Multiple Solutions and Corresponding Power Output of Nonlinear Piezoelectric Energy Harvester

Abstract

Energy harvesting is used for an increasing number of small electronic devices and sensors in various applications. Ambient sources of vibration are exploited to provide low levels of power to devices where battery replacement is difficult. One of the simplest concepts for energy harvesting from mechanical vibrations is based on a linear mechanical resonator combined with a piezoelectric transducer. In this case, mechanical energy scavenged from mechanical stress or strain is transferred to electrical voltage. However, such devices work most efficiently in the vicinity of a resonant frequency and it is difficult to tune them in the presence of variable ambient conditions. On the other hand, nonlinear devices seem to be more effective in such conditions due to the broader frequency spectrum of their response. In this paper, we analyse the dynamics of a nonlinear flexible beam with a piezoelectric layer and a magnetic tip mass under the harmonic excitation. The additional magnets define system multistability, including a tristable configuration. The resonant curves and basins of attraction are predicted and can be helpful in choosing the optimal values of the system parameters.