Joggers may soon be able to light up a small electronic device just by wearing a jacket.
The lightweight jacket, developed at the University of Massachusetts Amherst, uses breathable, pliable, metal-free electrodes to fabric that transports enough electricity to power small electronics.
“Our lab works on textile electronics,” Trisha Andrews, a material scientist, said in a statement. “We aim to build up the materials science so you can give us any garment you want, any fabric, any weave type and turn it into a conductor.
“Such conducting textiles can then be built up into sophisticated electronics,” she added. “One such application is to harvest body motion energy and convert it into electricity in such a way that every time you move, it generates power.”
The researchers were able to generate small electric currents through relative movement of layers in an effect called triboelectric charging, where materials become electrically charged as they create friction by moving against a different material.
“By sandwiching layers of differently materials between two conducting electrodes, a few microwatts of power can be generated when we move,” Andrews said.
The research team was able to coat fabrics with a conducting polymer—poly(3,4-ethylenedioxytiophene or PEDOT)—using the vapor deposition method to make plain-woven, conducting fabrics that are resistant to stretching and wear and remain stable after washing and ironing. They used an extremely thin coating, with the thickest coating used at about 500 nanometers to retain the fabric’s hand feel.
The researchers tested the PEDOT films for electrical conductivity, fabric stability, chemical and mechanical stability. They also tested the textile parameter effects on conductivity of 14 fabrics, including five cottons with different weaves, linen and silk from a craft store.
“Our article describes the materials science needed to make these robust conductors,” Andrews said. “We show them to be stable to washing, rubbing, human sweat and a lot of wear and tear.”
After testing, the PEDOT coating did not change the feel of any of the fabrics, nor did it significantly change the fabric weight.
Scientists can now use this technology to overcome the obstacle of power-generating electronics mounted on plastic or cladded, veneer-like fibers to make garments heavier and possibly less flexible.
“There is strong motivation to use something that is already familiar, such as cotton/silk thread, fabrics and clothes, and imperceptibly adapting it to a new technological application,” Andrews said. “This is a huge leap for consumer products, if you don’t have to convince people to wear something different than what they are already wearing.”
According to Andrews, it was surprising how much stress clothes go through on a daily basis.
A wearable device could be used by the military to monitor health data remotely, which is also increasingly valuable in the health care industry.
