State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China.
Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, China.
ACS Appl Mater Interfaces. 2022 Jan 19;14(2):3165-3175. doi: 10.1021/acsami.1c20163. Epub 2022 Jan 7.
Humidity sensors have been widely used for humidity monitoring in industry and agriculture fields. However, the rigid structure, nondegradability, and large dimension of traditional humidity sensors significantly restrict their applications in wearable fields. In this study, a flexible, strong, and eco-friendly bacterial cellulose-based humidity sensor (BPS) was fabricated using a two-step method, involving solvent evaporation-induced self-assembly and electrolyte permeation. Rapid evaporation of organic solvent induces the formation of nanopores of the bacterial cellulose (BC) surface and promotes structural densification. Furthermore, the successful embedding of potassium hydroxide into the sophisticated network of BC effectively enhanced the sensing performance of BPS. The BPS exhibits an excellent humidity sensing response of more than 10 within the relative humidity ranging from 36.4 to 93% and strong (66.4 MPa) and high flexibility properties owing to the ultrafine fiber network and abundant hydrophilic functional groups of BC. Besides being strong and thin, BPS is also highly flexible, biodegradable, and humidity-sensitive, making it a potential candidate in wearable electronics, human health monitoring, and noncontact switching.
湿度传感器在工农业领域的湿度监测中得到了广泛应用。然而，传统湿度传感器的刚性结构、不可降解性和大尺寸严重限制了它们在可穿戴领域的应用。本研究采用溶剂蒸发诱导自组装和电解质渗透的两步法，制备了一种柔性强、环保的基于细菌纤维素的湿度传感器 (BPS)。有机溶剂的快速蒸发诱导细菌纤维素 (BC) 表面形成纳米孔，并促进结构致密化。此外，成功将氢氧化钾嵌入 BC 的复杂网络中，有效提高了 BPS 的传感性能。BPS 在相对湿度为 36.4%至 93%的范围内表现出超过 10 的出色湿度传感响应，并且由于 BC 的超细纤维网络和丰富的亲水性官能团，具有很强的 (66.4 MPa) 和高柔韧性。除了强度高和厚度薄之外，BPS 还具有高柔韧性、可生物降解和湿度敏感性，使其成为可穿戴电子、人体健康监测和非接触式开关等领域的潜在候选材料。
