Fibre Laser Microchanneling of Polymethyl Methacrylate (PMMA)
A. Sen, B. Doloi and B. Bhattacharyya
Experimental studies of fibre laser microchanneling on polymethyl methacrylate (PMMA) sheets at atmospheric conditions intend to find out the effect of various process parameters on the response criteria: depth and width of the microchannels and the widths of the heat affected zone (HAZ). A basic experimental study has been reported for the microfabrication of PMMA microchannels to utilize them for various microfluidic applications. The significance of the current research work is not only confined to facilitate the fibre laser system for microfluidic applications, but also to improve the aspect ratios (microchannel depth/width) of the fabricated microchannels as well as to identify significant reduction of HAZ from the microchanneling zones. The various process parameters: scan speed; average power; pulse frequency and number of passes with different ranges, were considered to achieve the aforementioned response criteria. The range of the process parameters includes scan speed of 10 to 300 mm/s, pulse frequency of 50 to 90 kHz, average power of 5.0 to 15.0 W and number of passes of 1 to 5; while pulse width was held constant at 90% of the cycle time. The experimental research work also includes the physical phenomena behind the fibre laser microchanneling of PMMA as well as the intricate analyses and explanations of each process parameter on the outcome of the microchannel geometries.
Keywords: Fibre laser, poly(methyl methacrylate) (PMMA), microchanneling, heat affected zone (HAZ), photo-thermal process, photo-chemical process