Since the beginning of the nineties, shape memory alloys (SMA) have become available for microsystems technology. Currently the breadth of research and development activities on SMA microactuators ranges from pure scientific topics of materials research to technological problems, such as micromachining, integration and contacting. The book gives an overview of recent achievements, describing the development of microvalves and linear actuators comprehensively from concept through prototype. Further key aspects included are three-dimensional models for handling complex SMA actuator geometries and coupled simulation routines that take multifunctional properties into account. Mechanical and thermal optimization criteria are introduced for actuator design, allowing an optimum use of the shape memory effect. It is shown that some of the prototypes presented, e.g. SMA microgrippers, already outperform conventional components.