3D Finite Element Modeling of Laser Machining PMMA

In order to predict groove shape on laser direct-write polymer microfluidic chip, a three-dimensional transient ablation model has been developed based on heat conduction theory and energy conservation at the erosion surface. The laser is assumed continuous wave Gaussian beam. The finite element surfaces on evaporation side are non-planar and approximated by bilinear polynomial surfaces. An iterative scheme is used to handle the geometric nonlinearity due to the unknown groove shapes. Numerical results about groove shapes and temperature distributions are presented and also compared with those experimental results. The model has been tested using PMMA(polydimethylsiloxane), it is found that numerical results show good agreement with experimental data