Patent ID: 6854830

Claim:
An injection and proportioning head comprising at least one thermal injection and proportioning device to supply a determined quantity of liquid, said device comprising: a hollowed out plane substrate ( 21 ) forming a liquid reservoir and covered, in order, by a directly deposited unconstrained dielectric insulating membrane ( 22 , 23 ) with a high thermal resistance, a directly deposited etched semi conducting layer forming the heating resistance ( 25 ); an orifice ( 24 ) enabling fluid communication with said liquid reservoir passing through said membrane and said semi conducting layer, and thereafter a photolithographed resin layer in the form of a nozzle ( 27 ) on said membrane, the duct ( 28 ) of said nozzle being in line with said orifice and the volume of said duct being such that the determined quantity of the liquid to be supplied can be controlled.