Capillary origami controlled by an electric field

Abstract

We show experimentally how an electric field can control the folding and unfolding of a thin elastic membrane around a liquid droplet. As the voltage is increased above a critical value the membrane unfolds completely. The transition is reversible, although the structure closes back for a lower critical tension. We propose scaling laws for these critical voltages based on the interaction between surface tension, elastic and electric energies. These scaling laws are in qualitative agreement with experiments and a simplified 2D simulation of the problem, providing a useful tool for designing practical micro-devices actuated by an electric field.