Laser Cut Hypotubes
Precision Mandrels, Wires and Tube Components for Medical Devices
We use laser cutting to produce mandrels and other hypodermic tube components where superior flexibility is required in the final product. Laser cut hypotubes are an alternative to the use of continuous coil made from round or flat wire. Laser cutting thin wall stainless tube or nitinol tube provides scope for variation in axial and longitudinal movements in comparison with wound coils, although the latter are a more economic solution where they can be used.
Thin wall stainless steel and nitinol tube can be cut at intervals along each tube to confer varying degrees of flexibility along the tube length. Laser cutting also allows entry and exit holes, slots and notches to be cut in tube.
Laser Cutting Process
The laser cutting process employs a focused laser beam to melt or ablate metal, creating a cut with a width known as the kerf width. Laser spot size is the main determinant of the kerf width of a cut, but the kerf width will generally be slightly larger than the laser spot size, and also depends on the material, its thickness, the power, type and speed of the laser cut. Types of lasers used to cut stainless steel and nitinol include Nd:YAG, fibre, picosecond, and femtosecond.
Femtosecond laser cutting avoids heat input into the part and thereby also cuts the build up of oxides, minimizing post-processing.
Applications of laser cut hypotubes
Articulating probe
Flexible nitinol wires pass through a rigid precision stainless steel tube to enable articulation of the tube end. This in turn allows surgery to take place around corners as the straight tube which is inserted into the end of the keyhole instrument turns into a hook at its end.
Should a more sophisticated steerable approach to the working site be required, there are alternative approaches to assembly, including the use of tube laser cutting, or a by welding or induction vacuum brazing a separate, more flexible nitinol tube to the end of the rigid stainless tube.
Ring electrodes
Stainless steel electrodes are cut to micron precision, allowing copper-based conducting wires to subsequently be laser welded to the electrode itself.
Thin Wall Tubes
Thin-wall stainless steel tubes and hypotubes can be precisely and cleanly cut to length by laser cutting. Whilst abrasive wheel cutting and electrochemical cutting are generally more economic, they are less successful then laser cutting for short tube lengths (below 3mm) and for very precise cutting with low kerf widths. This is where laser cutting becomes the preferred tube cutting method.
