Yan Wenzhong, Jones Talmage, Jawetz Christopher L, Lee Ryan H, Hopkins Jonathan B, Mehta Ankur
Electrical and Computer Engineering Department, UCLA, USA.
Mechanical and Aerospace Engineering Department, UCLA, USA.
Mater Horiz. 2024 Aug 12;11(16):3805-3818. doi: 10.1039/d4mh00584h.
Recent advances in active materials and fabrication techniques have enabled the production of cyclically self-deployable metamaterials with an expanded functionality space. However, designing metamaterials that possess continuously tunable mechanical properties after self-deployment remains a challenge, notwithstanding its importance. Inspired by push puppets, we introduce an efficient design strategy to create reversibly self-deployable metamaterials with continuously tunable post-deployment stiffness and damping. Our metamaterial comprises contracting actuators threaded through beads with matching conical concavo-convex interfaces in networked chains. The slack network conforms to arbitrary shapes, but when actuated, it self-assembles into a preprogrammed configuration with beads gathered together. Further contraction of the actuators can dynamically tune the assembly's mechanical properties through the beads' particle jamming, while maintaining the overall structure with minimal change. We show that, after deployment, such metamaterials exhibit pronounced tunability in bending-dominated configurations: they can become more than 35 times stiffer and change their damping capability by over 50%. Through systematic analysis, we find that the beads' conical angle can introduce geometric nonlinearity, which has a major effect on the self-deployability and tunability of the metamaterial. Our work provides routes towards reversibly self-deployable, lightweight, and tunable metamaterials, with potential applications in soft robotics, reconfigurable architectures, and space engineering.
活性材料和制造技术的最新进展使得能够生产具有扩展功能空间的周期性自展开超材料。然而，设计出在自展开后具有连续可调机械性能的超材料仍然是一项挑战，尽管其很重要。受推偶的启发，我们引入了一种高效的设计策略，以创建具有连续可调展开后刚度和阻尼的可逆自展开超材料。我们的超材料由收缩致动器组成，这些致动器穿过珠子，珠子在网络化链中具有匹配的锥形凹凸界面。松弛的网络可以符合任意形状，但在被驱动时，它会自组装成珠子聚集在一起的预编程配置。致动器的进一步收缩可以通过珠子的颗粒堵塞动态调节组件的机械性能，同时使整体结构变化最小。我们表明，在展开后，这种超材料在以弯曲为主的配置中表现出显著的可调性：它们的刚度可以增加超过35倍，阻尼能力变化超过50%。通过系统分析，我们发现珠子的锥角会引入几何非线性，这对超材料的自展开性和可调性有重大影响。我们的工作为可逆自展开、轻质且可调的超材料提供了途径，在软机器人技术、可重构架构和空间工程中具有潜在应用。
