#microswimmer

[fuckyeahfluiddynamics]

Swimming With Cilia

Like most microswimmers, these Synura uvella algae use cilia to swim. Cilia are tiny, hair-like appendages that flap to produce thrust. Even under a microscope, the cilia are hard to see because they are so thin and move quickly in and out of the microscope's narrow focus.  (Video and image credit: L. Cesteros; via Nikon Small World in Motion) Read the full article

[fuckyeahfluiddynamics]

Ciliary Pathlines

For tiny creatures, swimming through water requires techniques very different than ours. Many, like this sea urchin larva, use hair-like cilia that they beat to push fluid near their bodies. The flows generated this way are beautiful and complex. (Image credit: B. Shrestha et al.) Read the full article

[fuckyeahfluiddynamics]

Synchronizing Cilia

Just like human swimmers, microswimmers have to coordinate their motion to swim. But unlike humans, swimmers like the freshwater alga Chlamydomonas reinhardtii doesn't have a brain to help it synchronize its cilia.  (Image credit: top - J. Larson, others - Y. Xia et al.; research credit: Y. Xia et al.; via APS Physics) Read the full article

[fuckyeahfluiddynamics]

The Best of FYFD 2023

A fresh year means a look back at what was popular last year on FYFD. Usually, I give a numeric list of the top 10 posts, but this year the analytics weren't as clear. So, instead, I'm combining from a few different sources and presenting an unordered list of some of the site's most popular content. (Image credits: sphinx - S. Boury et al., ear model - S. Kim et al., maze - S. Mould, dandelion - S. Chaudhry, water tank - P. Ammon, e. coli - R. Ran et al., drop impact - R. Sharma et al., Leidenfrost - L. Gledhill, toilet - J. Crimaldi et al., engine sim - N. Wimer et al., rivers - D. Coe, fin - F. Weston, snake - P. Schmid, nebula - J. Drudis and C. Sasse, flames - C. Almarcha et al.) Read the full article

[fuckyeahfluiddynamics]

Overcoming Turbulence

Despite their microscopic size, many plankton undertake a daily migration that covers tens of meters in depth. As they journey, they must contend with currents, turbulence, and other flows that could knock them off-course. (Image credit: Picturepest/Flickr; research credit: R. Bearon and W. Durham)

[fuckyeahfluiddynamics]

Mixing With E. Coli

What happens when a flow meets swimming micro-organisms? Does the flow affect the swimmers? And how do the swimmers affect the flow in turn? Those are the questions behind the experiment seen here. (Image and research credit: R. Ran et al.; see also 1 and 2)

[fuckyeahfluiddynamics]

Rising Through Turbulence

Plankton -- microscopic creatures with often limited swimming abilities -- can face daily journeys of hundreds of vertical meters in the ocean. That's a daunting prospect for any tiny swimmer. (Image credit: top - B. de Kort, illustration - R. Monthiller et al.; research credit: R. Monthiller et al.; via APS Physics)

[fuckyeahfluiddynamics]

For many microswimmers, like bacteria or spermatozoa, swimming through common fluids is like moving through mud. Unless they can produce enough thrust to overcome a fluid's yield-stress, they are effectively stuck in a solid. (Image credit: SwedishStockPhotos; research credit: F. Nazari et al.; via APS Physics)