An Energy Harvesting Scheme with Temperature Threshold Triggered Generation for Heat Event Autonomous Monitoring

This paper proposes a temperature threshold triggered energy harvesting scheme for potential monitoring thermal event. The demonstrated prototype comprises a generation cantilever and a bimetallic cantilever that magnetically attract together. When the structure is heated to a pre-set temperature threshold, heat absorption induced bimetallic effect of the bimetallic cantilever will cause sufficiently bend of the generation cantilever to get rid of the magnetic attraction and vibrate freely to generate electricity. After the heat in the bimetallic cantilever is dissipated, the two cantilevers attract together again to return to the original state. Under continual heating, the temperature threshold triggered cycle is repeated to intermittently generate electricity. In this paper, the temperature threshold of the harvester is modeled, and the harvester prototype is fabricated. When triggered at 71°C, the harvester is tested to generate Vpp of 1.14 V and power of 1.077 µW within one cycle.