Magazine Articles
The articles below are from the Spring 2009 Issue of the AILU Magazine
Enhancing UV laser machining of medical guide polymers
Lasers are used widely in the manufacture of medical devices. Their ability to produce highly repeatable and accurate features in a non contact and sterile environment is beneficial to an industry where mistakes can cost more than just money. Traditionally medical devices have been made of metal and the main laser processes have been cutting and marking, utilising Nd:YAG and, more recently, fibre laser sources. The items range in size and intricacy from large orthopaedic devices down to micro-scale implantable stents. Minimally invasive medical devices, of which stents are an example, form a large potential market for laser micromachining equipment. As medical devices change in both their form and function, so too must the laser processes be adapted to meet new challenges in terms of materials of construction and cost reduction.
For these applications, polymers will need to be processed in some form, either by cutting, marking drilling or welding, and the existing laser equipment, designed mainly for metal processing, is not capable of doing the job. Although CO2 and other infrared sources can be used to melt polymers, their relatively long wavelength and in some cases their beam quality, prevent micron scale features being produced. New sources and/or processes will need to be developed.
The choice of laser for processing depends predominately on the polymer being machined. The main drivers for the polymer are the bond energies and its absorption spectra. Finding the right laser wavelength is only the start of the solution; part presentation and manipulation, especially for non-flat catheter type products, is also extremely important.
David Gillen
Blueacre Technology Ltd
IMAGE: 250µm diameter cog (on a match head for scale)
AILU members can log in to the AILU web site and download this article free of charge. Otherwise click here to order a copy’
Precision laser cutting
Where conventional cutting technologies like milling, sawing and wire EDM reach their limits, laser cutting opens new possibilities. According to the specific application, the advantages of the laser cutting process can be numerous in terms of efficiency, precision, speed, material variety and flexibility. Many cutting applications are only possible with lasers.
Pulsed Nd:YAG lasers are still the workhorses for fine laser cutting of a broad range of materials - especially highly reflective metals. For the cutting of thin sheets, Yb:Glass fibre lasers and Yb:YAG disk lasers, with their outstanding beam quality, are the lasers of choice. These lasers might not be universal tools like the pulsed Nd:YAG lasers, but especially together with the new Trumpf Cutassist technology new standards have been set in terms of cutting small material thicknesses and increased process speed.
Sublimation cutting using short and ultra-short pulse lasers provides a different approach, resulting in unrivalled cutting quality with negligible heat input on the processed material. From prototypes to serial production the laser demonstrates its superiority wherever filigree housings and structural components with smooth cutting surfaces and sharp cut edges are needed. Deciding which laser is best suited really depends on the specific application.
Evolutionary enhancements in laser fusion cutting technology (e.g. Cutassist technology) have improved the quality and cutting speed, at the same time making the laser even more competitive. In the field of laser sublimation cutting a revolutionary step has been made with the development of industrial ultra-short pulse lasers. The industrial use of picosecond Yb:YAG disk lasers is not only targeted at replacing conventional cutting methods but also at enabling new applications in micro processing.
Alexander Knitsch
Trumpf Laser Gmbh+Co.KG
IMAGE: 3D laser cutting a none reamer made from stainless steel
AILU members can log in to the AILU web site and download this article free of charge. Otherwise click here to order a copy’
Back to top
Subcontract laser-based engineering companies form this group. For more details about their activities, see 
The successful launch of the Design for Laser Manufacture site took place in September 2007, see here. To add your own information, images and videos please contact us.
The Medical Group was launched in 2007. To join the group and influence its development, please contact the AILU Office. For more details see 
The Micro:Nano Group activities were launched at the 10th Microprocessing workshop in June 2008. For more details see 
The aim of the Products and Process Innovation Group is to provide a focus for universities and other organisations involved in laser and/or laser materials processing development and/or research, to identify their common needs and create the possibility of joint initiatives and activities with industrial laser users. For more details see 
The 
