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 repairTreatments for pathogenic disease and cancerResponses to physical traumas, with new methods of first aidSurgery, and emergency or critical careNeurography, spinal restoration and brain repair (nanostructures)Nutrition and digestionReproductive modifications Cosmetics Sports and recreation – performance augmentationVeterinary and space medicineStrategies 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

NanolasersThe 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 unambiguouslyis being investigated.

NASA Ames nanotechnology

Nano and BioTechnology Research at NASA AmesM. Meyyappan and Harry Partridge

NASA Ames Research CenterMoffett Field, CA 94035

AbstractThis 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, andcomputational optoelectronics.

Link to Report