New method found to handle individual graphene sheets

MIT Technology Review : Researchers having been creating graphene sheets by cleaving single layers from larger pieces and carving them into the proper shape. But it is difficult to then pick up the tiny pieces and move them around. Although Scotch tape works well for that task, it picks up everything it touches—the targeted flakes and untargeted ones alike. Now Xu-Dong Chen and colleagues at Nankai University in China have found a way to improve the Scotch tape technique: They first use a laser to carve a particular graphene flake. Then they cover the entire substrate with photoresist. Shining a laser on the photoresist above the patterned graphene dissolves the photoresist and frees the patterned graphene flake, which can then be picked up by the Scotch tape. The eventual goal is to be able to isolate and stack selected layers of graphene sheets to create van der Waals heterostructures that exhibit superconductivity and other exotic electronic behavior.