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Multimodal and Covert–Overt Convertible Structural Coloration Transformed by Mechanical Stress
Author(s) -
Zhou Qitao,
Park Jun Gyu,
Bae Juyeol,
Ha Dogyeong,
Park Jungyul,
Song Kyungjun,
Kim Taesung
Publication year - 2020
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.202001467
Subject(s) - materials science , covert , colored , structural coloration , stress (linguistics) , composite material , nanotechnology , optoelectronics , photonic crystal , philosophy , linguistics
Most materials and devices with structurally switchable color features responsive to external stimuli can actively and flexibly display various colors. However, realizing covert–overt transformation behavior, especially switching between transparent and colored states, is more challenging. A composite laminate of soft poly(dimethylsiloxane) (PDMS) with a rigid SiO 2 ‐nanoparticle (NP) structure pattern is developed as a multidimensional structural color platform. Owing to the similarity in the optical properties of PDMS and SiO 2 NPs, this device is fully transparent in the normal state. However, as their mechanical strengths differ considerably, upon compressive loading, a buckling‐type instability arises on the surface of the laminate, leading to the generation of 1D or 2D wrinkled patterns in the form of gratings. Finally, an application of the device in which quick response codes are displayed or hidden as covert–overt convertible colored patterns for optical encryption/decryption, showing their remarkable potential for anticounterfeiting applications, is demonstrated.