CAREER: Reconfigurable Dynamic Metamaterials Interacting with Flowing Fluids

设计能够与流动的流体有效互动的可重构超材料的能力可以彻底改变一系列医疗和机器人设备的设计和操作，从可自我重构的心血管假体到被动控制的软瓣膜和可变形的软机器人。这些设备通常工作在高能量含量的环境中，流体流动不稳定，但没有技术使它们能够收集和重新引导这些能量，以高效和自主地执行分布式驱动，而不依赖外部能源。实现这一愿景的一个引人注目的范例是使用多稳定的超材料，这种材料通过非线性转变波存储和选择性地释放能量--这些大幅度波顺序地将元素从一种稳定状态切换到另一种状态。这项学院早期职业发展(Career)补助金将支持为流动响应型多稳定超材料建立分析和实验基础的研究，这种材料表现出可调的动态特性，并通过利用流体-结构相互作用来执行理想的任务。这些超材料将构成构建块，用于设计在流体刺激下维持目标功能的动态系统。这一职业项目将实施一项雄心勃勃的计划，将研究与教育相结合，并制定创新的公共宣传战略，展示动态超材料领域的社会效益，并激发高中生的兴趣。通过将机械超材料和流体流动环境相结合，这项研究将展示如何利用流体-结构相互作用和过渡波来有效地在动态系统和流场中实现所需的动态行为。结合分析、数值和实验方法，流体-亚结构相互作用将被用作两个“动态旋钮”：(1)操纵多稳态超材料中的形状重构以达到驱动目的；(2)通过超材料中的过渡波前控制流体流量。可重新编程的动态特性和自调节流量能力将结合在一起，被动地获得按需刚性和分布式驱动。这项研究将代表着未来工程结构发展的一个里程碑，具有前所未有的可调动态性能和流动诱导的形状变化。由此产生的自适应元结构将显著增强具有分布式智能能力的自驱动超材料领域。这项研究的结果将是在可自我重构的心血管植入物、游泳超机器人和被动流量控制系统设计方面的飞跃。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The ability to engineer reconfigurable metamaterials that efficiently interact with flowing fluids can revolutionize the design and operation of a wide range of medical and robotic devices, from self-reconfigurable cardiovascular prostheses, to passively controlled soft valves and deformable soft robots. These devices often operate in high-energy content environments, with unsteady flowing fluids, but no technology exists to enable them to harvest and redirect this energy to perform distributed actuation efficiently and autonomously, without relying on external sources of energy. A compelling paradigm for achieving such vision is to use multistable metamaterials that store and selectively release energy through nonlinear transition waves -- these large amplitude waves sequentially switch elements from one stable state to another. This Faculty Early Career Development (CAREER) grant will support research to build the analytical and experimental foundations for flow-responsive multistable metamaterials that manifest tunable dynamic properties and perform desirable tasks by harnessing fluid-structure interactions. These metamaterials will form building blocks for designing dynamic systems that sustain targeted functionalities under fluidic stimuli. This CAREER project will carry out an ambitious plan for integrating research and education and for developing innovative strategies for public outreach that showcase the societal benefits of the field of dynamic metamaterials and spark interest among high school students. By combining mechanical metamaterials and fluid flow environments, this research will show how fluid-structure interactions and transition waves can be leveraged to efficiently achieve desired dynamic behaviors in both dynamic systems and flow fields. With a combination of analytical, numerical, and experimental methods, fluid-metastructure interactions will be used as a twofold “dynamic knob” to (1) manipulate shape reconfigurations in multistable metamaterials for actuation purposes and to (2) control fluid fluxes through transition wavefronts in metamaterials. Reprogrammable dynamic properties and self-regulating flow capabilities will be coupled to passively obtain rigidity on demand and distributed actuation. This research will represent a milestone towards the development of future engineered structures with unprecedented tunable dynamic properties and flow-induced shape transformations. The resulting adaptive metastructures will significantly enhance the field of self-actuating metamaterials with distributed intelligent capabilities. The results of this research will be a leap forward in the design of self-reconfigurable cardiovascular implants, swimming meta-robots, and passive flow-rate control systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.