ACS Nano. 2017 Nov 28;11(11):11350-11357. doi: 10.1021/acsnano.7b05885. Epub 2017 Nov 08.

Chameleon-Inspired Mechanochromic Photonic Films Composed of Non-Close-Packed Colloidal Arrays.

ACS nano

Gun Ho Lee, Tae Min Choi, Bomi Kim, Sang Hoon Han, Jung Min Lee, Shin-Hyun Kim

PMID: 29095594 DOI: 10.1021/acsnano.7b05885

Abstract

Chameleons use a non-close-packed array of guanine nanocrystals in iridophores to develop and tune skin colors in the full visible range. Inspired by the biological process uncovered in panther chameleons, we designed photonic films containing a non-close-packed face-centered-cubic array of silica particles embedded in an elastomer. The non-close-packed array is formed by interparticle repulsion exerted by solvation layers on the particle surface, which is rapidly captured in the elastomer by photocuring of the dispersion medium. The artificial skin exhibits a structural color that shifts from red to blue under stretching or compression. The separation between inelastic particles enables tuning without experiencing significant rearrangement of particles, providing elastic deformation and reversible color change, as chameleons do. The simple fabrication procedure consists of film casting and UV irradiation, potentially enabling the continuous high-throughput production. The mechanochromic property of the photonic films enables the visualization of deformation or stress with colors, which is potentially beneficial for various applications, including mechanical sensors, sound-vision transformers, and color display.

Keywords: chameleons; colloidal crystals; mechanochromism; non-close-packed arrays; structural colors

Publication Types

• Journal Article
• Research Support, Non-U.S. Gov't