Two researchers at the University of South Carolina (USC) have demonstrated how one day, your clothing may be used to charge your cell phone or tablet.
If it works it could solve one of the more aggravating occurrences of modern life – having your cell phone battery die just before you make an important call. In the future, electronics may be part of your wardrobe.
"We wear fabric every day," said Xiaodong Li, a professor of mechanical engineering at USC. "One day our cotton T-shirts could have more functions; for example, a flexible energy storage device that could charge your cell phone or your iPad."
Li and colleague Lihong Bao started with an ordinary T-shirt from a local discount store. They soaked it in a solution of fluoride, dried it and baked it at high temperature. They excluded oxygen in the oven to prevent the material from charring or simply bursting into flames.
When they were finished their T-shirt's fibers had been transformed from cellulose to activated carbon. The material was still flexible and could be folded without breaking.
Now, the once-cotton T-shirt was also a repository for electricity. By using small swatches of the fabric as an electrode, the researchers showed that the flexible material, which Li's team calls “activated carbon textile,” acts as a capacitor. Capacitors are components of nearly every electronic device on the market, and they have the ability to store electrical charge.
But the research team didn't stop there. They next coated the individual fibers in the activated carbon textile with “nanoflowers” of manganese oxide. Just a nanometer thick, this layer of manganese oxide greatly enhanced the electrode performance of the fabric.
"This created a stable, high-performing supercapacitor," said Li.
A supercapacitor you happen to be wearing, so you never have to look for an outlet.
According to Li, this hybrid fabric, in which the activated carbon textile fibers are coated with nanostructured manganese oxide, improved the energy storage capability beyond the activated carbon textile alone. The hybrid supercapacitors were resilient: even after thousands of charge-discharge cycles, performance didn't diminish more than 5 percent.
"By stacking these supercapacitors up, we should be able to charge portable electronic devices such as cell phones," Li said.
That's all well and good, but Li and his team didn't say how comfortable that once-cotton T-shirt was after going through the process. But one scientific breakthrough at a time.