Blister test to measure the out-of-plane shear modulus of few-layer graphene.

We measure the out-of-plane shear modulus of few-layer graphene (FLG) by a blister test. During the test, we employed a monolayer molybdenum disulfide (MoS) membrane stacked onto FLG wells to facilitate the separation of FLG from the silicon oxide (SiO) substrate. Using the deflection profile of the blister, we determine an average shear modulus of 0.97 ± 0.15 GPa, and a free energy model incorporating the interfacial shear force is developed to calculate the adhesion energy between FLG and SiO substrate. The experimental protocol can be extended to other two-dimensional (2D) materials and layered structures (LS) made from other materials (WS, hBN, .) to characterize their interlayer interactions. These results provide valuable insight into the mechanics of 2D nano devices which is important in designing more complex flexible electronic devices and nanoelectromechanical systems.