▎ 摘　　要

Graphene has huge application potential in the field of micro-nano devices, and due to the micro/nano-level application size, the thermal expansion coefficient of graphene has a certain impact on device performance. In this paper, a comprehensive study was carried out by molecular dynamics on the in-plane and through-plane thermal expansion effect of graphene. First of all, the in-plane thermal expansion coefficients of zigzag and armchair graphene were analyzed; they were similar and relatively close to the experiment value in the temperature range of 223-428 K. Secondly, the through-plane thermal expansion effect of double-layered graphene was investigated; the thermal expansion coefficient of through-plane was an order of magnitude larger than that of in-plane. Finally, the influence of graphene stacking on the thermal expansion effect was studied; Order-stacked graphene has a greater thermal expansion effect than that of AB- and ABC-stacked graphene. These discoveries in this article are of great significance to the development and application of graphene-based micro-nano devices.