Electrostatic droplet formation and ejection of colloid

This paper presents a novel mechanism of electrostatic micro droplet formation and ejection using charged colloid as fluid. Unlike conventional electrostatic jetting which requires a high operating voltage, we offer a commercially viable, low operating voltage for droplet-on-demand operation based on a layered electrode structure of nozzle. The layered electrode structure of nozzle allows the formation, acceleration, and ejection of a droplet to be controlled by the voltage signals applied to individual electrodes. A simulation study indicates that the proposed mechanism allows less than 100 volt of operating voltage for the formation and ejection of a few pico-liter volume of droplet. Investigation includes the effects of the following factors on the droplet formation and ejection: 1) The shape of meniscus inside the nozzle. 2) The electric field distribution. 3) The density of charged nano particles in colloid.