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Capillary‐Force‐Driven Self‐Assembly of 4D‐Printed Microstructures
Author(s) -
Liu Xiaojiang,
Wei Mengxiao,
Wang Qiong,
Tian Yujia,
Han Jiamian,
Gu Hongcheng,
Ding Haibo,
Chen Qiang,
Zhou Kun,
Gu Zhongze
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202100332
Subject(s) - materials science , capillary action , microstructure , wetting , self assembly , nanotechnology , lithography , curvature , 3d printed , composite material , optoelectronics , geometry , mathematics , medicine , biomedical engineering
Abstract Capillary‐force‐driven self‐assembly is emerging as a significant approach for the massive manufacture of advanced materials with novel wetting, adhesion, optical, mechanical, or electrical properties. However, academic value and practical applications of the self‐assembly are greatly restricted because traditional micropillar self‐assembly is always unidirectional. In this work, two‐photon‐lithography‐based 4D microprinting is introduced to realize the reversible and bidirectional self‐assembly of microstructures. With asymmetric crosslinking densities, the printed vertical microstructures can switch to a curved state with controlled thickness, curvature, and smooth morphology that are impossible to replicate by traditional 3D‐printing technology. In different evaporating solvents, the 4D‐printed microstructures can experience three states: (I) coalesce into clusters from original vertical states via traditional self‐assembly, (II) remain curved, or (III) arbitrarily self‐assemble (4D self‐assembly) toward the curving directions. Compared to conventional approaches, this 4D self‐assembly is distance‐independent, which can generate varieties of assemblies with a yield as high as 100%. More importantly, the three states can be reversibly switched, allowing the development of many promising applications such as reversible micropatterns, switchable wetting, and dynamic actuation of microrobots, origami, and encapsulation.