Bidirectionally Symmetric Self-Assembly of Switchable Chiral Microstructures Based on Angle Compensation and pH Regulation Strategy for Chiroptical Metamaterials

Chiral metamaterials have attracted pronounced attention due to their great potential in detecting vortex-structured light and enantiomeric chiral molecules. However, most previously-explored rigid chiral structures are constrained by poor tunability, resulting from their inability to achieve bidirectionally symmetric fabrication. Though the integration of smart materials with femtosecond laser printing has advanced the development of 3D tunable microstructures, unfortunately, the asymmetric deformation of those smart materials breaks the chiral symmetry of fabricated structures. Herein, a feasible strategy namely angle compensation coupling with laser-induced self-assembly of pH-sensitive microstructures to restore the symmetry of chiral self-assemblies, is proposed. Relying on the laser-printing guided capillary force self-assembly, the targeted chiral microstructures featuring bidirectional symmetry and shape-morphing reversibility are successfully harvested, witnessing its unparalleled fabricating flexibility and accurate controllability. Significantly, once the vortex light serves as a probe, the assembled chiral enantiomers yield symmetrically distributed dichroism spectra, evidencing the feasibility of current approaches. This work grants a paradigm for the rapid and steerable manufacture of chiral metasurfaces and further enhances the potential in the fields of optical communication, chemical sensing, and chiral photonics.