Abstract
Piezoelectricity and pyroelectricity in wool and hair were observed by Martin early in 1941. The piezoelectric effect in wood was investigated in detail by Bazhenov (1961). Both converse and direct effect of shear piezoelectricity in wood was demonstrated by Fukada (1955). Bending piezoelectricity in bone was first discovered by Yasuda (1953). Shear and longitudinal piezoelectricity in bone and tendon was quantitatively investigatged by Fukada & Yasuda (1957, 1964).