Laser welding offers precise heat control for joining two parts with low risk of overburning them. After adjusting laser power and welding speed, the team conducted welding and measured the shear strength of samples. The goal is enhancing the shear strength of plastic sheets by investigating COC, PE, PETG, and PC materials and welding patterns for microfluidic applications. The selection of plastics considered chemical, thermal, and optical factors. Despite advantages of laser welding, welding speed and laser power must be determined to optimize strength and avoid overburning. Limited past studies of plastic absorption for transparent and black colors caused significant deviation in absorption coefficient data. The team conducted laser welding using the Through Transmission method to minimize thermal distortion and ensure uniform bond integrity across the microfluidic interface. Black plastics were placed at the bottom to absorb heat while transparent plastics allowed laser transmission. Samples were cut into smaller pieces and cleaned to remove residue. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were used to collect glass transition and decomposition temperatures for plastic combinations. Based on ASTM D732, samples were tested by Instron to measure shear strength. The lap shear test measured adhesive strength between samples. As the project progresses, the team will investigate different plastic materials, determine the best welding patterns, and optimize the shear strength of final plastic samples.