CAREER: Biomimetic Swarm of Active Colloids with Off-Center Interaction Sites

微机器人领域正在迅速发展，并为工程应用带来了巨大的希望，如靶向治疗，环境修复和微尺度货物运输。与微生物类似，微型机器人从环境中获取能量，并在流体中自我推进，以执行微尺度的任务。微型机器人太小，无法容纳电子单元进行编程或相互通信。相反，它们的结构和相互作用被设计成利用粒子间的物理通信，并执行或促进决策。受鱼群、鹿群和鸟群动态的启发，该奖项的目标是进行必要的基础研究，以建立一类新的微型机器人，作为模仿生物学的变革性功能的平台。与动物类似，这些微粒可以避免聚集并将它们自身定向成一组，使得它们产生受控的定向运动。因此，他们克服了目前阻碍利用microrobot群的运输和工程应用的合作行为。在所提出的系统的microrobots偏心排斥相互作用网站，新的相互作用出现的主动自推进与被动扭矩的颗粒中心的耦合。这些主动-被动混合相互作用导致微型机器人的仿生集体运动，即使在可以忽略不计的水动力相互作用的制度。为了建立一个基础框架，研究远离边界和限制下的新兴仿生现象，将开发连续动力学模型来研究大规模系统，线性稳定性分析将用于研究相变，基于代理的主动布朗模拟用于分析粒子的相对排列，并阐明运动晶体和类液体状态的出现。教育研究将衡量动手实验和增强现实方法对高中生学习成果和自我效能感的影响之间的对比，以探索有关微型机器人和低雷诺流体力学的科学思想。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The field of microrobotics is growing rapidly and holds great promise for engineering applications such as targeted therapeutics, environmental remediation, and microscale cargo delivery. Similar to microorganisms, microrobots harvest energy from their environment and self-propel in fluids to perform tasks at the microscale. Microrobots are too small to host electronic units to be programmed or be able to communicate with each other. Instead, their structures and interactions are engineered to exploit physical inter-particle communication and to perform or facilitate decision making. Inspired by the dynamics of schools of fish, herds of deer, and flocks of birds, the objective of this award is to perform the foundational research necessary to establish a new class of microrobots as a platform for transformative functionalities that mimic biology. Similar to the animals, these microparticles can avoid aggregation and orient themselves in a group such that they generate controlled directional motions. Thus, they overcome barriers that currently impede the exploitation of microrobot swarms for transport and engineering applications enabled by cooperative behavior. In the proposed system of microrobots with off-center repulsive interaction sites, new interactions emerge from the coupling of active self-propulsion with passive torques about the particle centers. These active-passive hybrid interactions lead to biomimetic collective motion of microrobots, even in the regime of negligible hydrodynamic interactions. To build a foundational framework and study the emergent biomimetic phenomena far from boundaries and under confinement, continuum kinetic models will be developed to study large-scale systems, linear stability analysis will be used to study phase transitions, and agent-based active Brownian simulations are employed to analyze the relative arrangement of particles and elucidate the emergence of motile-crystal and liquid-like states. Educational studies will measure the contrasts between the impacts of the hands-on experiments and augmented reality approaches on learning outcomes and self-efficacy of high school students in exploring scientific ideas about microrobotics and low Reynolds hydrodynamics. An interactive research-oriented undergraduate course on biomimicry and microrobotics will be offered and its intended impact on the career pathway selection of the students will be examined.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.