Modeling the micro-scale static friction coefficient of the MEMS silicon surfaces affected by Ag and Au deposition using the thermal evaporation method

Abstract

In different macro-scale applications, regarding what should be done, many of the prepared surfaces are immediately used after machining with no limitation. Since the micro-electromechanical applications have different conditions, their different properties, such as friction and adherence, must be checked. In the present study, using the thermal evaporation method, the silver and gold layers with different thicknesses were deposited on the silicon surfaces widely used in micromechanical systems (e.g. micro-assembly). Thereafter, the effects of the deposition on the geometrical properties of the surfaces were studied. Also, the effects of the deposition on the adherence and friction properties of the surfaces were examined by modeling the geometrical condition. To this end, the height function distribution was used to exploit the surface friction model in conjunction with the DMT surface adhesion model. The results show the extent to which gold affects the adhesion and friction properties of the coated surfaces.

Keywords:

• Micro/nano-scale friction
• thermal evaporation deposition
• surface roughness
• adhesion forces
• micro-electromechanical systems