Wearable biosensors for health monitoring lack a lightweight, long-lasting power supply. A new method was developed for making a charge-storing system that is easily integrated into clothing for embroidering a charge-storing pattern onto any garment.
Batteries or other 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 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.
Supercapacitors are ideal candidates for wearable charge storage circuits because they have inherently higher power densities compared to batteries. But incorporating electrochemically active materials with high electrical conductivities and rapid ion transport into textiles is challenging. The vapor coating process creates porous conducting polymer films on densely twisted yarns that can be easily swelled with electrolyte ions and maintain high charge storage capacity per unit length as compared to prior work with dyed or extruded fibers.
Future work focuses 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.