Low-power Hybrid Energy Harvesting System Based on the Joint Operation of Glucose Biofuel Cells and Thermoelectric Generator

Wearable devices continuously gain their popularity due to flexibility and opportunity to enable more applications and services, in particular, in healthcare industry. Guarantying long-term operation for these devices is among the key challenges at the design stage. In this work, we propose a multi-source energy harvesting system to address this problem. The proposed solution is based on two technologies namely an Enzymatic Biofuel Cell (BFC) and a low-temperature gradient Thermoelectric Generator (TEG) which are capable of generating power from human perspiration and heat, respectively. Upon designing BFC, we designed a functional circuit that combines it with the TEG. The resulting BFC has an output voltage of 200 mV and a power of about 7 nW. An array of BFCs is used as a source for initial push to start up the internal logical control circuit of the DC-DC controller. The low-temperature gradient TEG with an output voltage ranging from 40 mV to 70 mV and a constant measured output power of 160 uW is used together with the BFCs for energy harvesting upon the initial starting of the DC-DC controller.