furthermore, the identification of gutter-flow-induced advection as an alternative mass transfer mechanism in two-phase flows could potentially lead to more efficient means of oil recovery from droplets trapped in porous media.

  9. Microfluidic System for Solution Array Based Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Dougherty, G M; Tok, J B; Pannu, S S; Rose, K A

    2006-02-10

    The objective of this project is to demonstrate new enabling technology for multiplex biodetection systems that are flexible, miniaturizable, highly automated, low cost, and high performance. It builds on prior successes at LLNL with particle-based solution arrays, such as those used in the Autonomous Pathogen Detection System (APDS) successfully field deployed to multiple locations nationwide. We report the development of a multiplex solution array immunoassay based upon engineered metallic nanorod particles. Nanobarcodes{reg_sign} particles are fabricated by sequential electrodeposition of dissimilar metals within porous alumina templates, yielding optically encoded striping patterns that can be read using standard laboratory microscope optics and PC-based image processing software. The addition of self-assembled monolayer (SAM) coatings and target-specific antibodies allows each encoded class of nanorod particles to be directed against a different antigen target. A prototype assay panel directed against bacterial, viral, and soluble protein targets demonstrates simultaneous detection at sensitivities comparable to state of the art immunoassays, with minimal cross-reactivity. Studies have been performed to characterize the colloidal properties (zeta potential) of the suspended nanorod particles as a function of pH, the ionic strength of the suspending solution, and surface functionalization state. Additional studies have produced means for the non-contact manipulation of the particles, including the insertion of magnetic nickel stripes within the encoding pattern, and control via externally applied electromagnetic fields. Using the results of these studies, the novel Nanobarcodes{reg_sign} based assay was implemented in a prototype automated system with the sample processing functions and optical readout performed on a microfluidic card. The unique physical properties of the nanorod particles enable the development of integrated microfluidic systems for

  10. Probing cell mechanical properties with microfluidic devices

    Science.gov (United States)

    Rowat, Amy

    2012-02-01

    Exploiting flow on the micron-scale is emerging as a method to probe cell mechanical properties with 10-1000x advances in throughput over existing technologies. The mechanical properties of cells and the cell nucleus are implicated in a wide range of biological contexts: for example, the ability of white blood cells to deform is central to immune response; and malignant cells show decreased stiffness compared to benign cells. We recently developed a microfluidic device to probe cell and nucleus mechanical properties: cells are forced to deform through a narrow constrictions in response to an applied pressure; flowing cells through a series of constrictions enables us to probe the ability of hundreds of cells to deform and relax during flow. By tuning the constriction width so it is narrower than the width of the cell nucleus, we can specifically probe the effects of nuclear physical properties on whole cell deformability. We show that the nucleus is the rate-limiting step in cell passage: inducing a change in its shape to a multilobed structure results in cells that transit more quickly; increased levels of lamin A, a nuclear protein that is key for nuclear shape and mechanical stability, impairs the passage of cells through constrictions. We are currently developing a new class of microfluidic devices to simultaneously probe the deformability of hundreds of cell samples in parallel. Using the same soft lithography techniques, membranes are fabricated to have well-defined pore distribution, width, length, and tortuosity. We design the membranes to interface with a multiwell plate, enabling simultaneous measurement of hundreds of different samples. Given the wide spectrum of diseases where altered cell and nucleus mechanical properties are implicated, such a platform has great potential, for example, to screen cells based on their mechanical phenotype against a library of drugs.

  11. Microfluidics on liquid handling stations (μF-on-LHS): an industry compatible chip interface between microfluidics and automated liquid handling stations.

    Science.gov (United States)

    Waldbaur, Ansgar; Kittelmann, Jörg; Radtke, Carsten P; Hubbuch, Jürgen; Rapp, Bastian E

    2013-06-21

    We describe a generic microfluidic interface design that allows the connection of microfluidic chips to established industrial liquid handling stations (LHS). A molding tool has been designed that allows fabrication of low-cost disposable polydimethylsiloxane (PDMS) chips with interfaces that provide convenient and reversible connection of the microfluidic chip to industrial LHS. The concept allows complete freedom of design for the microfluidic chip itself. In this setup all peripheral fluidic components (such as valves and pumps) usually required for microfluidic experiments are provided by the LHS. Experiments (including readout) can be carried out fully automated using the hardware and software provided by LHS manufacturer. Our approach uses a chip interface that is compatible with widely used and industrially established LHS which is a significant advancement towards near-industrial experimental design in microfluidics and will greatly facilitate the acceptance and translation of microfluidics technology in industry.

