Excimer laser fabrication of polymer microfluidic devices

Silicon has been a primary material for fabrication of microelectromechanical systems (microfluidic devices in MEMS) for several decades. This is due to the fact that the MEMS techniques were derived from those used for microfabrication in the semiconductor industry. These techniques are well developed, and can be readily applied for silicon based MEMS fabrication. Nowadays, alternative manufacturing materials and techniques are needed for reducing costs and meeting new requirements. Polymers have many advantages because of their low costs and applications in microfluidics. This article describes processes for fabricating polymer-based MEMS, including machining and bonding techniques. Microfluidic parts are machined on polymers with a KrF excimer laser (λ=248 nm). Mask patterning and direct laser writing techniques are used. A silicon-on-glass process and an infrared laser bonding process are applied to assemble the machined parts with transparent cover glasses or plastics. As an example, a polymer micropump is fabricated and tested. It is shown that with the use of polymer materials, the performance of the pump is greatly improved.