A handy liquid metal based electroosmotic flow pump

Abstract

A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions.

Electroosmotic flow hysteresis for dissimilar ionic solutions

“…EOF has been employed for various applications in microfluidics, including mixing of analytes, 1,2 pumping of fluid, 3,4 separation of particles 5 /chemical species, 6 sample trapping, 7 and pre-concentration. 8,9 In many of these practical applications, two or more types of fluids with different properties are often involved, with one displacing another.…”

Electroosmotic Flow Pump

“…Figure 7 shows a handy liquid-metal (GaInSn)-based EOF pump fabricated in a PDMS microfluidic chip [47]. In this pump, the liquid metal is a kind of metal alloy (GaInSn), which can be easily injected into microchannels by a simple syringe.…”

Fast Fabrication of Flexible Functional Circuits Based on Liquid Metal Dual‐Trans Printing

“…With its intrinsically combined characters of both high electrical conductivity and excellent fl uidity, such materials are particularly convenient to be used for fabricating fl exible electronics. For these reasons, the liquid metal has been increasingly investigated as an excellent electronic material for making stretchable antennas, [ 12 ] bioelectrodes, [ 13 ] capacitors and inductors, [ 14 ] strain sensor, [ 15 ] pressure sensor, [ 16 ] curvature sensor, [ 17 ] micropump, [ 18 ] and so on. Meanwhile, various techniques that targeted for patterning the liquid metal have also been put forward, such as inkjet printing, [ 19,20 ] microfl uidic channel injection, [ 21,22 ] masked deposition, [23][24][25] imprinting, [ 26 ] microcontact printing, [ 27 ] stamp lithography, [ 27 ] 3D printing, [ 28,29 ] and direct writing, [30][31][32][33][34] etc.…”