Deformable liquid droplets for optical beam control.

We demonstrate a liquid droplet whose surface profile can be reshaped by voltage. As the dielectric force increases, the dome of a liquid droplet could touch the top substrate and become flat. While the voltage is removed, the droplet recovers to its original spherical shape. By choosing proper liquids, the required voltage for such a shape change is relatively low and the transition speed is fast. Potential application of such a deformable droplet for optical beam control is discussed.