管理提醒: 本帖被 silverks 执行加亮操作(2011-05-27)
The U.S. National Nanotechnology Initiative uses the term "nanotechnology"
to describe:
* Research and technology development aimed to work at atomic and
molecular scales, in the length scale of approximately 1 - 100 nanometer
range;
* The ability to understand, create and use structures, devices and
systems that have fundamentally new properties and functions because of
their nanoscale structure;
* The ability to control – to see, measure and manipulate – matter on
the atomic scale to exploit those properties and functions.
"Nanotechnology stands out as a likely launch pad to a new technological era
because it focuses on perhaps the final engineering scales people have yet
to master," says a 1999 report: Nanotechnology: Shaping the World Atom by
Atom, by the National Science and Technology Council. The ability to build
structures molecule by molecule would allow scientists to create new
structural materials 50 times stronger than steel of the same weight, making
possible the construction of a Cadillac weighing 100 pounds, according to
Ralph Merkle of the Xerox Palo Alto Research Center. It could also, he says
in an article in MIT's Technology Review, "give us surgical instruments of
such precision and deftness that they could operate on the cells and even
molecules from which we are made."
Some of the methods necessary to build structures consisting of large
numbers of precisely arranged atoms include molecular self-assembly, in
which molecular building blocks assemble themselves in pre-designed ways.
Using this technique, researchers have created carbon nanotubes with
diameters of about one ten-thousandth of a human hair that can be used as
miniature structural materials, electronic components and drug-delivery
systems. Scientists also depend on such tools as Scanning Tunneling
Microscopes and Scanning Probe Microscopes to build images on surfaces,
manipulate atoms into miniature structures, or yze the identities of
atoms and molecules one atom at a time.