Translating Chirality into Multidirectional Motion through Broadband Chiroptical MXenes

TL;DR

This paper introduces a chiral MXene-based soft actuator that uses circularly polarized light to achieve multidirectional motion, leveraging broadband chiroptical properties and supramolecular chirality for advanced photothermal control.

Contribution

It presents the first CPL-driven soft actuator utilizing chiral MXenes with broadband circular dichroism for multidirectional deformation, integrating molecular chirality with mechanical actuation.

Findings

Achieved 30% differential temperature rise with CPL.

Demonstrated broadband circular dichroism from UV to NIR.

Implemented ternary CPL-based control for soft robotics.

Abstract

The integration of chirality into functional materials enables control of light-matter interactions beyond binary illumination (on/off). Conventional photoactuators rely on binary modulation, limiting them to unidirectional motion. In contrast, we introduce a ternary optical logic paradigm where actuation direction is encoded by the handedness of circularly polarized light (CPL). Here, we establish a chiral Ti$_{3}$C$_{2}$T$_{x}$ MXene platform bridging molecular chirality and mechanical actuation. Phenylalanine enantiomers are covalently anchored onto MXene nanoflakes via chiral nanopainting. The 2D confinement forces ligands into vertically aligned supramolecular networks. Interlayer-spacing analysis and simulations corroborate that such supramolecular networks unlock exceptionally broadband circular dichroism from the ultraviolet to the near-infrared. This supramolecular chirality synergizes with MXene's plasmonic properties to drive handedness-dependent photothermal conversion, with a 30\% differential temperature rise between matched and mismatched CPL. Embedding this chiral MXene into thermoresponsive hydrogels realizes, to the best of our knowledge, the first CPL-driven soft actuator that implements LCP/RCP/off as a ternary input to program multidirectional deformation based on a photothermal mechanism. This molecular-to-macroscopic translation demonstrates a new paradigm for chirality-encoded soft robotics and adaptive photonics.