Nitinol Micro Actuators from Sputter Deposition for Local Drug Delivery

Nitinol Thin Films from Sputter Deposition processes is a highly innovative micro manufacturing technology for future micro-mechanical, electronic and actuator systems for smart implants. It is feasible to use different Nitinol functional material behaviours and characteristics for e.g. advanced local drug delivery (LDD) applications. In contrast to the processing of traditional Nitinol semi-finished materials sputter deposition allows the development of sandwich-like systems using highly flexible and active micro structured membranes down to single micro-meter dimensions.

In this study we investigated the mechanical, physico-chemical and fatigue behaviour for two types of LDD concepts. These drug reservoir and pump concepts were based on passive super-elastic and active one-way shape-memory effect. In both concepts the Nitinol Thin Films were processed to a typical Af-temperature (ASTM F2082). The actuation and application dynamics were analysed and optimized by finite element analysis (FEA) to achieve a wide operational window with high accuracy. All system building blocks were mechanically characterized and the fatigue behaviour was examined and compared by accelerated functional fatigue testing. A detailed comparison and correlation between both concepts to quantify the pro’s and con’s of each concept will be presented to give more insights. A weighted matrix based on these results will be reviewed.