Why Thick Can Be Slick

摘要

A main impediment to the development and commercialization of micro- and nanoelectromechanical systems has been the difficulty in effectively lubricating the small-scale moving parts. Greasing the sliding interfaces in the usual way, with liquids, fails because they are readily squeezed out of the contact region. The resulting friction and wear have catastrophic consequences for the functionality of the device. To keep the lubricant within the contact region, molecules can be functionalized so that they self-assemble into a protective and strongly adhering coating on the surface. But problems still remain, primarily insufficient antiwear performance and the difficulty of scaling up the coating process to the size of a wafer (1).