Watch Scientists Control Liquid Metal with Surface Tension and Low Voltage (VIDEO)

Learning how to control liquid metals could have huge applications for the future. We could potentially create reconfigurable electronic circuits, antennas and other technologies. Now, scientists may have just found a way to control these metals; the trick lies in the oxide "skin" of the metal.

In order to find out whether or not they could control liquid metals, the researchers used a liquid metal alloy of gallium and indium. The bare alloy actually has a remarkably high surface tension of about 500 millinewtons. This causes the metal to bead up into a spherical blob. Then, the researchers applied very low voltages to the metal alloys.

"But we discovered that applying a small, positive charge-less than one volt-causes an electrochemical reaction that creates an oxide layer on the surface of the metal, dramatically lowering the surface tension from 500 mN/meter to around 2 mN/meter," said Michael Dickey, one of the researchers, in a news release. "This change allows the liquid metal to spread out like a pancake, due to gravity."

What's truly interesting is that the change in surface tension is also reversible. By flipping the polarity of the charge from positive to negative, the scientists can cause the oxide to be eliminated and restore the high surface tension. This could be huge in terms of creating malleable circuits.

"The resulting changes in surface tension are among the largest ever reported, which is remarkable considering it can be manipulated by less than one volt," said Dickey. "We can use this technique to control the movement of liquid metals, allowing us to change the shape of antennas and complete or break circuits. It could also be used in microfluidic channels, MEMS, or photonic and optical devices. Many materials form surface oxides, so to the work could extend beyond the liquid metals studied here."

The findings are published in the journal Proceedings of the National Academy of Sciences.

Want to see the metals in action, check out the video below, courtesy of YouTube.