采用CO2激光直写加工技术在聚甲基丙烯酸甲酯(PMMA)基片表面直写微通道,分析了CO2激光扫描速度和加工次数对加工质量的影响。在加工次数相同的情况下,微通道宽度和深度与扫描速度成反比,在一定速度范围内,微通道深度与扫描速度呈近似线性关系;在扫描速度一定的情况下,微通道的深度和宽度随着加工次数的增加逐渐增大,微通道宽度与加工次数呈不规则幂函数关系。分别在表面光滑、表面打毛和表面附着水膜的基片上加工微通道,并对通道的几何尺寸和粗糙度进行了比较分析。在2种不同实验条件下加工出水力直径为80μm的微通道,并对微通道的相对粗糙度进行比较,发现通过在基片表面附着水膜的方法可以有效地降低相对粗糙度。这种工艺改进,能够使采用CO2激光直写法加工PMMA基微流控芯片更可行。 Micro-channels were written on the surface of polymethylmethacrylate (PMMA) substrate using CO2 laser direct writing technology. The effects of CO2 laser scanning speed and processing times on the processing quality were analyzed. In the case of the same processing times, the microchannel width and depth are inversely proportional to the scanning speed. Within a certain speed range, the microchannel depth and the scanning speed have an approximately linear relationship. When the scanning speed is constant, the depth and width of the microchannel With the increase of the number of processing increases gradually, the microchannel width and the number of processing showed an irregular power function relationship. The microchannels were processed on the substrate with smooth surface, surface roughening and water film attached on the surface, respectively. The geometrical dimensions and roughness of the channels were compared. The microchannel with hydraulic diameter of 80μm was fabricated under two different experimental conditions and the relative roughness of the microchannels was compared. It is found that the relative roughness can be effectively reduced by attaching the water film to the surface of the substrate. This process improvement can make PMMA-based microfluidic chips more feasible by CO2 laser direct writing.