The continuous electrowetting effect observed in gallium-based liquid metals presents an efficient electrical driving mechanism for manipulating milli- and micro-fluids. Remarkably, this method can generate robust flow fields with a minimal voltage requirement of approximately 1 volt. However, a persistent challenge arises from the formation of a surface oxide layer during continuous electrowetting, which acts as an interfering factor compromising driving stability and controllability. The intricate coupling mechanism between the oxide layer and the flow field has remained elusive, thereby hindering the widespread application of this effect in milli- and micro-fluidic systems.

To tackle this challenge, a collaborative effort has been undertaken by Professor Wang Wei's team from the School of Integrated Circuits, National Key Laboratory of Science and Technology on Micro/Nano Fabrication, and Advanced Innovation Center for Integrated Circuits at Peking University, alongside Professor Chwee Teck Lim's team from the National University of Singapore. By establishing a Faraday depolarization theoretical model, they have successfully unveiled the regulatory patterns governing flow field modes in liquid metal droplets, both with and without oxide layer coverage.