Harvard scientists make odd-shaped bubbles

CAMBRIDGE, Mass., Dec. 14 (UPI) -- Harvard University scientists say they've found gas bubbles can exist in stable, non-spherical shapes without the application of external force.

The researchers say they created the micron- to millimeter-scale peapod-, doughnut- and sausage-shaped bubbles by coating ordinary gas bubbles with a tightly packed layer of tiny particles and then fusing them.

"Particles have been used to stabilize emulsions and foams for over 100 years," said lead author Anand Bala Subramaniam, a research associate in Harvard's Division of Engineering and Applied Science.

"However, we've demonstrated that not only are particles useful for making bubbles last longer, they fundamentally alter the properties of these bubbles," said Subramaniam.

Study co-author Howard Stone, a professor of engineering and applied mathematics, said, "The ability to alter the shapes of bubbles and liquid drops in products like ice cream or shaving foams or creams may provide a means to alter the consistency or texture of these products. The non-spherical bubbles could also find use as vessels for delivering drugs, vitamins or flavors."

The findings are described on the Web site of the journal Nature.