Agarose is a stable hydrophilic material commonly used for relative humidity sensing application. Agarose porous nature causes changes in its refractive index as relative humidity change. Micro bottle resonators are a promising choice for sensing applications due to their good quality factor. In this work, the effect of agarose gel concentration on micro‐bottle ability to detect relative humidity changes was investigated. The agarose gel coating was made in two different concentrations 0.5% and 1%. These two concentrations were used as coating for microbottle resonators with the diameter of 190 μm. The micro‐bottle samples were made by the soften‐and‐compress technique. In the humidity range of 35%–85% RH, the 0.5% agarose gel coated microbottle had a sensitivity of 0.1077 dB/RH%. The microbottle resonator coated with the 1% solution showed a lower sensitivity of 0.0899 dB/RH%. This improvement in sensitivity with lower agarose gel concentration is due to the pore size of agarose gel. Yet, both concentrations showed improvement in sensitivity compared to the bare micro‐bottle showing that agarose can be a potential choice for building sensitive efficient relative humidity sensors.

中文翻译：

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琼脂糖浓度对带涂层的微瓶谐振器进行湿​​度检测的影响

琼脂糖是一种稳定的亲水材料，通常用于相对湿度传感应用。琼脂糖的多孔性会导致其折射率随相对湿度的变化而变化。由于其良好的品质因数，微瓶谐振器是传感应用的有前途的选择。在这项工作中，研究了琼脂糖凝胶浓度对微瓶检测相对湿度变化的能力的影响。以两种不同的浓度0.5％和1％制成琼脂糖凝胶涂层。这两个浓度用作与190的直径涂覆用于microbottle谐振器微米。微瓶样品是通过软化和压缩技术制成的。在35％至85％RH的湿度范围内，涂有0.5％琼脂糖凝胶的微瓶的灵敏度为0.1077 dB / RH％。涂有1％溶液的微瓶共振器显示出较低的灵敏度，为0.0899 dB / RH％。琼脂糖凝胶浓度较低时灵敏度的提高是由于琼脂糖凝胶的孔径引起的。然而，与裸露的微瓶相比，两种浓度均显示出灵敏度的提高，表明琼脂糖可能是构建灵敏，高效的相对湿度传感器的潜在选择。