Patent ID: 7714480

Claim:
A piezoelectric/electrostrictive membrane sensor comprising: a ceramic substrate having a thin diaphragm portion and a thick portion integrally provided on the peripheral edge of the thin diaphragm portion, and including a cavity formed by the thin diaphragm portion and the thick portion so as to communicate with the outside; a piezoelectric/electrostrictive element having a laminate structure arranged on the outer surface of the thin diaphragm portion of the ceramic substrate and including a membranous piezoelectric/electrostrictive body, and a lower electrode and an upper electrode between which the piezoelectric/electrostrictive body is sandwiched; and terminal electrodes which connect the lower electrode and the upper electrode to a power source; wherein the thin diaphragm portion of the ceramic substrate oscillates in conjunction with then, driving of the piezoelectric/electrostrictive element; wherein at least one of the upper, lower and terminal electrodes contain sulfur; and wherein the piezoelectric/electrostrictive body contains an alkali metal or an alkaline earth metal, and wherein the piezoelectric/electrostrictive body also contains a sulfide and a main component of the terminal electrodes near a surface of the piezoelectric/electrostrictive body.