Rofin's stent cutting system uses a femtosecond laser

Manufacturing medical devices from tube stock typically relies on laser fusion cutting with pulse widths in the µs-scale. Even with an optimum setup this cutting process is not completely free from burrs and recast inside the tube, requiring post-processing by ultrasound polishing on stainless steel and CoCr. The shape memory alloy nitinol can, in certain instances, be prone to chemical and mechanical damage during post-processing. However, the only post-processing required with femtosecond lasers is simple ultrasonic cleaning. This improves post-processing efficiency significantly, in particular with such sensitive materials. Femtosecond lasers process materials faster than energy can diffuse within the atomic lattice, therefore no heat is transferred to the surrounding material, which in turn eliminates any recast, burr and distortion. Bio-absorbable stents are at the heart of numerous research and development activities. But the use of bio-absorbable polymers such as polylactic acid and polyglycolic acid has suffered due to their low melting points. This makes them very difficult to machine with traditional cutting lasers and the resultant heat affected zone resulted in unacceptable cut quality. In contrast, femtosecond lasers have achieved excellent results with vascular stents showing high-precision edge quality. Bio-absorbable polymers edges can be cut perfectly with high precision despite their low melting points and poor absorption The StarCut Tube Femto mechanics have been adapted to the specific requirements for handling thin-walled, mechanically fragile semi-finished products.