"Nitinol Thin Films for Medical Devices: Past Attempts and Vision for the Future"

Although Nitinol thin film technology has been proposed as a new manufacturing process almost 20 years ago but applications for medical devices were still lacking. The authors review early research work and attempts to use Nitinol sputter technology for micro actuators and medical devices, such as filters, stents, grafts, drug eluting and micro patterned surfaces. Limitations of past efforts, such as limited film thicknesses and little data in mechanical and fatigue performance have hampered the potential application of sputter technology for new generation medical devices. Recent data suggest that Nitinol thin film structures can reliably be produced up to approximately 70µm thickness. Although characteristics of thin films are not yet fully understood, superior tensile test and fatigue data have been demonstrated compared to conventional Nitinol. The possibility to obtain “thick film” structures with predictable mechanical data opens a wide range of future potential medical applications. A significant future potential as BioMEMS devices and in the areas of neurostimulation, cardiac rhythm management, ophthalmology, cochlea implants and other applications.