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Field-effect pump: liquid dielectrophoresis along a virtual microchannel with source-gate-drain electric fields
Fu-Min Wang1, I-Pei Lu2, Chih-Ting Lin1
1Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan.
Lab on a Chip
|June 15, 2021
Summary
Field-effect pumps (FEPs) use liquid dielectrophoresis to create virtual microchannels for precise liquid transport. Flow rate is controlled by electric fields, enabling applications in microfluidics and beyond.
Area of Science:
- Microfluidics
- Electromechanics
- Physical Chemistry
Background:
- Traditional microfluidic systems often rely on external pumps, leading to issues like dead volume and complex setups.
- Liquid dielectrophoresis (LDEP) offers a novel approach for manipulating fluids at the microscale.
Purpose of the Study:
- To introduce and characterize field-effect pumps (FEPs) for pump-less liquid transport using LDEP.
- To demonstrate the tunable flow rate and operational regions of FEPs, analogous to field-effect transistors (FETs).
- To explore the potential of FEPs in microfluidic applications, including stream merging and handling biological samples.
Main Methods:
- Implementation of FEPs utilizing parallel plates and controlled electric fields to generate virtual microchannels.
- Investigation of liquid flow rate (Q) control via the difference in the square of electric field strengths (ΔE2DS and ΔE2GD).
- Characterization of FEP operation in linear, transition, and saturation regions based on applied electric field parameters.
- Construction of a field-effect stream merger using coupled FEPs.
- Preliminary studies using whole blood and particle solutions.
Main Results:
- FEPs enable pump-less liquid transport through wall-less virtual microchannels.
- Adjustable flow rate (Q) is achieved by modulating electric field strength differences (ΔE2DS).
- FEPs exhibit distinct operational regions (linear, transition, saturation) analogous to FETs, influenced by gate and drain field strengths.
- Virtual microchannel dimensions and flow resistance are modulated by electric fields, allowing for flow control and pinch-off.
- A functional stream merger was demonstrated, showcasing FEP versatility.
- Preliminary tests indicate FEPs are compatible with whole blood and particle suspensions.
Conclusions:
- Field-effect pumps offer a promising, pump-less method for precise microfluidic liquid manipulation.
- The ability to control flow rate and create virtual microchannels opens new avenues for microfluidic device design.
- FEPs demonstrate significant potential for applications in biological sample handling and complex fluidic operations.
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