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

微型机器人领域正在迅速发展，并在靶向治疗、环境修复和微型货物运输等工程应用方面有着巨大的前景。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，在微尺度上执行任务。微型机器人太小了，无法容纳电子设备，无法进行编程，也无法相互通信。相反，它们的结构和相互作用被设计成利用物理粒子间的通信，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，以建立一种新的微型机器人类别，作为模拟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，并将自己定位在一个群体中，从而产生受控的定向运动。因此，它们克服了目前阻碍微型机器人群用于运输和由合作行为实现的工程应用的障碍。在所提出的具有偏心排斥相互作用点的微型机器人系统中，主动自推进与围绕粒子中心的被动力矩的耦合产生了新的相互作用。这些主动-被动混合作用导致微型机器人的仿生集体运动，即使在可以忽略的水动力相互作用的情况下也是如此。为了建立一个基本的框架，并研究远离边界和受约束的仿生现象，将发展连续介质动力学模型来研究大系统，线性稳定性分析将用于研究相变，基于智能体的主动布朗模拟将用于分析粒子的相对排列和解释运动晶态和类液态的出现。教育研究将衡量动手实验和增强现实方法对高中生在探索关于微型机器人和低雷诺流体动力学的科学思想方面的学习结果和自我效能的影响之间的对比。将提供一门面向研究的交互式仿生学和微型机器人学本科课程，并将审查其对学生职业道路选择的预期影响。该奖项反映了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 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.