Institute of Microstructure Technology, Karlsruher Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Soft Matter. 2017 Jun 21;13(24):4328-4334. doi: 10.1039/c7sm00154a.
Inspired by complex multi-functional leaf and petal surfaces, we introduce a mechanically directed self-assembly process to create linearly oriented micro- and nanosized surface wrinkles in an all-polymer bi-layer system based on a shape-memory polymer substrate. By systematically investigating the influence of coating thickness and substrate programming strain on wrinkle period and height, we reveal how to control the structure size from a few hundred nanometers up to several microns. As a parameter unique to shape memory polymers, we demonstrate that the temperature during the recovery process can also be utilized to tailor the structure dimensions. Furthermore, we advance the method with a second structuring step to mimic the hierarchically structured petal surfaces of tulips and daisies. The presented structuring method provides a large-scale, mold-free, and very cost-effective way for the full-polymer fabrication of micro and sub-microstructures with adjustable structure size and intrinsic irregularity.
受复杂多功能叶片和花瓣表面的启发，我们引入了一种机械导向自组装工艺，在基于形状记忆聚合物基底的全聚合物双层系统中创建线性定向的微纳米表面皱纹。通过系统地研究涂层厚度和基底编程应变对皱纹周期和高度的影响，我们揭示了如何从几百纳米到几微米的范围内控制结构尺寸。作为形状记忆聚合物的一个独特参数，我们证明了在恢复过程中的温度也可用于调整结构尺寸。此外，我们通过第二个结构化步骤来推进该方法，以模拟郁金香和雏菊的分层结构花瓣表面。所提出的结构化方法为具有可调节结构尺寸和固有不规则性的全聚合物微结构和亚微结构的大规模、无模具和非常经济高效的制造提供了一种方法。
