Multiple electrosprays emitted from an array of holes

Orifices instead of needle capillaries can be used for electrospraying liquids in steady cone-jet mode. This novel device has been used for multiplexing cone-jet menisci anchored at the rim of orifices drilled on a slide. The stability and reliability of the electrospraying process from holes improve substantially when orifices are drilled in dielectric materials with hydrophobic surfaces. The manufacturing process of high compactness multi-electrospray atomizers becomes much easier and cheaper if holes instead of needles are used as emitters. Very cheap multi-hole electrospray atomizers, bearing up to 37 holes and with a compactness of up to 115 emitters per square centimeter, have been home-made and successfully operated. The current and droplet size distribution of the spray issued from these atomizers agreed quite well with those issued from a single source of electrospray, provided that the same flow rate was being electrosprayed throughout each one of the orifices of the multi-injector, and that this value was equal to that issued from the single electrospray source. (C) 2005 Elsevier Ltd. All rights reserved.