A Tribological Study of Multiply-Alkylated Cyclopentanes and Perfluoropolyether Lubricants for Application to Si-MEMS Devices

Lubrication of Micro-Electro-Mechanical Systems (MEMS) is a major constraint in MEMS applications, restricting the designs and practical usages of such devices. Possible lubricants and methods have been investigated in this paper, comparing perfluoropolyether (PFPE) lubricant with multiply-alkylated cyclopentanes (MACs). The effectiveness of both the lubricants in reducing friction and enhancing the wear life was investigated in a new method of MEMS lubrication known as Localised-Lubrication or “Loc-Lub.” Friction and wear tests were conducted in a flat-on-flat test geometry under a normal load of 50 g and a sliding velocity of 5 mm s^?1 in reciprocation, with Si as the substrate. Further tests were conducted at higher loads, to compare wear durability between lubricants and methods. It was found that MACs have a propensity to remain cohesive during the tests due to higher surface tension and provide better friction and wear properties when tested under reciprocating sliding conditions, as a complete film is present between the two surfaces. The results show that MAC lubricant is more effective in extending the wear life and reducing friction under the tested conditions compared to PFPE.