TECHNOLOGY

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Milestone

• 1959 R. Feynman Delivers “ Plenty of Room at the

Bottom”

• 1974 First Molecular Electronic Device Patented

• 1981 Scanning Tunneling Microscopic (STM)

• 1986 Atomic Force Microscopy (AFM) Invented

• 1987 First single-electron transistor created

• 1991 Carbon Nanotubes Discovered

• 2000 US Launches National Nanotechnology

Initiative

• 2002. 01 ITRI Nano Research Center Established

What is a Nanomaterial?

• Nanomaterials are commonly defined as

materials with an average grain size less

than 100 nanometers.

• One billion nanometers equals one meter

• Nanopowder

– Building blocks (less than 100 nm in

diameter)

for more complex nanostructures.

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• Nanotechnology is the art and science of manipulating

matter at the nanoscale (down to 1/100,000 the width of a

human hair) to create new and unique materials and

products...with enormous potential to change society.

• 1 nanometer (nm) = 1 billionth of a meter.

• Human exposure and accommodation nothing new.

• We cannot assume that nanomaterials are the same as

their bulk counterpart...but also cannot assume that they

are more toxic.

• Every particle should be tested on a case-by-case basis.

Different types of Nanomaterial

• Nanopowder

– Building blocks (less than 100 nm in diameter)

for more complex nanostructures.

• Nanotube

– Carbon nanotubes are tiny strips of graphite

sheet rolled into tubes a few nanometers in

diameter and up to hundreds of micrometers

(microns) long.

– The Strongest Material

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Nano Powders:

• Advanced nanophase materials synthesized from

nanopowders have improved properties.

• Such as stronger and less breakable ceramics.

They may conduct electrons, ions, heat, or light

more readily than conventional materials.

• Exhibit improved magnetic and catalytic properties.

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• Some nanotechnology has been around for a

while: nano-size carbon black particles (a.k.a.

high-tech soot) have gone into tires for 100

years as a reinforcing additive.

• A vaccine, which often consists of one or more proteins with nanoscale dimensions. • The nanoworld is a weird borderland

between the realm of individual atoms and molecules (where quantum mechanics rules)

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Nanotech—deals with materials and systems

having these key properties: they have at least one

dimension of about one to 100 nanometers, they

are designed through processes that exhibit

fundamental control over the physical and chemical

attributes of molecular-scale structures, and they

can be combined to form larger structures. May

boast superior electrical, chemical, mechanical or

optical properties —at least in theory.

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New tools capable of imaging and manipulating single

molecules or atoms have ushered in the new age of

nano. The icons of this revolution are scanning probe

microscopes—the scanning tunneling microscope and

the atomic force microscope, among others—capable of

creating pictures of individual atoms or moving them from

place to place.

Varied approaches to fabricating nanostructures have

emerged in the nanoworld.

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Approaches to fabricating nanomaterials:

• Top-down – Breaking down matter into more basic

building blocks. Frequently uses chemical or thermal

methods, patterning (using photolithography) and

etching away material, as in building integrated circuits

• Bottoms-up – Building complex systems by combining

simple atomic-level components, self-assembly of atoms

and molecules, as in chemical and biological systems

Bottom-up approach frequently used when constructing

nanomaterials for use in medicine

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• Carbon nanotubes are hollow cylinders made of sheets

of carbon atoms and can be divided into single-walled

carbon nanotubes (SWNTs) and multi-walled carbon

nanotubes (MWNTs).

• SWNTs possess a cylindrical nanostructure with a high

aspect ratio, formed by rolling up a single graphite sheet

into a tube.

• SWNTs are, typically, a few nanometers in diameter and

up to several microns long.

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General areas of application are as follows:

• manufacturing and industrial processes

(catalysts, filters, and so on);

• transport, aeronautical and space

engineering;

• biomedicine, pharmaceuticals, targeted

drug delivery;

• imaging, sensors, monitoring;

• environmental management;

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General areas of application are as follows:

• food technology, additives, packaging;

• materials, surfaces, textiles, fabrics;

• sports and entertainment technology;

• cosmetics, fragrances, toiletries;

• Information and Communications Technology

(ICT);

• Intelligence, surveillance and defence.

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Examples of specific products containing

engineered nanoparticles (such as carbon

nanotubes) that are already on the consumer

market are: textiles, sportswear, golf balls, tennis

rackets, plastic mouldings in vehicles and scratch

resistant paint, car tyres, sunscreen and certain

electronic consumer goods. Many other products,

including nano catalysts and nano-filters, are

available to manufacturers.

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Several synthesis methods are used to produce

carbon nanotubes. The three most commonly used

methods are the arc discharge, laser ablation, and

chemical vapor deposition (CVD) techniques. While

the arc and laser methods can produce large

quantities of carbon nanotubes they lead to resilient

contaminants, including pyrolytic and amorphous

carbon, that are difficult to remove from the sample.

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New fabrication methods such as high pressure

carbon monoxide (HiP CO), have created

commercial supplies of carbon nanotubes with

more than 90% purity with competitive prices. In

contrast, the less scalable CVD process yield

carbon nanotubes with defined properties. This

method produces both multiwalled and single-

walled nanotubes depending on the temperature.

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