Evaluation of Triboelectric Energy Generators based on Military Textiles

Triboelectric generators convert waste mechanical energy into useable electrical energy. This paper focuses on harvesting waste energy during military operation in the field and converting it into electrical energy that could supplement batteries used to power electronic devices. In this study triboelectric energy generators were fabricated from nine army textiles and tested for use in impact energy harvesting (for harnessing solider motions such as walking and rucking) and wind energy harvesting (for harnessing wind-driven fluttering motions of shelters or parachutes). It was found that triboelectric generators consisting of army textiles having nylon fibers with water repellent side and back coating, paired with Polytetrafluoroethylene (PTFE) layers performed best in impact tests, followed closely by an army textile with an equal proportion of nylon and cotton fibers and wrinkle-free finish coating. For the wind test, an army textile having nylon fibers and fluorocarbon coating paired with PTFE layers performed best. It was also found that the use of silver particle-loaded Polydimethylsiloxane (PDMS) electrode layers improved the performance of the generators relative to copper tape electrode layers. All textile samples performed better in impact testing than in wind. The maximum average voltage recorded for the impact tests was 7.8 V while the maximum recorded for wind testing was 1.3 V. Finally, a triboelectric generator was integrated into a soldier's boot and the energy harvesting performance was evaluated for different motions of the wearer including walking, rucking, and running. The output voltage increased with increasing speed and angle of inclination for all operations. The maximum voltage recorded was 0.7 V for walking at 2 mph and 5% inclination, while it was 2.22 V for rucking at 6 mph and 2.33 V for running at 10 mph.