(481b) Design of Electrothermal Pumps Using Resistive Heaters

Electrothermal pumping induces fluid motion through the interaction of an electric field with temperature gradients within the fluid. Non-uniform heating is traditionally generated through Joule heating. Therefore, the applied electric field serves two purposes simultaneously: (i) to heat the fluid through internal Joule heating and (ii) to drive electrothermal motion. This presentation describes a new method of electrothermal pumping using thin film resistive heaters. External heating, in effect, introduces non-uniform temperatures independent of the applied field. Various external heating design configurations will be introduced and compared to internal heating mechanisms. Geometries include (i) asymmetric electrodes, (ii) symmetric interdigitated electrodes, and (iii) travelling wave electrothermal pumping. Numerical simulations will demonstrate the advantages of using thin film resistive heaters. For example, using asymmetric electrodes, electrothermal pumping using thin film heaters is over 2.5 times more energy efficient than Joule heating alone. In addition, external heating allows for electrothermal pumping to be applied towards low conductivity samples.