Maple Leaf Inspired Conductive Fiber with Hierarchical Wrinkles for Highly Stretchable and Integratable Electronics
Maple Leaf Inspired Conductive Fiber with Hierarchical Wrinkles for Highly Stretchable and Integratable Electronics
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DOI：
10.1021/acsami.2c12746
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发表时间：
2022-10-17
影响因子：
9.5
通讯作者：
Mao, Jifu
中科院分区：
文献类型：
--
作者：
Gao, Yaya;Yu, Lingyao;Mao, Jifu
可拉伸和耐用的导体对于可穿戴设备、机器人、人机界面和其他人工智能产品的开发具有重要意义。然而，在大变形下，可拉伸结构的失效和机械性能（刚性导电层和弹性芯基板）的不匹配限制了理想的应变不敏感导电性和低滞后。本文基于分形几何学原理，结合表面改性、界面聚合和改进的预应变整理方法，以枫叶的独特形状为灵感，制备了具有层次褶皱的可拉伸导电纤维，突破了这一困境。通过有限元方法的屈曲分析预测的褶皱的形状和尺寸与所制造的纤维上的实际褶皱（30-80 μ m的宏观褶皱和4-6 μ m的微观褶皱）的形状和尺寸很好地吻合。这种分层褶皱导电纤维（HWCF）不仅表现出优异的应变不敏感导电性，其表示为相对电阻变化Δ R/R 0 = 0.66，其中R 0为初始电阻，Δ R为混凝土应变达到600%后的电阻变化，而且还具有低滞后（0.04）通过在300%应变和长期耐久性下的Δ R/R 0应变的拉伸和释放曲线之间的面积差计算（>1000次拉伸-释放循环）。此外，具有这种仿生结构设计的弹性导电纤维还可以作为用于照明的高度可拉伸的电路，以及通过微小且快速的电阻变化来监测大应变下的人体运动。这种智能仿生材料在可拉伸电子领域具有广阔的应用前景。
Stretchable and durable conductors are significant to the development of wearable devices, robots, human-machine interfaces, and other artificial intelligence products. However, the desirable strain-insensitive con-ductivity and low hysteresis are restricted by the failure of stretchable structures and mismatch of mechanical properties (rigid conductive layer and elastic core substrate) under large deformation. Here, based on the principles of fractal geometry, a stretchable conductive fiber with hierarchical wrinkles inspired by the unique shape of the maple leaf was fabricated by combining surface modification, interfacial polymerization, and improved prestrain finishing methods to break through this dilemma. The shape and size of wrinkles predicted by buckling analysis via the finite element method fit well with that of actual wrinkles (30-80 mu m of macro wrinkles and 4-6 mu m of micro wrinkles) on the fabricated fiber. Such hierarchically wrinkled conductive fiber (HWCF) exhibited not only excellent strain-insensitive conductivity denoted by the relative resistance change Delta R/R0 = 0.66 with R0 the original resistance and Delta R the change of resistance after the concrete strain reaching up to 600%, but also low hysteresis (0.04) calculated by the difference in area between stretching and releasing curve of the Delta R/R0 strain under 300% strain and long-term durability (>1000 stretching- releasing cycles). Furthermore, the elastic conductive fiber with such a bionic structure design can be applied as highly stretchable electrical circuits for illumination and monitors for the human motion under large strains through tiny and rapid resistance changes as well. Such a smart biomimetic material holds great prospects in the field of stretchable electronics.