Herein, we report a novel hybrid auxetic foam (HAF) with high energy dissipation and self-healing properties prepared by integrating shear thickening gel (STG) with auxetic polyurethane foam (APF). Due to the synergetic action of shear thickening property of STG and the negative Poisson's ratio of APF, HAF shows better impact protection performance than APF and PU foam. The quasi-static compression test shows the energy dissipation ability of HAF is around 4 times that of APF. The dynamic impact test demonstrates that the force reduction of HAF increases by as high as 64 %, compared to APF. Notably, the force reduction improvement of the HAF is much higher than other hybrid auxetic materials. It is also found that the peak force of HAF is reduced as the amount of STG increases. Additionally, the peak force difference between HAF and APF becomes larger when they are subjected to higher impact energies, due to the rate-dependent effect of STG inside the foam. The Poisson's ratio results for HAF with different STG content under low and high compression strain rates reveal that the dimension of auxetic cell structures and STG content are required to be carefully designed to maximize the synergistic effect of auxetic property and shear thickening property. Besides, HAF demonstrates self-healing ability, allowing it to repair damage sustained during use and can be assembled like Lego blocks to make structures with any irregular shapes. Our work provides ideas for the development of advanced auxetic materials, with the potential to revolutionize a wide range of applications.

中文翻译：

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集成剪切增稠凝胶的高能量消散和自修复拉胀泡沫

在此，我们报道了一种通过将剪切增稠凝胶（STG）与拉胀聚氨酯泡沫（APF）相结合而制备的具有高能量耗散和自修复性能的新型混合拉胀泡沫（HAF）。由于STG的剪切增稠特性和APF的负泊松比的协同作用，HAF表现出比APF和PU泡沫更好的冲击防护性能。准静态压缩试验表明HAF的耗能能力约为APF的4倍。动态冲击测试表明，与 APF 相比，HAF 的减力幅度高达 64%。值得注意的是，HAF 的减力改进远远高于其他混合拉胀材料。还发现，随着 STG 量的增加，HAF 的峰值力降低。此外，由于泡沫内部 STG 的速率依赖性效应，当 HAF 和 APF 受到更高的冲击能量时，它们之间的峰值力差异变得更大。不同STG含量的HAF在低和高压缩应变率下的泊松比结果表明，需要仔细设计拉胀细胞结构的尺寸和STG含量，以最大限度地发挥拉胀性能和剪切增稠性能的协同效应。此外，HAF还具有自愈能力，可以修复使用过程中遭受的损坏，并且可以像乐高积木一样组装成任何不规则形状的结构。我们的工作为先进拉胀材料的开发提供了思路，有可能彻底改变广泛的应用。