High strain behavior of composite thin film piezoelectric membranes
The behavior of thin-film piezoelectric membranes at high deflections and strains for use as generators is examined. Experiments are conducted with a bulge tester to obtain pressuredeflection relationships, residual stresses, and electrical output characteristics of the piezoelectric membranes. A model is developed using an energy minimization technique. The experimental results are compared to the modeled results. Experimental results have shown that increasing PZT thickness and the Ti ratio of the PZT chemistry lead to increased power output for a given deflection. The presence of tensile residual stress in the composite structure can result in lower deflections for a given force and thus impact electrical output. Increasing the Ti ratio leads to a reduction in residual stress.
residual stress pzt mems