Interface-Regulated Humidity-Sensing Transparent Flexible Film: Antibacterial Properties Facilitate Human–Computer Interaction and Health Monitoring

Abstract

During periods of high incidence of infectious diseases, non-contact wearable intelligent humidity sensors with both excellent antibacterial properties and superior sensing performance are particularly critical. Possessing superior transparency, flexibility, and antibacterial properties, this film enables precise humidity monitoring and effectively suppresses the proliferation of pathogenic bacteria. Moreover, it can adapt well to the deformation of electronic devices without damaging their surface morphology and aesthetic appearance. In this study, an interface regulation strategy was employed: a multi-network synergy mechanism was constructed among 3-mercaptopropyltrimethoxysilane (MPTMS), cellulose nanofibers (TOCNF), polyvinyl alcohol (PVA), perovskite (Cs2SnCl6), and zinc oxide (ZnO). A high-performance cellulose-based humidity sensor (S-CPCZ) was successfully prepared. This sensor exhibits a detection range of 11–95% RH, a response/recovery time reaches 2 s/4 s, a maximum sensitivity of 3.42 × 106 Ω/%RH, a hysteresis of less than 1%, and long-term stability exceeding 200 days. It can quickly capture fluctuations in respiratory humidity and in the humidity of the microenvironment on the body surface. This material exhibits high transparency and excellent flexibility, which enables it to withstand slight deformations from human behaviors. In addition, its remarkable antibacterial performance can greatly inhibit microbial growth under humid conditions. The S-CPCZ sensor can effectively overcome the limitations of conventional non-contact humidity sensors in practical scenarios, exhibiting promising application prospects in non-contact human–computer interaction as well as sports and health monitoring.