Photoswitches operating upon ns pulsed laser irradiation

We present a potential photoswitch, which undergoes reversible mechanical actuation induced exclusively by photons. The photoswitch is a polymer-based film doped with spiropyran photochromic molecules. It undergoes repeatable mechanical cycles controlled by ns laser pulses of specific wavelengths. The polymer matrix is mechanically activated due to particular photoisomerization processes of the incorporated photochromic molecules, resulting in its contraction and lengthening in a highly controllable manner. We present herein the way that the switching time of this novel photoswitch depends on different laser parameters such as the energy and the repetition rate. (c) 2005 Elsevier B.V. All rights reserved.