Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Argonne researchers create active material out of microscopic spinning particles

29.05.2020

At the atomic level, a glass of water and a spoonful of crystalline salt couldn't look more different. Water atoms move around freely and randomly, while salt crystals are locked in place in a lattice. But some new materials, recently investigated by researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory, show an intriguing propensity to sometimes behave like water and sometimes like salt, giving them interesting transport properties and holding potential promise for applications like mixing and delivery in the pharmaceutical industry.

These so-called active materials contain small magnetic particles that self-organize into short chains of particles, or spinners, and form a lattice-like structure when a magnetic field is applied.


Self-assembled dynamic lattice of spinners. The Voronoi diagram is overlaid with the observed lattice. The spinners are blurred because of the long exposure time that enabled precise identification of the rotational axes for all spinners.

Credit: Argonne National Laboratory

 "Active materials need an external energy source to maintain their structure," said Argonne materials scientist Alexey Snezhko, an author of the study.

"The interesting thing is that you can have these very quickly rotating structures that give the appearance of a yet larger system that is still, but it remains quite active." -- Argonne materials scientist Alexey Snezhko

Unlike in previous experiments involving active materials, which looked at particles that demonstrated linear motion, these new spinners acquire a handedness -- like right- or left-handedness -- that causes them to rotate in a specific direction.

This twirling rotation of the suspended self-assembled nickel spinners creates a whirlpool-like effect, in which different particles can get sucked in to the vortices created by their neighbors. 

"The particles don't move on their own, but they can be dragged around," Snezhko said. "The interesting thing is that you can have these very quickly rotating structures that give the appearance of a yet larger system that is still, but it remains quite active."

As the particles start to come together, the whirlpools created by the spinning motion -- in conjunction with the magnetic interactions -- pull them even closer, creating a fixed crystalline-like material, even as the spinners still rotate.

The Argonne researchers wanted to know how a non-spinner particle would be transported through the active lattice. According to Snezhko, the rapid whirling of the spinners creates the ability for these other cargo particles to move through the lattice much more quickly than they would through a normal material. "In regular diffusion, the process of getting a particle from one side of the material to the other is temperature-dependent and takes a much longer period of time," he said.

The transport of a non-spinner particle is also dependent upon the spacing between the spinners. If the spinners are located sufficiently far apart, the non-spinner particle will travel chaotically between different spinners, like a raft traveling down a series of whitewater rapids. If the particles in the lattice come closer together, the non-spinner particle can become trapped in an individual cell of the lattice.

"Once the particle comes within a cell through its own chaotic motion, we can modify the field so that the lattice slightly shrinks, making the probability of the particle to leave that location in the lattice very low," Snezhko said.

The material also showed the ability to undergo self-repair, similar to a biological tissue. When the researchers made a hole in the lattice, the lattice reformed.

By looking at systems with purely rotational motion, Snezhko and his colleagues believe that they can design systems with specific transport characteristics. "There are many different ways for getting an object in a material from point A to point B, and this type of self-assembly could be tailored for different dynamics," he said.

###

A paper based on the study, "Reconfigurable structure and tunable transport in synchronized active spinner materials," appeared in the March 20 issue of Science Advances.

The study was funded by DOE's Office of Science. Other authors of the paper included Argonne's Koohee Han and Gasper Kokot, as well as Shibananda Das, Roland Winkler, and Gerhard Gompper of the Forschungszentrum Jülich in Germany.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

Media Contact

Diana Anderson
ddanderson@anl.gov
630-252-4593

 @argonne

http://www.anl.gov 

Diana Anderson | EurekAlert!
Further information:
https://www.anl.gov/article/argonne-researchers-create-active-material-out-of-microscopic-spinning-particles
http://dx.doi.org/10.1126/sciadv.aaz8535

More articles from Materials Sciences:

nachricht Looking at linkers helps to join the dots
10.07.2020 | King Abdullah University of Science & Technology (KAUST)

nachricht Goodbye Absorbers: High-Precision Laser Welding of Plastics
10.07.2020 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Looking at linkers helps to join the dots

10.07.2020 | Materials Sciences

Surprisingly many peculiar long introns found in brain genes

10.07.2020 | Life Sciences

Goodbye Absorbers: High-Precision Laser Welding of Plastics

10.07.2020 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>