Low-cost chemical surface smoothing of CO2 laser-etched acrylic using WELD ON 4 acrylic solvent cement

With the increasing use of micro-manufactured devices and the demand for low-cost fabrication techniques, this study presents a simple and scalable surface polishing method for laser etched acrylic using WELD-ON 4 acrylic solvent cement, a solvent typically used for bonding thermoplastics. The method’s effectiveness was evaluated by treating acrylic samples up to three times and analyzing changes in transparency, surface roughness average (Ra), luminescence, and wettability. Results show that even a single treatment significantly improved surface smoothness, reduced light scattering, and brought contact angle and optical clarity closer to those of unetched acrylic. After three treatments, the surface became isotropic, with laser-etched lines disappearing. Specifically, a 60% reduction in Ra was observed in the direction perpendicular to the etched lines, while the parallel direction initially showed a similar trend, followed by a slight increase attributed to the formation of surface irregularities caused by the re-solidification of dissolved acrylic. Contact angle measurements indicated that the surface remained hydrophilic, with controllable wettability based on the number of treatments. Overall, this method provides a low-cost, cleanroom-free solution for improving the surface finish of laser-fabricated acrylic components. Its compatibility with complex or recessed geometries makes it particularly suitable for microfluidic devices and other precision applications requiring both optical clarity and controlled surface properties.