Capability Of Sputtered Micropatterned NiTi Thick Films

Today, most NiTi devices are manufactured by a combination of conventional metal fabrication steps, e.g. melting, extrusion, cold working, etc., and are subsequently structured by high accuracy laser cutting. This combination has been proven to be very successful; however, there are several limitations to this fabrication route, e.g. in respect to the fabrication of more complex devices, miniaturization, mechanical properties, the combination of different materials or the integration of further functionality. These issues have to be addressed in order to develop new devices and applications.

The fabrication of micro patterned films by using magnetron sputtering, UV lithography and wet etching has been demonstrated to have a great potential to overcome limitations of conventional device manufacturing. Due to its fabrication characteristics, this method allows the production of devices with high structural accuracy, smooth edge profile, at layer thicknesses up to 75 µm and consequently high aspect ratios. The aim of this study is to present recent developments in this field of technology, its advantages, as well as new possible applications in the medical and non-medical field. These developments include among others membranes for micro pumps, tensile TEM grids or connector structures, as well as NiTi structures covered with NiTi membranes for their potential use as filters, heart valve components or aneurysm treatments. The properties of these devices will be discussed.