INVESTIGATIONS OF PHOTOCHROMIC POLYPEPTIDES

Bacteriorhodopsin provides researchers with a vision of the possibilit ies for an engineered optical material. Photochromic polypeptides are synthetic materials that have similar potential applications as bacter iorhodopsin. The light-induced coil-to-helix conformation change can b e used to develop materials having light-induced changes in birefringe nce. Recent investigations of light-sensitive polypeptides in solution and as thin films give increased knowledge of structure-property rela tionships. The behavior of bacteriorhodopsin-based optical materials p rovides a list of materials requirements needed to explore the feasibi lity of photochromic polypeptide thin film development. Major challeng es include decreasing photofatigue, designing films with thermal back reaction half-life in seconds and large light-induced changes in refra ctive index.