Rofin, Starnberg, Germany, has released the new StarCut Tube Femto, one of the first systems to offer cold laser cutting for medical device manufacturing.
Femtosecond lasers process materials faster than energy can diffuse within the atomic lattice. Therefore, no heat is transferred to the surrounding material, which eliminates any recast and burr. The StarCut Tube Femto integrates a compact laser source with field-proven high reliability and long-term stability, essential properties for industrial manufacturing, but hard to find in ultra-fast laser sources.
Manufacturing of 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 free from burrs and recast inside the tube. Thus post-processing usually includes steps like broaching, chemical etching for removing of oxide layers and electrochemical polishing for edge rounding. The nitinol material (memory shape alloy) is prone to chemical and mechanical damage during post-processing in many cases. With femtosecond lasers, post-processing is shortened to a simple ultrasound cleaning. This improves post-processing efficiency significantly, in particular with these sensitive materials.
Bio-absorbable stents are at the heart of numerous research and development activities. But the usage of bio-absorbable polymers like polylactic acid and polyglycolic acid suffered from their low melting points, making them very difficult to machine with traditional cutting lasers. The large heat affected zone was responsible for heavy micro-structural changes. In contrast, femtosecond lasers already have achieved good results with vascular stents, showing perfect high-precision edge quality.
The StarCut Tube Femto mechanics were adapted to the specific requirements for handling thin-walled, mechanically fragile semi-finished products. The new system complements the StarCut Tube series.