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Summary: Scaling laws for pulsed electrohydrodynamic drop formation
C.-H. Chen, D. A. Saville, and I. A. Aksaya
Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544
Received 22 August 2005; accepted 23 August 2006; published online 20 September 2006
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. © 2006 American Institute of Physics.
DOI: 10.1063/1.2356891
Among contemporary techniques for drop generation,
pulsed electrohydrodynamic EHD jetting may be the only
one that can produce drops on demand with dimensions a
decade or so smaller than the nozzle.1,2
The large neck-down
ratio derives from the EHD cone-jet transition produced by
an external voltage pulse.3
This transition is fundamental to
electrospray ionization4
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