Ultrashort pulse (USP) lasers are an established technology to manufacture nitinol medical devices. USP lasers offer a great variety of processing parameters which can be utilized for fine cutting, laser lathe and ablation of nitinol. Usually, several hundreds of kHz are used to penetrate the material with pulses of fixed energy and frequency. New USP laser sources are offering a so-called burst mode which can be used to precisely control the energy deposition into the material by adjusting the temporal pulse distribution. Depending on the applied process parameters, this leads to a cut through or ablation of some material besides a modification of the irradiated surface. Previous work showed that the bulk material is not affected by such laser light whereas the laser-matter interface is changed. The perpendicular irradiated surfaces are dominated by laser-induced periodic surface structures (LIPSS) which are oriented to the direction of polarization of the laser beam and by cone-like protrusions (CLPs). These modified surfaces allow, e.g., different roughness, wetting, corrosion, bioactivity, and ultimately tribological properties. The effect of such femtosecond laser-generated structures was shown for stainless steel and titanium. Complex medical devices might benefit from locally adjusted surface properties e.g. reduced frictional force between tissue and device or improved adhesion due to an increased surface area through microstructures.

Advanced micromachining processes like laser micromachining, electric discharge machining (EDM) and milling are key processes when fabricating Nitinol medical devices. Unfortunately, each machining process alters the thermomechanical properties of Nitinol - especially around the processing zone. To judge how much this affects the functionality of Nitinol devices, precise knowledge about the micromachining processes applied is crucial. Performance of a medical device from a manufacturer point of view is governed by its geometry. Attainable geometries are linked to the respective machining technology. Lastly the process itself might be limited concerning surface roughness, contour accuracy, and aspect ratio. Ecological aspects include the achievable material removal rate (MRR, volume per time) and necessary post processes. In this work, the authors report on recent developments in the field of micromachining Nitinol, especially in which way the respective technology affects the properties and the design of medical components. A comparative analysis of micromachining technologies is presented.