C05

C05: Amplification of the Electroosmotic Flow on Superhydrophobic Surfaces

Using electrodes to generate a surface charge density at the gas-liquid interfaces, Image: Steffen Hardt/Institute for Nano- and Microfluidics
Using electrodes to generate a surface charge density at the gas-liquid interfaces, Image: Steffen Hardt/Institute for Nano- and Microfluidics

Project C05 focuses on the amplification of electroosmotic flow (EOF) along superhydrophobic surfaces. EOF represents liquid transport by electric fields inside a channel or along a surface, and finds a variety of applications in the fields of microfluidics and lab-on-a-chip technology. Theoretical results suggest that EOF along a superhydrophobic surface can be increased by more than two orders of magnitude compared to an unstructured surface. For this purpose, auxiliary electrodes can be used to generate a surface charge density at the gas-liquid interfaces if the liquid wets the surface in the Cassie state (see figure). The goal of this project is to explore the limits of EOF amplification, for example due to the Cassie-to-Wenzel transition. If successful, the project could open new perspectives for the electric-field driven pumping of liquids.