Optimized piezoelectric energy harvesters for performance robust operation in periodic vibration environments
By: Wen Cai
Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210, USA
Energy harvesters with a wide frequency range, long lifetime, and high output power are preferred in power supply for wireless devices. Motivated to guide the design of a robust energy harvesting platform in a confined space, an analytical model adopted the Euler-Bernoulli beam theory for a laminated beam is first presented to predict the nonlinear response. Then with the existing model a multi-objectives optimization method based on the genetic algorithm considering the frequency range, strain level, and output power is proposed to learn the influence of nonlinearity, beam shape, and tip mass on the robust design. The optimization results indicate that a tapered beam with minor monostable nonlinearity, mounted a relatively small mass at the free end will be the best option for the robust system design. In addition, for the multi-objective problem, the weights assigned to different cost functions will influence the dominant factor in the optimization, which will in turn affect the final optimal design. Comparing with the other two objectives, the cost function for the voltage is more sensitive to the change of weights.