Reversible Mechanochromisms via Manipulating Surface Wrinkling

Abstract

Mechanochromic structural-colored materials have promising applications in various domains. In this Letter, we report three types of reversible mechanochromisms in simple material systems by harnessing mechano-responsive wrinkling dynamics including (i) brightness mechanochromism (BM), (ii) hue change mechanochromism (HCM), and (iii) viewable angle mechanochromism (VAM). Upon stretching, the BM device exhibits almost a constant hue but reduces light brightness due to the postbuckling mechanics-controlled deformation, while the HCM device can change the hue from blue to red with almost constant intensity because of the linear elastic mechanics-controlled deformation. The VAM device shows a constant hue because of the thin film interference effect. However, the viewable angles decrease with increasing applied strain owing to the light scattering of wrinkles. All of the mechanochromic behaviors exhibit good reversibility and durability. We clearly elucidated the underlying mechanisms for different mechanochromisms and demonstrated their potential applications in smart displays, stretchable strain sensors, and antipeeping/anticounterfeiting devices.

Tunable Structural Color with Gradient and Multiaxial Polydimethylsiloxane Wrinkling

“…[27][28][29] We have previously demonstrated the design of tunable optical gratings [30] using this method (building on the previous demonstrations with polymer bilayer laminates [31] ). The impact of the PDMS substrate thickness on the mechanochromic response of 1D plasma oxidized PDMS films has been recently reported, [32,33] and color tunability according to illumination and viewing angle examined. Recently, the incorporation of polystyrene nanoparticles and the use of wire-bar coating (yielding regular arrays) was demonstrated to produce both angle-independent and -dependent structural colors, upon plasma exposure and wrinkling.…”

Responsive Structural Colors Derived from Geometrical Deformation of Synthetic Nanomaterials

“…For wrinkles whose λ 0 varies with strain, λ w can be calculated according to the principle of 2D grating. [ 133 ]…”

Active modulation of reflective structural colors

“…Changing the structure for dynamic structural colors has been previously explored by many groups. [17][18][19] Therefore in this review, we focus on changing the permittivity of the system and the surrounding. There are several ways to achieve this.…”