Energy Based Analysis of Laser Microchanneling Process on Polymethyl Methacrylate (PMMA)

CO₂ laser micromachining provides low cost machining solution for fabrication of three dimensional microfluidic channels on poly-methyl-methacrylate(PMMA). In this research work CO₂ laser microchanneling process has been analyzed from the first principle. Considering the Gaussian distribution of laser beam, an energy based model has been proposed to predict the microchannel depth and channel profile. For fabricating microfluidic devices, PMMA has emerged as a cheap alternative to many other costly materials like silicon, quartz etc. Its material properties like absorptivity and thermal properties have been investigated. In order to physically verify the proposed model, experiments have been performed on a 3 mm thick PMMA sheet and actual and predicted results have been compared. Simultaneous TGA/DSC tests have been conducted to determine various thermal properties of PMMA. Since thermal conductivity of the PMMA is very low, the conduction loss has been neglected while developing the model. The proposed model successfully predicts the channel depth and profile without much loss of accuracy. energy based analysis has been found to be simple yet powerful method to predict the channel dimensions for low thermal conductivity materials.