US Patent 7815798 Discrete drop dispensing device and method of use

A discrete drop dispensing device comprises a substrate comprising an upper surface and a lower surface and orifices extending from the upper surface to the lower surface, adapted to receive a fluid at a flow rate. The discrete drop dispensing device also comprises an oscillator disposed adjacent to the substrate and configured to vibrate the substrate to expel drops having a substantially equal volume of the fluid. The flow rate is substantially identical to a drop dispensing rate. A method and a device for performing liquid chromatography are also described. The method comprises automatically adjusting the drop dispensing rate to a change in the flow rate or a change in a composition of a mobile phase of the fluid.