Inspired by the beauty of natural motions presented in biological systems, synthetic photoresponsive soft materials were developed to mimic natural movements. Recent advancements of supramolecular soft robotic systems can functionalize the system with external stimuli‐responsiveness, e.g., light, heat, pH, and ions, but high structural arrangements are generally required. A supramolecular soft robotic system of spiropyran amphiphiles was reported previously, which enables macroscopic motions without high macroscopic structural requirements (high orientation order and structural uniformity). Herein, subtle modifications of the molecular design (i.e., different chain‐lengths of the alkyl‐linker) enable adjustments of packing parameters of spiropyran amphiphiles between open ‐ and closed ‐isomers. Upon macroscopic soft scaffolds formed by a shear‐flow method, the scaffolds with shorter chain‐lengths of the alkyl‐linker of spiropyran amphiphiles sustain photoactuations, while no photoactuation is observed with longer chain‐lengths of the alkyl‐linker of spiropyran amphiphiles.
Tc et al. (Sun,) studied this question.