MIT researchers discovered that crumpling graphene paper (made from graphene sheets bonded together) results in a low-cost material that is very useful for extremely stretchable supercapacitors for flexible devices.
Crumpling the graphene paper results in a "chaotic mass of folds. The researchers developed a simple supercapacitor using this material, that can easily be bent, folded, or stretched to as much as 800% of its original size. The material can be crumpled and flattened up to a 1,000 times, without a significant loss of performance.
To actually make this crumpled graphene paper, the researchers used a mechanical device that first compressed the graphene paper it in one direction, creating a series of parallel folds or pleats, and then in the other direction, leading to a chaotic, rumpled surface. When stretched, the material’s folds simply smooth themselves out. The simple supercapacitor used hydrogel insulating layer (another highly deformable and stretchable material) placed between two crumpled graphene paper electrodes.