Experimental characterization to fabricate CO2 laser ablated PMMA microchannel with homogeneous surface

Polymethyl methacrylate (PMMA) is widely used for fabrication of microfluidic devices. PMMA, in the recent times, has emerged as an alternative to glass base microfluidic devices owing its convenience in handling, low cost, less weight and excellent optical properties. Due to the high transparency of PMMA and absorption properties in near infrared and UV regions, laser machining can be employed. This work reports characterization of a CO2 laser system, with a wavelength of 10.6 mm, for microfluidic channel fabrication on PMMA. Variety of channels were fabricated by varying CO2 laser system parameters - power, scan speed, pulse frequency and resolution. Power was varied up to its limiting value of 30 W. Surface profile for each of the fabricated channel was recorded and obtained data was analysed. Optimization was done to identify and establish parameters to obtain channels corresponding to specified width and depth. The profile of the channels was observed to have Guassian profile which can be attributed to the Guassian nature of incident laser beam. Effects of post processing using acetone and dichloromethane (DCM) vapour exposure were also studied. (C) 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Advances in Materials & Manufacturing Technologies.