scientists create the first stretchable and washable battery

one step closer to comfortable and convenient wearable tech

researchers at the university of british columbia (UBC) in canada have created a battery that works even when stretched to twice its length or after being washed. developed by dr. ngoc tan nguyen and his colleagues bahar iranpour, evan cheng and dr. john madden, the flexible, washable battery could revolutionize wearable devices.

dr. ngoc tan nguyen explains,‘wearable electronics are a big market and stretchable batteries are essential to their development. 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.’

dr. ngoc tan nguyen

images by kai jacobson/UBC

to make it flexible, the team ground the key compounds of the battery—zinc and manganese dioxide—into small pieces and embedded them into a rubbery plastic. the battery comprises several ultra-thin layers of these polymers wrapped inside a casing of the same polymer. this construction creates an airtight, waterproof seal that ensures the integrity of the battery through repeated use.

to test the waterproof seal, PhD student bahar iranpour suggested tossing the battery in the laundry. so far, it’s withstood 39 wash cycles.‘we put our prototypes through an actual laundry cycle in both home and commercial-grade washing machines. they came out intact and functional and that’s how we know this battery is truly resilient,’ says iranpour.

on the choice of zinc and manganese dioxide, nguyen explains, ‘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.’

the battery is embedded in a rubbery plastic to make it flexible

in addition to its flexibility and washability, the team at UBC also says the battery is affordable.‘the materials used are incredibly low-cost, so if this is made in large numbers, it will be cheap,’ says dr. john madden, director of UBC’s advanced materials and process engineering lab who supervised the work.

the research has been published in a paper here and the researchers are already working to increase the battery’s power output and cycle life. the battery could be applied to watches and patches for measuring vital signs, and integrated with clothing that can actively change color or temperature.

‘wearable devices need power. by creating a cell that is soft, stretchable and washable, we are making wearable power comfortable and convenient,’ concludes madden.