Temperature and Humidity Metrology, CSIR-National Physical Laboratory, Dr K. S. Krishnan Marg, New Delhi 110012, India.
Academy of Scientific & Innovative Research (AcSIR), Ghaziabad-201002, India.
Phys Chem Chem Phys. 2024 Aug 7;26(31):21186-21196. doi: 10.1039/d4cp01148a.
The present work shows the improved humidity sensing characteristics of TiO nanoparticles in the form of a nanocomposite with multiwalled carbon nanotubes (MWCNTs) prepared by a hydration-dehydration method. The structural and morphological characterizations of TiO-MWCNTs confirm the nanocomposite formation without any other impurities and with an improved surface area. The pure TiO and nanocomposite films are deposited on IDE coated flexible poly-ethylene terephthalate (PET) substrates by a drop casting method. The nanocomposite shows improved sensitivity (1246.2 MΩ/%RH) and an ultrafast response/recovery time (2 s/1 s) with a minimal hysteresis of 0.27%RH. Further, the flexible nanocomposite sensor is tested for human healthcare applications including respiratory monitoring, apnea like situations, and skin moisture detection. The sensor can distinguish different breath patterns like normal, fast, deep and apnea like situations significantly. Skin moisture detection can also be performed using the nanocomposite sensor in a non-invasive manner. Overall, this study represents an environmentally friendly, easy to fabricate, flexible TiO-MWCNT nanocomposite based improved humidity sensor for application in human healthcare and wearable devices.
本工作展示了通过水热脱水法制备的 TiO 纳米粒子与多壁碳纳米管（MWCNTs）的纳米复合材料在湿度感测方面的改善特性。TiO-MWCNTs 的结构和形态特征证实了纳米复合材料的形成，没有任何其他杂质，并且比表面积得到了提高。通过滴铸法将纯 TiO 和纳米复合材料薄膜沉积在涂有 IDE 的柔性聚对苯二甲酸乙二醇酯（PET）基底上。纳米复合材料显示出改进的灵敏度（1246.2 MΩ/%RH）和超快的响应/恢复时间（2 s/1 s），滞后性最小为 0.27%RH。此外，该柔性纳米复合传感器还可用于包括呼吸监测、类似呼吸暂停的情况以及皮肤湿度检测在内的人类健康护理应用。该传感器能够显著区分正常、快速、深度和类似呼吸暂停的不同呼吸模式。也可以使用纳米复合材料传感器以非侵入性的方式进行皮肤湿度检测。总的来说，这项研究代表了一种环保、易于制造、灵活的基于 TiO-MWCNT 纳米复合材料的改进型湿度传感器，可应用于人类健康护理和可穿戴设备。
