Self-rolling allows the bilayer to transform into a 3D structure in response to specific external stimulation, such as heat, humidity, ions, etc. Herein, we report a 4D printing bilayer with a top sodium alginate layer and bottom polycaprolactone layer that could be rolled up to a tubular structure upon exposure to heat and Ca2+ solution stimulation. The discrepancy in the swelling and thermal-responsiveness between alginate and polycaprolactone induced the self-rolling under different stimuli. The self-rolling behavior of the bilayer depends on the aspect ratio, thickness ratio of the bilayer film, the pattern, and external stimuli. Thus, a tailorable surface of the self-rolled tube was obtained by tuning the bilayer parameter and the stimuli medium to meet varied demands. This controllable shape changing provides a strategy for the preparation of well-defined tubular structures. Besides, the biocompatibility of bilayer film suggests the potential application in the field of biomedical device such as vascular stent.
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机译:自滚动允许双层响应特定的外部刺激(如热量、湿度、离子等)转变为 3D 结构。在此,我们报道了一种 4D 打印双层,其顶部为海藻酸钠层,底部为聚己内酯层,在暴露于热和 Ca2+ 溶液刺激时可以卷成管状结构。海藻酸盐和聚己内酯在溶胀和热响应性上的差异诱导了不同刺激下的自滚动。双层膜的自卷行为取决于长宽比、双层膜的厚度比、图案和外部刺激。因此,通过调整双层参数和激励介质来满足不同的需求,获得了可定制的自轧管表面。这种可控的形状变化为制备明确的管状结构提供了一种策略。此外,双层膜的生物相容性表明了在血管支架等生物医学器械领域的潜在应用。
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