Efficient energy scavengers by flexible robot arm with non-uniform cross-section

The vibration-based energy scavenger consists of beams with piezoelectric layers and proof mass, is usually designed by single-link or cantilever beam configurations. In order to overcome inherent problems, for example, insufficient bandwidth and model inaccuracies, we consider the motion of a two-link flexible arm with non-uniform cross-section. The governing equations consist of coupled non-linear partial differential equations (PDE) with appropriate boundary conditions. Most of the energy scavengers are based on linear electromechanical devices excited at resonance. Besides, realistic vibration environments can be described as stochastic, multi-frequency and time varying. Thus, narrow band linear systems could be highly inefficient under these conditions. On the contrary, non-linear systems are capable of responding over a broad frequency range and can have efficient performance in realistic vibration environments. The author shows that with the proposed non-linear-coupled set-up, the efficiency objectives are satisfied. In this research, tapered beam structure is exploited to achieve large bandwidth, tolerable excitation amplitude and maximum output power. The author also presents some simulation and experimental results to demonstrate the efficiency of proposed energy harvesting system. Consequently, the theoretical approach is verified by simulated and experimental results in compliance.