Mesogen‐Mimetic Anisotropic Crosslinkers for Load‐Bearing Liquid Crystal Elastomer Artificial Muscles

Vollständiger Abstract

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ABSTRACT Liquid crystal elastomers (LCEs) can generate large reversible contractions, but their practical work output is often limited by thermal softening and insufficient load‐bearing capability at actuation temperatures. Here, we introduce PBB‐TT as a mesogen‐mimetic anisotropic tetrathiol crosslinker for molecularly reinforced LCE actuators. Unlike conventional flexible or non‐rod‐like crosslinkers that mainly provide isotropic molecular connectivity, PBB‐TT incorporates a phenylene bisbenzoate‐based anisotropic rigid core into a covalent LCE network. Although PBB‐TT itself does not exhibit an independent liquid–crystalline phase, its liquid–crystal‐compatible rigid core, tetrafunctional thiol connectivity, and flexible thioether/ether spacers enable it to function as an anisotropic reinforcing junction that improves high‐temperature elastic stress support while retaining monodomain alignment for thermal actuation. The optimized PBB‐LCE‐16 withstood 8.7 MPa tensile stress, maintained a storage modulus of 5.52 MPa at 160°C, generated a blocking stress of 2.21 MPa, and achieved 31.24% actuation strain, 631 kJ m − 3 volumetric work capacity, and 728 J kg −1 gravimetric work density under a 175 g load. Residual photoreactivity further enabled adhesive‐free welding, electrothermal lifting of a 1 kg load, gripping, and repair. This work establishes anisotropic crosslinker design as a molecular strategy for load‐bearing LCE artificial muscles.