mindmap root((NANO)) nanotechnology The science of manipulating materials on an atomic or molecular scale, especially to build microscopic devices such as robots.
🌱Nanotechnology is now seen as contributing to numerous environmental solutions, from cleaning up hazardous waste sites to producing strong but lightweight materials for auto bodies. 🌳Nanotechnology, or nanotech for short, deals with matter at a level that most of us find hard to imagine, since it involves objects with dimensions of 100 billionths of a meter （1/800th of the thickness of a human hair） or less. The chemical and physical properties of materials often change greatly at this scale. Nanotechnology is already being used in automobile tires, land-mine detectors, and computer disk drives. Nanomedicine is a particularly exciting field: Imagine particles the size of a blood cell that could be released into the bloodstream to form into tiny robots and attack cancer cells, or "machines" the size of a molecule that could actually repair the damaged interiors of individual cells. nanosecond One billionth of a second.
🌱When he finally asked if she would marry him, it took her about a nanosecond to say yes. 🌳The nonserious use of nanosecond is probably much more common than the proper technical use. In measurement terms such as nanosecond, nanogram, and nanometer, nano- means "billionth"; in other kinds of words, its meaning isn't quite so precise. In computers, the speed of reading and writing to random access memory （RAM） is measured in nanoseconds. By comparison, the speed of reading or writing to a hard drive or a CD-ROM player, or for information to travel over the Internet, is measured in milliseconds （thousandths of a second）, which are a million times longer than nanoseconds. nanostructure An arrangement, structure, or part of something of molecular dimensions.
🌱In the 1990s the physics department, which had been doing extensive research on microstructures, began to get deeply involved in nanostructures, including nanofoam, nanoflakes, and nanofibers. 🌳Two important types of nanostructure are nanocrystals （tiny crystals, often of semiconducting material） and nanotubes （tiny tubes, usually of pure carbon）. Nanocrystals made from semiconductors change color depending on their size, and are being used for such tasks as detecting viruses in living cells. Nanotubes can conduct enormous amounts of electrical current, far more than metal wires. They are the basic material of tiny "paper" batteries, which can be rolled, folded, or cut while still producing power. Nanotubes are also now being used in materials for lightweight tennis rackets and golf clubs, and may soon enable the manufacture of TV screens no thicker than a film. nanoparticle A tiny particle whose size is measured in billionths of a meter.
🌱Nanoparticles of iron are being used to clean up soil pollution, helping break down molecules of dangerous substances into simple compounds. 🌳Nanoparticles of a material usually have very different qualities from those that the material has at its ordinary scale, which is one reason why there's such excitement about the possibilities for how they might be used in future technologies. Many uses have already been developed. Aluminum nanoparticles added to rocket fuel can make the fuel burn twice as fast and release much more energy. Silicon nanoparticles are increasing the energy efficiency of solar cells by allowing the energy from ultraviolet light to be captured for the first time. Other nanoparticles are now helping prevent rust in metals, produce stronger batteries, enhance the diagnosis of cancer, and improve the filtering of water, and the number of other applications is growing fast.