Polarization-Dependent Ultrasensitive Dynamic Wrinkling on Floating Films Induced by Photo-Orientation of Azopolymer

Angew Chem Int Ed Engl. 2022 Aug 1;61(31):e202203715. doi: 10.1002/anie.202203715. Epub 2022 Jun 10.

Abstract

Ubiquitous surface wrinkling has been well-studied theoretically and experimentally. How to modulate the stress state of a liquid-supported system for the unexploited wrinkling capabilities remains a challenge. Here we report a simple linearly-polarized-light illumination to spatiotemporally trigger ultrasensitive in situ dynamic wrinkling on a floating azo-film. The smart combination of the liquid substrate with photoresponsive azo-moieties leads to the light-induced ultrafast wrinkling evolution, accompanied by unprecedented sequential wrinkling orientation conversion (from polarization-parallel to polarization-perpendicular). The involved different polarization-dependent sequential photo-orientation for azo side chains and azo-grafted main chains of azopolymers is disclosed experimentally for the first time. Meanwhile, programmable dynamic wrinkling with all-optical switchable surface topographies is available, which has wide application potentials in photoresponsive soft photonics.

Keywords: Azopolymer; Dynamic Wrinkling; Photo-Orientation; Photochemistry; Thin Films.