Shape memory micro-mechanisms for medical applications

This paper describes the design of micro-mechanisms actuated by shape memory alloys to be used for different medical applications. They are all illustrations of a very simple micro-actuation technology conceived around a wire-like shape memory element. At the same time they show how a hybrid microsystem can be conceived and what are the specific problems when applying shape memory micro-actuation. Four different systems are described. The first one is a very simple microvalve to be used in drug delivery systems. The three other examples are situated in the minimal invasive surgery area: a mirror actuation system, a zooming system, and a bending actuator for colonoscopy.