Wang Yongkang, Zhou Zanxin, Li Rui, Wang Jianru, Sha Baolin, Li Shuang, Su Yewang
State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China.
Nanomaterials (Basel). 2023 Sep 11;13(18):2542. doi: 10.3390/nano13182542.
The design of non-buckling interconnects with thick sections has gained important applications in stretchable inorganic electronics due to their simultaneous achievement of high stretchability, low resistance, and low heat generation. However, at the same time, such a design sharply increased the tensile stiffness, which is detrimental to the conformal fit and skin comfort. Introducing the fractal design into the non-buckling interconnects is a promising approach to greatly reduce the tensile stiffness while maintaining other excellent performances. Here, a hierarchical theory is proposed for the tensile stiffness of the non-buckling fractal-inspired interconnects with an arbitrary shape at each order, which is verified by the finite element analysis. The results show that the tensile stiffness of the non-buckling fractal-inspired interconnects decreases with the increase in either the height/span ratio or the number of fractal orders but is not highly correlated with the ratio of the two adjacent dimensions. When the ratio of the two adjacent dimensions and height/span ratio are fixed, the tensile stiffness of the serpentine fractal-inspired interconnect is smaller than that of sinusoidal and zigzag fractal-inspired interconnects. These findings are of great significance for the design of non-buckling fractal-inspired interconnects of stretchable inorganic electronics.
具有厚截面的非屈曲互连结构的设计，因其同时实现了高拉伸性、低电阻和低发热，在可拉伸无机电子学中获得了重要应用。然而，与此同时，这种设计大幅提高了拉伸刚度，这对贴合度和皮肤舒适度不利。将分形设计引入非屈曲互连结构是一种很有前景的方法，可在保持其他优异性能的同时大幅降低拉伸刚度。在此，针对各阶具有任意形状的非屈曲分形启发式互连结构的拉伸刚度，提出了一种分层理论，并通过有限元分析进行了验证。结果表明，非屈曲分形启发式互连结构的拉伸刚度随着高度/跨度比或分形阶数的增加而降低，但与两个相邻尺寸的比值相关性不高。当两个相邻尺寸的比值和高度/跨度比固定时，蛇形分形启发式互连结构的拉伸刚度小于正弦形和之之之字形分形启发式互连结构。这些发现对于可拉伸无机电子学的非屈曲分形启发式互连结构的设计具有重要意义。
