Mechanics of microblister tests in 2D materials accounting for frictional slippage

Abstract

The blister test, in which a thin film adhered on a substrate is subject to a uniform transverse pressure from an underlying cavity, is increasingly utilized for the characterization of two-dimensional (2D) materials. Conventional theoretical models of the blister test often assume idealized interfacial conditions such as zero slippage or zero friction. However, experiments indicate that 2D materials can glide over the substrate with a finite interfacial slip resistance. In this study, a theoretical model of blister accounting for frictional slippage at the interface is developed. Subsequent proper normalization makes the model scale independent and serves as a bridge between the actual experiment and molecular dynamics (MD) simulations. On this basis, the inherent differences are revealed between the different interface hypotheses. And especially, to the best of our knowledge, elasticity-adhesion interaction is discussed in detail for the first time under the condition of frictional slippage, enabling a successful amendment to the measurement of interfacial adhesion. Finally, a simplified model is proposed for extracting mechanical properties of 2D materials based on the microblister test.