A fried breakfast food popular in Spain provided the
inspiration for the development of doughnut-shaped droplets that may provide
scientists with a new approach for studying fundamental issues in physics,
mathematics and materials.
The doughnut-shaped droplets, a shape known as toroidal, are
formed from two dissimilar liquids using a simple rotating stage and an
injection needle. About a millimeter in overall size, the droplets are produced
individually, their shapes maintained by a surrounding springy material made of
polymers. Droplets in this toroidal shape made of a liquid crystal – the same
type of material used in laptop displays – may have properties very different
from those of spherical droplets made from the same material.