Research on constitutive model of hybrid photovoltaic/piezoelectric actuation mechanism

Opto-mechanical actuators do not require hard-wired connections to control light source. Accordingly, the control commands will not be influenced by undesirable electric noises. Without accessorial devices and connecting wires, photonic control which conforms to the lightweight trend of space structure has great research value. PLZT photostrictive actuator can only induce actuation strain along its polarized direction, so it has the deficiency of one-way actuation. In this paper, the novel hybrid photovoltaic/piezoelectric actuation mechanism is proposed to remedy this deficiency. The ultraviolet light-driven PLZT induced voltages are used to drive piezoelectric actuator. Based on the equivalent electrical model, constitutive model is established to define the time history of actuation strain of piezoelectric actuator driven by photovoltage. Experimental platform is established to verify this established constitutive model. A logical switch is designed to realize positive and negative connection switch between PLZT photovoltaic generator and piezoelectric actuator. It is experimentally validated that the piezoelectric actuator can induce both positive and negative control forces.