Designing a boost converter of micro energy harvester using thermal and vibration input for biomedical devices

Abstract

This work presents a designed of boost converter Hybrid Micro Energy Harvester (HMEH) using thermal and vibration of human body for biomedical application. Thermal converts temperature differences directly into electrical energy. While vibration is based on human movement like walking and shaking body that is able to generate an AC voltage. Having two sources overcome the limitation caused by a single source harvester and improves system functionality. The inputs are set to 0.2V, 0.3V and 0.5V to represent thermal, vibration and combination of thermal and vibration (hybrid) respectively. A rectifier is designed to convert vibration input from AC to DC voltages. The proposed boost converter is used to step-up the small input voltage from thermal and vibration at 2 kHz. The inductance is varied from 0.4μH to 1.2μH, 0.9μH to 2.9μH and 0.3μH to 0.9μH for vibration, thermal and hybrid input respectively. However, the optimize value for the designed is 0.9μH for all sources to achieve the regulated output of 2.0 to 4.0V. Both rectifier and boost converter circuit consist of MOSFET as the heart of the operation. In this paper, the circuits are designed, modeled and simulated using PSPICE software.