Low-Cost and Rapid Shaping of Nitinol for Medical Device Prototyping

This paper describes the methodology for rapid prototyping of nitinol structures by heat setting. Nitinol is a shape memory alloy commonly used in implantable medical devices. The proposed technique, based on 3D printing, can be used to effectively iterate multiple nitinol designs for different types of medical devices. We describe a rapid and low-cost process of ceramic replica molding of standard 3D printed parts to create high-temperature resistant fixtures, suitable for heat setting of nitinol. The technique represents a low cost (<$20 materials per fixture) and rapid (as quickly as 16 h for a volume less than 1.25 × 105 mm3) method for shaping nitinol, a technique that typically is costly, labor intensive, and requires specialized equipment. Our method satisfies a need for cost-effective, rapid prototyping of nitinol for implantable medical devices, and we show an example set of shaped nitinol wires, clips, and stents. This method is straightforward and can be easily applied by researchers to rapidly iterate medical device designs.