Multiplexed electrospray emitters fabricated by rapid laser micromachining

This technical note documents the fabrication and performance of multiplexed electrospray emitters by rapid laser micromachining. A low cost 1064-nm fiber laser marker system is used to precisely, rapidly and selectively remove materials from a sheet of conductive silicone rubber, which is chemically inert. The laser pulse energy, scanning speed and machining path are judicially chosen to create clean and round micro posts that form external nozzle structures. This laser micromachining technique offers sufficient precision for ensuring uniform pressure drop across each fluid flow channel even at relatively low flow rate per nozzle. The uniformity of the operation from nozzle to nozzle is confirmed by measuring the diameter of each cone-jet. The results suggest that the laser micromachining is a rapid and convenient technique for fabricating multiplexed electrospray emitters.