Rensselaer Polytechnic Institute researchers said their finding might lead to new types of miniature camera lenses, cell phone displays and other microscale fluidic devices.

The team led by Professor Theodorian Borca-Tasciuc placed droplets of water-based solutions containing bismuth telluride nanoparticles onto a Teflon-coated silicon wafer. When an electrical field was applied to the droplet, the researchers observed a strong change in the angle at which the droplet was in contact with the wafer. That change was much higher than observed in liquids without the nanoparticles.

"You use the same electrical field but you get more change in shape with the nanofluid," Borca-Tasciuc said. "We know the nanoparticles are critical in this process because without them the effect is much less strong."

The ability to easily change the contact angle of droplets of nanofluids has potential applications for efficiently moving liquids in microsystems, creating new methods of focusing lenses in miniature cameras or cooling computer chips, the researchers said.

The study, conducted with Professor Ganapathiraman Ramanath, post-doctoral research associate Arup Purkayastha and graduate student Raj Dash appeared in the journal Nanotechnology.