Material scientists at University of Massachusetts Amherst, US, have reported that they’ve developed a method for making a lightweight, charge-storing device that can be integrated into clothing.

Trisha Andrew, the materials chemist who led the team, explained: “Batteries or other kinds of charge storage are still the limiting components for most portable, wearable, ingestible or flexible technologies. The devices tend to be some combination of too large, too heavy and not flexible.”

The team’s method uses a micro-supercapacitor and combines vapour-coated conductive threads with a polymer film, plus a special sewing technique to create a flexible mesh of aligned electrodes on a textile backing. The resulting solid-state device is said to have a high ability to store charge for its size and is capable of powering wearable biosensors.

According to Trisha, while researchers have managed to miniaturise many different electronic circuit components, until now the same could not be said for charge-storing devices. “With this paper, we show that we can literally embroider a charge-storing pattern onto any garment using the vapour-coated threads that our lab makes. This opens the door for simply sewing circuits on self-powered smart garments.”

Trisha and her team are currently working with others at the UMass Amherst Institute for Applied Life Sciences’ Personalized Health Monitoring Center on incorporating the new embroidered charge-storage arrays with e-textile sensors and low-power microprocessors to build smart garments that can monitor a person’s gait and joint movements throughout a normal day.