| AVS 58th Annual International Symposium and Exhibition | |
| Tribology Focus Topic | Wednesday Sessions |
| Session TR-WeA |
| Session: | Emerging Interfaces of Tribological Importance |
| Presenter: | Sidharam Pujari, Wageningen University, The Netherlands |
| Authors: | S.P. Pujari, Wageningen University, The Netherlands H. Zuilhof, Wageningen University, The Netherlands |
| Correspondent: | Click to Email |
Micro-electro-mechanical systems (MEMS) are considered to be an important technology for the development of several products in daily life such as electronics, medical devices, and packaging. Even after tremendous progress in fabrication of miniaturized devices based on silicon materials, the development of highly robust surfaces with low friction and resistance against wear is still a challenging subject of accomplishment . To accomplish this goal, new fluorine-containing terminal alkynes were synthesized and self-assembled onto Si(111) substrates to obtain fluorine containing organic monolayers. Such covalently bound organic monolayers have similar surface properties as polytetrafluoroethylene (Teflon), but these monolayers are more stable than traditionally coated PTFE. The combination of these properties yields a highly improved wear resistantance.
A combination of spectroscopic (XPS, IR), microscopic (AFM), and contact angle measurements shows these monolayers were to be ordered and highly hydrophobic. Increasing the amount of fluorine on the alkyne precursor resulted in monolayers with a greatly reduced adhesion to silica probes, as well as an almost 5-fold decrease in the coefficient of friction on the surface. Overall, this yields a friction coefficient that is – to the best of our knowledge – lower than reported for any other fluorine-containing monolayer. In addition, these fluorinated monolayers displayed no sign of wear at high loads. Therefore, the use of such highly durable fluorine-containing monolayers can significantly expand the range of applications for MEMS. Therefore, this work opens a route to design new materials with tailor-made properties for a wider range of applications in MEMS-based devices.