C7+Nanotechnology

nanometer - one billionth (1/1000000000) of meter - the size of molecule

bottom-up method researchers seek to build larger and more complex systems molecule-by-molecule. Molecules are designed and created that have the ability to spontanesously self-assemble when a chemical or physical trigger is applied.

Top-down method material is altered (removed/added to) by mechanical or chemical means. (ex. photolithography and electron beam) already well known and commercialized.

Allotrope of carbons are mentioned in the text page 22. Allotrope is distinct crystalline form in which an element can exist in. The allostrope of carbons include diamond and graphite

The Buckminsterfullerence has sisty carbons arranged in hexagons and pentagons to give a geodesic spherical structure.

Concentric means the objects that share the same center, axis or origin with one inside the other. Circles, tubes, cylindrical shafts, and else may be concentric to another.

Bundles of tubes have high tensile strength because each of carbon atom has strong bonds with five to six other carbon atoms. Hence nanoobjects are extremely rigid yet, because of the empty space within the tube, very light.

However, although graphite has very strong bonds to three other carbon atoms, the bonds between the layers of carbon atom fields in grphite is very weak. Hence this layer can slide each other so graphite is one of the softest natural materials. they are used in pencil lead, as well known.

(Quantum affect) The behavior of electrons within nanotube depends on the length of tube, and the property of nanotube shifts from conductor to semiconductor according to its form.

Computer More powerful computers/information storage devices

Medical New approaches for medical diagnosis, tratment, drug delivery 1. Nanomedicine 2. Nanoshells 3. Nanogels 4. Nanomachines

Military 1. Improved weapons 2. Conventional structural materials replaced by more rigid(x100)+lighter materials

Energy 1. Improved capacity of betteries 2. New technologies for energy production and conversion (fuel cells, solid-state lighting, photocoltaics)

CHALLENGES No internationally agreed protocols for toxicity testing of nanoparticle No standardized protocols for evaluating environmental impact of nanoparticles Need some sanity in issueing patents Education furue generation scientists and engineers.

Nanoparticles may enter the body by three majoy process: Inhalation, Swallowing, and Penetration through the skin ex) 1. Cause tissue damage through inducing inflammation in respiratory tract 2. Ingeested nanoparticles may cause permanent liver damage by excessive immune response accumulated by nanoparticles

Grey goo (Goo = large mass of replicating nanomachines lacking large-scale structure, which may/may not actually appear goo-like) hypothetical end-of-the-world scenario involving molecular nanotechnology out-of-control self-replicating robots consume all matter on Earth while building more of themselves