Cold-marking of medical devices
All medical instruments have to be labeled according to the Unique Device Identification System (UDI). The most practical technology for this application is laser marking. The laser beam makes a permanent modification to the surface of the object, which – as opposed to printed labels cannot be removed by solvents. Therefore the micron scale resolution enabled by the laser beam allows for the marking of even the smallest medical devices. Stainless steel, which most medical instruments are made of, is typically resistant to chemical reagents used for sterilisation before use. However, after marking the surface by CW or long pulse lasers, stainless steel is locally overheated and tends to have its properties altered. This results in corrosion in the modified areas, especially after washing devices in aggressive chemical reagents.
The marking of surfaces using femtosecond lasers features a minimal Heat Affected Zone (HAZ). The top layer of the surface is almost instantly evaporated and the layers below remain practically unaffected. This process is also called ‘cold ablation’. By selecting the appropriate pulse energy, scanning speed, number of pulses in burst, or changing pulse duration, it is possible to achieve high contrast black or white marking on the stainless steel. This method is ideal for medical application marking, since the stainless steel doesn’t lose its properties and these marks can withstand various working conditions.
Indylit 10 laser is a perfect tool for the marking of medical devices. It has a broad range of variable parameters like: pulse repetition rate (single pulse to 1 MHz) , pulse energy (up to 100 µJ), burst mode, pulse duration (450 fs – 3 ps), which allows to select the best regime for desired result. The laser is air cooled and compact which makes its integration into the laser marking system much easier. Excellent beam quality (M² and circularity) allows to make smallest marks with the best resolution.