Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers make droplets dance

19.07.2013
Researchers from Aalto University and Paris Tech have placed water droplets containing magnetic nanoparticles on strong water repellent surfaces and have made them align in various static and dynamic structures using periodically oscillating magnetic fields. This is the first time researchers have demonstrated reversible switching between static and dynamic self-assembly.

"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
robin.ras@aalto.fi and olli.ikkala@aalto.fi
p. +358 50 432 6633 and +358 50 4100454
Aalto University School of Science, Department of Applied Physics
Video 1
Magnetically triggered droplet splitting on a superhydrophobic surface
http://youtu.be/3PRogMaSo40
Video 2
Self-assembly of magnetic droplets on a superhydrophobic surface
http://youtu.be/ehvFFbFFsjg
Video 3
Reversible switching between static and dynamic self-assembly of magnetic droplets

http://youtu.be/UtBNbDhTKR4

Link to images: http://aalto.digtator.fi/public/65eb474dc8B1.aspx
Courtesy of Mika Latikka and Jaakko Timonen / Aalto University
Figure 1. Static self-assembly of seven magnetic droplets on a copper substrate with superhydrophobic coating.
Figure 2. Snapshot of a dynamic self-assembly of three magnetic droplets. This pattern is reversibly formed of the static seven-droplet pattern (Figure 1) by an application of an oscillating magnetic field.
Information about the article:
http://www.sciencemag.org/content/341/6143/253.full?sid=0d197496-08c7-4790-a9ea-2cc5862c4611

***

Aalto University Communications
PO Box 17800, 00076 AALTO, FINLAND
viestinta@aalto.fi
facebook.com/aaltouniversity
twitter.com/universityaalto
Aalto University, Finland is a new multidisciplinary science and art community in the fields of science, economics, and art and design. The University is founded on Finnish strengths, and its goal is to develop as a unique entity to become one of the world's top universities. Aalto University's cornerstones are its strengths in education and research. At the new University, there are 20,000 basic degree and graduate students as well as a staff of 5,000 of which 370 are professors.

| Aalto University
Further information:
http://www.aalto.fi
http://www.sciencemag.org/content/341/6143/253.full?sid=0d197496-08c7-4790-a9ea-2cc5862c4611

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>