From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates
From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates
复制标题
DOI：
10.1002/adma.202008434
复制
发表时间：
2021-04-15
影响因子：
29.4
通讯作者：
Ware, Taylor H.
中科院分区：
文献类型：
--
作者：
Kim, Hyun;Abdelrahman, Mustafa K.;Ware, Taylor H.
裂纹通常与材料失效有关。然而，裂缝也可以用来在材料表面上形成周期性图案，就像在鳄鱼和大象的皮肤上观察到的那样。在合成材料中，表面图案对微米和纳米级制造工艺至关重要。在这里，提出了一种策略，使自由编程的聚合物表面上的裂纹图案，然后使用这些裂纹图案的其他材料。在液晶聚合物网络（LCN）上沉积薄膜金属期间形成裂纹，并且裂纹遵循聚合物的空间图案化分子顺序。这些图案化的亚微米级裂纹具有0.98 +/-0.02的序参数，并且容易在柔性基板上形成超过厘米级的区域。LCN的图案化使得裂纹能够转角、螺旋方位角或从一点辐射。导电油墨可以填充到这些定向裂缝中，从而产生柔性、各向异性和透明的导体。这种基于材料的裂纹图案化处理方法能够在不使用昂贵的光刻方法的情况下对裂纹的取向、长度、宽度和深度进行前所未有的控制。这种方法有望实现电子、传感器、流体、光学和其他具有微米和纳米级特征的设备的新架构。
Cracks are typically associated with the failure of materials. However, cracks can also be used to create periodic patterns on the surfaces of materials, as observed in the skin of crocodiles and elephants. In synthetic materials, surface patterns are critical to micro- and nanoscale fabrication processes. Here, a strategy is presented that enables freely programmable patterns of cracks on the surface of a polymer and then uses these cracks to pattern other materials. Cracks form during deposition of a thin film metal on a liquid crystal polymer network (LCN) and follow the spatially patterned molecular order of the polymer. These patterned sub-micrometer scale cracks have an order parameter of 0.98 +/- 0.02 and form readily over centimeter-scale areas on the flexible substrates. The patterning of the LCN enables cracks that turn corners, spiral azimuthally, or radiate from a point. Conductive inks can be filled into these oriented cracks, resulting in flexible, anisotropic, and transparent conductors. This materials-based processing approach to patterning cracks enables unprecedented control of the orientation, length, width, and depth of the cracks without costly lithography methods. This approach promises new architectures of electronics, sensors, fluidics, optics, and other devices with micro- and nanoscale features.