Modeling and analysis of a bimorph piezoelectric cantilever beam for voltagegeneration

Abstract

Piezoelectric materials (PZT) have shown the ability to convert mechanical forces into anelectric field in response to the application of mechanical stresses or vice versa. Thisproperty of the materials has found extensive applications in a vast array of areasincluding sensors and actuators. The study presented in this paper targets themodeling of a PZT bender for voltage and power generation by transforming ambientvibrations into electrical energy. This device can potentially replace the battery thatsupplies the power in a microwatt range necessary for operating sensors and datatransmission. One of the advantages is that it is maintenance-free over a long time span.The feasibility of this application has been repeatedly demonstrated in the literature, but areal demonstration of a working device is partially successful because of the variousdesign parameters necessary for a construction of the PZT bender. According to aliterature survey, the device can be modeled using various approaches. This paperfocuses on the analytical approach based on Euler–Bernoulli beam theory andTimoshenko beam equations for the voltage and power generation, which is thencompared with two previously described models in the literature: the electricalequivalent circuit and energy method. The three models are then implemented in aMatlab/Simulink/Simpower environment and simulated with an AC/DC power conversioncircuit. The results of the simulation and the experiment have been compared anddiscussed.