Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
Department of Polymer Science, University of Akron, Akron, Ohio 44325-3909, USA.
Nature. 2017 Sep 28;549(7673):497-501. doi: 10.1038/nature23673. Epub 2017 Sep 4.
Despite the versatility of synthetic chemistry, certain combinations of mechanical softness, strength, and toughness can be difficult to achieve in a single material. These combinations are, however, commonplace in biological tissues, and are therefore needed for applications such as medical implants, tissue engineering, soft robotics, and wearable electronics. Present materials synthesis strategies are predominantly Edisonian, involving the empirical mixing of assorted monomers, crosslinking schemes, and occluded swelling agents, but this approach yields limited property control. Here we present a general strategy for mimicking the mechanical behaviour of biological materials by precisely encoding their stress-strain curves in solvent-free brush- and comb-like polymer networks (elastomers). The code consists of three independent architectural parameters-network strand length, side-chain length and grafting density. Using prototypical poly(dimethylsiloxane) elastomers, we illustrate how this parametric triplet enables the replication of the strain-stiffening characteristics of jellyfish, lung, and arterial tissues.
尽管合成化学具有多功能性，但在单一材料中实现机械柔软性、强度和韧性的某些组合可能具有挑战性。然而，这些组合在生物组织中很常见，因此在医疗植入物、组织工程、软机器人和可穿戴电子等应用中是必需的。目前的材料合成策略主要是爱迪生式的，涉及各种单体、交联方案和封闭的溶胀剂的经验混合，但这种方法只能有限地控制性能。在这里，我们提出了一种通过在无溶剂刷状和梳状聚合物网络（弹性体）中精确编码它们的应力-应变曲线来模拟生物材料力学行为的通用策略。该代码由三个独立的结构参数-网络链长度、侧链长度和接枝密度组成。使用典型的聚二甲基硅氧烷弹性体，我们说明了这种参数三元组如何能够复制水母、肺和动脉组织的应变硬化特性。
