Electrohydrodynamic coating fluid delivery apparatus and method

摘要

An apparatus and method for improved control of low viscosity fluid flow during electrohydrodynamic spray deposition of the fluid to coat small targets, such as medical devices like stents. The apparatus includes a target holder which applies a first electrical potential to a target, a coating fluid transporter such as a wick, a siphon tube or a siphon tube with a wick therein along which the coating fluid flows from a reservoir to a dispensing end of the transporter, and an electrode which applied a second electrical potential to the coating fluid sufficient to cause the coating fluid to be attracted from the dispensing end of the transporter toward the target. This provides a target coating apparatus with highly self-regulating coating fluid flow characteristics despite the low viscosity of the coating fluid, while producing highly consistent and uniform target coatings.