Nanotechnology: a bird view

1. What is Nanotechnology?

Nanotechnology is the creation of functional materials, devices and systems through control of matter on the nanometer length scale (1-100 nanometers), and exploitation of novel phenomena and properties (physical, chemical, biological, mechanical, electrical...) at that length scale. For comparison, 10 nanometers is 1000 times smaller than the diameter of a human hair. A scientific and technical revolution has just begun based upon the ability to systematically organize and manipulate matter at nanoscale. Payoff is anticipated within the next 10-15 years.

The essence of nanotechnology is the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization. Compared to the behavior of isolated molecules of about 1 nm or of bulk materials, behavior of structural features in the range of about 1 to 100 nm exhibit important changes. Nanotechnology is concerned with materials and systems whose structures and components exhibit novel and significantly improved physical, chemical, and biological properties, phenomena, and processes due to their nanoscale size. The goal is to exploit these properties by gaining control of structures and devices at atomic, molecular, and supramolecular levels and to learn to efficiently manufacture and use these devices. Maintaining the stability of interfaces and the integration of these "nanostructures" at micron-length and macroscopic scales are all keys to success. New behavior at the nanoscale is not necessarily predictable from that observed at large size scales. The most important changes in behavior are caused not by the order of magnitude size reduction, but by newly observed phenomena intrinsic to or becoming predominant at the nanoscale. These phenomena include size confinement, predominance of interfacial phenomena and quantum mechanics. Once it becomes possible to control feature size, it will also become possible to enhance material properties and device functions beyond what we currently know how to do or even consider as feasible. Being able to reduce the dimensions of structures down to the nanoscale leads to the unique properties of carbon nanotubes, quantum wires and dots, thin films, DNA-based structures, and laser emitters. Such new forms of materials and devices herald a revolutionary age for science and technology, provided we can discover and fully utilize the underlying principles.

2. Various aspects of nanotechnology

Nanostructured materials: a broad class of materials, with microstructures modulated in zero to three dimensions on length scales less than 100 nm; materials with atoms arranged in nano clusters, which become the constituent grains or building blocks of the material; any material with at least one dimension in the 1-100m range. Nanocrystals, nanowires, nanotubes, nanorods, nanoparticles, biomolecules, nanostructured polymer, nanostructured coatings and nanocatalysis are all nanostructured materials:

Nanofabrication:

Nanomanipulation:

Nanolithography:

Nanosensors:

Quantum behaviors and scaling limit of CMOS:

Nanoelectronics:

Nanophotonics: Nanophotonics is the manipulation of light at a spatial scale smaller than its wavelength, and includes both photonic crystals

Nanomechanics:

Nanomagnetics: Molecular complexes with a net magnetic moment can be considered as single domain nano scale magnets. However, in technological applications (e.g. data storage), such molecular magnets may suffer from poor magnetic densities. Magnetic network materials (“crystal engineering”), where magnetic centers are combined with organic linker molecules in three dimensional nano porous structures are being studied. These materials have great structural flexibility due to the variable coordination chemistry of the transition metal centers. Through changes in the ligands it is possible to control the magnetic properties of the material (Wilson et al, JACS 2000, 122, 11370).

Nanochemistry:

Nanobiotechnology:

Nanoinstrumentation:

Nanoscale Modeling and Simulation: