Controlling electrohydrodynamic pumping in microchannels through defined temperature fields

Abstract

An electrohydrodynamic micropump driven by a high-frequency traveling electric wave (1–10MHz) at low voltage (4–10V) is presented. The pumping rate is dependent on the profile (inhomogeneities) of the dielectric properties of the medium. Defined temperature fields serve as a versatile mean for the control of these profiles. We produce temperature fields in two ways: by the electric wave itself and by external Peltier elements. We investigated experimentally the influence of two-dimensional and three-dimensional electrode arrays on the pumping behavior and compared it to theoretical predictions of temperature field calculations using finite element analysis. The two results are in good agreement. Furthermore, we demonstrate the effect of an additional external temperature field that results in an advanced performance of the pump.