CAREER: Nonlinear and Nonlocal Phenomena in Biological Hydrodynamics

University Of California-San Diego, La Jolla CA

Investigators

Abstract

CBET-0746285 Lauga An integrated research and educational program is dedicated to the theoretical and experimental study of novel fluid mechanics phenomena arising in swimming microorganisms. For the most part, the study of swimming cells has been limited in the past to single organisms moving in Newtonian fluids. The scope is broadened by investigating their nonlinear and nonlocal hydrodynamics. Specifically, The PI's group will: develop a general framework for biological and synthetic locomotion in complex fluids by quantifying how viscoelastic stresses affect the kinematics and energetics of swimming cells, and demonstrating for the first time how viscoelastic fluids can be exploited to design novel propulsion strategies as well as local probes for normal stress differences in non-Newtonian fluids; provide theoretical evidence that swimming microorganisms interacting hydrodynamically form a chaotic dynamical system; propose hydrodynamics mechanisms contributing to symmetry-breaking in the beat patterns of oscillating biological filaments (cilia), and collaborate with cell biologists to experimentally quantify the phenomenon of phase-locking occurring when two or more similar filaments (flagella) are oscillating near each other; and lead an ambitious, integrated research and educational initiative in biological and complex fluids, in combination with broad contributions to the scientific community, to promote an interdisciplinary approach to problem-solving in fluid mechanics. This program addresses novel fluid mechanics phenomena to help resolve outstanding questions in biology. The interdisciplinary research approach combines theoretical work, macro-scale experiments and, in collaboration with biologists, micro-scale experiments. The primary goals are to uncover new, interesting, and useful fluid mechanics behavior, to advance our scientific understanding of the mechanical forces arising in many biological processes, such as reproduction, and to contribute to the development of new engineering devices and methods. Immediate impact will be in the fields of fluid mechanics and biology, but the results will also be applicable in other broad domains such as microfluidics, physics, applied mathematics, and will stimulate further theoretical and experimental work. In addition to their biological significance, the ideas and techniques developed in this study will be relevant to a number of technological and applied systems, including the development of new microrheology techniques, the design of synthetic locomotor systems, and the control of coupled micron and nanoscale mechanical oscillators and cantilevers. A strong emphasis of this program's educational component is a new bio-fluids integrated research and teaching program to be established, comprising new undergraduate and graduate courses with a dedicated undergraduate experimental research infrastructure and the interdisciplinary training of graduate students. Also, two outreach programs for underrepresented minorities aimed at elementary and high-school students will emphasize the value of scientific inquiry. A new campus-wide seminar series on locomotion will be created. Furthermore, the PI plans to co-author a textbook on low-Reynolds number locomotion, and will organize activities to increase the influence of the educational and research activities of the fluids community. The results of this research program will be broadly disseminated and will have potentially important benefits to society, in particular for reproduction, bacterial infection and virtually every instance where flagellated and ciliated cells are present and interact.