Development of a Multi-Stage Electroosmotic Flow Pump Using Liquid Metal Electrodes

Area of Science:

• Microfluidics
• Electrokinetics
• Materials Science

Background:

• Micro electroosmotic flow (EOF) pumps are crucial for microfluidic devices.
• Fabricating noncontact electrodes for EOF pumps can be challenging.
• Liquid metal offers a simple, cost-effective electrode material.

Purpose of the Study:

• To propose and demonstrate a multi-stage EOF pump using liquid metal noncontact electrodes.
• To achieve high-flow-velocity performance in microfluidic pumping.
• To provide design guidance for optimizing EOF pump parameters.

Main Methods:

• Fabrication of noncontact electrodes by injecting liquid metal into polydimethylsiloxane (PDMS) channels.
• Construction of a multi-stage EOF pump configuration.
• Experimental measurement of flow velocity using fluorescent particle imaging in deionized (DI) water.

Main Results:

• A five-stage EOF pump design achieved a flow velocity of 5.57 μm/s at 10 V with a 20 μm PDMS gap.
• Parametric studies investigated the influence of PDMS gap, channel dimensions, and stage number.
• The proposed pump design demonstrated effective performance for high-flow-velocity applications.

Conclusions:

• Liquid metal electrodes provide a viable method for fabricating noncontact electrodes in microfluidic devices.
• The multi-stage EOF pump design is effective for achieving high flow velocities.
• This technology holds significant potential for various high-flow-velocity microfluidic applications.