Enhancing vibration isolation and energy harvesting via a quasi-zero stiffness electromagnetic system

Vibration-related issues are common causes of failure in precision machines, and energy harvesting techniques can help mitigate harmful vibrations and recycle waste energy. This Letter introduces an electromagnetic energy harvester utilizing a quasi-zero stiffness mechanism to achieve simultaneous vibration isolation and energy harvesting. The system utilizes mutually exclusive magnets to generate positive stiffness and flexible bending beams to offer negative stiffness, which counterbalances each other to realize quasi-zero stiffness. Physical prototypes were fabricated, and their vibration isolation and energy harvesting performance were assessed under various magnet distances and excitation conditions. Experimental results validate that the proposed system achieves both vibration isolation and energy harvesting. It exhibits outstanding vibration isolation performance when the frequency exceeds 5 Hz. Notably, the magnet distance significantly affects the energy harvesting performance: compared to the 37 mm configuration, adjusting the magnet distance to 41 and 39 mm increased the power output by 54.9% and 31.7%, respectively. This study lays an important foundation for advancing integrated vibration isolation and energy harvesting technologies.