A novel self-starting ultra low-power and low-voltage two-stage DC-DC boost converter for microbial energy harvesting

This paper presents a novel self-starting low-voltage step-up DC-DC converter for energy harvesting from ultra-low-power and low-voltage energy sources. The proposed structure consists of two stages: the first stage is an autonomous oscillator, which provides the self-start-up capability with low-input voltages, and the second stage is a controllable reverse conventional buck-boost converter. The converter is simulated using ORCAD 16.5 and also its laboratory prototype is fabricated. Simulation results and experimental tests confirm that this converter is able to harvest ultra-low powers as small as 40μW from a microbial fuel cell, while feeding a 510 kΩ load with a DC voltage over 2.7V.