▎ 摘　　要

Background As a one-atom-thick material, the mechanical loading of graphene in large scale remains a challenge, and the maximum tensile strain that can be realized is through a flexible substrate, but only with a value of 1.8% due to the weak interfacial stress transfer. Objective Aims to illustrate the interface reinforcement brought by formvar resins as a buffering layer between graphene and substrates. Methods Single crystal graphene transferred to different substrates, applied with uniaxial stretching to compare the interface strength, and finite element analysis was performed to simulate tensile process for studying the influence of Poisson's ratio of the buffering layer for interface reinforcement. Results In this work we use formvar resins as a buffering layer to achieve a maximum uniaxial tensile strain of 3.3% in graphene, close to the theoretical limit (3.7%) that graphene can achieve by flexible substrate stretching. The interface reinforcement by formvar is significantly higher than that by other polymers, which is attributed to the liquid-solid phase transition of formvar for more conformal interfacial contact and its suitable Poisson's ratio with graphene to avoid its buckling along the transverse direction. Conclusions We believe that these results can provide guidance for the design of substrates and interfaces for graphene loading, as well as the support for mechanics analysis of graphene-based flexible electronic devices.