How to Make Non-Spherical Bubbles

Left to their own devices, bubbles like the soap bubbles you blew as a child will always assume the shape of a sphere because it's the shape that has the smallest surface area for a given volume and therefore the most stable.

But by coating the bubbles in tiny particles, Howard Stone, an engineer at Harvard University in Massachusetts, and colleagues have molded bubbles to look like sausages, doughnuts and other shapes.

The sausage-shaped bubbles pictured above was created by coating them with fluorescently labeled polystyrene particles 200 nm in diameter.

The particles jam together, enabling the bubbles to maintain unequal stresses along their surfaces and to take on a non-spherical shape. The particles can even be used to make odd shaped liquid droplets. The researchers think that non-spherical bubbles may occur naturally as well.

The study was detailed in the Dec. 14 issue of the journal Nature.