MSE Talks: Daniel Harris, Brown University

Speaker: Daniel Harris, Brown University

Title:: Propulsion and interaction of wave-propelled interfacial particles

Abstract: When an asymmetric floating body is internally or externally vibrated, the self-generated capillary wavefield can lead to steady propulsion or rotation. In this talk, I will discuss several related and recently discovered systems that leverage this propulsion mechanism. On a vibrating fluid substrate, freely floating particles are shown to self-propel along straight paths or rotate in place, depending sensitively on the particle asymmetries and driving parameters. By combining multiple asymmetries, particles can be remotely steered along curvilinear trajectories via modulation of the driving frequency alone. Such surfing particles interact at a distance through their mutual wavefield, and exhibit a rich array of collective dynamics. Particle-level actuation can also lead to propulsion as realized by the “SurferBot”: an untethered centimeter-scale vibrobot that self-propels along a fluid interface using an onboard vibration motor and battery. Overall, these highly accessible and tunable macroscopic systems serve as novel platforms for exploring active and driven matter interacting in fluid environments, as well as other fundamental concepts in physics more generally.

Bio: Daniel M. Harris is an Associate Professor of Engineering at Brown University in the Fluids and Thermal Sciences group. Before joining Brown, Dan was a Postdoctoral Research Associate and Lecturer at the University of North Carolina at Chapel Hill in the Department of Mathematics. Dan received his B.S. in Mechanical Engineering from Cornell University in 2010 and his Ph.D. in Applied Mathematics from MIT in 2015. Dan’s primary research interests are in interfacial phenomena, microfluidics, and transport phenomena. His research involves an integrated experimental and theoretical approach. Dan has also received numerous awards for his scientific visualizations, including being selected as the winner of the 2016 NSF/Popular Science Visualization Challenge in Photography, as well as numerous prizes from the American Physical Society’s Gallery of Fluid Motion and Gallery of Soft Matter.