"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.
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."