They want to mimic nature, by designing and building their own nanostructures from scratch, atom by atom and molecule by molecule. They aim to tailor new entities with customized features, such as electrical conductivity, mechanical strength, and optical properties, by combining molecules of appropriate shapes and sizes into the right patterns. Research teams have already developed some of the tools that will permit engineers to design nanostructures. IBM scientists set the stage in 1981, when they invented an instrument called the scanning tunneling microscope. A group at the University of North Carolina, funded by NSF, is now developing a sophisticated joystick that controls a scanning tunneling microscope.
Scientists can use that device to start assembling nanostructures that consist of complex molecules.
An NSF-supported team at Rice University, meanwhile, is working with nanotubes. These thin cylinders of carbon atoms, with diameters of about one nanometer, have one-sixth of the density of steel but about ten times as much strength. Eventually, the team predicts, collections of nanotubes could reinforce composite materials or coat the surfaces of cars and airplanes, greatly increasing the surfaces' strength and durability. Other groups, including one at the University of Strasbourg in France, are developing techniques called molecular self-assembly. The concept is to design molecular building blocks that automatically snap together, just like the components of modular classrooms in schools.