Physicists Make Square Droplets and Liquid Lattices (phys.org) 13
Aalto University reports via Phys.Org: When two substances are brought together, they will eventually settle into a steady state called thermodynamic equilibrium; examples include oil floating on top of water and milk mixing uniformly into coffee. Researchers at Aalto University in Finland wanted to disrupt this sort of state to see what happens -- and whether they can control the outcome. In their work, the team used combinations of oils with different dielectric constants and conductivities. They then subjected the liquids to an electric field. "When we turn on an electric field over the mixture, electrical charge accumulates at the interface between the oils. This charge density shears the interface out of thermodynamic equilibrium and into interesting formations," explains Dr. Nikos Kyriakopoulos, one of the authors of the paper. As well as being disrupted by the electric field, the liquids were confined into a thin, nearly two-dimensional sheet. This combination led to the oils reshaping into various completely unexpected droplets and patterns.
The droplets in the experiment could be made into squares and hexagons with straight sides, which is almost impossible in nature, where small bubbles and droplets tend to form spheres. The two liquids could be also made to form into interconnected lattices: grid patterns that occur regularly in solid materials but are unheard of in liquid mixtures. The liquids can even be coaxed into forming a torus, a donut shape, which was stable and held its shape while the field was applied -- unlike in nature, as liquids have a strong tendency to collapse in and fill the hole at the center. The liquids can also form filaments that roll and rotate around an axis. One of the exciting results of this work is the ability to create temporary structures with a controlled and well-defined size which can be turned on and off with voltage, an area that the researchers are interested in exploring further for creating voltage-controlled optical devices. Another potential outcome is the ability to create interacting populations of rolling microfilaments and microdroplets that, at some elementary level, mimic the dynamics and collective behavior of microorganisms like bacteria and microalgae that propel themselves using completely different mechanisms. The research has been published in the journal Science Advances.
The droplets in the experiment could be made into squares and hexagons with straight sides, which is almost impossible in nature, where small bubbles and droplets tend to form spheres. The two liquids could be also made to form into interconnected lattices: grid patterns that occur regularly in solid materials but are unheard of in liquid mixtures. The liquids can even be coaxed into forming a torus, a donut shape, which was stable and held its shape while the field was applied -- unlike in nature, as liquids have a strong tendency to collapse in and fill the hole at the center. The liquids can also form filaments that roll and rotate around an axis. One of the exciting results of this work is the ability to create temporary structures with a controlled and well-defined size which can be turned on and off with voltage, an area that the researchers are interested in exploring further for creating voltage-controlled optical devices. Another potential outcome is the ability to create interacting populations of rolling microfilaments and microdroplets that, at some elementary level, mimic the dynamics and collective behavior of microorganisms like bacteria and microalgae that propel themselves using completely different mechanisms. The research has been published in the journal Science Advances.
Do't they mean cubical (Score:1)
or is it just 2 dimensional
Re: (Score:2)
As well as being disrupted by the electric field, the liquids were confined into a thin, nearly two-dimensional sheet. This combination led to the oils reshaping into various completely unexpected droplets and patterns.
It's in the bloody summary.
Re: (Score:3)
Re: (Score:2)
Are we now RTFS?
Re: Do't they mean cubical (Score:1)
You look lonely (Score:2)
I'm just going by the small number of comments the story has received as it times off the top page... But I notice there's a bunch of such low-interest stories these days.
Are "we" so jaded by too much innovation and discovery? Or could the story have been presented in a different way that might have generated more interest? Perhaps some titular linkage to a useful outcome?
Me? I do everything sideways these days. I actually start with the old stories in search of Funny comments that are actually funny. Few
Wonder what this means (Score:2)
for things like fuel injection, inkjet printers and paint sprayers?
Re: (Score:2)
Probably not much. Because the electrical field only disrupts the interface layer between two different materials, there would be no practical way to select only the thin layer between them.
It might be possible to spray two different liquids through a combined nozzle, along with an electrical charge, to change the way they interact after they leave the nozzle, but the article doesn't mention any research into this.
Liquid lenses? (Score:2)
How is this different from liquid lenses?
3D Printing (Score:2)
Another post explores this in terms of printing but I wonder how it could apply to 3d printing, especially at a building level.
How strong would the field need to be, how strong would the dialectic property need to be, and how long would it need to be applied to create something like a concrete pillar.
Could it be used to create an internal structure? Could we use a polymer and some metals to create skeletal structures or internal circuitry? Then maybe apply another process to harden it.
What precision does th
Duh (Score:2)
completely unexpected droplets and patterns
I do not understand, why did they not expect this behavior, because from my perspective this finding was obvious as it is tacitly implied within the framework of my conjecture.