310 citations · 2.7k across the 56 of their papers we have counts for
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Lagrangian dynamics unveil polymer conformation in viscoelastic flows
Louison Thorens, Gabriel Juarez, Jeffrey S. Guasto +1
The complex flow behavior of viscoelastic fluids emerges from a feedback between fluid stress and the out-of-equilibrium conformational dynamics of their constituent polymer chains…
Quantification of Flagellar Gait Changes with Combined Shape Mode Analysis and Swimming Simulations
Kelli E. Gutierrez, Becca Thomases, Paulo E. Arratia +1
Many different microswimmers propel themselves using flagella that beat periodically. The shape of the flagellar beat and swimming speed have been observed to change with fluid rhe…
Undulatory swimming in viscoelastic fluids under confinement
D. Gagnon, B. Thomases, R. D. Guy +1
Low Reynolds number swimmers frequently move near boundaries, such as spirochetes moving through porous tissues and sperm navigating the reproductive tract. Furthermore, these micr…
Effect of fluid elasticity on the emergence of oscillations in an active elastic filament
Kathryn G. Link, Robert D. Guy, Becca Thomases +1
Many microorganisms propel through complex media by deformations of their flagella. The beat is thought to emerge from interactions between forces of the surrounding fluid, passive…
Life in Complex Fluids: Swimming in Polymers
Paulo E. Arratia
Many microorganisms live and evolve in complex fluids. Examples include mammalian spermatozoa in cervical mucus, worms (e.g., \textit{C. elegans}) in wet soil, and bacteria (e.g.,…
Mixing in chaotic flows with swimming bacteria
Ranjiangshang Ran, Quentin Brosseau, Brendan C. Blackwell +3
This is a manuscript accepted for publication on Physical Review Fluids, Gallery of Fluid Motion special issue. The manuscript is associated with a poster winner of the 39th Annual…
Flow and aerosol dispersion from wind musical instruments
Quentin Brosseau, Ranjiangshang Ran, Ian Graham +2
In the midst of the COVID-19 pandemic, many live musical activities had to be postponed and even canceled to protect musicians and audience. Orchestral ensembles face a particular…
Perspectives on viscoelastic flow instabilities and elastic turbulence
Sujit S. Datta, Arezoo M. Ardekani, Paulo E. Arratia +20
Viscoelastic fluids are a common subclass of rheologically complex materials that are encountered in diverse fields from biology to polymer processing. Often the flows of viscoelas…
Bacteria hinder large-scale transport and enhance small-scale mixing in time-periodic flows
Ranjiangshang Ran, Quentin Brosseau, Brendan C. Blackwell +3
Understanding mixing and transport of passive scalars in active fluids is important to many natural (e.g. algal blooms) and industrial (e.g. biofuel, vaccine production) processes.…
Bacterial activity hinders particle sedimentation
Jaspreet Singh, Alison E. Patteson, Bryan O. Torres Maldonado +2
Sedimentation in active fluids has come into focus due to the ubiquity of swimming micro-organisms in natural and industrial processes. Here, we investigate sedimentation dynamics…
Flow Resistance and Structures in Viscoelastic Channel Flows at Low Re
Boyang Qin, Paul F. Salipante, Steven D. Hudson +1
The flow of viscoelastic fluids in channels and pipes remain poorly understood, particularly at low Reynolds numbers. Here, we investigate the flow of polymeric solutions in straig…
Sedimentation and diffusion of passive particles in suspensions of swimming Escherichia coli
Jaspreet Singh, Alison E. Patteson, Prashant K. Purohit +1
Sedimentation in active fluids has come into focus due to the ubiquity of swimming micro-organisms in natural and artificial environments. Here, we experimentally investigate sedim…
The cost of swimming in generalized Newtonian fluids: Experiments with C. elegans
David A. Gagnon, Paulo E. Arratia
Numerous natural processes are contingent on microorganisms' ability to swim through fluids with non-Newtonian rheology. Here, we use the model organism Caenorhabditis elegans and…
Characterizing Elastic Turbulence in Channel Flows at Low Reynolds number
Boyang Qin, Paulo E. Arratia
We experimentally investigate the flow of a viscoelastic fluid in a parallel shear geometry at low Reynolds number. As the flow becomes unstable via a nonlinear subcritical instabi…
Flow analysis of the low-Reynolds number swimmer C. elegans
Thomas D. Montenegro-Johnson, David A. Gagnon, Paulo E. Arratia +1
Swimming cells and microorganisms are a critical component of many biological processes. In order to better interpret experimental studies of low Reynolds number swimming, we combi…
Undulatory swimming in shear-thinning fluids: Experiments with C. elegans
David A. Gagnon, Nathan C. Keim, Paulo E. Arratia
The swimming behaviour of microorganisms can be strongly influenced by the rheology of their fluid environment. In this manuscript, we experimentally investigate the effects of she…
Fluid-Induced Propulsion of Rigid Particles in Wormlike Micellar Solutions
David A. Gagnon, Nathan C. Keim, Xiaoning Shen +1
In the absence of inertia, a reciprocal swimmer achieves no net motion in a viscous Newtonian fluid. Here, we investigate the ability of a reciprocally actuated particle to transla…
The structure and dynamics of self-assembling colloidal monolayers in oscillating magnetic fields
Alison E. Koser, Nathan C. Keim, Paulo E. Arratia
Many fascinating phenomena such as large-scale collective flows, enhanced fluid mixing and pattern formation have been observed in so-called active fluids, which are composed of pa…
Self-assembling paramagnetic colloids in oscillating magnetic fields
Alison E. Koser, Nathan C. Keim, Paulo E. Arratia
Many fascinating phenomena such as large-scale collective flows, enhanced fluid mixing and pattern formation have been observed in so-called active fluids, which are composed of pa…
Dropping the Ball: The effect of anisotropic granular materials on ejecta and impact crater shape
Philip Drexler, Nathan Keim, Paulo Arratia
In this fluid dynamics video, we present an experimental investigation of the shape of impact craters in granular materials. Complex crater shapes, including polygons, have been ob…
Undulatory swimming in fluids with polymer networks
D. A. Gagnon, X. N. Shen, P. E. Arratia
The motility behavior of the nematode Caenorhabditis elegans in polymeric solutions of varying concentrations is systematically investigated in experiments using tracking and veloc…
A nonlinear elastic instability in channel flows at low Reynolds numbers
L. Pan, A. Morozov, C. Wagner +1
It is presently believed that flows of viscoelastic polymer solutions in geometries such as a straight pipe or channel are linearly stable. Here we present experimental evidence th…
Fluid Elasticity Can Enable Propulsion at Low Reynolds Number
Nathan C. Keim, Mike Garcia, Paulo E. Arratia
Conventionally, a microscopic particle that performs a reciprocal stroke cannot move through its environment. This is because at small scales, the response of simple Newtonian flui…
Undulatory locomotion of {\it C. elegans} on wet surfaces
Xiao N. Shen, J. Sznitman, P. Krajacic +2
The physical and bio-mechanical principles that govern undulatory movement on wet surfaces have important applications in physiology, physics, and engineering. The nematode {\it C.…