Numerical study of cantilevers with non-uniform width for enhancing the performance of vibration-driven micropower generator based on piezoelectric conversion

This study is dedicated to investigation of rectangular- and trapezoidal-shaped cantilevers for achieving improved efficiency of the piezoelectric micropower generation. The developed finite element model of a unimorph piezotransducer with a proof-mass at the tip is used to examine how different cantilever shapes and proof-mass dimensions influence stress distribution, dynamic response and voltage output of the microgenerator. Numerical results indicate that cantilevers with increasingly triangular shape permit markedly larger kinematic excitation magnitudes and generate slightly larger voltages for a comparable deflection level