An ultrahigh fatigue resistant liquid crystal elastomer-based material enabled by liquid metal

Abstract

The low crosslink density characteristic of liquid crystal elastomer (LCE) materials causes poor fatigue resistance performance, which has seriously plagued their prospects in industrial applications. Here we report that the introduction of 5 wt% liquid metal nanodroplets (average diameter: ca. 195 nm) into the LCE network can dramatically reinforce the corresponding composite's mechanical properties, in particular ultrahigh fatigue resistance, capable of bearing unprecedented 10,000 tensile cycles within a large range of strain amplitude up to 70% and 2000 times of continuous actuating deformations. Furthermore, this liquid metal-incorporated LCE composite material exhibits large actuation stroke (maximum actuation strain: 55%), high actuation stress (blocking stress: 1.13 MPa), fully reversible thermal/photo-actuation functions, and self-healing ability at moderate temperatures, which qualifies the composite material for high-load actuators.

Tough and Photo-Plastic Liquid Crystal Elastomer with a 2-Fold Dynamic Linker for Artificial Muscles

“…By using the isostrain mode in Figure E, the M-LCESe x film was fixed at a constant 0.01% strain in tension and its contractile stress was measured at different temperatures. During a heating–cooling cycle, M-LCESe 0.2 gave a contractile stress of 1.96 MPa at 80 °C, being also superior to many LCEs in the literature (Figure F). – This strong contraction stress may originate from its dense H-bonds and high elastic modulus at the isotropic phase (Figure S19B,C). Under a constant stress, the actuation strain and the working capacity was measured (Figures G and S20).…”