Rapid electrocapillary deformation of liquid metal with reversible shape retention

A low-voltage, low-power method of electrically deforming a liquid-metal droplet via the direct manipulation of its surface tension is presented. By imposing a quasi-planar geometry on the liquid metal, its sensitivity to electrocapillary actuation is increased by more than a factor of 40. This heightened responsiveness allows the liquid metal to be deformed at rates exceeding 120 mm/s, greater than an order of magnitude faster than existing techniques for electrical deformation. Significantly, it is demonstrated how this process can be combined with voltage-controlled oxide growth on the surface of non-toxic, gallium-based liquid metals to reversibly form and maintain arbitrary, high-energy shapes.