College of Textile and Clothing Engineering, Soochow University, Suzhou215123, China.
National Engineering Laboratory for Modern Silk, Suzhou215123, China.
ACS Appl Mater Interfaces. 2023 Feb 8;15(5):7392-7404. doi: 10.1021/acsami.2c20390. Epub 2023 Jan 24.
Conductive polymer composite-based strain sensors are essential components of flexible wearable devices. However, nonmonotonic responses with shoulder peaks limit their practical application. Herein, we innovatively optimized the shoulder-peak phenomenon in a strain-sensing composite nanofiber filament by regulating carbon nanomaterial dispersion. Further, the preparation methods, characteristics, and performances of the filament strain sensors were systematically introduced. On this basis, transmission electron microscopy, finite element analysis, and mathematic and structural evolution models were used to explore the origin of shoulder peaks and explain the sensing mechanism of conductive networks. Results confirmed that the beacon tower-shaped conductive network designed by constructing nanofiller agglomerates could cause strain concentration and resist the Poisson transverse contraction of nanofibers, considerably improving the monotonicity and sensitivity of the sensor. The strain-sensing performance was optimal when the nanofillers were dispersed using 2.5 wt % of an anionic dispersant. The sensor exhibited a maximum detective strain of 120%, an ultralow detection limit of 0.01%, and high sensitivity and linearity of 9.66 and 0.996 within 20% strain, respectively. Moreover, it showed the advantages of a fast response time (120 ms), excellent durability (3000 cycles), anti-interference, washability, and antibacterial capability. Finally, a smart Kinesio tape was developed for protecting/treating the human body and detecting joint/muscle movement via simple sewing.
基于导电聚合物复合材料的应变传感器是柔性可穿戴设备的重要组成部分。然而，具有肩部峰的非单调响应限制了它们的实际应用。在此，我们通过调节碳纳米材料的分散，创新性地优化了应变传感复合纳米纤维丝中的肩部峰现象。此外，系统地介绍了丝应变传感器的制备方法、特性和性能。在此基础上，利用透射电子显微镜、有限元分析以及数学和结构演化模型，探讨了肩部峰的起源，并解释了导电网络的传感机制。结果证实，通过构建纳米填料聚集体设计的灯塔形导电网络可以引起应变集中并抵抗纳米纤维的泊松横向收缩，从而显著提高传感器的单调性和灵敏度。当纳米填料分散在 2.5wt%的阴离子分散剂中时，应变传感器的性能最佳。该传感器的最大检测应变可达 120%，检测下限低至 0.01%，在 20%应变范围内具有高灵敏度和线性度，分别为 9.66 和 0.996。此外，它还具有快速响应时间（120ms）、优异的耐用性（3000 次循环）、抗干扰性、可清洗性和抗菌能力等优点。最后，通过简单的缝合，开发了一种智能肌内效贴，用于保护/治疗人体以及检测关节/肌肉运动。
