Self-shaping composites with programmable bioinspired microstructures
Self-shaping composites with programmable bioinspired microstructures
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DOI：
10.1038/ncomms2666
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发表时间：
2013-04-01
影响因子：
16.6
通讯作者：
Studart, Andre R.
中科院分区：
文献类型：
--
作者：
Erb, Randall M.;Sander, Jonathan S.;Studart, Andre R.
形状变化是多种自然结构中普遍存在的功能，包括种子传播单位、攀缘植物和食肉植物。许多这些天然材料通过在特定方向上使用纤维素微原纤维来改变形状，以各向异性地限制其有机基质在外部刺激下的膨胀/收缩。这与合成形状记忆系统中发现的材料特定机制形成对比。在这里，我们提出了一个强大的和通用的方法来复制这种不寻常的形状变化机制的自然系统的人工仿生复合材料。该技术基于利用弱外部磁场远程控制复合材料内增强无机颗粒的取向。将这种增强方向控制与可膨胀/可收缩聚合物基体相结合，可以创建复合材料，其形状变化可以通过编程改变到材料的微观结构中，而不是外部施加。这种受生物启发的方法可以产生具有不寻常的可逆性、扭曲效果和特定地点可编程形状变化的复合材料。
Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material's microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.