Design and optimization of a piezoelectric-electromagnetic hybrid energy harvester for sustainable smart agriculture systems

Abstract The promotion of smart agriculture is key to sustainable agriculture and reducing environmental impact. In order to achieve the development of self-powered sustainable smart agriculture, in this paper, a piezoelectric-electromagnetic hybrid energy harvester (PEHEH) is proposed, which based on the magnetic coupling. Composed of a magnetic turntable, coil, driving magnet, response magnet, and piezoelectric cantilever beam, the PEHEH integrates electromagnetic and piezoelectric energy harvesting through magnetic coupling. By fully exploiting magnetic coupling, the PEHEH combines these two energy harvesters, ensuring efficient energy conversion. The non-contact magnetic coupling force excites the piezoelectric cantilever beam, facilitating efficient energy harvesting, enhancing conversion efficiency, and prolonging the operational lifespan. A series of experiments were conducted to investigate the impact of response magnet size and position on the output voltage of the PEHEH. The results show that the prototype, when assembled in accordance with the optimal structural parameters, is capable of providing a continuous and stable power supply for smart agricultural low-power sensors and small electronic devices. In particular, the PEHEH demonstrates high stability and reliability in soil temperature and humidity sensor monitoring, LED light compensation applications. It provides a new power supply solution for sustainable smart agriculture.