All-printed, Fast Response Flexible Humidity Sensor based on Hexagonal-WO 3 Nanowires for Multifunctional Applications.

The utilization of printing techniques for the development of high-performance humidity sensors holds immense significance for various applications in the fields of Internet of Things, agriculture, human healthcare, and storage environments. However, the long response time and low sensitivity of current printed humidity sensors limited their practical applications. Herein, a series of high-sensing performance flexible resistive-type humidity sensors are fabricated by the screen-printing method, and the hexagonal tungsten oxide (h-WO 3 ) is employed as the humidity sensing material due to its low cost, strong chemical adsorption ability, and excellent humidity sensing ability. The as-prepared printed sensors exhibit high sensitivity, good repeatability, outstanding flexibility, low hysteresis, and fast response (1.5 s) in a wide relative humidity (RH) range (11-95% RH). Furthermore, the sensitivity of humidity sensors can be easily adjusted by altering the manufacturing parameters of the sensing layer and interdigital electrode to meet the diverse requirements of specific applications. The printed flexible humidity sensors possess immense potential in various applications, including wearable devices, non-contact measurements, and packaging opening state monitoring. This article is protected by copyright. All rights reserved.