Blister Test to Measure the Out-of-Plane Shear Modulus of Few-Layer Graphene

TL;DR

This paper introduces a blister test method to measure the out-of-plane shear modulus of few-layer graphene, providing insights into interlayer interactions crucial for 2D material-based nano devices.

Contribution

The study develops a novel blister test technique using MoS2 membranes to accurately measure the out-of-plane shear modulus of FLG and models interfacial adhesion energy.

Findings

Measured shear modulus G of FLG as 0.97 ± 0.15 GPa.

Developed a free energy model including interfacial shear force.

Method applicable to other 2D materials and layered structures.

Abstract

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 (MoS2) membrane stacked onto FLG wells to facilitate the separation of FLG from the silicon oxide (SiOx) substrate. Using the deflection profile of the blister, we determine an average shear modulus G 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 SiOx substrate. The experimental protocol can be extended to other two-dimensional (2D) materials and layered structures (LS) made from other materials (WS2, hBN, etc.) 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.