ABSTRACT
Because of the very large surface-area-to-volume ratios of micro-devices, adhesion/stiction has been considered the most important failure mode and the major obstacle for the commercialization of micro-electromechanical systems (MEMS). In this chapter, most important surface forces are introduced. The physical origin and mathematical models of these surface forces are presented. Then, adhesion effects such as wetting and surface energy, which are related to these surface forces, are extensively discussed. Self-assembled monolayers (SAMs) have recently received considerable attention as molecular-level lubricants in MEMS. The structure and the surface characteristics of SAMs are introduced. Experiments, molecular dynamics (MD) simulations, and theoretical models on the adhesion force between the atomic force microscope (AFM) tip and sample are discussed in detail. Finally, the adhesion problems related to super-hydrophobic lms are discussed.
