No abstract

A conducting droplet set on the lower plate of a condenser acquires an electrical charge when subjected to an electrical field. Above a threshold value the electrical force lifts the droplet. If the droplet's charge does not leak away, the droplet moves up to the upper electrode and bounces on it. Coating the upper electrode with a dielectric layer allows the otherwise regular droplet back and forth motion to be controlled. This new idea is applied to a droplet-based microfluidic system which drives droplets by electrowetting on a planar array. In this way additional flexibility is achieved since droplets can be displaced and controlled in the three space dimensions.