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

University Of Massachusetts Boston, Dorchester MA

Investigators

Abstract

Non-technical abstract Understanding 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 abstract Active 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.