A Multi-Source Energy Harvesting System to Power Microcontrollers for Cryptography

This paper presents a multi-source energy harvesting system for vibration, thermal, and solar energy from automobiles, which aims to power a micro controller (MCU) for cryptography. Each building block adopts a maximum power extraction scheme to match the unique characteristic of the energy source. Resistive impedance matching with a buck-boost converter is adopted for vibration and thermal energy harvesting, and maximum power point tracking for solar energy harvesting. The proposed system provides two regulated voltages, 3.3 V and 5 V, to power an MCU. An energy level indicator indicates the current energy level stored in the storage device. The MCU processes a cryptography algorithm accordingly based on the current energy level. The system is able to cold start, i.e., even if the storage device is drained completely, it can start.