Use of Sheet Material for Rapid Prototyping of Cardiovascular Stents

Manufacturing of cardiovascular stents most commonly involve the use of tubular precursors and laser microcutting of the stent mesh, followed by chemical and electrochemical surface treatments. For mass manufacturing purposes, this production route is well-established, while for small batch or prototype production it proves to be cumbersome. Especially concerning newly developed alloys based, the production of microtubes is time consuming and highly costly. On the other hand, production of these new alloys in sheet metal form is a simpler approach, since the process uses non-dedicated tools and is easier as opposed to extrusion and tube drawing. Accordingly, in this work, the use of sheet material as precursor for rapid prototyping of cardiovascular stents is proposed. In particular, a ns-pulsed fiber laser is used for cutting permanent AISI 316L. Laser microcutting conditions are investigated in terms of generated spatter and kerf geometry. Chemical etching is employed to clean the dross generated around the cut kerf. A novel stent geometry allowing for transforming the sheet material to a tubular form is employed to produce prototype stents.