Assembling sandwich serpentine structures with soft functional materials creates an effective way to high-performance stretchable devices. In order to achieve better design criteria for the application of serpentine-shaped stretchable systems, this paper explores the mechanics governing the deformation mechanisms of the sandwich serpentine structures. Firstly, detailed three-dimensional (3-D) numerical simulations were conducted to well capture the deformation modes. Secondly, a theoretical model was developed within the simplified 1-D formulation. Numerical and theoretical investigations reveal the important features of the underlying materials (including the representative low-modulus elastomers) and mechanics aspects of the polymer/metal/polymer sandwich serpentine interconnects system with strain-isolating layers, and their dependence on key design variables (including the material selection and thickness of both the isolation layer and the serpentine clad). Three distinct deformation modes of the sandwich serpentine structures were observed and discussed: 1) Global buckling; 2) Local wrinkling; and 3) Planar bending. By theoretically analyzing the wrinkling wavelengths, we propose a simple design criterion for the strain-isolating layers that indicates a transition from local wrinkling to global buckling, with the increasing thickness of the isolation layer. Results will be useful to mechanical design of stretchable systems with high levels of the elastic stretchability.

用柔软的功能材料组装夹心蛇形结构可为高性能可拉伸设备提供有效的方式。为了达到更好的设计标准来设计蛇形可伸展系统，本文探讨了控制三明治蛇形结构变形机理的机理。首先，进行了详细的三维（3-D）数值模拟，以很好地捕获变形模式。其次，在简化的一维公式中建立了理论模型。数值和理论研究揭示了基础材料（包括代表性的低模量弹性体）的重要特征以及具有应变隔离层的聚合物/金属/聚合物夹层蛇形互连系统的力学特性，以及它们对关键设计变量的依赖关系（包括隔离层和蛇形覆层的材料选择和厚度）。观察并讨论了夹层蛇形结构的三种不同的变形模式：1）整体屈曲；2）局部起皱；3）平面弯曲。通过对折皱波长进行理论分析，我们为应变隔离层提出了一个简单的设计标准，该标准表明随着隔离层厚度的增加，从局部折皱过渡到整体屈曲。结果对于具有高水平弹性可拉伸性的可拉伸系统的机械设计将是有用的。观察并讨论了夹层蛇形结构的三种不同的变形模式：1）整体屈曲；2）局部起皱；3）平面弯曲。通过对折皱波长进行理论分析，我们为应变隔离层提出了一个简单的设计标准，该标准表明随着隔离层厚度的增加，从局部折皱过渡到整体屈曲。结果对于具有高水平弹性可拉伸性的可拉伸系统的机械设计将是有用的。观察并讨论了夹层蛇形结构的三种不同的变形模式：1）整体屈曲；2）局部起皱；3）平面弯曲。通过对折皱波长进行理论分析，我们为应变隔离层提出了一个简单的设计标准，该标准表明随着隔离层厚度的增加，从局部折皱过渡到整体屈曲。结果对于具有高水平弹性可拉伸性的可拉伸系统的机械设计将是有用的。