Authors: J-W Chen, J. Zybko and J.T. Clements
Affilation: NanoSciences, Inc., United States
Pages: 483 - 488
Keywords: microfluidics, lab-chips, microarrays, polymer MEMS, laser welding
As polymer-based microfluidic devices, lab-chips and diagnostic platforms are pushed towards increasingly smaller geometries, advances in diode laser technology now allow for cleaner and more precise assembly. Coupling the use of photolithographic methods and mask-sets have enabled new assembly and bonding techniques for a wide range of biomedical devices and implantables. Additionally, the growing use of these devices in smaller formats has led to designs requiring a film seal. New technologies integrating diode lasers now makes it possible to join plastic microfluidic structures, and sub-components, by using laser light to join the elements at the interface, producing bond areas with line resolutions as tight as 1 micron. The assembly process is accomplished without adhesives, diffused heat, vibration, or the formation of particulate contamination, and has proven a superior alternative when facing concerns regarding biocompatibility. This technique has demonstrated flexibility not only in the manner in which the laser light can be delivered, but also in the materials which can be joined: from impregnated thin-films to thicker substrate platforms. In addition, laser diode welding can now be achieved with either a moving spot seal or a photolithographic masking process: The mask technique allows for freely definable geometries to be generated on a metal-coated glass using the photolithographic process. Where the metal is etched away, the laser light is allowed to pass, transferring the pattern onto the substrate. Dedicated masks allow for flexibility and an automatic alignment can precisely position the mask within +/- 1.0 microns.