Pyroelectric Effect in Bone and Tendon

Abstract

INVESTIGATIONS have recently been made into the generation of electric potentials in bone subjected to mechanical stress^1–5. Shamos, Lavine and Shamos⁵ and Fukada and Yasuda³ have suggested that the potentials are the result of a piezoelectric effect in the collagen of the bone. Fukada and Yasuda have also found a piezoelectric effect in the collagen of the Achilles tendons of a horse and a cow⁴. Other workers^1,2 have suggested that the electric potentials in bone may be generated either by the bending of mucopolysaccharide molecules such as hyaluronic acid or by stress at the interface between collagen and hydroxyapatite. The polar crystal structure of the collagen molecule means that it could exhibit a pyroelectric effect as well as piezoelectricity. We have therefore investigated the existence and magnitude of the pyroelectric effect, and tried to find the origin of the electric potentials in stressed bone.