In a recent paper, published in the journal Advanced Functional Materials Trisha Andrew and colleagues from the University of Massachusetts Amherst have outlined a new method of applying breathable, pliable and metal-free electrodes to everyday clothing which could generate enough electricity to power smart electronics.
“Our lab works on textile electronics. 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,” Andrew says.
Remote monitoring of health data is increasingly valued by the military and the health care industry, while novel approached to harvesting sustainable energy are highly sought after by environmental researchers and activists alike.
In the lab, the research team used a technique called vapour deposition to coat fabrics with a 500-nanometre layer of a conducting polymer – poly(3,4-ethylenedioxytiophene), also known as PEDOT – to make a plain-woven, conducting fibre that’s resistant to stretching, washing and ironing.
The fabric generates electricity via the relative movement of layers, called triboelectric charging. Two layers of differently charged materials are sandwiched between conducting electrodes, and as they rub against each other during movement, a small electric current is generated.
Andrew and colleagues report a number of tests with 14 different materials, designed to assess their conductivity, chemical and mechanical stability, and textile parameter effects before and after coating them with a conducting polymer. PEDOT coating did not change the feel of the fabric, and only increased its weight by around two percent.
According to Andrew, over the last 10 years, vapour deposition has become easy to scale while remaining cost-effective. This could be used to make smart electronics nearly imperceptible, thereby increasing the likelihood of success on the market.
“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,” explained Andrew.
After the initial work was done earlier this month, the team had also developed a flexible, wearable heart rate monitor with 8 electrodes (a typical one at a hospital has 12) fitted inside a sports bra. They will soon commence testing with volunteers.
“We’re working on taking any garment you give us and turning it into a solar cell so that as you are walking around the sunlight that hits your clothes can be stored in a battery or be plugged in to power a small electronic device,” Andrew summarised her project.