Experimental Study of Tribological Properties of Silicon-Based MEMS/NEMS Surface with Atomic Force Microscope

A comparative study of the micro-tribological properties of silicon-based component and octadecyltrichlorosilane (OTS) molecular lubricant film which was prepared on Si(100) substrate, and their adhesive and tribological properties were mainly investigated by AFM/LFM. Meanwhile, the effect of relative humidity and scanning velocity was taken into consideration. The results show that the adhesive force of OTS film is much smaller the one of Si (100) substrate which leads to a relatively low friction coefficient, thereby the OTS film presents better lubricant performance; Besides, the Si(100) substrate is much more affected by the variation of humidity than OTS film; The velocity effect on the frictional performance is more significant for Si(100) component due to the Si(OH)4 lubricant film caused by the tribo-chemical reaction. A thermally activated capillary condensation model while taking the surface roughness effect into consideration is also adopted to explain the humidity and velocity effects on the adhesive and tribological properties theoretically. In addition, the durability tests indicate that the OTS lubricant film exhibits not only better wearability but also stability comparatively