A solar energy harvester with an improved MPPT circuit for wearable IoT applications

peer reviewedOne of the main issues of wearable IoT devices is the limited battery technology. Energy harvesting will be a key development for health and fitness oriented wearable devices that can measure signals continuously. In this paper, an analog maximum power point tracking (MPPT) circuit is presented to power a wearable pulse sensor with a Bluetooth low energy (BLE) module for transmission. The proposed MPPT algorithm uses only the output current to extract the maximum power from a exible solar panel. The whole energy harvesting system was implemented and tested. Experiment results validate that the solar energy harvester has an overall efficiency of 66.5% and can provide sufficient power for the measurement of the pulse sensor and transmission with a BLE module. © 2017 EAI