High sensitivity humidity sensor based on the U-shaped tapered no-core fiber coated with MXene

• Jiayi Cong, Mengxin Yang, Daozi Zhou, Lei Meng, Shuai Feng, and Min Lv
• received 03/27/2024; accepted 04/29/2024; posted 04/30/2024; Doc. ID 524913
• Abstract: Ti3C2Tx MXene is an emerging two-dimensional material, which has good potential in relative humidity (RH) measurement because of its unique layer structure, strong hydrophilic nature and large specific surface ar-ea. Here, a high-performance RH sensor integrating Ti3C2TX MXene nanosheets and U-shaped tapered no-core fiber (UTNCF) is proposed. The sensing principle is based on mode interference. The change of ambient RH leads to the change of the refractive index (RI) of Ti3C2Tx MXene, which eventually leads to the shift of the trans-mission spectrum of the sensing probe. The average sensitivity is 1.11 nm/%RH in the RH range of 45% to 80% and the response time is 25 ms. The proposed mi-cro-nano fiber RH sensor has the advantages of high sensitivity, fast response, good repeatability and stabil-ity. In addition, the proposed sensor has a broad appli-cation prospect in human respiratory monitoring, in-dustrial and agricultural production and environmental monitoring.