飞秒激光湿法刻蚀技术制备光纤微流传感器

Optofluidic sensor chip has become one research hotspots in the field of biochemical analysis due to its ultracompact configuration and highly integrated functions. At present optofluidic sensor chips are usually fabricated in some transparent substrates and the light coupling is based on space optical method, which has low coupling efficiency, complex optical system and poor stability. In this project, femtosecond laser assisted wet etch method is proposed to fabricate 3D microfluidic channel in silica fiber, which is used for the light interaction with the measured medium. Good light-guiding performance of silica fiber makes it easy to achieve high coupling efficiency that presents a new direction for optofluidic sensor chip. The project will investigate: (1) Mechanism and machining technique of femtosecond laser assisted wet etch in silica fiber; (2) Configuration design of optical fiber microfluidic sensors; (3) Fabrication and performance test of optical fiber microfluidic sensors. We expect to make a significant contribution to the development of femtosecond laser micromachining method in the field of novel optical fiber sensors.

光微流传感芯片因结构极其紧凑且功能高度集成，已成为化学和生物分析领域的研究热点之一。目前光微流传感芯片通常制备在透明基片内，依靠空间光学耦合方式进行光信号的导入和导出，其耦合效率低、光学系统复杂、稳定性差。本项目首次提出采用飞秒激光湿法刻蚀技术在石英光纤内部制作三维微流通道，构建光与被测物相互作用的反应池，并借助光纤波导极佳的传光性能灵活实现低损耗耦合，为光微流传感芯片技术提出了新方向。具体研究内容：（1）石英光纤中的飞秒激光湿法刻蚀技术的机理和工艺研究；（2）光纤微流传感器的结构设计；（3）光纤微流传感器的制备与传感性能研究。项目的实施有望推动飞秒激光微加工技术在新型光纤传感技术领域的发展。

通过一根光纤上实现各种功能性微结构的集成，光纤微流芯片能够自动完成生物和化学分析中的各种常规与特殊功能，如进样、样品预处理、混合、分离和检测等等，从而推动生化分析过程中的微型化、自动化、集成化与便携化。本项目开展了基于飞秒激光湿法刻蚀技术的光纤微流传感器的研制工作，实现了飞秒激光-光纤湿法刻蚀工艺，实现了高灵敏度的光纤微流传感器的理论设计，实现了三种干涉式光纤微流传感器的实验制备，实现了100000nm/RIU的折射率灵敏度。本项目申请中国发明专利11项（授权1项，其他10项为公布实审阶段）；申请中国实用新型专利9项（全部授权）；发表论文27篇（SCI收录26篇，EI收录1篇），其中中科院一区论文3篇，二区论文14篇；培养在站博士后4人、博士生3人和硕士生12人。本项目研究突破传统飞秒激光加工技术难以克服的瓶颈问题，推动了飞秒激光微加工在光纤微流器件领域的发展。本项目具有重要的科学意义和实用价值。