Experimental Research On Micro Channel Processing Of Polymethyl Methacrylate With Excimer Laser Assisted Micro Milling

With the rapid development of high-tech fields,the demand for microfluidic chips is increasing.PMMA is cheap,easy to mold,has good optical performance and biocompatibility,and is a mainstream material for making microfluidic chips.Laser-assisted micro-milling technology as an advanced processing technology provides a new approach to microfluidic chips.Based on the background of laser-assisted micro-milling of plexiglass microchannels,the mechanism of excimer laser-assisted micro-milling was explored.Based on this,a 248 nm excimer laser-assisted micro-milling system was designed and built.Finally,the processing system was set up.The molecular laser-assisted micro-milling of plexiglass microchannels was experimentally studied,and the excimer laser-assisted micro-milling process parameters were preliminary studied.The characteristics of excimer lasers and the characteristics of excimer laser-etched polymer materials are reviewed.Three physicochemical models of excimer laser-etched polymer materials are introduced,including photochemical model,photothermal model and photothermal-photochemical model.The theory of thermal knowledge analyzes the effects of laser radiation and heat generated by shearing on the distribution of temperature field,and combines the mechanism of minimum cutting thickness to lay the theoretical foundation for the next excimer laser-assisted micro-milling experimental research.An excimer laser-assisted micro-milling system was designed.According to the design requirements,the technical parameters of the processing system were proposed,and the system was modularly designed.The main modules included: precision displacement module,micro milling cutter and electric spindle module,laser auxiliary module and online visual inspection module.Planning the layout of the processing system and the configuration of the main components,and according to the accuracy of the distribution program,the main components of the processing system for a reasonable selection.The experimental study of 248 nm excimer laser-assisted micro-milling was carried out,and the influence of different process parameters on the surface quality of the microchannel processing was studied.Experimental factors Within the selected range of variation,scanning speed and spindle speed have a greater influence on the surface roughness(Ra)of the workpiece microchannel.Relative to the laser parameters,the milling parameters have a strong influence on the surface roughness Ra of the microchannel.For laser parameters.Based on the optimized combination of process parameters,the surface roughness of the processed plexiglass microchannels can reach about Ra 50 nm,the edges are clean,and the channel width is uniform.