Laser Transmission Welding (LTW) is a highly efficient and reliable technique for joining thermoplastic polymeric materials. Initially popularized in the automotive, mechanical, and electronics industries for welding large plastic parts, this method has now become increasingly valuable in microfabrication—especially for sealing microfluidic chips.
How Laser Transmission Welding Works
The LTW process involves two polymer layers:
-
One must be optically transparent to the laser’s wavelength.
-
The other must be absorbent to convert the laser energy into heat effectively.
When the two parts are pressed together under a controlled force, the laser beam passes through the transparent top layer and is absorbed by the bottom absorbent layer. This energy absorption transforms optical energy into heat, which then conducts upward, softening both polymer layers at the interface. The resulting localized melting and mixing of materials enables the formation of a strong, precise, and hermetic bond (see Fig. 1).
Benefits of Laser Transmission Welding for Microfluidics
-
Clean and Particle-Free Sealing: No adhesives or mechanical fasteners are needed.
-
High Precision: Perfect for delicate microchannels and intricate device layouts.
-
Scalable and Repeatable: Suitable for both prototyping and mass production.
-
Biocompatibility: Maintains the chemical integrity of lab-on-chip devices.
Applications in Microfluidic Technology
Laser transmission welding is now a go-to technique for fabricating microfluidic devices used in diagnostics, drug delivery, cell analysis, and lab-on-a-chip applications. Its ability to create micro-scale, leak-free seals makes it ideal for ensuring the integrity and performance of biomedical and analytical systems.
Want to Know More?
At Microfluidic. tech, we explore the latest manufacturing methods for lab-on-a-chip systems, including laser welding, soft lithography, and micro-milling. Subscribe to our newsletter or contact us to learn how we can help optimize your microfluidic design and prototyping workflow.
