PIEZOELECTRICITY. “Due to its attractive properties and applications, it is tempting to ask if ferroelectricy, like piezoelectricity and pyroelectricity, has also evolved in biological tissues through natural selection … the piezoelectric effect is now generally thought to play an essential role in biological force sensing … piezoelectricity has also been suggested to be one of the toughening mechanisms in seashells.”
http://physics.aps.org/articles/v5/19