"We are conducting this line of research because it opens up a way to create new responsive and intelligent systems and materials," said Dr. Robin Ras of Aalto University.
Self-assembly is a process in which multiple components form organized structures or patterns without external direction. The process is very interesting both for scientists and industry, because many natural systems rely on self-assembled structures and they can further inspire technological applications.
"The structure formation can either be static, driven by energy minimization, or dynamic, driven by continuous energy feed. Over the years we have managed to create functional materials based on static self-assembled hierarchies. This model system paves the way towards even more versatile dynamic materials, wherein the structures are formed by feeding energy," said Academy Professor Olli Ikkala.
By using the new model system, the researchers demonstrated that static droplet patterns can transform reversibly into dynamic ones when energy is fed to the system via an oscillating magnetic field. The transition was observed to be complex and the most complicated patterns emerged when the energy feed was just enough to enter the dynamic self-assembly regime.
In addition to the hard science behind the self-assembly, the droplet patterns are also visually captivating.
"In some patterns, the motion of the droplets resembles that of dancing. We find it simply beautiful," said Dr. Jaakko Timonen.
This work is part of the newly completed doctoral thesis of Jaakko Timonen at the Aalto University Department of Applied Physics. It is a multidisciplinary research, combining expertize in magnetic nanoparticle synthesis, superhydrophobic surfaces, and in-depth understanding of self-assemblies.
"Jaakko Timonen´s broad expertize was instrumental in combining three seemingly unrelated fields: magnetic nanoparticles water repellent coatings, and self-assembly," said Dr. Ras.
The results were published in Science on July 19, entitled “Switchable Static and Dynamic Self-Assembly of Magnetic Droplets on Superhydrophobic Surfaces”.
Further information/interviews:Dr. Robin Ras and Academy Professor Olli Ikkala
http://youtu.be/UtBNbDhTKR4Link to images: http://aalto.digtator.fi/public/65eb474dc8B1.aspx
***Aalto University Communications
| Aalto University
Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences