Low-voltage electrowetting on a lipid bilayer formed on hafnium oxide

Abstract

We present a class of electrowetting systems in which lipid bilayers on thin hafnium oxide films function as reversibly wettable dielectrics, eliminating the need for solid organic dielectrics (e.g., fluoropolymers) in electrowetting systems. These bilayers self-assemble on hafnium oxide in oil, yielding a dielectric stack that can withstand high electric fields, enabling high contact angle changes at unprecedentedly low voltages. We demonstrate that these electrowetting systems can be virtually free of contact angle saturation with low oil-water surface energies (<1 mJ/m2), allowing for a reversible contact angle change from over 140° to under 10° using less than 1 V actuation.