Scaling laws for pulsed electrohydrodynamic drop formation

A pulsed electrohydrodynamic jet can produce on-demand drops much smaller than the delivery nozzle. This letter describes an experimentally validated model for electrically pulsed jets. Viscous drag in a thin nozzle limits the flow rate and leads to intrinsic pulsations of the cone jet. A scale analysis for intrinsic cone-jet pulsations is derived to establish the operating regime for drop deployment. The scaling laws are applicable to similar electrohydrodynamic processes in miniaturized electrospraying systems. (c) 2006 American Institute of Physics.