Thermally responsive multiscale surface patterns.

In this paper, we present a mechanically-driven technique for the design and fabrication of switchable, programmable, and multiscale surface patterns using liquid crystal elastomers (LCEs). Our proposed fabrication approach eliminates the complicated multi-step processing or hybrid patterning techniques commonly required in existing multiscale structured surface technologies. We integrate UV-induced cross-linking with buckling instability in an LCE film to generate multilevel surface patterns in a single-step process. The resulting surface patterns are fully reversible under thermal cycling across the nematic-isotropic transition and can be pre-programmed through controlled variations in material and geometrical properties. We demonstrate that the generated surface patterns induce pronounced anisotropic droplet sliding behavior, highlighting their potential for directional and controllable fluid transport. Together, these results establish LCEs as a powerful and versatile platform for reversible, multiscale surface patterning, opening new opportunities for adaptive interfaces and multifunctional smart surfaces.