Because of the difficulty of fabricating rigid-body joints and assembling parts in micro-electro-mechanical systems (MEMS), compliant mechanisms offer several advantages to MEMS designers. However, motion of compliant segments generally involves large, non-linear deflections which are difficult to predict using linear beam theory. This paper discusses MEMS design using the pseudo-rigid-body model. This model has been developed to permit simplified prediction of nonlinear deflections in compliant mechanisms, allowing traditional mechanism theory to be used in design. The design process is validated by testing MEMS structures designed using this model. The model successfully predicted the motion of the compliant MEMS, even for very large deflection paths. The mechanisms designed and tested achieved larger deflections and more complex motion than was previously possible.