Flowable MXene/cellulose nanofibers conductor for linear and high-accuracy strain sensing

• Published in: Journal of materials science 2023-02, Vol.58 (8), p.3597-3607
• Main Authors: Dou, Chun, Wei, Dafei, Xu, Minxuan, Song, Tengyue, Kong, Zhe, Zheng, Xin, Shi, Yueqin, Li, Xin, Zhang, Qi
• Format: Article
• Language: English
• Subjects: Cellulose; Cellulose fibers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Composites & Nanocomposites; Crystallography and Scattering Methods; Human motion; Insulation; Landing sites; Materials Science; Muscles; MXenes; Nanofibers; Neurological diseases; Polymer Sciences; Sensitivity; Sensors; Solid Mechanics; Strain distribution; Stretchability
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-023-08220-0

Stretchable strain sensors can detect the bio-signals generated by human motions in real-time and play an important role in human health monitoring. However, due to the balance between sensitivity and stretchability, developing strain sensors with both high gauge factor (GF) and wide linear range are still a great challenge. Here, we develop a flowable sensitive material based on the simple two-step mixing of cellulose nanofibers (CNF) and MXene in water. The various strain is reflected by the changing in conductive path built by MXene. And the insulating CNF will spread into a spatial network, offering plenty of landing sites for the MXene, which not only improve its dispersion, but also optimize the sensing performance. A device filled up with the flowable sensitive materials can reveal a linear response in a broad sensing range up to 100%, with a fast response ( τ 1  = 143 ms), high sensitivity (GF = 1.7) and excellent accuracy (maximum error = 1.14%). Such a wearable strain sensor was successfully applicable for human health monitoring (e.g., pulse, muscle motion, neurological disease and obesity) and easily integrated into an matrix for recognizing the planar–strain distribution.