Measuring Rapid Enzymatic Kinetics by Electrochemical Method in Droplet-Based Microfluidic Devices with Pneumatic Valves

Zuoyan Han; Wentao Li; Yanyi Huang; Bo Zheng

doi:10.1021/ac900811y

Measuring Rapid Enzymatic Kinetics by Electrochemical Method in Droplet-Based Microfluidic Devices with Pneumatic Valves

Analytical Chemistry ◽

10.1021/ac900811y ◽

2009 ◽

Vol 81 (14) ◽

pp. 5840-5845 ◽

Cited By ~ 99

Author(s):

Zuoyan Han ◽

Wentao Li ◽

Yanyi Huang ◽

Bo Zheng

Keyword(s):

Electrochemical Method ◽

Microfluidic Devices ◽

Enzymatic Kinetics ◽

Pneumatic Valves

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Transient Modelling of Pneumatic Valves in Centrifugal Microfluidic Devices

Volume 7: Fluids Engineering ◽

10.1115/imece2016-66386 ◽

2016 ◽

Author(s):

Michael R. Moon ◽

Lin Lin

Keyword(s):

Surface Tension ◽

Point Of Care ◽

Low Cost ◽

Microfluidic Devices ◽

Novel Technologies ◽

Fluid Handling ◽

Pneumatic Valves ◽

Microfluidic Valves ◽

And Control ◽

Micrometer Scale

Point of care medical instruments benefit from compact fluid handling systems in the microliter range. To handle fluid volumes this small, many novel technologies have been studied. Pneumatic valves offer advantages over other microfluidic valves, including robustness and low cost. These valves are used in centrifugal microfluidic devices, a very active area of research, and take advantage of pneumatic and centrifugal pressure to aliquot and control the flow of fluid. The physics of fluids at the micrometer scale are complex and modelling their behavior using CFD software is challenging. Representing adhesion, surface tension, and other multiphase interactions is critical to accurately model microfluidic behavior. Centrifugal devices must also consider Coriolis, centrifugal, and Euler effects. In this study, a pneumatic valve was designed and simulated using commercial CFD software. The device was also fabricated for verification of the simulation. The simulation demonstrated the multiphase interactions of fluid and air within the rotating device. In a transient analysis of the model, a 6 μl volume of water is held in stable equilibrium by a compressed volume of air at low RPM, while at a higher RPM, the fluid is observed to displace the compressed air as a result of Rayleigh-Taylor instability. Actual devices with comparable geometry were built and tested. The behavior of the valve predicted in the model was in agreement with experimental results produced from the actual devices. The results of the simulation captured the stabilizing effect of both pneumatic pressure and surface tension at low RPM, as well as the instability that results from increased centrifugal and Euler pressure at higher RPM.

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Pneumatic valves in folded 2D and 3D fluidic devices made from plastic films and tapes

Lab on a Chip ◽

10.1039/c4lc00173g ◽

2014 ◽

Vol 14 (10) ◽

pp. 1665-1668 ◽

Cited By ~ 20

Author(s):

Gregory A. Cooksey ◽

Javier Atencia

Keyword(s):

Microfluidic Devices ◽

Plastic Films ◽

Fluidic Devices ◽

Pneumatic Valves ◽

2D And 3D

Elastomeric valves integrated into foldable microfluidic devices built with tapes.

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Superhydrophilic Surfaces for Antifoqging and Antifouling Microfluidic Devices

JALA Journal of the Association for Laboratory Automation ◽

10.1016/j.jala.2009.10.012 ◽

2010 ◽

Vol 15 (2) ◽

pp. 114-119 ◽

Cited By ~ 54

Author(s):

Pragneshkumar Patel ◽

Chang K. Choi ◽

Dennis Desheng Meng

Keyword(s):

Microscopic Study ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Electrochemical Method ◽

Oxygen Plasma ◽

Fluorescent Proteins ◽

Microfluidic Devices ◽

Contact Angles ◽

Water Contact ◽

Superhydrophilic Surfaces

Superhydrophilic surfaces are investigated for their potential to provide antifogging and antifouling properties for microfluidic devices. Two types of exemplary superhydrophilic surfaces are prepared, including polyester films treated by oxygen plasma and indium tin oxide-coated glasses treated by an electrochemical method. The superhydrophilicity of the treated surfaces presented herein is confirmed by their near-zero water contact angles. Their corresponding antifogging and antifouling capability is examined. The fluorescence microscopic study has confirmed the significantly reduced adhesion of the fluorescein and fluorescent proteins after the surfaces are treated to be superhydrophilic, indicating their potential for antifouling applications. The degradation of the superhydrophilicity under different humidity conditions is also investigated.

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