Printable Liquid Metal Foams That Grow When Watered
Printable Liquid Metal Foams That Grow When Watered
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DOI：
10.1002/adma.202308862
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发表时间：
2024-01-29
影响因子：
29.4
通讯作者：
Dickey，Michael D.
中科院分区：
文献类型：
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作者：
Krisnadi，Febby;Kim，Seoyeon;Dickey，Michael D.
含有液态金属 (LM) 作为连续相的糊剂和“泡沫”（液态金属泡沫，LMF）表现出金属特性，同时表现出糊剂或腻子状的流变行为。这些特性使 LMF 能够通过在室温下进行的工艺（例如印刷）图案化为柔软且可拉伸的电导体和热导体。这项工作中最简单的LMF是通过在空气中搅拌LM制成的，从而将氧化物衬里的空气“袋”带入LM中。据报道，将少量水（低至 1 wt%）混合到此类 LMF 中，可利用已知的放出氢气和产生氧化物的反应，产生显着的泡沫。由此产生的结构可以约为其原始体积的 4-5 倍，并具有令人着迷的属性组合：孔隙率、导电性和对环境条件的响应性。这种扩展可用于一种 4D 打印，其中图案化导体“生长”、填充空腔，并随时间改变形状和密度。长期过度接触水最终会消耗 LMF 中的金属。然而，当控制与水的接触时，多孔 LMF 的金属特性可以得到保留。
Pastes and “foams” containing liquid metal (LM) as the continuous phase (liquid metal foams, LMFs) exhibit metallic properties while displaying paste or putty‐like rheological behavior. These properties enable LMFs to be patterned into soft and stretchable electrical and thermal conductors through processes conducted at room temperature, such as printing. The simplest LMFs, featured in this work, are made by stirring LM in air, thereby entraining oxide‐lined air “pockets” into the LM. Here, it is reported that mixing small amounts of water (as low as 1 wt%) into such LMFs gives rise to significant foaming by harnessing known reactions that evolve hydrogen and produce oxides. The resulting structures can be ≈4–5× their original volume and possess a fascinating combination of attributes: porosity, electrical conductivity, and responsiveness to environmental conditions. This expansion can be utilized for a type of 4D printing in which patterned conductors “grow,” fill cavities, and change shape and density with respect to time. Excessive exposure to water in the long term ultimately consumes the metal in the LMF. However, when exposure to water is controlled, the metallic properties of porous LMFs can be preserved.