Researchers at the Oak Ridge National Laboratory's Department of Energy have developed a new method to create networks of water droplets at room temperature. Their research could lead to a better understanding of several biological systems. The study could also help build equipment that harvests water from fog.
Researchers have been trying to create air-stable water droplet networks known as droplet interface bilayers for quite some time now. Hagan Bayley and colleagues wrote an article in 2009 detailing the advances made in techniques used to create these bilayers.
The interface of water droplet network mimics cell membranes, which could help researchers understand several biological mechanisms such as ion channels and protein analysis. However, the methods used by earlier research groups were complex.
"The way they've been made since their inception is that two water droplets are formed in an oil bath then brought together while they're submerged in oil," said Pat Collier, lead author of the study. "Otherwise they would just pop like soap bubbles."
In the present study, researchers placed water droplets on a super-hydrophobic surface that had a coating of oil. The team found that the droplets formed a network and didn't merge with one another.
"When you have those lipids at the interfaces of the water drops, it's well known that they won't coalesce because the interfaces join together and form a stable bilayer," said Jonathan Boreyko, co-author. "So our surprise was that even without lipids in the system, the pure-water droplets on an oil-infused surface in air still don't coalesce."
According to the researchers, a thin film of oil between the droplets prevents them from mixing.
The research will lead to a better understanding of droplet behavior, scientists said. Controlling the movement of water droplets is important in developing devices that can harvest water from fog.
Last year, University of Engineering and Technology of Peru researchers had developed a novel billboard that draws water from air.
"These bilayers can be used in anything - from synthetic biology to creating circuits, to bio-sensing applications," Boreyko said in a news release. "For example, we could make a bio-battery or a signaling network by stringing some of these droplets together. Or, we could use it to sense the presence of airborne molecules."
The study is published in the journal Proceedings of the National Academy of Sciences.