超精密工程与纳米技术英文文献和中文翻译(3)
From all that above mentioned, a big question arises.Which is the future of nanotechnology?, see Fig. 5. Thereis not a straightforward answer, since the future of nanotech-nology lies somewhere between science and fiction. The newapplications and devices that are currently under investiga-tion by scientists and engineers, promise to bring revolutionto each field they will be applied.Nanotechnology has already a profound place in manufac-turing in many fields of science and engineering. It appearsthat the computer science and medicine may be most likelyaffected, since they both are directed towards molecular scalemanipulation of matter. Nevertheless, other fields of applica-tion, like materials science, automotive industry and spaceresearch, will be greatly benefited from the evolution of nan-otechnology.In the field of computer science, new quantum comput-ers are designed. Automotive and aerospace industry havea demand for “systems-on-a-chip”, in which miniaturizationallows all electronic systems, like computer, memory, guid-ance, navigation, communication, power, sensors, actuators, A.G. Mamalis / Journal of Materials Processing Technology 161 (2005) 1–9 5 to fit on a tiny chip. Such systems cannot be materialized withpresent technologies, but their deployment will lead to a newera of computer and aviation systems, space transportationand exploration. The expectation of such systems is to re-duce the cost of air transportation and make them even morereliable.Another area the scientists are turned to is biotechnol-ogy, which can be considered as the application of biolog-ical knowledge and techniques to produce innovative mate-rials, devices and systems. There is a great overlap amongbiotechnology, nanotechnology and information technology.The coupling of these technologies with other leading edgeaerospace technologies can produce breakthroughs in vehi-cle concepts, enable new science, introduce new computersystems, and improve communications, transportation andhealth care.The future medical aspects of nanotechnology concentrateon the combination of mechanical and electrical systems withhuman cells and tissues. A great expectation is also the mini-mization of invasive surgery. New miniaturized machines willenter the human body, focus on the damaged area and proceedwith its healing task. The development of new biocompati-ble materials will permit the replacement of damaged nervesby artificial equivalents, the restoration of hearing or sightand the improved adhesion of living tissue cells on prostheticimplants.Interest in nanotechnology is greatly increasing world-wide leading to an extensive research funded each year. TheUSA and Japan are the leading forces of nanotechnologyresearch, but Europe and other countries are also moving to-wards this kind of technology due to its increasing demand.The Virtual Institute VISION On-Line, built upon the presentactivities of the European Society for Precision Engineeringand Nanotechnology, is constituted from regional centers inUK, France, Germany and Italy and official national nodes inSpain, Greece, Netherlands, Belgium, Finland, Canada andJapan, with a clear focus to “on-line” technical assistance, ed-ucation and training, addresses a range of “on-line” servicesto promote industrial growth in the ultraprecision technolo-gies, including ultraprecision engineering, microengineeringand microelectronics, microelectromechanical systems, nan-otechnology and the support precision technologies, nano andprecision metrology. The new and expanding markets of thesetechnologies are demanding miniaturized, more reliable andcustomized devices at ever-increasing rates and reduced cost.A comprehensive review on nanotechnology is presentedin Ref. [5].3. Nanostructured materialsNanotechnology processes made possible the manipula-tion of atoms and, therefore, the design and manufacture ofthe nanostructured materials. Materials often behave in adifferent way when they are nanostructured. This is accom-plished by having every atom or molecule in a designated location. The resulting materials and systems can be ratio-nally designed to exhibit novel and significantly improvedoptical, chemical, mechanical and electrical properties.3.1. Carbon nanotubesThe newly invented third type of carbon, after graphiteand diamond, the C60, may be used as a dry lubricant in me-chanical applications. Carbon nanotubes [6] are promisingbuilding blocks for nanosystems; they consist of honeycomblattices, rolled into cylinders with Atomic Force Microscopy,having a nanometer-scale diameter and length of about a mi-cron. Their weight is about one-sixth of the weight of steel, theYoung’s modulus about five times and their tensile strengthmore than 100 times those of steel. They are even strongerthan diamond, because their carbon-carbon band lengths areshorter than the related ones in diamond. A potential structureof a nanotube system is shown in Fig. 6. Such materials arevery light and, at the same time, very strong and, therefore,they can be used as structural materials for aerospace andbone surgery applications. Furthermore, due to their currentcarrying capacity (for example, the current carrying capac-ity of nanometer-scale carbon wires is about 100 thousandtimes better than that of copper) they are suitable for applica-tions in integrated circuits for performing functions currentlyperformed by semiconductor devices in electronic circuits.3.2. NanoparticlesNanoparticles have larger active surfaces per unit volumeand mass, exhibiting greater chemical activity and, therefore,they can be used as catalysts. Nanostructured materials canalso be built in such a way that they will be biocompatiblefor implants.