CAREER: Interfacial behavior of motile bacteria at structured liquid crystal interfaces

非技术摘要了解细菌如何与复杂的界面相互作用对于揭开微生物生命的奥秘至关重要。这些界面是流体相遇的地方，在细菌适应、营养收集和气体交换方面发挥着关键作用，为微生物在不同条件下茁壮成长的能力提供了宝贵的见解。不幸的是，由于科学家在研究复杂材料时面临的技术挑战，人们对细菌与这些结构域的相互作用知之甚少。这项研究旨在增进我们对界面如何影响活微生物运动的了解。研究小组利用被称为液晶的有序材料作为模型系统，研究微生物如何与复杂的环境相互作用。液晶的特征是液体和固体之间的性质。利用液晶的可调特性，该团队探索了设计界面属性的方法，增强了对细菌流动和结构状态的控制。这项工作具有前景广阔的技术前景，因为它为开发适用于生物传感、生物修复和疾病治疗等领域的新功能系统开辟了道路。除了技术影响，该项目还与教育和推广计划相结合，这些计划包括软材料的例子，以改善对生命科学学生的物理教学，为来自代表性不足群体的本科生创造机会，在早期阶段体验研究，并使公众享受科学。技术摘要活动材料是由相互作用的元素组成的结构化系统，推动运动和产生流动。监管这些流动的愿望推动了研究努力，以开发适用于各个领域的功能系统。该项目解决了建立有效机制来控制活性材料流动的挑战。它主要致力于探索液晶界面，以管理活性材料的动态组装。这项研究的目的是加深对有序材料如何影响活性材料的基本行为以及如何成功地设计界面来调节活性实体内的流动的理解。以自行式细菌为模型系统，研究了界面各向异性和拓扑缺陷对活性物质动力学的影响。该团队使用包括光刻、3D打印和微流体在内的各种微制造技术，对液晶进行限制，并对其表面缺陷进行工程设计，以指导细菌的集体行为。从该项目中获得的见解有助于开发在不同领域具有实际影响的变革性应用程序，特别是那些需要将混沌动力学转化为有用工作的应用程序。该项目还通过将教育和研究结合起来促进教育机会，为来自非传统背景的本科生创造机会，在早期阶段探索与软材料有关的项目，为他们接受高等教育和在STEM就业做好准备。此外，首席研究人员正在开发一种独特的方法，通过实施与软物质有关的主题并阐明物理概念和生物系统之间的强烈联系，来改进对生命科学专业学生的物理教学。通过了解活性物质在复杂流体界面中的行为所获得的洞察力和知识也通过培训模块和教育工作坊传播给普通观众。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。

Non-technical abstractUnderstanding how bacteria interact with complex interfaces is crucial for unraveling the mysteries of microorganism life. These interfaces, where fluids meet, play a pivotal role in bacterial adaptation, nutrient gathering, and gas exchange, offering valuable insights into microorganisms' ability to thrive in diverse conditions. Unfortunately, the interactions of bacteria with these domains are poorly understood due to the technical challenges scientists face in studying complex materials. This research aims to advance our knowledge of how interfaces influence the movement of living microorganisms. The research team utilizes ordered materials called liquid crystals, characterized by properties between liquids and solids, as a model system to study how microorganisms interact with intricate environments. Leveraging the tunable features of liquid crystals, the team explores ways to engineer the interface properties, enhancing control over bacterial flows and structural states. This work carries promising technological prospects as it opens avenues for the development of new functional systems applicable across fields including biosensing, bioremediation, and disease treatment. In addition to the technological impacts, the project is integrated with educational and outreach plans that incorporate examples of soft materials to improve the teaching of physics to life science students, create opportunities for undergraduate students from underrepresented groups to experience research at an early stage, and make science enjoyable to the general public.Technical abstractActive materials are structured systems of interacting elements that propel motion and generate flows. The aspiration to regulate these flows has driven research efforts to develop functional systems applicable across various domains. This project addresses the challenge of establishing effective mechanisms to control flows in active materials. Mainly, it delves into exploring liquid crystal interfaces to govern the dynamic assembly of living active materials. The goal of this research is to deepen the understanding of how ordered materials influence the fundamental behaviors of active materials and how interfaces can be successfully designed to regulate flows within active entities. Self-propelled bacteria are utilized as a model system to investigate the impact of interfacial anisotropy and topological defects on the dynamics of active materials. Employing diverse microfabrication techniques, including lithography, 3D printing, and microfluidics, the team undertakes the confinement of liquid crystals and the engineering of their surface defects to direct the collective behavior of bacteria. The insights gained from this project contribute to the development of transformative applications with practical implications in diverse fields, especially those requiring the transformation of chaotic dynamics into useful work. The project also promotes educational opportunities by integrating education and research through the creation of opportunities for undergraduate students from nontraditional backgrounds to explore projects related to soft materials at an early stage, to prepare them for higher education and careers in STEM. In addition, the principal investigator is developing a distinct approach to improve the teaching of physics to life science students by implementing topics related to soft matter and elucidating the strong connections between physical concepts and biological systems. The insights and knowledge gained from understanding how active materials behave at complex fluid interfaces are also disseminated to general audiences through training modules and educational workshops.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.