Piezoelectricity, pyroelectricity and ferroelectricity in biomaterials: Speculation on their biological significance

Many thousands of papers have been published on the piezoelectric, pyroelectric and ferroelectric properties of single crystals, ceramics, polymers and liquid crystals. Yet fewer than 100 papers have appeared on these properties in biological materials. Piezoelectric and pyroelectric effects have been measured on a number of plant and animal tissues and the possible existence of ferroelectricity has been suggested also. This paper reviews some measurements and speculates on their significance. Specific examples include piezoelectricity in a crystalline material in the pineal gland of the brain, pyroelectricity in the heat sensing organs of certain varieties of snakes and beetles, and ferroelectricity in the conduction of action potentials in nerve and muscle cells.