Numerical investigation of microchannel geometry for effective on-chip biofluid delivery by AC electrothermal effect

Although there exist tremendous needs for on-chip biofluid delivery, research in this field has yielded limited numbers of devices for real-world applications. One challenge is the difficulty for micropumps to meet the requirements of being low cost to fabricate, easy to integrate and effective for intended applications at the same time. This research focuses on AC electrothermal (ACET) micropumps based on planar interdigitated electrodes, due to their practicality in fabrication and operation, and compatibility with biochemical fluids. Our prior work has optimized the design of electrode dimensions for a fixed microchannel design. This work finds that microchannel dimensions can also affect ACET micropumps significantly, with respect to flow rate and electric impedance loading. This work first considers the constraints arising from impedance loading by ACET micropumps on power supplies, then the investigation describes several key parameters (threshold height, saturation thickness), to arrive at an appropriate microchannel geometry for the effective delivery of biofluids. The optimized microchannel is expected to incorporate well into a multifunctional lab-chip system to transport biofluids efficiently.