DISNEYLAND used to have a ride called Adventures Thru Inner Space. It simulated a trip down through magnitudes of scale to a microverse filled with what looked like glowing Mickey Mouse heads. They were supposed to be water molecules, two hydrogen atoms for the ears and a big oxygen atom for the face--H2O. Uncle Walt was reminding his guests that everything is made of the same fundamental stuff: atoms.
But we don't operate at the atomic level. We make things by heating, boiling or hacking at huge hunks of a given material until it's the right shape--from tree to table, say, or iron ore to ear. Gradually, though, a new field of science is being born, based on the idea that individual atoms and molecules can be manipulated to create anything--any material, any food, any substance-more efficiently and more abundantly than even nature can. Most of the objects in this microverse are measured in nanometers-billionths of a meter-so the new science is called nanotechnology.
The idea isn't new. In 1959 the physicist Richard Feynman predicted atom-by-atom manipulation would revolutionize computing and material science. But it was an engineer named K. Eric Drexler who named nanotechnology. In 1981 he proposed "molecular machinery able to position reactive groups to atomic precision." In other words, build things from the atoms up.
The holy grail of nanotech is the universal assembler, a hypothetical submicroscopic robot with legs capable of putting molecules together like Legos. "It could be reprogrammed to build a wide range of useful products, and it would be able to make copies of itself," says Ralph Merkle, a researcher at Xerox PARC. Assemblers might float in a liquid that supplies fuel and raw molecules to build with. The result, saynanotechies, would be an unceasing stream of nearly free stuff. Diamond could become a building material. "Diamond has a strength-to-weight ratio over 50 times that of steel," Merkle says. "Imagine taking the space shuttle and reducing its structural weight by a factor of 50." How about nanites in the bloodstream, repairing cellular damage? Paints and dyes that change color? It's easy to see how nano guys can start to sound a little religious.
The universal assembler is still the stuff of science fiction, but labs around the world are dreaming nano dreams. Rick Smalley, who won a Nobel Prize in 1996 for the discovery of a new carbon molecule called fullerene--also known as buckyballs--has hopes for what's called scanning probe microscopy. In SPM, a cantilevered arm drags across a surface, moving atoms into place. Smalley makes SPM even more precise by attaching to the tip of the arm a "buckytube" made of several buckyballs. "We'll have fingers, extensions of our own body, that can reach down and touch an atom, a molecule, an enzyme, and nudge it over," he says.
Nanotechnology may also arise from the fact that some materials, in effect, build themselves. In nature, structures such as proteins assume the correct shape due to interactions among their subunits. George Whitesides, a chemist at Harvard, makes materials do the same tricks by carefully controlling their surface characteristics so they connect in predictable ways. "In the distant future," says Whitesides, "you might begin to assemble electronic systems this way."
"Drexlerian" nanotechnology is still a ways off. "Star Trek" replicators, or invisible "utility fogs" that can coalesce into useful shapes-a screwdriver, perhaps, or a dinette set-remain dreams. Even the faithful wonder where a universal assembler would get instructions or power, or how it could control every chemical interaction. But, says Chris Peterson, Drexler's wife and the executive director of the Foresight Institute, where they study nanotech and its societal implications, "this is an engineering problem, really." It might even be solvable outside Tomorrowland.