Ware Taylor H, Biggins John S, Shick Andreas F, Warner Mark, White Timothy J
Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA.
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080, USA.
Nat Commun. 2016 Feb 23;7:10781. doi: 10.1038/ncomms10781.
Synthetic approaches to prepare designer materials that localize deformation, by combining rigidity and compliance in a single material, have been widely sought. Bottom-up approaches, such as the self-organization of liquid crystals, offer potential advantages over top-down patterning methods such as photolithographic control of crosslink density, relating to the ease of preparation and fidelity of resolution. Here, we report on the directed self-assembly of materials with spatial and hierarchical variation in mechanical anisotropy. The highly nonlinear mechanical properties of the liquid crystalline elastomers examined here enables strain to be locally reduced >15-fold without introducing compositional variation or other heterogeneities. Each domain (⩾0.01 mm(2)) exhibits anisotropic nonlinear response to load based on the alignment of the molecular orientation with the loading axis. Accordingly, we design monoliths that localize deformation in uniaxial and biaxial tension, shear, bending and crack propagation, and subsequently demonstrate substrates for globally deformable yet locally stiff electronics.
通过在单一材料中结合刚性和柔韧性来制备能够局部控制变形的定制材料的合成方法，一直是人们广泛探索的目标。自下而上的方法，如液晶的自组装，与自上而下的图案化方法（如通过光刻控制交联密度）相比，具有潜在优势，这体现在制备的简易性和分辨率的保真度上。在此，我们报道了具有空间和层次化机械各向异性变化的材料的定向自组装。本文研究的液晶弹性体的高度非线性力学性能，能够在不引入成分变化或其他不均匀性的情况下，使局部应变降低超过15倍。每个区域（⩾0.01 mm(2)）基于分子取向与加载轴的对齐，对载荷表现出各向异性的非线性响应。因此，我们设计了在单轴和双轴拉伸、剪切、弯曲和裂纹扩展中能够局部控制变形的整体材料，随后展示了用于全局可变形但局部坚硬的电子产品的基板。
