Finite Element Approach to Model Displacement Control of Smart Beams Using Photostrictive Optical Actuators

The objective of this research work is to investigate the displacement control of smart beams of different boundary conditions using photostrictive optical actuators. The authors have developed a computational method useful for design of systems incorporating thin film photostrictive actuators. The element has been implemented in an in-house finite element code. A finite element for static analysis of photostrictive thin films has already been developed and verified with analytical analysis approach of another author. Also the effect of different parameters such as actuator thickness, incident light intensity and convective heat transfer coefficient in the actuation of beam using the thin film photostrictive actuators has been investigated by the authors. In this current work, derived finite element for static analysis of photostrictive thin films has been used to investigate the application of photostrictive actuators for optimum displacement control of beam structure of various boundary conditions. Studies are performed on the effects of various actuator location and length on photoactuation. Photostrictive materials are ferrodielectric ceramics that have a photostrictive effect. The photostrictive effect arises from a superposition of the photovoltaic effect and the converse piezoelectric effect. Photostrictive materials are (Pb, La)(Zr, Ti) O3 ceramics doped with WO3 , called PLZT, exhibit large photostriction under uniform illumination of high-energy light. Photostrictive actuators can directly convert photonic energy to mechanical motion. Photostrictive materials can produce strain as a result of irradiation from high-intensity light. Neither electric lead wires nor electric circuits are required. Thus, photostrictive actuators are relatively immune from electrical interference. They have potential use in numerous MEMS devices where actuation of microbeams is a common phenomenon.Copyright © 2009 by ASME