Abstract
<title>Abstract</title> <p>Architecture can enhance toughness across length scales, but the influence of feature size is poorly understood. Here, we develop a size-affected framework predicting how architectural and material toughening combine to enhance fracture resistance. We first show toughness is not an intrinsic property – single materials exhibit a 1.5-fold increase in work of fracture when their thickness matches constituent plastic-zone sizes. We then develop an analytic architectural toughening framework based on experiments and finite-element modeling of single-material polymer laminates fabricated at micro- and macroscales. Combining architecture and sizeenhanced toughening, we experimentally demonstrate a 5-fold increase in work of fracture in a single material, and numerically predict an 8.7-fold increase for layered materials with dimensions equal to their architectural plastic-zone sizes. This quantitative framework enables the design of tough materials from any constituent and can be applied recursively to optimize toughness hierarchically like what is found in natural materials.</p>