Brave New World, Too Small to See

April 1, 2009 — -- Ever try swimming with your boots on? Or threading a needle while blindfolded? How about assembling a jigsaw puzzle with both hands tied behind your back?

All of those challenges are pretty close to impossible, but they are child's play compared to what scientists are trying to accomplish in the exploding world of nanotechnology. The field involves the manipulation of matter on the atomic level, producing new materials in which the whole is much more than the sum of its parts.

It has enormous potential, not only in high tech fields like medicine and energy, but in nearly everything from your "kitchen to your space shuttle," said physicist Oleg Gang, who leads a research project at Brookhaven National Laboratory in Upton, N.Y.

"I believe we (in nanotechnology) are approximately where we were in chemistry 100 years ago," Gang said in a telephone interview.

At that time, the production of what are now basic products, like plastic and polymers, was expensive and illusive, because scientists didn't really understand the fundamental processes. But as understanding grew, so did the manufacturing techniques, and now "plastics are everywhere."

The same should happen with nanotechnology, Gang said, but right now, scientists are barely knocking at the door.

The modern obsession with building things one atom at a time was launched in an electrifying lecture given by physicist Richard Feynman at the California Institute of Technology in 1959, titled "There's plenty of room at the bottom."

Feynman challenged a roomful of scientists -- some of whom are leaders in the field today -- to work on ways to build devices by manipulating one atom at a time, thus controlling the entire process and ending up with a cheaper, better way to build just about anything. In theory, it should be possible to pour the contents of one beaker into another and have it spit out silicon chips, or candy bars, or whatever.

That classic lecture set science on a course that has turned out to be very daunting, because before Feynman's dream can be realized, scientists must first understand how nature manages to do it so easily. Living organisms, including humans, are indeed assembled from the bottom up as atoms do what the genetic code tells them to do, one at a time.

Building Crystals

That's one of the reasons Gang and his team, which includes chemists and biologists, attempted to mimic nature's way by creating a synthetic DNA (which carries the blueprint for each organism) to "talk" atoms into doing what the scientists wanted them to do.

A nanometer is only one billionth of a meter, and not too long ago the task would have been impossible because no one could "see" what they were doing at a scale that small. New imaging devices have made that possible now, to some extent, but it's still pretty hard to make atoms link up with the right atoms to form some kind of a structure.

"We don't have tweezers that small," Gang said.

But Gang's team found another way, and it has so far proven successful.

Like DNA, "you can use some bio-molecules that have specific types of interactions," he said. The process allows the scientists to encode particles to talk only to those they are supposed to talk to.

"I can assign a last name to each particle, and we can tell Smith to talk to particle Brown, but not to some other particle," Gang added. By "talking," he means linking, so that the right particles combine with the right partners to build a basic structure.

The team, which published its most recent study March 29 in the journal Nature Materials, has succeeded in building clusters of nanoparticals. That has already attracted the attention of manufacturers.

New materials manufactured this way could have enhanced optical, magnetic, and absorption characteristics that could make them especially useful in solar energy panels and biological sensors.

More efficient sensors could capture more energy from light emitted by the sun, and turn that energy more efficiently into more electricity, so this is the kind of thing that could transform the world we know into a world we so far have only dreamed of -- a world where there is an abundant, cheap and inexhaustible source of energy.

It has to come someday, and maybe this is the beginning, but Gang would be the first to warn against too much optimism.

At this point, he doesn't want to even think about the end product. Thinking about possible applications limits the scope of scientific inquiry, because there's a specific goal out there.

Instead, he and hundreds of others like him in research laboratories scattered around the world, are working just to understand the basic processes, and how one atom can be convinced to link up with another atom with a very predictable result.

A High-Stakes Game

The stakes here are so high, and the opportunity for failure so great, that it would be foolish to ask these folks to step up the pace. Devices that can be produced by self-assembly might eventually self-assemble into something quite different, some critics worry.

That's particularly troubling because one of the most promising applications of nanotechnology is in medicine. Tiny "machines" could be sent directly to troubled areas in the human body, make all necessary repairs, and then self-destruct. At least that's the intended goal.

But the very process of working at the tiny scale of nanotechnology introduces changes that may not be expected. New materials could have new properties, for example, because at that scale, ordinary materials change.

That also happens in the world we already know. Gang points out that combining hydrogen and oxygen makes water, and water has characteristics that are not shared with either of its component parts.

But it doesn't always work that way. Combining oxygen with hydrogen also produces explosive rocket fuel. In fact, it's what powers the main engines of the space shuttle.

So, as exciting as nano seems these days, it's not a bad idea to understand the entire process.

"You cannot advance before you explore what's around you," Gang said. "You cannot grow a tree in three days. It's not going to be a tree. It's just going to be something weak, and it's going to fail. You need some time to mature, and this is a field that needs time to mature."