Patent ID: 8870102

Claim:
An electrospray head for use in an electrospraying apparatus, the electrospray head comprising: a body; an actuator disposed in said body; an internal surface in said body defining a conduit, said conduit having an inlet for receiving a fluid to be sprayed and an outlet for emitting said fluid; and a movable wall forming a portion of said internal surface defining the conduit; wherein said movable wall is arranged to co-operate with said actuator to constrict or dilate said conduit upon operation of the actuator; wherein the movable wall is located adjacent the outlet of the conduit whereby the effective exit dimensions of the conduit can be varied by controlling the actuator; wherein the actuator comprises an expandable member disposed adjacent said movable wall, and means for varying the expansion of said expandable member; whereby the effective exit dimensions of the conduit can be varied by controlling the actuator to provide an additional element of control to affect the fluid dynamics and the creation of an electrospray plume.