Oscillatory rheotaxis of artificial swimmers in microchannels

  title={Oscillatory rheotaxis of artificial swimmers in microchannels},
  author={Ranabir Dey and Carola M Buness and Babak Vajdi Hokmabad and Chenyu Jin and Corinna C. Maass},
  journal={Nature Communications},
Biological microswimmers navigate upstream of an external flow with trajectories ranging from linear to spiralling and oscillatory. Such a rheotactic response primarily stems from the hydrodynamic interactions triggered by the complex shapes of the microswimmers, such as flagellar chirality. We show here that a self-propelling droplet exhibits oscillatory rheotaxis in a microchannel, despite its simple spherical geometry. Such behaviour has been previously unobserved in artificial swimmers… 

Mode-Switching of Active Droplets in Macromolecular Solutions

Typical bodily and environmental fluids encountered by biological swimmers consist of dissolved macromolecules such as proteins and polymers, often rendering them non-Newtonian. To mimic such

Self-Propulsion of Chemically Active Droplets

Microscopic active droplets are able to swim autonomously in viscous flows. This puzzling feature stems from solute exchanges with the surrounding fluid via surface reactions or their spontaneous

Steady state propulsion of isotropic active colloids along a wall

Active drops emit/absorb chemical solutes, whose concentration gradients cause interfacial flows driving their own transport and the propulsion of the droplet. Such non-linear coupling enables active

We the Droplets: A Constitutional Approach to Active and Self-Propelled Emulsions

Self-Propelled Swimming Droplets



Chirality-induced bacterial rheotaxis in bulk shear flows

Combining experimental, numerical, and theoretical analysis, a comprehensive study of the transport of motile bacteria in shear flows reveals the scaling laws behind the average rheotactic velocity at moderate shear rates using a chirality parameter and explains the reorientation dynamics leading to saturation at largeShear rates from the marginal stability of a fixed point.

Fight the flow: the role of shear in artificial rheotaxis for individual and collective motion.

This study studies experimentally and by computer simulations the rheotaxis of self-propelled gold-platinum nanorods in microfluidic channels for dynamic self-assembly and the delivery of payloads to targeted locations.

Understanding the onset of oscillatory swimming in microchannels.

It is demonstrated that higher-order hydrodynamic moments cause rod-like swimmers to follow oscillatory trajectories in quiescent fluid between two parallel plates, using a combination of lattice-Boltzmann simulations and far-field calculations.

Emergence of Bimodal Motility in Active Droplets

To explore and react to their environment, living micro-swimmers have developed sophisticated strategies for locomotion - in particular, motility with multiple gaits. To understand the physical

Relating Rheotaxis and Hydrodynamic Actuation using Asymmetric Gold-Platinum Phoretic Rods.

Rheotactic response infers the nature of difficult to measure flow fields of an active particle, establishes its dependence on swimmer type, and shows how Janus rods can be tuned for flow responsiveness.

Rheotaxis of Bimetallic Micromotors Driven by Chemical-Acoustic Hybrid Power.

A hybrid strategy is presented that can achieve both positive and negative rheotaxis of synthetic bimetallic micromotors by employing a combination of chemical fuel and acoustic force.

Rheotaxis of spherical active particles near a planar wall.

It is shown that, for a broad class of spherical active particles, rheotactic behavior may emerge via a mechanism which involves "self-trapping" near a hard wall owing to the active propulsion of the particles, combined with their rotation, alignment, and "locking" of the direction of motion into the shear plane.

Bacterial rheotaxis

It is predicted that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions.

Self-propulsion in 2D confinement: phoretic and hydrodynamic interactions.

Insights from the current work suggest that biological and artificial swimmers sense their surroundings through long-ranged interactions, that can be modified by altering the surface properties.