Li Jinjian, Qu Jian, Liu Yi, Li Yan, Qu Shiliang
Harbin Institute of Technology, Harbin, Heilongjiang, China.
Harbin Institute of Technology Weihai, Weihai, Shandong, China.
Nanophotonics. 2022 Oct 24;11(21):4615-4625. doi: 10.1515/nanoph-2022-0505. eCollection 2022 Dec.
A novel fiber-tip micro flowmeter based on optofluidic microcavity filled with silver nanoparticles solutions (SNS) is proposed. CW fiber laser was used to heat SNS that can emit heat obviously due to the excellent optic-thermo effect. The heat generated by the silver nanoparticles would be taken away as the microfluidic flows over the fiber microcavity until thermal balance is established under different velocity. The effective refractive index (RI) of the SNS changed followed by temperature of the thermal balance. The dips of the Fabry-Perot interference spectrum shift and the flow velocity can be demodulated. Moreover, the sensor can measure the flow rate with a high sensitivity due to the superior thermal conductivity and specific heat capacity of sidewalls. The max flow rate sensitivity can reach 1.5 nm/(μL/s) in the large range of 0-5 μL/s with a detection limitation (DL) of 0.08 μL/s. The Micron scale probe-type flowmeter has strong robustness and can be used to measure flow rate in tiny space. The heating medium also has an excellent biological compatibility and is not contact with the fluidics directly. As such, we believe that the proposed fiber-tip micro flowmeter has great application potentials in haematology, oil prospecting, ocean dynamics and drug research.
提出了一种基于填充银纳米颗粒溶液（SNS）的光流体微腔的新型光纤尖端微流量计。连续波光纤激光器用于加热SNS，由于其优异的光热效应，SNS能明显发热。当微流体流过光纤微腔时，银纳米颗粒产生的热量会被带走，直到在不同流速下达到热平衡。SNS的有效折射率（RI）随热平衡温度而变化。法布里 - 珀罗干涉光谱的凹陷会发生移动，从而可以解调流速。此外，由于侧壁具有优异的热导率和比热容，该传感器能够以高灵敏度测量流速。在0 - 5 μL/s的大范围内，最大流速灵敏度可达1.5 nm/(μL/s)，检测限（DL）为0.08 μL/s。这种微米级探针型流量计具有很强的鲁棒性，可用于在微小空间中测量流速。加热介质还具有优异的生物相容性，且不与流体直接接触。因此，我们认为所提出的光纤尖端微流量计在血液学、石油勘探、海洋动力学和药物研究等方面具有巨大的应用潜力。
