A novel rope-driven piezoelectric energy harvester for multidirectional vibrations

Many piezoelectric energy harvesters can harvest single direction vibration effectively. However, practical ambient vibration may be multidirectional. To capture multidirectional vibration, this paper proposes a rope-driven piezoelectric energy harvester (RPEH). The RPEH consists of two piezoelectric cantilevers, which are coupled through a non-extensible rope and a proof mass. Dynamical responses and energy harvesting performance of the RPEH under multidirectional vibrations is investigated in the experiment. It is observed that multidirectional vibrations will cause the motion of the proof mass, and then the proof mass drives the two piezoelectric cantilevers to vibrate through the rope. Compared to the linear piezoelectric cantilever, experimental results show operation bandwidth of the proposed harvester is improved by 140%, 40% and 140% in three directions (x-direction, y-direction or z-direction), respectively.