Center for Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000, Belgrade, Serbia.
Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080, Belgrade, Serbia.
Nanotechnology. 2021 Jan 8;32(2):025505. doi: 10.1088/1361-6528/abb973.
Humidity sensing is important to a variety of technologies and industries, ranging from environmental and industrial monitoring to medical applications. Although humidity sensors abound, few available solutions are thin, transparent, compatible with large-area sensor production and flexible, and almost none are fast enough to perform human respiration monitoring through breath detection or real-time finger proximity monitoring via skin humidity sensing. This work describes chemiresistive graphene-based humidity sensors produced in few steps with facile liquid phase exfoliation followed by Langmuir-Blodgett assembly that enables active areas of practically any size. The graphene sensors provide a unique mix of performance parameters, exhibiting resistance changes up to 10% with varying humidity, linear performance over relative humidity (RH) levels between 8% and 95%, weak response to other constituents of air, flexibility, transparency of nearly 80%, and response times of 30 ms. The fast response to humidity is shown to be useful for respiration monitoring and real-time finger proximity detection, with potential applications in flexible touchless interactive panels.
湿度感应对于各种技术和行业都很重要，从环境和工业监测到医疗应用等领域都有涉及。尽管湿度传感器种类繁多，但很少有解决方案能够同时具备轻薄、透明、与大面积传感器生产兼容、灵活等特点，几乎没有一种能够快到通过呼吸检测来进行人体呼吸监测，或者通过皮肤湿度感应来实时监测手指接近情况。本工作描述了一种基于化学电阻的石墨烯湿度传感器，它可以通过简单的液相剥离和随后的Langmuir-Blodgett 组装来制备，从而实现任意大小的有效面积。石墨烯传感器提供了独特的性能参数组合，其电阻变化高达 10%，在相对湿度 (RH) 水平在 8%至 95%之间具有线性性能，对空气中的其他成分的响应较弱，具有柔韧性、近 80%的透明度和 30ms 的响应时间。实验结果表明，这种快速响应湿度的特性可用于呼吸监测和实时手指接近检测，有望应用于灵活的非接触式交互面板。
