Mechanical stability and sticking are the troublesome problems in microfabrication andoperation processes when separations of components in MEMS are in the sub-micrometer regime.Some mechanical effects including quantum mechanical effect should be taken into account forsolving the problems. The influence of capillary forces on sticking of a surface micromachined mi-crocantilever in ambient environment or the rinse liquid and the influence of quantum mechanicaleffect such as the Casimir effect on sticking and stability of a micro membrane strip cavity structurein vacuum were investigated. A factual rough model theory about sticking problem under theCasimir effect was suggested for the first time. The study on the design of anti-sticking structuresunder different forces shows that sticking and stability of microcantilevers and micro membranestrip cavities has something to do with Young’s modulus of materials, surface properties, length ofstructures, thickness of structures and separation between the fixed surface and the deflectingcomponent. But, it is independent of width of structures. The map of the size design of anti-stickingstructures was put forward for the first time. This also provides a way to design a MEMS structurewith high resistance to collapse. Mechanical stability and sticking are the troublesome problems in microfabrication andoperation processes when separations of components in MEMS are in the sub-micrometer regime. Mechanical effects including bestial mechanical effects should be taken into account forsolving the problems. The influence of capillary forces on sticking of a surface micromachined mi-crocantilever in ambient environment or the rinse liquid and the influence of quantum mechanic effect such as the Casimir effect on sticking and stability of a micro membrane strip cavity structure in vacuum were investigated. A factual rough model theory about sticking problem under the Casimir effect was suggested for the first time. The study on the design of anti-sticking structuresunder different forces that that sticking and stability of microcantilevers and micro membranestrip cavities have something to do with Young’s modulus of materials, surface properties, length ofstructures, thickness of structures and separation between the fixed surface and the deflectingcomponent. But, it is independent of width of structures. The map of the size design of anti-stickingstructures was put forward for the first time. This also provides a way to design a MEMS structure with high resistance to collapse .