Patent ID: 8899731

Claim:
An ink jet printing device comprising: a pressure chamber formed in a housing; a first actuator membrane having a first membrane width W m,1 and a first membrane length L m,1 the first membrane width being equal to or smaller than the first membrane length, the first actuator membrane is arranged to form a first flexible wall of the pressure chamber; a first piezo-electric part being operatively connected to a surface of the first actuator membrane; a second actuator membrane having a second membrane width W m,2 and a second membrane length L m,2 , the second membrane width being equal to or smaller than the second membrane length, the second actuator membrane is arranged to form a second flexible wall of the pressure chamber; and a second piezo-electric part being operatively connected to a surface of the second actuator membrane, wherein the second flexible wall is mechanically decoupled from the first flexible wall, and wherein the first piezo-electric part and second piezo-electric part are located in separate cavities formed in the housing.