Scientists at the U.S. Department of Energy’s Argonne National Laboratory have discovered a way to use a microscopic swirling flow to rapidly clear a circle of tiny bacteria or swimming robots.
“This discovery offers a new approach for control and manipulation of microscopic swimmers,” said Argonne physicist and co-author Igor Aronson, and it could be useful in tiny microfluidic (“lab-on-a-chip”) devices that can quickly run chemical or biological analyses or perform tasks.
In the study, published in Nature Communications, the researchers placed a magnetic particle in the center of a liquid film filled with swimming bacteria.
Normally the bacteria swim randomly; but when scientists spun the particle by applying a rotating magnetic field, the swimmers shot away from the center, like a school of fish that suddenly realized there’s a shark in their midst.
What’s actually happening is that the particle is rotating, creating a small vortex around itself. The bacteria swim parallel to the stream lines and are quickly pushed outward — except for a few that get sucked in right next to the particle.
They’re not pushed out by centrifugal force, said Argonne scientist Andrey Sokolov, who co-authored the paper; dead bacteria, which aren’t swimming, are not pushed out with their living companions.
“Because of the curvature of the flow, some swim in and are trapped on the rotating particle, and others are forced to swim out of the curved flow,” Sokolov said.
This technique could separate live from dead bacteria, or different species, bacterial strains or mutants from one another. “The shape and swimming rates of different species would mean they separate,” Aronson said.
“At certain frequencies of rotation, the bacteria self-organize into a spiral-shaped halo, creating a microscopic galaxy — similar to our galaxy Milky Way, but trillions of trillions (1024) of times smaller,” Sokolov said.
In addition to new understanding of the forces governing microswimmers and their environments, the vortex technique could help prevent biofilms from forming and disrupting microfluidic devices, the authors suggested.
They are particularly interested in creating systems in which microswimmers could assemble gears to build a tiny machine and then power it, Aronson said.
Aronson and Sokolov also modeled the results theoretically and saw good alignment between computer models and observed results, they said.
Learn more: Moving microswimmers with tiny swirling flows
The Latest on: Microswimmers
via Google News
The Latest on: Microswimmers
- Liquid crystal droplets as versatile microswimmerson October 29, 2019 at 6:51 am
Their results are published in the journal Physical Review Letters. Cell-like artificial microswimmers could provide new and exciting applications, for example, a swimming microscopic drug-delivery ...
- Microswimmers manipulate single particles and cellson October 29, 2019 at 1:49 am
With this goal, scientists in the USA and China have created acoustically powered bubble-based microswimmers that can manipulate individual particles and cells in a crowded environment without ...
- Controllable Microswimmers Move Around Individual Cells in 3Don October 28, 2019 at 12:32 pm
Controlling a magnetic field to move individual cells is very hard, so in this case it is used to set the direction of these microswimmers. The actual power results from the fact that these devices ...
- 3D steerable, acoustically powered microswimmers for single-particle manipulationon October 25, 2019 at 11:08 am
1 Department of Chemistry, Biochemistry and Molecular Biology, Physics, and Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802, USA. 2 Department of Surgery, ...
- Synchronized Swimming under the Microscopeon September 30, 2019 at 5:00 pm
Now, researchers like Tang are further developing such micron-scale motors to make them steerable. These machines, broadly known as microswimmers, range in size from a few hundred nanometers to a few ...
- Microswimmers - see and be seenon April 5, 2019 at 12:14 am
By designing experiments with artificial microswimmers, physicists at the University of Konstanz were able to show that the formation of stable groups requires only few skills: forward visual ...
- Motile Active Matter: Nanomachines, Microswimmers, and Swarmson February 28, 2019 at 4:00 pm
Winter School within the DFG Priority Programme 1726 “Microswimmers – From Single Particle Motion to Collective Behavior” Active matter is a novel class of nonequilibrium materials composed of a large ...
- Collaborative Research: Shepherding Biomedical Microswimmers Using Magnetic Fieldson February 27, 2019 at 4:00 pm
Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge ...
- Adaptive locomotion of artificial microswimmerson January 18, 2019 at 11:48 am
We demonstrate that coupling the structural and magnetic properties of artificial microswimmers with the dynamic properties of the fluid leads to adaptive locomotion in the absence of on-board sensors ...
- First plant-based ‘microswimmers’ could propel drugs to the right locationon December 18, 2018 at 11:59 am
The plant material makes these microswimmers biodegradable and less likely to be rejected by the human body. The magnetic layer allows scientists to control the motors’ movement. When the scientists ...
via Bing News