  12. Automated microfluidic screening assay platform based on DropLab.

    Science.gov (United States)

    Du, Wen-Bin; Sun, Meng; Gu, Shu-Qing; Zhu, Ying; Fang, Qun

    2010-12-01

    This paper describes DropLab, an automated microfluidic platform for programming droplet-based reactions and screening in the nanoliter range. DropLab can meter liquids with picoliter-scale precision, mix multiple components sequentially to assemble composite droplets, and perform screening reactions and assays in linear or two-dimensional droplet array with extremely low sample and reagent consumptions. A novel droplet generation approach based on the droplet assembling strategy was developed to produce multicomponent droplets in the nanoliter to picoliter range with high controllability on the size and composition of each droplet. The DropLab system was built using a short capillary with a tapered tip, a syringe pump with picoliter precision, and an automated liquid presenting system. The tapered capillary was used for precise liquid metering and mixing, droplet assembling, and droplet array storage. Two different liquid presenting systems were developed based on the slotted-vial array design and multiwell plate design to automatically present various samples, reagents, and oil to the capillary. Using the tapered-tip capillary and the picoliter-scale precision syringe pump, the minimum unit of the droplet volume in the present system reached ~20 pL. Without the need of complex microchannel networks, various droplets with different size (20 pL-25 nL), composition, and sequence were automatically assembled, aiming to multiple screening targets by simply adjusting the types, volumes, and mixing ratios of aspirated liquids on demand. The utility of DropLab was demonstrated in enzyme inhibition assays, protein crystallization screening, and identification of trace reducible carbohydrates.

  13. Hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chips using positive temperature coefficient ceramic heater.

    Science.gov (United States)

    Wang, Xia; Zhang, Luyan; Chen, Gang

    2011-11-01

    As a self-regulating heating device, positive temperature coefficient ceramic heater was employed for hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chip because it supplied constant-temperature heating without electrical control circuits. To emboss a channel plate, a piece of poly(methyl methacrylate) plate was sandwiched between a template and a microscopic glass slide on a positive temperature coefficient ceramic heater. All the assembled components were pressed between two elastic press heads of a spring-driven press while a voltage was applied to the heater for 10 min. Subsequently, the embossed poly(methyl methacrylate) plate bearing negative relief of channel networks was bonded with a piece of poly(methyl methacrylate) cover sheet to obtain a complete microchip using a positive temperature coefficient ceramic heater and a spring-driven press. High quality microfluidic chips fabricated by using the novel embossing/bonding device were successfully applied in the electrophoretic separation of three cations. Positive temperature coefficient ceramic heater indicates great promise for the low-cost production of poly(methyl methacrylate) microchips and should find wide applications in the fabrication of other thermoplastic polymer microfluidic devices.

  14. Selection of Easily Accessible PCR- and Bio-Compatible Materials for Microfluidic Chips

    KAUST Repository

    Xiao, Kang

    2013-10-30

    Conventional fabrication of microfluidic chip is a complicated and time, effort and material consuming process. Consequently, due to high expenses, it has poor applicability for performing mass biological analysis by microfluidics. In this study, we repor

  15. A Microfluidics-HPLC/Differential Mobility Spectrometer Macromolecular Detection System for Human and Robotic Missions

    Science.gov (United States)

    Coy, S. L.; Killeen, K.; Han, J.; Eiceman, G. A.; Kanik, I.; Kidd, R. D.

    2011-01-01

    Our goal is to develop a unique, miniaturized, solute analyzer based on microfluidics technology. The analyzer consists of an integrated microfluidics High Performance Liquid Chromatographic chip / Differential Mobility Spectrometer (?HPLCchip/ DMS) detection system

  16. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-11-04

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax o

  17. Femtosecond laser fabrication for the integration of optical sensors in microfluidic lab-on-chip devices

    NARCIS (Netherlands)

    Osellame, R.; Martinez-Vazquez, R.; Dongre, C.; Dekker, R.; Hoekstra, H.J.W.M.; Ramponi, R.; Pollnau, M.; Cerullo, G.; Corkum, P.; Silvestri, de S.; Nelson, K.A.; Riedle, E.; Schoenlein, R.W.

    2009-01-01

    Femtosecond lasers enable the fabrication of both optical waveguides and buried microfluidic channels on a glass substrate. The waveguides are used to integrate optical detection in a commercial microfluidic lab-on-chip for capillary electrophoresis.

  18. Femtosecond laser fabrication for the integration of optical sensors in microfluidic lab-on-chip devices

    NARCIS (Netherlands)

    Osellame, R.; Martinez Vazquez, R.; Dongre, C.; Dekker, R.; Hoekstra, H.J.W.M.; Pollnau, M.; Ramponi, R.; Cerullo, G.

    2008-01-01

    Femtosecond lasers enable the fabrication of both optical waveguides and buried microfluidic channels on a glass substrate. The waveguides are used to integrate optical detection in a commercial microfluidic lab-on-chip for capillary electrophoresis

  19. A Microfluidics-HPLC/Differential Mobility Spectrometer Macromolecular Detection System for Human and Robotic Missions

    Science.gov (United States)

    Coy, S. L.; Killeen, K.; Han, J.; Eiceman, G. A.; Kanik, I.; Kidd, R. D.

    2011-01-01

    Our goal is to develop a unique, miniaturized, solute analyzer based on microfluidics technology. The analyzer consists of an integrated microfluidics High Performance Liquid Chromatographic chip / Differential Mobility Spectrometer (?HPLCchip/ DMS) detection system

  20. A centrifugal microfluidic platform for point-of-care diagnostic applications

    CSIR Research Space (South Africa)

    Hugo, S

    2014-02-01

    Full Text Available -of-care health diagnostics, environmental diagnostics and chemical and biological production. Microfluidic disc design, manufacture and assembly Centrifugal microfluidic disc devices can be designed using a computer aided design (CAD) program such as Solidworks...