Goudarzi Ali, Mohammadimasoudi Mohammad, Khoshkhati Farid
Opt Express. 2023 Dec 18;31(26):43067-43074. doi: 10.1364/OE.507123.
The measurement of airflow velocity is crucial in various fields, and several sensing approaches have been developed for detecting airflow, including optical fiber-based flowmeters. However, these sensors often require complex fabrication processes and precise optical alignment. In this paper, a simpler and more cost-effective approach has been used to measure air flow rate by utilizing the birefringence property of liquid crystals (LCs). LCs possess distinct optical characteristics, and their reorientation due to airflow can be detected by observing the intensity of the output light between crossed polarizers. The novelty of this study is the utilization of a textile grid to hold the LC layer, which simplifies the fabrication process. This LC-based gas flowmeter offers a simple, low-cost setup and provides rapid performance. This research presents what we believe to be a new approach to calculate airflow by exploiting the optical properties of LCs, which is a new frontier in gas flow measurement. The proposed airflow meter is capable of detecting airflow rates ranging from 0 l/min to 7.5 l/min with an accuracy of 0.5 l/min. It exhibits a stable response time in 75 seconds, and the sensor maintains acceptable stability over time.
气流速度的测量在各个领域都至关重要，并且已经开发了几种用于检测气流的传感方法，包括基于光纤的流量计。然而，这些传感器通常需要复杂的制造工艺和精确的光学对准。在本文中，一种更简单且更具成本效益的方法被用于通过利用液晶（LC）的双折射特性来测量空气流速。液晶具有独特的光学特性，并且由于气流导致的其取向变化可以通过观察交叉偏振器之间输出光的强度来检测。本研究的新颖之处在于利用织物网格来固定液晶层，这简化了制造过程。这种基于液晶的气体流量计提供了一种简单、低成本的设置并且性能快速。这项研究提出了我们认为是一种通过利用液晶的光学特性来计算气流的新方法，这是气体流量测量的一个新前沿。所提出的气流计能够检测0 l/min至7.5 l/min的气流速率，精度为0.5 l/min。它在75秒内表现出稳定的响应时间，并且传感器随时间保持可接受的稳定性。
