A dual-catalyst strategy for liquid crystal elastomers with actuation stability and efficient reprogrammability

Abstract

The introduction of dynamic covalent bonds (DCBs) endows liquid crystal elastomers (LCEs) with reprocessability while maintaining structural integrity, expanding their potential applications in advanced shape-morphing devices. Actuation stability of covalent adaptable LCEs is critical for prolonging service life; however, existing solutions may compromise reprocessability and reuse. Here, we propose a dual-catalyst strategy to achieve both long-term actuation stability and efficient programmability in covalent adaptable LCEs. A volatile catalyst and a thermal-latent catalyst are applied, each enabling transesterification but functioning independently in two sequential stages. In the first stage, stable actuation in the presence of the latent catalyst is realized, withstanding up to 10,000 cyclic actuation—significantly surpassing the maximum of 1,000 cyclic actuation reported in previous works. In the second stage, efficient reprocessability is achieved by activating the thermal-latent catalyst to release a strong base. Moreover, the spatial–temporal activation of the latent catalyst enables localized, gradient, and stepwise orientation. This strategy provides a novel solution to balancing the trade-off between actuation stability and reprocessability, which can also be extended to other covalent adaptable networks.