Guo Huijing, Thirunavukkarasu Naveen, Mubarak Suhail, Lin Huang, Zhang Chen, Li Yonggui, Wu Lixin
School of Chemistry, Fuzhou University, Fuzhou 350116, China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Polymers (Basel). 2023 Mar 20;15(6):1535. doi: 10.3390/polym15061535.
Wearable flexible sensors with high sensitivity and wide detection range are applied in motion detection, medical diagnostic result and other fields, but poor resilience and hysteresis remain a challenge. In this study, a high-resilience foam sensor was prepared through a combination of additive manufacturing and green physical foaming method. The conductive filaments were prepared by using MWCNTs-modified TPU by the physical method of melt blending. Samples were prefabricated using the FFF printer and then saturated with CO in an autoclave before being removed and heated to foam. The composite foam effectively reduced residual strain, demonstrating the high resilience of the 3D-printed composite materials with a foam porous structure. The residual strain of the sample before foaming was >6% after a single cycle, and then gradually increased. The residual strain of the foamed samples is less than 5%. In addition, composite foam has high sensitivity and can monitor subtle pressure changes (040 kPa). The sensing performance of the composite foam was evaluated, and the current signal remained stable under different loading rates and small compression strains (25%). By using this highly resilient conductive composite material, a hierarchical shoe insole was designed that successfully detected human walking and running movements.
具有高灵敏度和宽检测范围的可穿戴柔性传感器被应用于运动检测、医学诊断结果等领域，但弹性差和滞后现象仍然是一个挑战。在本研究中，通过增材制造和绿色物理发泡方法相结合制备了一种高弹性泡沫传感器。通过熔体共混的物理方法，使用多壁碳纳米管改性的热塑性聚氨酯制备导电长丝。使用熔融沉积成型（FFF）打印机预制样品，然后在高压釜中用二氧化碳饱和，再取出加热发泡。复合泡沫有效地降低了残余应变，证明了具有泡沫多孔结构的3D打印复合材料具有高弹性。发泡前样品在单循环后残余应变大于6%，然后逐渐增加。发泡样品的残余应变小于5%。此外，复合泡沫具有高灵敏度，能够监测细微的压力变化（040 kPa）。对复合泡沫的传感性能进行了评估，在不同加载速率和小压缩应变（25%）下电流信号保持稳定。通过使用这种高弹性导电复合材料，设计了一种分层鞋垫，成功检测到了人类的行走和跑步动作。
