A first-principles calculations investigate the superlubricity and adhesion performance of structural superlubricity micro-components on polydimethylsiloxane surface

Abstract

Adhesion and friction are crucial considerations in the design of microelectromechanical systems because they can directly influence the energy, dissipation and wear of the system. Current related studies are primarily conducted between graphite and hard materials, such as graphite, mica and gold, but lack the theoretical support of superlubricity on the surfaces of related flexible substrates, such as Polydimethylsiloxane (PDMS). Consequently, friction and wear at the flexible interface represent a significant challenge in the failure of microelectromechanical systems devices. In this paper, we use density functional theory to simulate the adhesion characteristics and friction behaviour of structural superlubricity micro-components on the surface of a flexible substrate in an atmospheric environment. The lower graphene layer of the structural superlubricity micro-components exhibits superior adhesion performance with the PDMS substrate. The increase in normal load is simulated by changing the spacing of layers. The interlayer bonding energy increases with increasing load. The transverse friction increases gradually with the increase in load, while the average friction coefficient decreases. Graphene can reach the superlubricity state on the PDMS substrate. The reliability of this phenomenon is verified by electrical performance. We also investigate the effect of tensile strain on the friction behaviour and electrical properties. These calculations should be combined with analysis of the mechanical properties to verify the reliability of the friction performance.