水辅助飞秒激光直写微流芯片和电磁微阀的研究

The Key of Water-assisted femtosecond laser direct writing technolgoy is the interaction of femtosecond laser and water. The generated a series of physical process can be used for etching transparent materials. This project based on the interaction of femtosecond laser and water and the theory of material etching for studying the processing efficiency and quality of 3D microfluidic chips and electromagnetic microvalve. Firstly, the interaction of femtosecond laser and water can induce breakdown. The relations between laser energy and the pressure of shock wave and high speed jet should be studied. Secondly, the water-assisted femtosecond laser direct writing was used to etch transparent materials for realizing 3D microfluidic chips with uniform diameter, regular shape and electromagnetic microvalve.The theoretical model of water-assisted femtosecond laser micromachining will be builded. The water-assisted femtosecond laser direct writing technology has potential application on micromachining. This project will enrich the mechanism study of interaction bewteen femtosecond laser and water. The water-assisted femtosecond laser direct writing thehnology will be applied on micromachining. Prospective study results will be the scientific evidence of the water-assisted femtosecond laser micromachining study.

水辅助飞秒激光直写技术的核心是利用飞秒激光与水相互作用产生的一系列物理过程对透明材料进行微加工。本项目基于飞秒激光与水相互作用和对材料的刻蚀理论对三维微流芯片和电磁微阀的加工效率和质量进行研究。首先，使飞秒激光与水相互作用，研究飞秒激光诱导水击穿产生的高压冲击波和高速水射流压强大小与激光能量的关系；其次，使用水辅助飞秒激光直写法对透明材料进行实验研究，以期获得直径均匀、形状规则的三维微流芯片和电磁微阀，建立水辅助飞秒激光微加工的理论模型，实现水辅助飞秒激光直写技术在微加工中的应用。本项目将丰富飞秒激光与水相互的机理，促进水辅助飞秒激光直写技术在微加工中的应用。预期研究成果将为水辅助激光加工研究提供科学依据。

建立飞秒激光诱导水击穿椭球模型，并分析了飞秒激光诱导水击穿刻蚀材料的机理，计算了诱导击穿产生的水下射流速度和烧蚀压强，优化了飞秒激光诱导水击穿加工的能量参数，并研究了激光能量与微流通道形状和直径大小的关系；依据理论和实验参数优化，实现了三维多层玻璃微流芯片制备，并且各层之间使用螺旋结构链接，避免了杂质对微流通道直角弯位置的堵塞；引入了一种基于压力的清洗方法，该方法能够有效清除激光刻蚀区域的材料粉末，保证激光连续诱导击穿蒸馏水对材料刻蚀，有效增长了制备的微流通道，并且能够加工任意形状组合的微流通道，提高了微流芯片制备的灵活性；制备了阵列螺旋微流通道和嵌套螺旋微流通道，将导电基质灌注其中，对其进行了电学性能测试，实验结果表明线圈内产生的磁场足够推动永磁体移动实现开关功能。最后在本项目支持下进行了微流芯片内阵列结构制备和可用于微流芯片集成的光纤高灵敏度探头试制。