Theoretical Analyses for Laser Machining Microchannels and Demonstration of Their Uses in Manufacture of a Microfluidic Optical Switch

Abstract

Silicon has been widely used to fabricate microfluidic devices due to the dominance of silicon microfabrication technologies available. In this paper, theoretical analyses are carried out to suggest suitable laser machining parameters to achieve required channel geometries. Based on the analyses, a low-power CO 2 laser was employed to create microchannels in Acrylic substrate for the use of manufacturing an optical bubble switch. The developed equations are found useful for selecting appropriate machining parameters. The ability to use a low-cost CO 2 laser to fabricate microchannels provides an alternative and cost-effective method for prototyping fluid flow channels, chambers and cavities in microfluidic lab chips.

Print-and-Peel Fabrication for Microfluidics: What’s in it for Biomedical Applications?

“…In addition to mechanical machining, non-contact (e.g., laser and ion-beam) milling offers venues for fabrication of microfluidic devices not only with submicrometer lateral resolution, but also with relief features having small width-to-depth aspect ratios. 12 , 41 , 42 , 78 , 79 Infrared lasers (such as carbon dioxide lasers, widely used for machining and processing) for example, have proven feasible for fabrication of polymer and glass components for microfluidic devices. 16 , 18 , 37 , 42 , 44 Employing ultraviolet lasers for micromachining, on the other hand, allows not only for improved resolution (due to the several-fold decrease in the diffraction limit), but also for utilization of photochemical ablation (due to the photoexcitation at relatively high frequencies).…”

Laser stenciling: a low-cost high-resolution CO2laser micromachining method

“…Furthermore, PMMA is an ideal choice because it is widely used for fabrication processes such as hot embossing and injection molding, making it easier to compare the laser machining technology to other methods [5]. Some example applications of microfluidic devices machined by CO 2 laser ablation include capillary electrophoresis and blood separation chips [8], multi-layer microfluidic structures that incorporate optical fiber technology [9], continuous-flow PCR microfluidic chips [16] and microchannels for manufacturing optical bubble switches [17].…”