Nanoarchitectonics with photoresponsive Hemiindigo amphiphiles into supramolecularly assembled soft robotics for controlled macroscopic motions

Abstract

Synthetic aqueous supramolecular assemblies mimic the natural biomolecular functions. One of the key material advancements of aqueous supramolecular assemblies is constructing life-like macroscopic materials with photoresponsive molecules via supramolecular strategies. Visible-light controlled indigoid-based aqueous supramolecular assemblies have been reported, but the photocontrolled robotic function and the hydrolytic stability of indigoid systems remain unexplored. To design biomimetic and biocompatible soft robotics, we establish visible-light responsive hemiindigo amphiphiles HIAn to construct supramolecular soft robotic systems via nanoarchitectonics approach. The isomerizations of HIAn are controlled by visible-light in both organic and aqueous media. HIAn molecules supramolecularly assemble across multiple length-scales into nanostructures, and further into biocompatible supramolecular macroscopic soft scaffolds in aqueous media. The photocontrolled isomerization of HIAn molecules allow supramolecular transformations in nano-structural changes, as well as photocontrolled bending motion in macroscopic length-scale. Photoactuation motions of HIAn macroscopic soft scaffold can be controlled by molecular structural deviations, concentration tuning of HIAn and selection of light sources. It demonstrates the importance of visible-light controlled supramolecular soft robotic systems by indigoid molecules for laying foundations of biomimetic soft robotic functional materials. Graphical abstract: [Figure not available: see fulltext.]