An Arizona State University research team has used a variation of origami, called kirigami, as a design template for batteries that can be stretched to more than 150 percent of their original size and still maintain full functionality. The team developed kirigami-based lithium-ion batteries using a combination of folds and cuts to create patterns. The prototype battery was sewn into an elastic wristband that was attached to a smart watch. The battery fully powered the watch and its functions - including playing video - as the band was being stretched. This type of battery could potentially be used to replace the bulky and rigid batteries that are limiting the development of compact wearable electronic devices.