Clothing with integrated electronic technology has a huge number of potential applications in the medical field. This technology can monitor vital signs, like breathing and muscle activity, as well as feed these stats back to computers, allowing cross talk between our clothing and machines.

One challenge in expanding wearables is making an electronic garment that meets the everyday needs of the material. It has to be flexible enough for comfortable movement, waterproof enough to be able to put through a washing machine, cheap enough to be cost efficient, and safe enough for every day close contact with the body.

A team from the University of British Columbia has been able to engineer a battery that fits all of these criteria. “Wearable electronics are a big market and stretchable batteries are essential to their development,” said author Dr. Ngoc Tan Nguyen. “However, up until now, stretchable batteries have not been washable. This is a critical addition if they are to withstand the demands of everyday use.”

The paper, published in Advanced Energy Materials, discussed the way the battery was reimagined from its traditional rigid lithium-ion form to a flexible zinc and manganese dioxide alternative. These materials were embedded in a polymer, forming a stretchable, cheap, and lightweight product. “We went with zinc-manganese because for devices worn next to the skin, it’s a safer chemistry than lithium-ion batteries, which can produce toxic compounds when they break,” stated Nguyen.

So far, the battery can withstand 39 wash cycles, an impressive display of the strong seal. “We put our prototypes through an actual laundry cycle in both home and commercial-grade washing machines,” says Bahar Iranpour, a member of the research group. “They came out intact and functional and that’s how we know this battery is truly resilient.”

The next step for this invention is to improve its power output and lifetime.

Source study: Advanced Energy Materials – Washable and Stretchable Zn–MnO2 Rechargeable Cell