针对目前PMMA微流道加工质量差和效率低的问题,对飞秒激光直写PMMA制备微流道的工艺技术进行了研究。通过实验分析了不同激光参数对微流道的宽度、深度、粗糙度、微流道两侧堆积物火山口高度的影响及变化规律。实验结果表明,当激光扫描速度为20 mm/s时,激光功率为0.5 W时,微流道粗糙度较低且变化幅度不明显；激光能量从0.5 W增加到0.75 W时,微流道的宽度、深度与激光能量呈线性关系增加；激光功率大于0.5 W时,随着激光功率以及加工次数的增加,微流道宽度、深度、粗糙度以及堆积物火山口的高度逐渐增加。经过计算得出,PMMA的烧蚀阈值为0.357 J/cm2。通过优化工艺参数,制备出粗糙度较低、表面光滑、深度为16 μm的微流道芯片。

Aiming at the poor quality and low efficiency of PMMA microfluidic channel machining, the fabrication process technology of PPMA microfluidic channel with direct-writing femtosecond laser was studied. The effects of different laser parameters on the width, depth, roughness of the microfluidic channel, and the crater height of the deposits on both sides of the micro-channel were analyzed,as well as the changing rules.The experimental results show that when the laser scanning speed is 20 mm/s and the laser power is 0.5 W, the roughness of the microfluidic channel is low and the variation range is not obvious; when the laser energy increases from 0.5 W to 0.75 W, the width and depth of the microfluidic channel increase linearly with laser energy ;when the laser power is greater than 0.5 W, the width, depth, roughness of the microfluidic, and the height of the crater of the deposits gradually increase with the increase of the laser power and the number of processing times. After calculation, the ablation threshold of PMMA is 0.357 J/cm2. By optimizing the process parameters, the microfluidic channel chip with low roughness, smooth surface and depth of 16 μm was prepared.