PHOTOPYROELECTRIC (P2E) SENSOR FOR TRACE HYDROGEN GAS-DETECTION

A new type of solid-state sensor for the detection of minute concentrations of hydrogen gas has been developed. The sensor is made of thin, commercially-available polyvinylidene fluoride (PVDF) pyroelectric film, sputter-coated with Pd (or a AlNi double layer). We show that the device probably monitors the change in the pyroelectric coefficient of the film due to electrostatic interactions of adsorbed hydrogen ions with the VDF polymer matrix upon hydrogenation and selective absorption by the metallic coating. Presently, hydrogen concentrations as small as 0.075%, in a flowing H2 + N2 mixture, have been detected. © 1990.