Wonderful Engineering

Scientists Create Batteries Made Out Of Fabrics For Wearables

Wearable technology will soon become a massive industry. The manufacturers seem to be hitting a snag in developing energy storage systems which are as thin and lightweight as fabric. A new creation from materials engineers will help streamline the wearables production for any garment. A team of chemists from the University of Massachusetts Amherst has developed the revolutionary charging system. The team was led by materials chemist Trisha Andrew. Andrew 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.”

Andrew and the team used a micro-supercapacitor for energy, dispersed through vapor-coated conductive threads. The team also used a unique sewing technique to create a flexible mesh of electrodes on the cloth back. This results in creating a device which has more charge than expected for its size. The researchers found that this device can easily power the wearable biosensors. The team said, “With this paper, we show that we can embroider a charge-storing pattern onto any garment using the vapor-coated threads that our lab makes. This opens the door for simply sewing circuits on self-powered smart garments.”

Andrew collaborated with a postdoc researcher Lushuai Zhang who served as the first author of the paper. They also worked with chemical engineering graduate student Wesley Viola. The team found in the preliminary studies that supercapacitors are the ideal candidates for wearable charging storage. This was because of their inherently higher power densities as compared to standard batteries. UMass researchers needed to upgrade the conventional supercapacitors so added electrochemically active materials to boost performance. The team showed that their vapor coating process creates porous conducting polymer films and thick yarns. Electrolyte ions can be added to the threads to boost the storage capacity per unit.

Andrew said that she had to defend her decision of using vapor deposition. She said that despite the high cost of vapor deposition to treat the textiles, it was still more effective than alternatives. The team explained in the study that the technology can be scaled up and made cost effective as well. Their first collaboration will be to figure out how to connect health monitoring into the fabrics. The team is currently working with other engineers at UMass Amherst Institute for Applied Life Sciences’ Personalized Health Monitoring. The center wants to incorporate their new embroidered arrays with e-textile sensors. This fabric will monitor a patient’s gait and joint movements during physical therapy and give the medical teams more accurate reading on the improvement of the patient’s condition.