Patent ID: 6919667

Claim:
A piezoelectric/electrostrictive film device comprising: a substrate having a thin-walled section and a thick-walled section formed around said thin-walled section; a piezoelectric/electrostrictive layer supported by said substrate and comprising a perovskite piezoelectric/electrostrictive material containing Pb and 0.1 to 0.5 wt % MnO 2 ; at least a pair of electrodes formed on said piezoelectric/electrostrictive layer; and means for applying a driving electric field to said piezoelectric/electrostrictive layer such that said piezoelectric/electrostrictive device is driven to satisfy: −0.8Ec≦E 1 ≦0; and 1000≦E 2 ≦4000; wherein E 1 (V/mm) and E 2 (V/mm) represent a minimum driving electric field and a maximum driving electric field applied to said piezoelectric/electrostrictive layer, respectively, and Ec (V/mm) represents a coercive electric field.