New Article in ACS Nano

posted Nov 2, 2017, 4:57 PM by Shin-Hyun Kim
Gun Ho Lee, Tae Min Choi, Bomi Kim, Sang Hoon Han, Jung Min Lee, and Shin-Hyun Kim, "Chameleon-Inspired Mechanochromic Photonic Films Composed of Nonclose-Packed Colloidal Arrays", ACS NanoAccepted for publication (2017).

Chameleon uses a nonclose-packed array of guanine nanocrystals in iridophores to develop and tune skin colors in full visible range. Inspired from the biological process uncovered in panther chameleons, we design photonic films containing a nonclose-packed face-centered cubic (fcc) array of silica particles embedded in an elastomer. The nonclose-packed array is formed by interparticle repulsion exerted by solvation layers on the particle surface, which is rapidly captured in the elastomer by photo-curing of the dispersion medium. The artificial skin exhibits the structural color that shifts from red to blue under stretching or compression. The separation between inelastic particles enables the 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.