On high-performance rotational energy harvesting with a novel cam-like dielectric elastomer generator

Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices. This paper proposes and investigates a novel cam-like dielectric elastomer generator (CDEG) for high-performance rotational energy harvesting. A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes (DEMs). Moreover, a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion, which can be further converted into electricity through the DEMs. First, the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system. Second, the prototype is fabricated, and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated. The experimental results show that adequate charging time and discharging time of the DEMs, which can be realized through the proposed cam-like mechanisms, are beneficial to the energy harvesting (EH) performance of the system. Third, with the validated theoretical model, numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement. Finally, the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG, demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.