Efficient and Robust Fabrication of Microscale Graphene Drums

Few-layer graphene drums have been extensively studied as bulging devices to analyze their mechanical and optical properties. A controllable and efficient fabrication method of such drums is of great significance for related studies. We propose a one-step approach to fabricate graphene drums through modified mechanical exfoliation. Graphene sheets are annealed on the prepatterned SiO2 substrate with micrometer-sized holes. With such an approach, one can fabricate graphene drums with larger height using higher annealing temperature or larger holes. Larger strain within the graphene drums could also be achieved using a higher annealing temperature. The strain of the graphene drums gradually decreases over time within 24 h. The underlying mechanism is attributed to the diffusion of gas molecules initially trapped at the graphite/substrate interface. This self-consistent mechanism prevents the drums from being destroyed by the pressure difference across graphene layers in principle. Compared with the existing method, our method provides an efficient and robust way of studying the mechanical, electrical, and optical properties of graphene, especially for the effects of strain and curvature.