State Key Laboratory Base for Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
ACS Appl Mater Interfaces. 2020 Oct 7;12(40):45306-45314. doi: 10.1021/acsami.0c13653. Epub 2020 Sep 25.
Flexible conductive composites can be used as wearable strain sensors, which are widely used in the fields of new-generation robotics, electronic skin, and human detection. However, how to make conductive composites that simultaneously possess flexibility, stretchability, self-healing, and sensing capability is challenging research. In this work, we innovatively designed and prepared a silicone polymer conductive composite. MXenes and amino poly(dimethylsiloxane) were modified by small biomolecules via an esterification reaction and a Schiff base reaction, respectively. The modified MXenes are uniformly dispersed, which endows the composite with good electrical conductivity. The reversibility of multiple hydrogen bonds and imine bonds in the composite system makes it have ideal tensile properties and high-efficiency self-healing ability without external stimulation. The conductive composite containing 10 wt % A-MXenes showed an elongation of 81%, and its mechanical strength could reach 1.81 MPa. After repair, the tensile properties and the electrical conductivity could be restored to 98.4 and 97.6%, respectively. In addition, the conductive composite is further evaluated for the value of wearable strain sensors. Even after cut-healed processes, the conductive composite can still accurately detect tiny human movements (including speaking, swallowing, and pressing). This kind of self-healing MXene/PDMS elastomers based on the modification of small biomolecules has great potential as wearable strain sensors. This simple preparation method provides guidance for future multifunctional flexible electronic materials.
柔性导电复合材料可用作可穿戴应变传感器，广泛应用于新一代机器人、电子皮肤和人体检测等领域。然而，如何制备同时具有柔韧性、拉伸性、自修复和传感性能的导电复合材料是一项具有挑战性的研究。在这项工作中，我们创新性地设计并制备了一种硅酮聚合物导电复合材料。通过酯化反应和席夫碱反应，分别对 MXenes 和氨基聚二甲基硅氧烷进行了小分子修饰。修饰后的 MXenes 均匀分散，赋予了复合材料良好的导电性。复合材料体系中多重氢键和亚胺键的可逆性使其具有理想的拉伸性能和高效的自修复能力，无需外部刺激。含有 10wt% A-MXenes 的导电复合材料伸长率达到 81%，其力学强度可达 1.81MPa。修复后，拉伸性能和电导率可分别恢复到 98.4%和 97.6%。此外，该导电复合材料进一步评估了其作为可穿戴应变传感器的价值。即使经过切割修复过程，该导电复合材料仍能准确检测微小的人体运动（包括说话、吞咽和按压）。这种基于小分子修饰的自修复 MXene/PDMS 弹性体作为可穿戴应变传感器具有巨大的潜力。这种简单的制备方法为未来多功能柔性电子材料提供了指导。
