A team from Arizona State University has developed a stretchable battery that can flex without losing power.
Taking inspiration from the Japanese art of kirigami – similar to origami, but with cuts in the paper for added flexibility – researchers have created a battery that can stretch to over 150 percent without breaking or interrupting the power supply. A special “plastic rolling” technique is used to prevent the film from cracking when folded or stretched.
Associate Professor Hanqing Jiang and his team tested their prototype by sewing it into an elastic cuff and using to to power a Samsung Gear 2 smartwatch. The battery maintained power to the watch when flexed, as shown in the video below.
While the prototype shown only supplied 80mAH of power, the researchers noted in their Scientific Reports article that, if scaled up to match the area covered by the elastic band, the kirigami battery could output around 700mAH – more than double the power output of the Gear 2’s inbuilt battery.
Tests also showed that, when compared to the Samsung Gear 2’s battery, the kirigami battery stayed at room temperature while the Gear 2 warmed up noticeably. With less energy lost to the atmosphere, it’s likely that kirigami batteries will also be more efficient and less potentially dangerous to sensitive electronics.
If wearables transition over to flexible batteries, it’s likely that a great deal of weight could be saved while extending the life of the wearable.