Scientists have developed a new method to create air-stable water beads that produces interlocking spheres of water in ambient conditions.
The Department of Energy's Oak Ridge National Laboratory (ORNL) research team discovered that when water droplets are placed on a superhydrophobic surface infused with a coating of oil, the droplets simply align themselves side by side and don't merge. They were also able to make non-coalescing water droplet networks without lipids, which are normally used to create an interlocking lipid bilayer between the water droplets, in the solution.
"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 study leader Pat Collier of ORNL in a press release.
Co-author Jonathan Boreyko added: "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. 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 together."
The resulting thin oil film squeezes between the pure water droplets, preventing them from merging into one. This newly-discovered technique will be of use in certain applications like biological sensing, membrane research, dew/fog-harvesting technology, synthetic biology and circuit creation. The bilayers can be used in making a bio-battery, a signaling network (done by stringing droplets together) and even to detect airborne molecules.
The research team studied the water droplets' other aspects as well. The study found ways to maneuver oil viscosity and tweak temperature and humidity levels to control the performance and lifetime of the water droplets.
This study was published in the Proceedings of the National Academy of Sciences.
