Laser materials processing is used across virtually every material, application, and industry due to its high precision, speed, and quality. Fiber lasers have seen widespread adoption due to their ease of integration and reliability. There is no such thing as a one-size-fits-all fiber laser, however – laser parameters like pulse duration and pulse energy have a dramatic impact on feature quality.
The cutting, welding, and marking of plastics and polymers can present unique challenges for traditional laser processing solutions. This is especially true for precision medical devices, which require high-quality features to ensure maximum device performance and patient safety.
Melting and other small imperfections caused by heat are a particular problem for medical device manufacturers. As a result, many are turning towards ultrafast lasers which offer “cold processing” to create these critical polymer components while avoiding excess heat.
How Do Ultrafast Lasers Work?
Ultrafast pulsed lasers, also referred to as ultrashort pulse lasers, emit extremely short pulses of focused light measured in femtoseconds or picoseconds. These ultrafast pulse durations mean that the laser energy interacts with the target material for just trillionths or quadrillionths of a second, substantially reducing the heat imparted compared to continuous wave processing.
Ultrafast lasers deliver exceptionally high peak power without inducing thermal effects on surrounding materials. The ultrafast pulse duration greatly limits the time available for heat to diffuse into the material surrounding the part feature. The result is “cold ablation” where individual pulses remove an extremely small volume of material as vapor while creating virtually no heat-affected zone.
Ultrafast Lasers vs. Nanosecond Lasers
Nanosecond lasers emit pulses of laser energy measured in billionths of a second. Compared to continuous wave and quasi-continuous wave lasers, nanosecond lasers offer significantly increased quality in many precision applications such as foil cutting and some micro-welding operations. However, nanosecond laser processing still has considerably more thermal impact on target materials than ultrafast lasers. Although this thermal impact is acceptable in most applications, excess heat must be avoided in precision medical devices.
(A) The edge of a polycarbonate blind disc machined with a nanosecond laser that displays excessive melting.
(B) The edge of a polycarbonate blind disc machine with an ultrafast laser displaying virtually no melting.
Excess heat can cause melting, foaming, carbonization, and combustion in sensitive polymers, rendering precision medical devices unusable. Consequently, ultrafast lasers have steadily increased in use for various medical devices, including medical tubing, catheters, and sensors for monitoring equipment.
The benefits of ultrafast laser processing extend beyond reduced heat-affected zones. The high peak power of ultrafast lasers enables the creation of permanent UDI marks critical for UDI traceability and compliance. Additionally, ultrafast lasers offer unmatched control over the precision and size of medical device features, such as cut widths and hole size. This allows engineers to optimize polymer part designs for improved performance, such as superior bending characteristics.
Getting Started with a Medical Device Laser Solution
Selecting the right ultrafast laser and laser process is crucial for maximizing quality and throughput in medical device applications. Fortunately, the laser welding experts at IPG are ready to help. Getting started is easy – send us a sample, visit one of our global application labs, or just tell us about your application.
