The largest tiny structures ever built have taken shape in the lab of two University of Rochester engineers. Glowing hollow spheres, cylinders, rings and disks of microscopic size are reportedly 1,000 times larger than the biggest "self-assembled" molecular structures ever coaxed into being by scientists working on what are known as nanostructures.
Some of the new forms involve millions of molecules, and are larger than most human body cells.
"In the world of self-assembly, these structures are giant," said graduate student X. Linda Chen, who worked on the project with her faculty adviser, chemical engineering professor Samson Jenekhe.
The fluorescing structures -- none larger than the width of a human hair -- start with a specially prepared polymer, a larger "building block" than previously attempted. Once prepared, the polymer molecules arrange themselves within minutes into separate, well-defined structures.
The shapes offer possibilities in such applications as drug delivery, adhesives, pesticides, photography, pollution control, cosmetics and paints. The work is reported in a recent issue of the journal Science.
-- Mike Vogel