[Image above] Credit: Rain Rabbit; Flickr CC BY-NC 2.0
It’s easy for us to stay connected to the internet because of advances in research. We have smart TVs and smart watches. And there are a multitude of products you can buy to create a smart home, including smart windows and smart appliances.
The problem with most smart devices is that they’re limited to the capacity of the power source they’re connected to. Researchers are still working to improve upon the battery, but until we can obtain the most power from the smallest cell, we will have to wait patiently for the next scientific breakthrough.
But back to clothing—researchers are not satisfied with clothes just being smarter. They now have to be more powerful, electronically-speaking.
A team of materials scientists at the University of Massachusetts Amherst has developed a way to turn fabric into a conductor of electricity that is capable of powering small electronics. By using vapor deposition, the research team converts woven fabric, such as linen or silk, into electrical conductors without affecting the inherent properties and characteristics of the fabrics.
The vapor deposition method the team used consists of coating fabrics with a 500-nm layer of a conducting polymer—in this case, poly(3,4-ethylenedioxytiophene), or PEDOT. The researchers tested a total of 14 different fabrics for conductivity and stability and were surprised at the results.
“You’d be amazed how much stress your clothes go through until you try to make a coating that will survive a shirt being pulled over the head,” Trisha Andrew, assistant professor of chemistry and materials scientist says in the university’s news release. The fabrics they tested survived enormous amounts of stress—including washing, rubbing, and bending.
This was important because the team wanted to keep the fabrics’ feel and weight as close to their original properties as possible.
“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,” Andrew explains. In other words, consumers are more likely to purchase and wear clothing with the look and feel of something they’re already used to.
Andrew explains they can take any garment, fabric, or weave type and turn it into a conductor. “Such conducting textiles can then be built up into sophisticated electronics,” she notes. “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.”
Once the coated fabrics survived the stress test, the team layered several of them between conducting electrodes. Moving the layers against each other builds up static electricity—or a triboelectric charge—generating enough power to light a bulb, as depicted in the research team’s photo below.
Credit: UMass Amherst
Industries that could benefit from this research include the military and health care industry, Andrew says. Her team will soon test a fitness bra they’ve developed that is outfitted with eight electrodes that can monitor heart rate.
The average consumer will eventually benefit with electronic wearables. “Our textiles can certainly be used by joggers or bicyclists to wear at night to power an LED array that flashes with the jogger/bicyclist’s body motions,” Andrew writes in an email.
And her team is already experimenting with the concept of storing solar energy in a garment to power small electronic devices. Does this mean we won’t have to worry about using up precious battery juice of our phones in between charges?
“At this stage, our textiles can be used to charge up a supercapacitor (charge storage component) that could act as a power bank for small electronics such as a phone,” Andrew added in an email. “However, at this time, the electronic circuitry we’ve developed cannot be directly interfaced to a phone, at least not yet. Perhaps sometime in the near future…”
The paper, published in Advanced Functional Materials, is “Rugged textile electrodes for wearable devices obtained by vapor coating off-the-shelf, plain-woven fabrics” (DOI: 10.1002/adfm.201700415).