Liquid metal flexible wearable triboelectric nanogenerator device for human energy harvesting

Humans generate a lot of irregular movements in their daily lives, and much of the movement energy is difficult to collect. This paper develops a wearable device based on a liquid metal (LM)-based frictional electric nanogenerator, including: flexible power-generating fiber, power-generating surface, and power-generating insole. Friction nano power generation fibers are prepared using LM, epoxy resin, and silicone. The power generation device could be formed by weaving the fibers in cross, mesh and spiral arrangement, with a maximum open circuit voltage of 142 mV and current of 1.06 A, which could be coded into intelligent clothing. Power generating surfaces use LM, nylon,polycaprolactone (PCL), and polyethylene terephthalate (PET) as friction electrodes. The LM-PCL produces a maximum open-circuit voltage of 2.4 V and a maximum current of 1.23 A when they form a friction electrode. Electricity-generating insoles are composed of silicone holes filled with LM, and the movement of the human foot generates electricity. With a friction area of 18.75 cm2, a maximum output voltage of 221 mV is obtained. These friction nano power devices have the advantages of a green environment, and low cost, which could be widely used in medical, biological, and clothing formulation fields.