Xu Hongtu, Liang Huan, Yang Yang, Liu Yawen, He Enjian, Yang Zhijun, Wang Yixuan, Wei Yen, Ji Yan
The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, China.
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China.
Nat Commun. 2024 Aug 27;15(1):7381. doi: 10.1038/s41467-024-51544-x.
To date, only one polymer can self-grow to an extended length beyond its original size at room temperature without external stimuli or energy input. This breakthrough paves the way for significant advancements in untethered autonomous soft robotics, eliminating the need for the energy input or external stimuli required by all existing soft robotics systems. However, only freshly prepared samples in an initial state can self-grow, while non-fresh ones cannot. The necessity of synthesizing from monomers for each use imposes significant limitations on practical applications. Here, we propose a strategy to rejuvenate non-fresh samples to their initial state for on-demand self-growth through the synergistic effects of solvents and dynamic covalent bonds during swelling. The solvent used for swelling physically transforms the non-fresh LCEs from the liquid crystal phase to the isotropic phase. Simultaneously, the introduction of the transesterification catalyst through swelling facilitates topological rearrangements through exchange reactions of dynamic covalent bonds. The rejuvenation process can also erase growth history, be repeated several times, and be regulated by selective swelling. This strategy provides a post-modulation method for the rejuvenation and reuse of self-growing LCEs, promising to offer high-performance materials for cutting-edge soft growing robotics.
迄今为止，只有一种聚合物能够在室温下无外部刺激或能量输入的情况下自生长至超过其原始尺寸的伸长长度。这一突破为无束缚自主软体机器人技术的重大进展铺平了道路，消除了所有现有软体机器人系统所需的能量输入或外部刺激。然而，只有初始状态的新鲜制备样品才能自生长，而非新鲜样品则不能。每次使用都需要从单体合成，这对实际应用造成了重大限制。在此，我们提出了一种策略，通过溶胀过程中溶剂和动态共价键的协同作用，使非新鲜样品恢复到初始状态以实现按需自生长。用于溶胀的溶剂将非新鲜液晶弹性体从液晶相物理转变为各向同性相。同时，通过溶胀引入酯交换催化剂，促进动态共价键的交换反应进行拓扑重排。恢复活力的过程还可以消除生长历史，重复多次，并通过选择性溶胀进行调控。该策略为自生长液晶弹性体的恢复活力和再利用提供了一种后调制方法，有望为前沿的软生长机器人技术提供高性能材料。
