Department of Petrochemical Materials, Chonnam National University, Yeosu-si 59631, Republic of Korea.
Sensors (Basel). 2023 Feb 10;23(4):1977. doi: 10.3390/s23041977.
Fast humidity sensors are of interest due to their potential application in new sensing technologies such as wearable personal healthcare and environment sensing devices. However, the realization of rapid response/recovery humidity sensors remains challenging primarily due to the sluggish adsorption/desorption of water molecules, which particularly impacts the response/recovery times. Moreover, another key factor for fast humidity sensing, namely the attainment of equal response and recovery times, has often been neglected. Herein, the layer-by-layer (LbL) assembly of a reduced graphene oxide (rGO)/polyelectrolyte is demonstrated for application in fast humidity sensors. The resulting sensors exhibit fast response and recovery times of 0.75 and 0.85 s (corresponding to times per RH range of 0.24 and 0.27 s RH, respectively), providing a difference of only 0.1 s (corresponding to 0.03 s RH). This performance exceeds that of the majority of previously reported graphene oxide (GO)- or rGO-based humidity sensors. In addition, the polyelectrolyte deposition time is shown to be key to controlling the humidity sensing kinetics. The as-developed rapid sensing system is expected to provide useful guidance for the tailorable design of fast humidity sensors.
快速湿度传感器因其在可穿戴式个人医疗保健和环境感应设备等新型传感技术中的潜在应用而受到关注。然而，快速响应/恢复湿度传感器的实现仍然具有挑战性，主要是由于水分子的吸附/解吸缓慢，这尤其影响响应/恢复时间。此外，快速湿度传感的另一个关键因素，即达到相等的响应和恢复时间，通常被忽视。本文通过层层（LbL）组装还原氧化石墨烯（rGO）/聚电解质，将其应用于快速湿度传感器。所制备的传感器具有快速的响应和恢复时间，分别为 0.75 和 0.85 s（对应于 RH 范围为 0.24 和 0.27 s RH 的时间），仅相差 0.1 s（对应于 0.03 s RH）。该性能超过了大多数先前报道的基于氧化石墨烯（GO）或 rGO 的湿度传感器。此外，还表明聚电解质的沉积时间是控制湿度传感动力学的关键。所开发的快速传感系统有望为快速湿度传感器的可定制设计提供有用的指导。
