High‐Contrast Optical Modulation from Strain‐Induced Nanogaps at 3D Heterogeneous Interfaces

Advanced Science

Jae‐Wook Jung¹  Sang‐Eon Lee¹  Jung‐Wuk Hong¹  Kwangjae Lee²  Young‐Seok Shim³  Seokhwan Min³  Seokwoo Jeon³  Youngjin Ham³  Donghwi Cho³  Sang‐Hyeon Nam³  Jonghwa Shin³  Junyong Park⁴ 

[1] Department of Civil and Environmental Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea;Department of Information Security Engineering Sang Myung University Cheonan‐si Chungcheongnam‐do 31066 Republic of Korea;Department of Materials Science and Engineering KAIST Institute for the NanoCentury Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea;School of Materials Science and Engineering Kumoh National Institute of Technology Gumi Gyeongbuk 39177 Republic of Korea;

关键词: 3D nanostructures;    air gaps;    scatterers;    smart windows;    stretchable nanocomposites;   

DOI  :  10.1002/advs.201903708

来源: DOAJ

【 摘 要 】

Abstract The realization of high‐contrast modulation in optically transparent media is of great significance for emerging mechano‐responsive smart windows. However, no study has provided fundamental strategies for maximizing light scattering during mechanical deformations. Here, a new type of 3D nanocomposite film consisting of an ultrathin (≈60 nm) Al2O3 nanoshell inserted between the elastomers in a periodic 3D nanonetwork is proposed. Regardless of the stretching direction, numerous light‐scattering nanogaps (corresponding to the porosity of up to ≈37.4 vol%) form at the interfaces of Al2O3 and the elastomers under stretching. This results in the gradual modulation of transmission from ≈90% to 16% at visible wavelengths and does not degrade with repeated stretching/releasing over more than 10 000 cycles. The underlying physics is precisely predicted by finite element analysis of the unit cells. As a proof of concept, a mobile‐app‐enabled smart window device for Internet of Things applications is realized using the proposed 3D nanocomposite with successful expansion to the 3 × 3 in. scale.

【 授权许可】

Unknown