Laser microcutting of sheet metal for prototyping expandable stent-like structures in permanent and biodegradable alloys

For biomedical devices, cardiovascular stents in particular, the employed material plays a crucial role in controlling the mechanical and biological behavior. However, the material properties are directly influenced by the production route and the stent geometry. Conventional stent manufacturing route consists of laser microcutting of microtubes. Microtube extrusion and drawing are both costly and time consuming at a prototyping level. Instead, sheet material can be obtained relatively easier using non-dedicated tooling. This work, proposes the use of laser microcutting of thin sheets for producing mesh structures that can be expanded in a tubular form with the aim of assessing processability and expandability. AISI 316L stainless steel and AZ31 Mg alloy are studied representing the well-established permanent stent material and a candidate biodegradable alloy. Surface finishing is carried out with chemical etching. A conventional balloon catheter is used for comparative expandability tests.