Abstract：In this paper, a novel locally resonant structure with energy harvesting capabilities is proposed, based on the analysis of bandgap mechanisms and energy localization effect in locally resonant phononic crystals. The vibration characteristics and energy harvesting capabilities of the structure are investigated using finite element methods (FEM). According to the resonant modes and the simplified "mass-spring" system model, the first seven-order resonant frequencies of the structure can be reduced to the frequency range of 50~250 Hz by changing material and geometric parameters. With a developed multi-core structure, dozens, perhaps hundreds, of resonant frequencies appear in the frequency range below 250 Hz and the lowest frequency is 20 Hz. Based on the harmonic response analysis of finite structures, these low and broadband resonance properties as well as the piezoelectric energy harvesting capabilities are confirmed to satisfy the low and broadband frequency requirements of the energy harvesting from ambient vibrations. These structures will be helpful for the self-powered microsystems, such as portable electronic devices, wireless sensor, microelectromechanical systems (MEMS) and so on, to extract energy from ambient low frequency vibrations.
2013, Vol. 34 
