UMass Amherst materials scientists create fabric alternative to batteries for wearable devices
A major factor holding back development of wearable biosensors for health monitoring is the lack of a lightweight, long-lasting power supply. Now scientists at the University of Massachusetts Amherst led by materials chemist Trisha L. Andrew report that they have developed a method for making a charge-storing system that is easily integrated into clothing for “embroidering a charge-storing pattern onto any garment.”
As Andrew explains, “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.”
Their new method uses a micro-supercapacitor and combines vapor-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 has a high ability to store charge for its size, and other characteristics that allow it to power wearable biosensors.
Andrew adds that while researchers have remarkably miniaturized many different electronic circuit components, until now the same could not be said for charge-storing devices.
Andrew and postdoctoral researcher and first author Lushuai Zhang, plus chemical engineering graduate student Wesley Viola, point out that supercapacitors are ideal candidates for wearable charge storage circuits because they have inherently higher power densities compared to batteries.
Andrew, who directs the Wearable Electronics Lab at UMass Amherst, notes that textile scientists have tended not to use vapor deposition because of technical difficulties and high costs, but more recently, research has shown that the technology can be scaled up and remain cost-effective.
She 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.
