An Energy Harvester Using Stacked Flexible-PCB Coils on a Ship Propulsion Shaft for Wireless Sensor System Applications

This work introduces a compact and high-power energy harvester (EH) designed for use on ship propulsion shafts to power wireless sensor systems (WSS). The proposed EH employs stacked flexible printed circuit board (F-PCB) coils to generate power from low-speed propulsion shafts. The rotor, measuring 3 mm in thickness, consists of six F-PCB sheets and integrates 12 coil bundles with a total coil turn count of 1104. The stator is assembled within a fixture suitable for installation in bearing housings. Voltage and power characteristics of the EH were evaluated over a rotational range of 20 to 100 rpm. Notably, at 100 rpm, the average voltage measured was 6.9 V, with a corresponding power output of 2,778.5 mW. This performance signifies a significant advancement over previous EH designs. The proposed EH features a simple structure, facilitating power design and prediction, and is adaptable to various rotational shaft applications.