Patent ID: 6401769
Filing Date: 2002-06-11
Classification: B01J,B01L,C40B,G01N

Abstract:
An apparatus for dispensing a predetermined volume of a liquid, comprising:at least one of a source and a reservoir for said liquid; a channel for conveying liquid from at least one of said source or said reservoir, said channel being defined by a pair of substrates having spacer elements between them and having internal surfaces and external surfaces, said channel also being provided with an outlet; and means for generating a pulse of gas; wherein said apparatus is constructed and arranged such that in use said pulse of gas causes a predetermined volume of said liquid to be ejected from said outlet, characterized in that said outlet comprises a pair of openings in said channel which face one another, said liquid being retained between said pair of openings in an absence of said pulse of gas by surface tension at each of said openings, said pulse of gas being directed towards one of said pair of openings to at least one of dispense and eject said predetermined volume of liquid from the other opening of said pair of openings, wherein said predetermined volume of liquid dispensed or ejected is determined essentially by planar dimensions of said pair of openings and spacing between said pair openings along an axis common to said pair of openings.