Patent ID: 8807711

Claim:
Ink jet print head, including: a pressure generation chamber for being in communication with a print head nozzle; and an actuator membrane for delimiting the pressure generation chamber, the actuator membrane comprising a multilayer package comprising a substrate and a piezoelectric actuator provided on the substrate, said piezoelectric actuator comprising a lower electrode, an upper electrode and at least one piezoelectric layer arranged between the lower electrode and the upper electrode, wherein the substrate and the upper electrode are arranged on opposite sides of the piezoelectric layer, wherein the upper electrode comprises a Titanium-Tungsten film, and wherein the thickness of the Titanium-Tungsten film is chosen such that thicknesses of the layers of the resulting substantially flat multilayer package fulfill the equation Σσ i t i ( z i −z 0 )=0, the sum being taken for all layers i=1, . . . , n, and in which σ=stress in layer i, t i =thickness of layer i, and (z i -z 0 )=distance between the center of layer i and a neutral plane of the multilayer package, wherein the neutral plane is the plane in which the bending tension is zero when the package is being bent.