Certain plastics known as shape-memory polymers switch to predetermined shapes when triggered by heat or light. Now, researchers have developed more-versatile versions of such polymers. When heated, each of the new triple-shape polymers switches to a second shape. Then, at a higher temperature, the plastic changes to a third form."For some applications, [these] more-complex deformations are required," says chemist Andreas Lendlein of the GKSS Research Center in Teltow, Germany. He, chemical engineer Robert Langer of the Massachusetts Institute of Technology, and their colleagues have already m... (p. 416)

A heavy dose of boron transforms silicon, the superhero material of electronics, into a superconductor. (p. 341)

A hair-darkening paste invented thousands of years ago forms lead-and-sulfur nanocrystals remarkably similar to those made in today's nanotechnology labs. (p. 350)