Wet-resistant, dustproof, and germproof self-powered lignocellulosic triboelectric filters for respiratory protection, monitoring, and diagnosis

Abstract

The moisture sensitivity and structural defects found in natural cellulose materials limit their ability to serve as substitutes for petroleum-based masks. This study uses a combination of methods, including retaining lignin, embedding silver particles in situ, and using a mixture of coarse and fine fibers to enhance the wet resistance, antibacterial properties, and triboelectric output of lignocellulosic materials. This approach also aimed to balance pressure drop and filtration efficiency. A triboelectric filter (Ag-LCTEF) using a perforated fluorinated ethylene propylene (FEP) film sandwiched between two sheets of Ag-embedded lignocellulose (Ag-LC) was assembled. The resulting Ag-LCTEF enabled self-powered continuous monitoring of breathing signals, boasting impressive submicron particle removal (99.70 %) and antibacterial efficiency (99.18 %), all while maintaining a relatively low-pressure drop of 76 Pa. Notably, the Ag-LCTEF displayed consistent performance and long-term durability even in high humidity conditions of 80 % RH. These remarkable achievements have spurred the suggestion of integrating respiratory protection, monitoring, and diagnostic functions, showcasing its potential for the next generation of wearable electronics. Moreover, naturally safe and biodegradable lignocellulose serves as an environmentally friendly replacement for petroleum-based materials.