研究背景
呼吸疾病如COVID - 19、甲型流感、病毒性流感和哮喘等持续对人们的生活构成挑战，是必须解决的重要健康问题。可穿戴湿度传感器可监测呼吸状态和体表湿度，湿度作为生理信号，在反映人体健康状况方面起着非常重要的作用。柔性湿度传感器作为可以感知外部湿度变化的设备，可以测量因湿度变化产生的物理变化，并将其转化为电信号或其方便检测的信号。其对外部湿度的检测依靠敏感材料完成，比如高分子聚合物、金属氧化物等等。其中某些新型纳米材料被应用于传感器制造中。目前制备方法简单且具有高灵敏度称为决定柔性湿度传感器能否被应用的重要因素，因此开发具有高灵敏度、制备简单的柔性湿度传感器具有重要意义。
研究成果
鲁东大学陈雪叶团队在期刊《Journal of Materials Chemistry A 》，发表名为“Non-contact porous composite fiber paper-based humidity sensor forwearable breathing and skin humidity monitoring”的论文。研究者利用简单的制造工艺制备出具有快速响应功能的柔性纸基湿度传感器，利用CO2激光器制备出插指电极结构，并同时利用复合纸纤维等纳米复合材料制备了具有多孔纤维结构的柔性湿度传感器。该制备方法不受任何条件限制，具有的适用性。
图文导读
Fig. 1 (a) Overall structure, (b) internal structure, (c) non-contact humidity response process, (d) experimental environment, and (e) reaction mechanism.
Fig. 2 (a) Preparation flow, (b) XRD patterns, (c) ultra-depth-of-field microscope images of the surface of paper and electrodes, (d) PLFC object and electrolytic oxidation of the metal electrode in air, (e) SEM of the moisture-sensitive paper, (f) SEM of the paper fiber pore electrode.
Fig. 3 Performance test of PLFC: (a) linear fit of humidity, (b) six cycles at 12% and 43% humidity, (c) corresponding amplitude of different humidity gases, (d) corresponding amplitude of moistened paper to different humidity gases,(e)electrolytic lithium chloride solution,(f) response of PLFC, (g) PLFC made of 10% concentration of lithium chloride in a 75% humidity environment, (h) humidity response of PLFC when there is a certain amount of moisture, (i) air and 75% RH gas and 43% RH gas at the time of PLFC contact.
Fig. 4 PLFC respiratory monitoring: (a) schematic diagram of respiratory monitoring, (b) Cheyne–Stokes breath, (c) breathing and pause breathing simulation perceptual performance, (d) normal breathing after coughing, (e) breathing through the nose and mouth, and huffing respectively, (f) saying “hello” in different languages, (g) rapid breathing, and (h) deep breathing.
Fig. 5 Application of PLFC in human skin humidity monitoring: (a) PLFC application scenarios and schematic diagram, (b) humidity response of various parts of the body and humidity response of wet cotton balls, (c) degree of moisture dissipation of various parts of the body, (d) corresponding amplitude of different distances between the palm and PLFC, (e) physical display of hot and cold water below PLFC, (f) the response of hot water and cold water in PLFC.
与展望
本文提出基于纸的湿度传感器PLFC，以A4纸为基底结合PFCTe制备而成，具有宽检测范围、高灵敏度、快速响应、高稳定性及线性度等特点，其工作机理涉及离子移动与水分子反应，通过特殊结构和材料特性实现对湿度的敏感响应，在传感器制造与性能表征方面有详细阐述，性能测试显示其在不同湿度条件下的良好表现，可用于呼吸和皮肤湿度监测，在呼吸监测中能区分不同呼吸模式，在皮肤湿度监测中能感知不同身体部位湿度及水分蒸发情况，对健康监测和疾病追踪有重要意义，且制备成本低适合大规模生产，在可穿戴医疗技术领域有潜在应用前景。
文献链接：https://pubs.rsc.org/en/Content/ArtICleLanding/2024/TA/D4TA05393A
审核编辑 黄宇
