Exotic scientific discoveries of our era-3

Nano-technology:

The world demand for energy is expected to double to 28 terawatts by the year 2050. Compounding the challenge presented by this projection is the growing need to protect our environment by increasing energy efficiency and through the development of “clean” energy sources. These are indeed global challenges, and their resolution is vital to our energy security. Recent reports on Basic Research Needs to Assure a Secure Energy Future and Basic Research Needs for the Hydrogen Economy have recognized that scientific breakthroughs and truly revolutionary developments are demanded. Within this context, nanoscience and nanotechnology present exciting and requisite approaches to addressing these challenges.

An interagency workshop to identify and articulate the relationship of nanoscale science and technology to the U.S's energy future was convened on March 16-18, 2004 in Arlington, Virginia. The meeting was jointly sponsored by the Department of Energy and, through the National Nanotechnology Coordination Office, the other member agencies of the Nanoscale Science, Engineering and Technology Subcommittee of the Committee on Technology, National Science and Technology Council. This report is the outcome of that workshop.

The workshop had 63 invited presenters with 32 from universities, 26 from national laboratories and 5 from industry. This workshop is one in a series intended to provide input from the research community on the next NNI strategic plan, which the NSTC is required to deliver to Congress on the first anniversary of the signing of the 21st Century Nanotechnology R&D Act, Dec. 3, 2003.
At the root of the opportunities provided by nanoscience to impact our energy security is the fact that all the elementary steps of energy conversion (charge transfer, molecular rearrangement, chemical reactions, etc.) take place on the nanoscale. Thus, the development of new nanoscale materials, as well as the methods to characterize, manipulate, and assemble them, creates an entirely new paradigm for developing new and revolutionary energy technologies. The primary outcome of the workshop is the identification of nine research targets in energy-related science and technology in which nanoscience is expected to have the greatest impact:

• Scalable methods to split water with sunlight for hydrogen production
• Highly selective catalysts for clean and energy-efficient manufacturing
• Harvesting of solar energy with 20 percent power efficiency and 100 times lower cost
• Solid-state lighting at 50 percent of the present power consumption
• Super-strong, light-weight materials to improve efficiency of cars, airplanes, etc.
• Reversible hydrogen storage materials operating at ambient temperatures
• Power transmission lines capable of 1 gigawatt transmission
• Low-cost fuel cells, batteries, thermoelectrics, and ultra-capacitors built from nanostructured materials
• Materials synthesis and energy harvesting based on the efficient and selective mechanisms of biology

The report contains descriptions of many examples indicative of outcomes and expected progress in each of these research targets. For successful achievement of these research targets, participants recognized six foundational and vital crosscutting nanoscience research themes:

• Catalysis by nanoscale materials
• Using interfaces to manipulate energy carriers
• Linking structure and function at the nanoscale
• Assembly and architecture of nanoscale structures
• Theory, modeling, and simulation for energy nanoscience
• Scalable synthesis methods

Discovery of carbon nano-tubes:

In 1991, Sumio Iijima of NEC, Japan observed multiwall nanotubes formed in a carbon arc discharge, and two years later, he and Donald Bethune at IBM independently observed single-wall nanotubes – buckytubes. The important observation of these nano-tubes is that their physical and electrical properties are drastically different from materials of the same element in macroscopic scale. The biggest impact of carbon nano-tubes is expected to be in what is called carbon-based electronics as against the present silicon-based electronics. The carbon-based electronics is expected to achive very high packing densities of components in integrated circuits and increase the speed of operation enormously. With silicon both packing densities and speed of operation have reached a saturation.

Nanotechnology gives sensitive read-out heads for compact hard disks:

This year's physics Nobel prize is awarded for the technology that is used to read data on hard disks. It is thanks to this technology that it has been possible to miniaturize hard disks so radically in recent years. Sensitive read-out heads are needed to be able to read data from the compact hard disks used in laptops and some music players, for instance.

In 1988 the Frenchman Albert Fert and the German Peter Grünberg each independently discovered a totally new physical effect – Giant Magnetoresistance or GMR. Very weak magnetic changes give rise to major differences in electrical resistance in a GMR system. A system of this kind is the perfect tool for reading data from hard disks when information registered magnetically has to be converted to electric current. Soon researchers and engineers began work to enable use of the effect in read-out heads. In 1997 the first read-out head based on the GMR effect was launched and this soon became the standard technology. Even the most recent read-out techniques of today are further developments of GMR.

A hard disk stores information, such as music, in the form of microscopically small areas magnetized in different directions. The information is retrieved by a read-out head that scans the disk and registers the magnetic changes. The smaller and more compact the hard disk, the smaller and weaker the individual magnetic areas. More sensitive read-out heads are therefore required if information has to be packed more densely on a hard disk. A read-out head based on the GMR effect can convert very small magnetic changes into differences in electrical resistance and there-fore into changes in the current emitted by the read-out head. The current is the signal from the read-out head and its different strengths represent ones and zeros.

The GMR effect was discovered thanks to new techniques developed during the 1970s to produce very thin layers of different materials. If GMR is to work, structures consisting of layers that are only a few atoms thick have to be produced. For this reason GMR can also be considered one of the first real applications of the promising field of nanotechnology.