Department of Materials Engineering, McGill University, Montréal, Québec H3A0C5, Canada.
Nanotechnology. 2017 Dec 1;28(48):485302. doi: 10.1088/1361-6528/aa94aa.
The present work presents a quantitative modeling framework for investigating the self-rolling of nanomembranes under different lattice mismatch strain anisotropy. The effect of transverse mismatch strain on the roll-up direction and curvature has been systematically studied employing both analytical modeling and numerical simulations. The bidirectional nature of the self-rolling of nanomembranes and the critical role of transverse strain in affecting the rolling behaviors have been demonstrated. Two fabrication strategies, i.e., third-layer deposition and corner geometry engineering, have been proposed to predictively manipulate the bidirectional rolling competition of strained nanomembranes, so as to achieve controlled, unidirectional roll-up. In particular for the strategy of corner engineering, microfabrication experiments have been performed to showcase its practical application and effectiveness. Our study offers new mechanistic knowledge towards understanding and predictive engineering of self-rolling of nanomembranes with improved roll-up yield.
本工作提出了一个定量建模框架，用于研究不同晶格失配应变各向异性下纳米膜的自卷。通过解析建模和数值模拟系统地研究了横向失配对卷起方向和曲率的影响。证明了纳米膜的自卷起的双向性质和横向应变对滚动行为的影响的重要性。提出了两种制造策略，即第三层沉积和角几何工程，以预测性地操纵应变纳米膜的双向滚动竞争，从而实现可控的单向卷起。特别是对于角工程策略，进行了微制造实验以展示其实际应用和有效性。我们的研究为理解和预测具有改进卷起收率的纳米膜的自卷起提供了新的机械知识。
