Fiber-optic anemometers have attracted an increasing attention over the past decade owing to their high sensitivity, wide dynamic range, low power consumption, and immunity to electromagnetic interference. However, expensive instruments may limit their practical applications. Herein, a new type of airflow sensor based on optical micro/nanofiber (MNF) is proposed and realized. The sensing element is a flexible polydimethylsiloxane (PDMS) cantilever embedded with a U-shaped MNF. Upon exposure to airflow, the induced deflection of the cantilever results in a bending-dependent transmittance variation of the embedded MNF. The performance of the sensor can be engineered by tuning the cantilever thickness and/or the MNF diameter. When four cantilevers are arranged in two orthogonal directions, the transmittance of each cantilever will be dependent on both flow speed and direction. By analysing the output signals of the four cantilevers, omnidirectional airflow with flow speed within 15 m/s were experimentally measured. In addition, a variety of voice and respiratory signals can be monitored and distinguished in real-time using an optimized cantilever with a resolution of 0.012 m/s, presenting great potential for health monitoring applications.

Graphic abstract

中文翻译：

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由光学微/纳米纤维实现的多功能气流传感器

光纤风速计由于其高灵敏度、宽动态范围、低功耗和抗电磁干扰等优点，在过去十年中引起了越来越多的关注。然而，昂贵的仪器可能会限制其实际应用。在此，提出并实现了一种基于光学微/纳米纤维（MNF）的新型气流传感器。传感元件是嵌入 U 形 MNF 的柔性聚二甲基硅氧烷 (PDMS) 悬臂。在暴露于气流时，悬臂的诱导偏转导致嵌入的 MNF 的弯曲依赖透射率变化。传感器的性能可以通过调整悬臂厚度和/或 MNF 直径来设计。当四个悬臂沿两个正交方向排列时，每个悬臂的透射率将取决于流速和方向。通过分析四个悬臂的输出信号，实验测量了流速在15 m/s以内的全向气流。此外，优化后的悬臂梁可以实时监测和区分各种语音和呼吸信号，分辨率为0.012 m/s，在健康监测应用中具有巨大潜力。

图形摘要