An automatic numerical approach to optimize flexible serpentine structure design

Abstract

Abstract The serpentine shape has been increasingly popular for the conductor design in flexible electronics due to its superior compliance and stretchability performance. The stretchability of the serpentine structure is highly dependent on the material strain threshold, serpentine geometry design, and the attachment substrate property. Therefore, identifying the parameters and their corresponding importance factors to the stretchability of the structure will help optimize the serpentine geometry. In the current work, a fully automated finite-element model has been developed to calculate the normalized maximum strain in the free-standing serpentine structure under uniaxial stretch loading conditions. A parametric study has been conducted to understand the serpentine geometry impacts on the maximum strain in the serpentine structure under the equivalent 10% uniaxial strain loading condition. The study shows that longer straight-line length, larger arc segment angle, and smaller serpentine with a fixed arc segment radius can help to reduce the maximum strain in the serpentine structure under uniaxial stretching. A random forest machine learning model suggests that the serpentine width and arc segment angle have the highest impact on the maximum strain in the serpentine structure. In the end, the proposed optimization strategy has also been used to optimize the strain distribution when the serpentine structure is attached to a polymer substrate.