Rod-shaped molecules can organize themselves by, say, lining up like sardines or grouping
into distinct layers when they form orderly fluids known as liquid crystals. If exposed to ultraviolet
(UV) light or heat, the molecules of some liquid crystals self-organize in a second way:
They link into long chains called polymers.
Now, scientists investigating such materials have accidentally created microscopic polymer
tubes that tangle themselves into clumps that resemble balls of yarn, report Pavel A. Kossyrev
and Gregory P. Crawford of Brown University in Providence, R.I.
"We were actually just trying to align the liquid crystals ... [but] ended up with this weird,
yarn-ball thing," Crawford says. "It was totally unexpected."
These bundles, described in the Dec. 4 Applied Physics Letters, represent more than just a
new type of polymer structure, Kossyrev explains. The balls behave in an unusual, possibly