Electrowetting of a Soft Elastic Gel.

A liquid drop may change its wettability on a surface with an applied voltage, known as electrowetting. Herein, we report an electrowetting phenomenon of a soft elastic gel, where gel elasticity plays an important role. We have designed experiments to measure the voltage-dependent adhesion energy between the gel and a metal electrode and proposed an electromechanical model for the electrowetting behavior of the gel. Our experiments have revealed that the voltage-dependent adhesion energy is an intrinsic material property of the polyvinyl chloride (PVC) gel, not affected by the electrode size, geometry, and the stressed state of the gel. Finally, we demonstrate that the predeformation of the gel can be used to tailor its electrowetting behavior.