This book offers a comprehensive coverage to the mechanics of microelectromechanical systems (MEMS), which are analyzed from a mechanical engineer's viewpoint as devices that transform an input form of energy into output mechanical motion (in the case of actuation) or that can operate with the reversed functionality (as in sensors) and convert an external stimulus, such as mechanical motion, into (generally) electric energy. The impetus of this proposal stems from the perception that such an approach might contribute to a more solid understanding of the principles governing the mechanics of MEMS, and would hopefully enhance the efficiency of modeling and designing reliable and desirably-optimized microsystems. The work represents an attempt at both extending and deepening the mechanical-based approach to MEMS in the static domain by providing simple, yet reliable tools that are applicable to micromechanism design through current fabrication technologies.