中文摘要：

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。

英文摘要：

CO2 laser direct-writing ablation micromachining technique is used to fabricate the microchannel on the polymethyl methacrylate（PMMA） substrate.The correlation between the process parameters（the beam translational velocity and the processing number of times） and the micromachining quality（the width and the depth of the microchannel） is investigated.For a given processing times,the depth and width of microchannel both decrease along with the enhancement of beam translational velocity.At fixed beam translational velocity,the depth and width are direct proportion to the processing times,respectively.The microchannel is fabricated on different PMMA substrates with smooth surface,rough surface and surface adhering water.The micromachining quality and the surface roughness of the microchannel are compared.The microchannel with a hydraulic diameter of 80 μm is fabricated under two experimental conditions,and the comparative experiment has been performed on the microchannel with the relative roughness.It is found that the relative roughness is minished effectively when a laser is used to make ablation of the microchannel on the PMMA substrate with surface adhering water.The improved fabrication procedure will be used to increase the availability of CO2 laser direct-writing ablation technique on the micromachining of the PMMA microfluidic chip.