Open AccessHigh‐Contrast Optical Modulation from Strain‐Induced Nanogaps at 3D Heterogeneous Interfaces
Author(s) -
Cho Donghwi,
Shim YoungSeok,
Jung JaeWook,
Nam SangHyeon,
Min Seokhwan,
Lee SangEon,
Ham Youngjin,
Lee Kwangjae,
Park Junyong,
Shin Jonghwa,
Hong JungWuk,
Jeon Seokwoo
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201903708
Subject(s) - materials science , nanocomposite , elastomer , modulation (music) , light scattering , scattering , smart material , optoelectronics , wavelength , nanotechnology , optics , composite material , acoustics , physics
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) Al 2 O 3 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 Al 2 O 3 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.