A nanometer (nm) is one thousand millionth of a meter. A single human hair is about 80,000 nm wide, a red blood cell is approximately 7,000 nm wide, a DNA molecule 2 to 2.5 nm, and a water molecule almost 0.3 nm. The term ”nanotechnology” was created by Norio Taniguchi of Tokyo University in 1974 to describe the precision manufacture of materials with nanometer tolerances1, but its origins date back to Richard Feynman’s 1959 talk

1. INTRODUCTION TO
NANNOTECHNOLOGY
By sreeremya.s
Asst professor,sree narayana guru
college,cbe

2. • A nanometer (nm) is one thousand millionth of a
meter.
• A single human hair is about 80,000 nm wide, a red
• blood cell is approximately 7,000 nm wide, a DNA
• molecule 2 to 2.5 nm, and a water molecule almost
• 0.3 nm. The term ”nanotechnology” was created by
• Norio Taniguchi of Tokyo University in 1974 to describe
• the precision manufacture of materials with
nanometer
• tolerances1, but its origins date back to Richard
• Feynman’s 1959 talk

3. • ”There’s Plenty of Room at the
• Bottom”2 in which he proposed the direct
manipulation
• of individual atoms as a more powerful form of
synthetic
• chemistry. Eric Drexler of MIT expanded Taniguchi’s
• definition and popularised nanotechnology in his 1986
• book ”Engines of Creation: The Coming Era of
• Nanotechnology”3.

4. • Nanomaterials: basic building
• blocks
• This section outlines the properties of three of
the most
• talked-about nanotechnologies: carbon
nanotubes,
• nanoparticles, and quantum dots6

5. • Carbon Nanotubes
• Carbon nanotubes, long thin cylinders of
atomic layers
• of graphite, may be the most significant new
material
• since plastics and are the most significant of
today’s
• nanomaterials.

6. • They
• are generally classified as single-walled (SWNT),
• consisting of a single cylindrical wall, or
multiwalled
• nanotubes (MWNT), which have cylinders within
the
• cylinders. When the press mentions the amazing
• properties of nanotubes, it is generally SWNT
they are
• referring to.

7. • Field Emission Based Devices. Carbon Nanotubes
have
• been demonstrated to be efficient field emitters
and
• are currently being incorporated in several
applications
• including flat-panel display for television sets or
• computers or any devices requiring an electron
• producing cathode such as X-ray sources (e.g. for
• medical applications).

8. • Supersensitive Sensors. Semiconducting nanotubes
• change their electrical resistance dramatically when
• exposed to alkalis, halogens and other gases at room
• temperature, raising hopes for better chemical sensors.
• The sensitivity of these devices is 1,000 times that of
• standard solid state devices.

9. • Nanotweezers. Two nanotubes, attached to electrodes
• on a glass rod, can be opened and closed by changing
• voltage. Such tweezers have been used to pick up and
• move objects that are 500 nm in size. Although the
• tweezers can pick up objects that are large compared
• with their width, nanotubes are so sticky that most
• objects can’t be released. And there are simpler ways
• to move such tiny objects.