Enhanced electromechanical coupling of piezoelectric beams through an innovative design

Abstract

International audienceThis work reports the finite element model simulations of an innovative design of piezoelectric cantilevers in order to maximize their global electromechanical coupling coefficient k².A strong electromechanical coupling coefficient is necessary for piezoelectric cantilever to improve their performances as vibration energy harvesters. Its value can be increased by minimizing the strain in the width direction of the beam.The purpose of the proposed design is to block the lateral deformations of the beam while allowing longitudinal deformations. This is implemented by placing several rigid bars on the piezoelectric patches in the width direction.Such a design is interesting when strong global electromechanical coupling coefficients are needed for resonant frequency tuning by electrical methods, or to increase the performance of lead-free materials that are still weakly coupled materials