According to an old Japanese proverb, we're fools whether we dance or not, so we might as well dance. Could the same be said for these waltzing water droplets? Researchers from Aalto University and Paris Tech demonstrated this dancing effect by placing water droplets, which contained magnetic nanoparticles, on strong water repellent surfaces and made them align in various static and dynamic structures using periodically oscillating magnetic fields. This is the first time that scientists have successfully demonstrated reversible switching between static and dynamic self-assembly.
Obviously, this study is not just about creating water droplets that can dance, although the effect is fascinating. Dr. Robin Ras of Aalto University said, "we are conducting this line of research because it opens up a way to create new responsive and intelligent systems and materials." The process of self-assembly — in which multiple components form organized structures or patterns without external direction — is interesting because many natural systems rely on such structures to create future 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 this new model system, researchers demonstrated that static droplet patterns can transform into dynamic ones by feeding energy into them via an oscillating magnetic field. The transition is a complex one and the researchers saw the most complicated patterns form when the energy feed was just enough to enter the dynamic self-assembly process.
The effect is that some of the water droplets appear to dance, creating something beautiful as a result of scientific discovery.
Via Science Mag