Short answers, pulled from the story.
Physicist Richard Feynman first described the concept in 1959 in his talk There's Plenty of Room at the Bottom, where he outlined the possibility of synthesizing materials through direct manipulation of atoms. The term "nano-technology" itself was first used by Norio Taniguchi in 1974.
Nanotechnology is defined as working with matter that has at least one dimension sized between 1 and 100 nanometers. One nanometer is one billionth of a meter. By comparison, DNA has a diameter of around 2 nm, and the smallest bacteria of the genus Mycoplasma are around 200 nm in length.
Gerd Binnig and Heinrich Rohrer received the Nobel Prize in Physics in 1986 for inventing the scanning tunneling microscope. Harry Kroto, Richard Smalley, and Robert Curl won the Nobel Prize in Chemistry in 1996 for discovering fullerenes. Peter Grünberg and Albert Fert received the Nobel Prize in Physics in 2007 for discovering giant magnetoresistance. Sumio Iijima won the inaugural Kavli Prize in Nanoscience in 2008 for discovering carbon nanotubes.
A two-year UCLA study found that lab mice consuming nano-titanium dioxide showed DNA and chromosome damage linked to cancer, heart disease, neurological disease, and aging. Research published in Nature Nanotechnology found that some carbon nanotubes could be as harmful as asbestos if inhaled in sufficient quantities. Studies also found that nanoparticles inhaled by rats settled in the brain and lungs, raising inflammation and stress biomarkers.
As of the 21st of August 2008, the Project on Emerging Nanotechnologies estimated that over 800 manufacturer-identified nanotech products were publicly available. New products were entering the market at a rate of three to four per week.
K. Eric Drexler and Richard Smalley debated whether molecular nanotechnology, specifically the use of mechanical assemblers to build objects atom by atom, was physically possible. Smalley argued that mechanically manipulating individual molecules faced insurmountable practical obstacles. The two exchanged letters in Chemical & Engineering News, the American Chemical Society publication, in 2003.