Electro-spinning involves drawing solutions of polymers into fibres using electrical charge.
The researchers have developed an all-fibre composite layer TENG that can be integrated with normal cloth.
“With our work, we are aiming to provide a new point of view towards wearable energy harvesters and smart textiles,” said Fukui’s Hiroaki Sakamoto. “The power generation device has flexibility and breathability since all components are composed of fibre materials.”
The tribo-electric membrane is made of two layers of electro-spun fibre – one of polyvinylidene fluoride (PVDF) and the other a nylon.
Silver nanowires cover these layers, and the team added a layer of electro-spun polystyrene between the silver wires and the tribo-electric membrane.
Mechanical motion while walking or running causes the triboelectric layers to touch and separate, which produces a charge that can be drawn away to power devices.
“Normally, the charge build-up on the triboelectric surface is gradually lost or dissipated, reducing the surface charge density and the output performance of the generator,” according to University of Fukui. “However, in this case, the added polystyrene membrane collects and traps the charge, retaining the surface charge density of the TENG.”
200V and 70mA/m2 was achieved over 90mm2 and 1μF could be charged to 2V in 40s with a 1Hz mechanical drive.
The University of Fukui worked with Nanjing University. The research is published as ‘An all-fibrous triboelectric nanogenerator with enhanced outputs depended on the polystyrene charge storage layer‘ in Nano Energy.