Stiffening Liquid Crystal Elastomers with Liquid Crystal Inclusions

Thiol–acrylate liquid crystal elastomers (LCEs) were doped with low-molecular-weight liquid crystals (5CB or 8CB), which phase-separated post-polymerization and developed strain-induced cybotactic smectic domains during polydomain→monodomain alignment. This inclusion dramatically stiffened the materials without sacrificing molecular order or thermal strain: monodomain LC‑LCEs showed ~6.5–9× higher Young’s modulus than pristine LCEs, with more than 2× higher work density and active thermal stroke up to ~25% under load. Polydomain LC‑LCEs exhibited an emergent linear-elastic regime before the soft-elastic plateau; SAXS/WAXS evidenced SmA‑like ordering within LC-rich domains (~130–220 nm correlation length). A capillarity-based mechanism plus frozen-in smectic layering explains the stiffening.