Nanotechnology

Nanotechnology

Nanotechnology

Nanotechnology: General Information and Background

Nanotechnology is a concept, a term that refers to many different

technologies.

All of these technologies are extremely small in scale – ―nano‖ is a

measurement that refers to the nanometre or 10-9 m.

A nanometre is the width of 10 hydrogen atoms lined up side-by-side. To

put this in perspective, a human hair is about 80,000 nanometres wide; the

head of a pin is about 1 million nanometres wide; a red blood cell is about

7,000 nanometres in diameter

A nanometer is the amount a man's beard grows in the time it takes him to

raise the razor to his face

The raw materials and some of the products of nanotechnology are all

extremely small in physical scale.

Nanoscience and nanotechnology often focus on the manipulation of the

most basic components of all matter — atoms and molecules — with great

precision

Nanotechnology

Nanotechnology: General Information and Background

Public Health and Toxicity Concerns

Public health concerns about nanotechnology products focus on

interactions between them and biological tissues and processes.

Some nanostructures may accumulate within tissues and organs and can

be taken up by individual cells.

Nanoscale particles and structures into cells do not seem to affect the

immune responses of cells that introducing larger particles and structures

do.

This ability not to trigger the immune system may be an advantage in

targeting specific cells with introduced drugs, but the particles may still have

some unintended effects. This means that nanostructures. although

attractive as potential drug delivery mechanisms may be a health hazard.

The extremely small size of nanostructures leads some to worry that the

structures might enter the food chain undetected.

Nanotechnology

• Materials reduced to the nanoscale can show different properties compared to

what they exhibit on a macroscale, enabling unique applications.

• For instance, opaque substances become transparent (copper); stable

materials turn combustible (aluminum); solids turn into liquids at room

temperature (gold); insulators become conductors (silicon).

• A material such as gold, which is chemically inert at normal scales, can serve

as a potent chemical catalyst at nanoscales. Much of the fascination with

nanotechnology stems from these quantum and surface phenomena that matter

exhibits at the nanoscale.

Lubick, N. (2008). Silver socks have cloudy lining. Environ Sci Technol. 42(11):3910 quoted in WikiPedia

Nanotechnology

Nanotechnology: General Information and Background

Nanomedicine:

Suggested applications in nanomedicine include:

Rapid cardiovascular repair

Treatments for pathogenic disease and cancer

Responses to physical traumas, with new methods of first aid

Surgery, and emergency or critical care

Neurography, spinal restoration and brain repair (nanostructures)

Nutrition and digestion

Reproductive modifications

Cosmetics

Sports and recreation – performance augmentation

Veterinary and space medicine

Strategies for biostasis and the control of aging processes;

human augmentation systems

By: Donald E. Marlowe

• Controlled molecular assembly : molecular assemblers will position molecules, bringing them together in a specific position, orientation, and sequence.

• By holding and positioning molecules, assemblers will control how the molecules react, building complex structures with atomically precise control.

• The parts are nanometer scale, and the transferred parts are just a few atoms large, shifting from handle to workpiece through a chemical reaction at a specific site.

• An assembler will work as part of a larger system that prepares tools, puts them on the conveyor, and controls the programmable positioning mechanism

The molecular-assembler concept

The molecular-assembler concept

• Their small moving parts will enable them to operate at high frequencies: because each motion traverses less than a millionth of a meter, each can be completed in less than a millionth of a second.

• This enables extremely high productivity.

• Machines of this sort will be complex systems that are several technology generations away. Indeed, no one is even trying to directly build molecular assemblers today, because nanotechnology is still in its infancy.

• We can see a path to assemblers and the early machines may resemble the small, simple productive nanosystems in nature and in biotechnology.

Molecular Manufacturing

• Molecular manufacturing will bring both great opportunities and great potential for abuse.

• Advanced systems could be used to build large, complex products cleanly, efficiently, and at low cost.

• Building with atomic precision, desktop-scale (and larger) manufacturing systems could produce the products like the following, with consequences for many global problems:

• Inexpensive, efficient solar energy systems, a renewable, zero-carbon emission source

• Desktop computers with a billion processors

• Medical devices able to destroy viruses and cancer cells without damaging healthy cells

• Materials 100 times stronger than steel

• Superior military systems

• More molecular manufacturing systems

Nanotechnology Molecular Manufacturing

Nanotechnology: General Information and Background

In Nanosystems, Dr. Drexler proposed and analyzed a variety of molecular

machines, including some too large to be specified and analyzed in atomic

detail. One such machine was a sorting rotor based upon modulated

receptors designed to bind and transport chemical species from a feedstock

solution. One of Dr. Drexler’s more recent projects has been to design in

atomic detail a simpler pump intended to provide some of the functionality of

the larger and more complex sorting rotors.

The pump and segment of chamber wall pictured here contain 6165 atoms.

Nanopore sensor

Nanopore Sensor

Applied voltage draws a DNA strand

and surrounding ionic solution

through a pore of nanometer

dimensions. The various DNA units

in the strand block ion flow by

differing amounts. In turn, by

measuring these differences in ion

current, scientists can detect the

sequence of DNA units. Atomistic

scale simulations performed on the

NASA Columbia supercomputer

(SGI Altix-3000) allow detailed study

of DNA translocation to enhance the

abilities of these sequencers. Solid-

state nanopores offer a better

temporal control of the translocation

of DNA, and a more robust template

for nano-engineering than biological

ion channels. The chemistry of solid-

state nanopores can be more easily

tuned to increase the signal

resolution. These advantages will

results in real-time genome

sequencing..

NASA Ames nanotechnology

Nanolasers

The complex interaction between light and nanometer structures, like wires, has possibilities as new

technology for devices and sensors. NAS researchers are studying light emission from a semiconductor

nanowire-typically 10-100 nanometers wide and a few micrometers long-which functions as a laser.

Lasers made from arrays of these wires have many potential applications in communications and sensing

for NASA.

NASA Ames nanotechnology

Nanowire

An engineered DNA strand between metal atom contacts

could function as a molecular electronics device.

Such molecules and nanostructures are expected to

revolutionize electronics. Understanding the

complex quantum physics involved via simulation

guides design.

AN ENGINEERED DNA STRAND

NASA Ames nanotechnology

Carbon Nanotubes - SEM Images

• Neural tree with 14 symmetric Y-junctions

• Branching and switching of signals at each junction similar to what happens in biological

neural network

• Neural tree can be trained to perform complex switching and computing functions

• Not restricted to only electronic signals; possible to use acoustic, chemical or thermal

signals

A novel data storage

system capable of

1015 bytes/cm2 is being

explored.

In this system, H atoms

would be designated as 0

and F atoms as 1.

A tip that can distinguish

between 0 and 1 rapidly

and unambiguously

is being investigated.

NASA Ames nanotechnology

Nano and BioTechnology Research at NASA Ames

M. Meyyappan and Harry Partridge

NASA Ames Research Center

Moffett Field, CA 94035

Abstract

This article provides an overview of nanotechnology and

biotechnology research at NASA Ames Research Center

and covers current results in the areas of carbon

nanotube (CNT) growth and characterization and

functionalization, nanotubes in scanning probe

microscopy, inorganic nanowires, biosensors, chemical

sensors, nanoelectronics optoelectronics, computational

nanotechnology, quantum device simulation, and

computational optoelectronics.

Link to Report