Optically driven actuator using photo-induced phase-transition polymer

A new optically driven actuator is proposed which utilizes the photoactive nature of a material that exhibits photo-induced phase-transition (PIPT). PIPT changes the material phases reversibly by photo irradiation of certain wavelength. The strain induced by the phase-transition was evaluated in a typical PIPT material, polydiacetylene crystal, as an important characteristic required for an actuator material. Using a thermal heat cycle, the strain induced by the phase-transition was measured to be 1.2, <0.03 and 0.72% at 410 K for the a, b and c axis, respectively. Material deformation using PIPT by single laser pulse was demonstrated for the first time. The observed deflection of the cantilever sample was explained by bimorph formation induced by phase-transition at the photo-irradiated surface. The mechanical response was very fast, less than 5 ms and the sample maintained deformation for more than 60 min. This wireless method will be useful for actuating micro and nanometer mechanical systems which need to move independently from electric wires. (C) 2002 Elsevier Science B.V. All rights reserved.