The production technology for nickel-titanium alloy self-expanding vascular stents continues to evolve.

Nickel-titanium alloy rope self-expanding vascular stents have likely undergone three major technological evolutions: spiral-coil structures, braided mesh支架, and fiber-optic laser-cut tubular stents.

Medical Nitinol Alloy Stent Performance Parameters

The electromagnetic coil-shaped stent is constructed from nickel-titanium alloy wires coiled into a compact structure. It’s easy to manufacture and highly flexible, but its main drawbacks include insufficient compressive strength and limited popularity—often leading to restenosis after surgery. As a result, this approach has gradually been phased out. In contrast, the mesh tissue stent is crafted by weaving nickel-titanium alloy filaments together, offering excellent flexibility yet relatively poor rigidity, which can sometimes cause displacement. Consequently, this type of stent is now used less frequently in clinical practice. On the other hand, the fiber-optic laser-cut tubular stent is currently the most widely used variety in clinical medicine. It’s manufactured using laser marking technology, which effectively addresses the shortcomings of earlier-generation designs. Notably, this stent avoids spot-welded structures altogether, and its contact with the diseased inferior vena cava is achieved through surface-level contact rather than point-to-point contact. This design significantly enhances its interaction with the vessel wall, minimizing the risk of displacement while maintaining robust load-bearing capacity—and all without compromising its slim profile.

The production technology for nickel-titanium alloy self-expanding vascular stents continues to evolve. Currently, the conventional methods used to manufacture nickel-titanium alloy wire vascular stents still face several challenges, including high product costs, limitations in the overall stent design, difficulty in achieving complex shapes, and the inability to meet critical performance requirements such as precision and smoothness.

PS selective laser melting has emerged as a novel additive manufacturing process for self-expanding nitinol alloy stents, though it hasn’t yet evolved into a fully commercialized technology for vascular stent production. Still, research institutions and scientific organizations have been actively exploring this application for several years, with key breakthroughs focusing on advancing more complex designs, refining nitinol alloy powder materials, and optimizing the additive manufacturing processes themselves. At the end of this article, 3D Science Valley highlights some of the most notable research achievements in China’s additive manufacturing sector for nitinol alloy vascular stents.

Process Development and Printing Material Formulation

A method has been developed to fabricate memory metal (nitinol alloy) vascular stents using a fully automated powder-bed laser processing technique—specifically, selective laser melting 3D printing. This method starts with the 3D solid model of the part to be processed, employing a high-energy laser to melt and fuse a powdered material system. By sequentially layering the powder and progressively melting and solidifying each layer, the process builds up the stent blank into its final reticulated structure. Finally, electrochemical polishing is applied to achieve the required ultra-smooth surface finish.

This method of fabricating vascular stents leverages the superelastic properties and shape-memory effect inherent in memory metals, further reducing the incidence of capillary restenosis during clinical treatment. Based on physical performance tests and bio-environmental simulation studies, the vascular stents demonstrate excellent biocompatibility with both surrounding tissues and blood, meeting stringent medical application standards. Additionally, the use of laser-based fabrication technology ensures exceptionally high precision in manufacturing, while the inert-gas protection applied during the molding process effectively addresses common challenges encountered in traditional stent production—such as rough surfaces, burrs, and oxidation—thereby enhancing the overall quality and reliability of the final product.