Fabrication and performance analysis of electrostatic micro droplet ejector

This paper proposes a monolithic fabrication and performance analysis electrostatic micro-droplet ejector. 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 nozzle's monolithic electrode structure. The monolithic electrode structure of the nozzle allows the formation, acceleration, and ejection of a droplet to be controlled by the voltage signals applied to control electrodes. The ground electrode is designed to have hole-tip shape. A hole-tip type ground electrode gives the electric field stronger than that for the bottom ground electrode. And ejection hole is coated a hydrophobic material (Teflon). So the liquid formed convex geometric shape of the meniscus between the hydrophilic and hydrophobic surfaces through the hydrophilic microchannel by capillary attraction. Formation and ejection in hydrophobic coating channel shows that stable D-type jetting property compared with hydrophilic coating channel.