Dong Guohua, Li Suzhi, Li Tao, Wu Haijun, Nan Tianxiang, Wang Xiaohua, Liu Haixia, Cheng Yuxin, Zhou Yuqing, Qu Wanbo, Zhao Yifan, Peng Bin, Wang Zhiguang, Hu Zhongqiang, Luo Zhenlin, Ren Wei, Pennycook Stephen J, Li Ju, Sun Jun, Ye Zuo-Guang, Jiang Zhuangde, Zhou Ziyao, Ding Xiangdong, Min Tai, Liu Ming
The Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Mechanical Behavior of Materials, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
Adv Mater. 2020 Dec;32(50):e2004477. doi: 10.1002/adma.202004477. Epub 2020 Nov 2.
Self-assembled membranes with periodic wrinkled patterns are the critical building blocks of various flexible electronics, where the wrinkles are usually designed and fabricated to provide distinct functionalities. These membranes are typically metallic and organic materials with good ductility that are tolerant of complex deformation. However, the preparation of oxide membranes, especially those with intricate wrinkle patterns, is challenging due to their inherently strong covalent or ionic bonding, which usually leads to material crazing and brittle fracture. Here, wrinkle-patterned BaTiO (BTO)/poly(dimethylsiloxane) membranes with finely controlled parallel, zigzag, and mosaic patterns are prepared. The BTO layers show excellent flexibility and can form well-ordered and periodic wrinkles under compressive in-plane stress. Enhanced piezoelectricity is observed at the sites of peaks and valleys of the wrinkles where the largest strain gradient is generated. Atomistic simulations further reveal that the excellent elasticity and the correlated coupling between polarization and strain/strain gradient are strongly associated with ferroelectric domain switching and continuous dipole rotation. The out-of-plane polarization is primarily generated at compressive regions, while the in-plane polarization dominates at the tensile regions. The wrinkled ferroelectric oxides with differently strained regions and correlated polarization distributions would pave a way toward novel flexible electronics.
具有周期性皱纹图案的自组装膜是各种柔性电子产品的关键组成部分，其中皱纹通常被设计和制造以提供独特的功能。这些膜通常是具有良好延展性的金属和有机材料，能够承受复杂的变形。然而，氧化物膜的制备，尤其是那些具有复杂皱纹图案的氧化物膜，由于其固有的强共价键或离子键，通常会导致材料出现裂纹和脆性断裂，因此具有挑战性。在此，制备了具有精细控制的平行、之字形和镶嵌图案的皱纹图案化钛酸钡（BTO）/聚二甲基硅氧烷膜。BTO层表现出优异的柔韧性，并且在平面内压缩应力下可以形成有序的周期性皱纹。在产生最大应变梯度的皱纹的峰谷处观察到增强的压电性。原子模拟进一步表明，优异的弹性以及极化与应变/应变梯度之间的相关耦合与铁电畴切换和连续偶极旋转密切相关。面外极化主要在压缩区域产生，而面内极化在拉伸区域占主导。具有不同应变区域和相关极化分布的皱纹铁电氧化物将为新型柔性电子产品铺平道路。
