Cellulose Nanofiber/Carbon Nanotube Dual Network-Enabled Humidity Sensor with High Sensitivity and Durability
Cellulose Nanofiber/Carbon Nanotube Dual Network-Enabled Humidity Sensor with High Sensitivity and Durability
复制标题
具有高灵敏度和耐用性的纤维素纳米纤维/碳纳米管双网络湿度传感器
DOI：
10.1021/acsami.0c07995
复制
发表时间：
2020-07-22
影响因子：
9.5
通讯作者：
Chen, Gang
中科院分区：
文献类型：
--
作者：
Zhu, Penghui;Ou, Huajie;Chen, Gang
湿度传感器已被广泛应用于工业领域的湿度监测，但传统的无机传感器的灵活性、耗时和昂贵的集成工艺严重限制了其在可穿戴电子设备中的应用。使用纸基湿度传感器被认为是克服这些缺点的一种可行的方法，因为它们具有良好的灵活性和可制造性，但它们仍然面临着耐用性差、灵敏度低等问题。在这项研究中，我们报道了一种基于合理设计的双层结构的高性能纸基湿度传感器，该双层结构由纳米多孔纤维素纳米纤维/碳纳米管(CNF/CNT)敏感层和微孔纸基组成。CNF和纸纤维表面的大量亲水性羟基使湿敏材料与外部环境之间通过氢键快速交换水分子，使纸基传感器具有良好的湿敏性能。得到的传感器在相对湿度为95%时的最大响应值为65.0%(Delta I/I-0)。此外，CNF/CNT层和纸层之间形成的机械互锁结构为传感器提供了强大的层间粘附性。得益于独特的结构，传感器还表现出出色的弯曲(最大曲率为22.2厘米(-1))和折叠耐用性(高达50次)。最后，作为概念验证，组装了一个简单的湿度测量装置，该装置对人体呼吸和空气湿度的变化具有良好的响应特性，表明我们的纸基湿度传感器具有很大的实际应用潜力。
Humidity sensors have been widely used for humidity monitoring in industrial fields, while the unsatisfactory flexibility, time consumption, and expensive integration process of conventional inorganic sensors significantly limit their application in wearable electronics. Using paper-based humidity sensors is considered a feasible method to overcome these drawbacks because of their good flexibility and roll-to-roll manufacturability, while they still face problems such as poor durability and low sensitivity. In this study, we report a high-performance paper-based humidity sensor based on a rationally designed bilayered structure consisting of a nanoporous cellulose nanofiber/carbon nanotube (CNF/CNT) sensitive layer and a microporous paper substrate. The vast number of hydrophilic hydroxyl groups on the surface of CNF and paper fibers enables fast water molecule exchange between the humidity-sensitive material and the external environment via hydrogen bonding, endowing the paper-based sensor with an excellent humidity responsive property. The obtained sensor displays a maximum response value of 65.0% (Delta I/I-0) at 95% relative humidity. Furthermore, the mechanical interlocking structure formed between the CNF/CNT layer and the paper layer provides the sensor with strong interlayer adhesion. Benefiting from the unique structure, the sensor also exhibits outstanding bending (with a maximum curvature of 22.2 cm(-1)) and folding durability (up to 50 times). Finally, as a proof of concept, a simple humidity-measuring device is assembled, which demonstrates an excellent responsive property toward human breath and the change of air humidity, indicating a great potential of our paper-based humidity sensor toward practical applications.