Komatsu Hiroaki, Kawamoto Yurika, Ikuno Takashi
Department of Applied Electronics, Graduate School of Advanced Engineering, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan.
Nanomaterials (Basel). 2022 Mar 12;12(6):940. doi: 10.3390/nano12060940.
The rapidly advancing technology of wearable and miniaturized electronics has increased the demand for low-cost high-performance flexible sensors. Herein, the preparation of translucent freestanding films consisting of cellulose nanofibers (CNFs) and ZnO nanoparticles (NPs) via a simple spray coating method is presented. The obtained nanocomposite films were thin (~10 µm) and flexible. The scanning electron microscopy and atomic force microscopy analysis revealed that the nanocomposite film was composed of regions of ZnO NP-modified CNFs and regions of aggregation of ZnO NPs with each other. The electrical conductance of the films was rapidly increased beyond 40 wt.% ZnO and reached up to >50 nA at 60 wt.% ZnO. This was attributed to the increased number of conductive paths formed by the ZnO NPs in the nanocomposite film when a certain threshold was crossed. The ZnO−CNF nanocomposite film exhibited a stable response over on/off cycles of UV light exposure. The responsivity and sensitivity of the nanocomposite film with 60 wt.% ZnO were 36.5 mA/W and 247, respectively. Even when the device was curved (radius of curvature: 3 mm), the response and sensitivity remained high. The developed nanocomposite films are expected to be applied as environmentally friendly flexible UV sensors.
可穿戴和小型化电子产品技术的迅速发展增加了对低成本高性能柔性传感器的需求。在此，介绍了通过简单的喷涂方法制备由纤维素纳米纤维（CNF）和氧化锌纳米颗粒（NP）组成的半透明独立薄膜。所获得的纳米复合薄膜很薄（约10微米）且具有柔韧性。扫描电子显微镜和原子力显微镜分析表明，纳米复合薄膜由氧化锌NP修饰的CNF区域和氧化锌NP相互聚集的区域组成。当氧化锌含量超过40 wt.%时，薄膜的电导率迅速增加，在氧化锌含量为60 wt.%时达到>50 nA。这归因于当超过一定阈值时，纳米复合薄膜中由氧化锌NP形成的导电路径数量增加。氧化锌-CNF纳米复合薄膜在紫外光照射的开/关循环中表现出稳定的响应。氧化锌含量为60 wt.%的纳米复合薄膜的响应度和灵敏度分别为36.5 mA/W和247。即使器件弯曲（曲率半径：3毫米），响应和灵敏度仍然很高。所开发的纳米复合薄膜有望用作环保型柔性紫外传感器。
