title: Tuning and Erasing Surface Wrinkles by Reversible Visible-Light-Induced Photoisomerization.
abstract: Periodic wrinkling across different scales has received considerable attention because it not only represents structure failure but also finds wide applications. How to prevent wrinkling or create desired wrinkling patterns is non-trivial because the dynamic evolution of wrinkles is a highly nonlinear problem. Herein, we report a simple yet powerful method to dynamically tune and/or erase wrinkling patterns with visible light. The light-induced photoisomerization of azobenzene units in azopolymer films leads to stress release and consequently to the erasure of the wrinkles. The wrinkles in unexposed regions are also affected and oriented perpendicular to the exposed boundary during the stress reorganization. Theoretical models were developed to understand the dynamics of the reversible photoisomerization-induced wrinkle evolution. This method can be applied for designing functional materials/devices, for example, for the reversible optical writing/erasure of information as demonstrated here.
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
authors.forename: Chuanyong
authors.initials: C
authors.lastname: Zong
authors.affiliation: AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
authors.forename: Haipeng
authors.initials: H
authors.lastname: Ji
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Han
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
authors.forename: Jixun
authors.initials: J
authors.lastname: Xie
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Wang
authors.affiliation: AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China. caoyanping@tsinghua.edu.cn.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Cao
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China. scjiang@tju.edu.cn.
authors.forename: Shichun
authors.initials: S
authors.lastname: Jiang
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China. chlu@tju.edu.cn.
authors.forename: Conghua
authors.initials: C
authors.lastname: Lu
keywords: azopolymers; isomerization; mechanical properties; photochemistry; wrinkling