1] Department of Biomedical Engineering, College of Engineering, University of Michigan, 2200 Bonisteel Blvd, Ann Arbor, MI 48109, USA [2] Macromolecular Science and Engineering Center, College of Engineering, University of Michigan, 2300 Hayward St., Ann Arbor, MI 48109, USA.
Sci Rep. 2013 Oct 23;3:3027. doi: 10.1038/srep03027.
While the formation of cracks is often stochastic and considered undesirable, controlled fracture would enable rapid and low cost manufacture of micro/nanostructures. Here, we report a propagation-controlled technique to guide fracture of thin films supported on soft substrates to create crack arrays with highly controlled periodicity. Precision crack patterns are obtained by the use of strategically positioned stress-focusing V-notch features under conditions of slow application of strain to a degree where the notch features and intrinsic crack spacing match. This simple but robust approach provides a variety of precisely spaced crack arrays on both flat and curved surfaces. The general principles are applicable to a wide variety of multi-layered materials systems because the method does not require the careful control of defects associated with initiation-controlled approaches. There are also no intrinsic limitations on the area over which such patterning can be performed opening the way for large area micro/nano-manufacturing.
虽然裂缝的形成通常是随机的，且被认为是不理想的，但受控断裂将能够快速且低成本地制造微/纳米结构。在这里，我们报告了一种传播控制技术，用于引导在软基底上支撑的薄膜的断裂，以创建具有高度可控周期性的裂缝阵列。通过在应变缓慢施加的条件下使用战略性定位的应力集中 V 形槽特征，可以获得精密的裂缝图案，在这种条件下，槽特征和固有裂缝间距匹配。这种简单但强大的方法在平面和曲面上都提供了各种精确间隔的裂缝阵列。由于该方法不需要与启动控制方法相关的缺陷的精细控制，因此通用原理适用于各种多层材料系统。而且，这种图案形成的面积也没有内在的限制，为大面积微/纳米制造开辟了道路。
