Top 10 Advances in Materials Science over 50 Years

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According to a report in magazine Today’s Materials on the 20th, over the past 50 years, significant breakthroughs have been achieved in the field of materials science, and some of these scientific achievements are changing—or have already changed—our lives. Among all these advancements, which ones can truly be considered the most important? Regarding such a highly specialized question, Today’s Materials provides a quite insightful answer. After consulting its editorial board and industry experts, the magazine compiled a list of the top 10 advancements in materials science over the past 50 years; those on this list not only arouse great interest but also prompt reflection. Of course, any kind of ranking is likely to spark controversy, especially when it comes to materials science. To minimize such disputes as much as possible, Today’s Materials adopted a relatively rational and balanced approach in making its selections; the top ten advancements listed include not only essential research findings but also various related research and development plans and guidelines. Surprisingly, what tops the list is not a specific research achievement, but rather a method for prioritizing research directions and formulating R&D plans—the \"International Semiconductor Technology Roadmap\". 　　It must be reminded that if you think material scientists are nothing but a group of unsung heroes, the list of the top ten advancements selected by Today’s Materials will certainly not receive the attention it deserves, nor will it spark enthusiasm among people. After all, the actual value of this ranking ultimately depends on your attitude toward materials science. Nevertheless, the rankings published by Materials Today are quite fair; the top ten innovations on the list are each changing our world in their own way. Here is the list of the top 10 advances in materials science over the past 50 years: 1. The International Semiconductor Technology Roadmap. Clearly, the International Semiconductor Technology Roadmap (ITRS) is not a specific research finding; rather, it is a method for identifying priority areas for research and formulating development plans. Nevertheless, it remains one of the most significant achievements in the field of materials science. By setting goals regarding innovation and technological needs, ITRS forces the microelectronics industry to engage in fierce competition, and there is only one outcome of such competition: progress. ITRS is the product of the integration of science, technology, and economics; it is hard to imagine anything that could drive the advancement of materials science more effectively than it does. The development of new materials, the manufacturing of products, and the design of equipment all benefit from it. The reason why ITRS has become the favorite of \"Materials Today\" is that electronics play a crucial role in the modern world, and the greatest achievement in materials science over the past 50 years lies in the continuous advancement of semiconductor processing technologies. 　　2. Scanning Probe Microscope This scanning tunneling microscope was invented by Heinrich Rohrer and Gerd Binnig from IBM’s research laboratory in Zurich; for this invention, the two were awarded the Nobel Prize in Physics in 1986. Scanning probe microscopy is a new type of microscopic technique; just this fact alone is sufficient to qualify it for inclusion on this list. What’s more important, however, is that the resolution of this microscope reaches the nanometer level. Not long after the invention of the scanning probe microscope, the atomic force microscope appeared, opening another door for people to enter the nanoworld. It has also played a significant role in the ongoing advancement of nanotechnology. 　　3. Giant Magnetoresistance Effect In 2007, French scientist Albert Fert and German scientist Peter Grünberg were awarded the Nobel Prize in Physics for their discovery of the giant magnetoresistance effect in 1988; therefore, it is not surprising at all that it is included in the list of the top ten advancements. The so-called giant magnetoresistance effect refers to the fact that when an external magnetic field changes, the resistance in thin films (a few nanometers thick) composed of magnetic and non-magnetic materials undergoes a significant change. Thanks to the efforts of IBM’s research laboratories, the giant magnetoresistance effect ultimately brought about a revolutionary change in hard drive read heads – read heads utilizing this technology are able to detect the magnetic information stored on hard drives by detecting changes in electric current. Due to its high sensitivity to weak magnetic fields, the giant magnetoresistance effect enables hard drive platters to become significantly thinner. As a result, the size of hard drives has continued to shrink, while their capacity has kept increasing. 　　4. Semiconductor lasers and light-emitting diodes Semiconductor lasers and light-emitting diodes were introduced in 1962, and their emergence was an important event in the history of materials science. Without this guy, long-distance communication, CD and DVD players, laser printers, barcode readers, and solid-state lighting devices would remain just a dream. It is worth mentioning that the advent of solid-state lighting devices can make a significant contribution to reducing energy consumption. 　　5. U.S. **Nanotechnology Initiative In 2000, President Clinton unveiled the details of the **Nanotechnology Initiative. This plan had a tremendous impact; it reinforced the importance of nanotechnology as an emerging field, and it also made this technology one of the most exciting areas in physics. **The Nanotechnology Program has provided substantial funding for the development of nanotechnology, and it has also opened up new avenues for raising funds for interdisciplinary research; this is undoubtedly a significant stimulus and influence for other parts of the world. **The nanotechnology program involves 26 separate institutions, with the research budget for 2008 estimated at around $15. It is the largest \"single investor\" in the field of nanotechnology research worldwide, having invested over $7 billion in the past 7 years. At present, 65 **have formulated similar nanotechnology research plans, and research and development in this field is already at the **leading level. In 2007, global R&D spending related to nanotechnology exceeded $12 billion. 　　6. Carbon fiber reinforced plastics Nowadays, modern synthetic materials are used in every aspect of life; we can find them in industries such as aerospace, transportation, packaging, and civil engineering. Among all synthetic materials, carbon fiber reinforced plastics undoubtedly play a leading role. Carbon fiber reinforced plastic is a matrix-free polymer formed from high-strength, high-hardness carbon fibers; it not only possesses high strength but is also lightweight. As early as the early 1960s, scientists began producing carbon fibers using rayon, polyacrylonitrile, and pitch-based precursors. The long, aligned aromatic compound molecular chains confer higher strength and hardness to carbon fibers. Thanks to the continuous development of carbon fiber technology and the advancements in design, manufacturing, and modeling, synthetic materials can now have controllable properties. Despite its high cost and the various difficulties encountered in its design, manufacturing, and recycling, carbon fiber reinforced plastics are being used more and more due to these advantages; the wings and fuselage of the new Boeing 787 aircraft are made from this material. 　　7. Lithium-ion battery materials It is hard to imagine what laptops and smartphones would be like without lithium-ion batteries—rechargeable batteries that use aqueous electrolytes cannot be compared to lithium batteries, which have a higher energy density. Lithium batteries emerged based on new types of electrode materials that can meet various requirements; to enhance usability, their cathodes feature a hollow structure to reduce weight. The research on lithium battery materials involves chemistry and electrochemistry. In the 1980s, John Goodenough of Oxford University and his colleagues, through relentless efforts, finally developed the negative electrode material LiCoO2. In 1991, Sony developed a carbon-based positive electrode material; by combining these two materials, we obtained the lithium-ion battery that made portable devices possible. Currently, research on anode materials for lithium-ion batteries is still ongoing. To protect the environment and increase energy density, researchers have abandoned toxic Co in favor of three-dimensional structures similar to LiFeO4. 　　8. Carbon nanotubes The discovery of carbon nanotubes in 1991 is attributed to Sumio Iijima of NEC, but scientists had observed them prior to that. In 1985, scientists discovered a new form of carbon during an experiment – the C60 buckyball. Although the excitement from this discovery had not yet subsided, Sumio Iijima’s observations of new fullerenium tubes piqued the scientists’ great interest. Due to their unique properties, these nanoscale carbon structures have become one of the hottest topics in the field of materials science. Carbon nanotubes are ranked eighth because we still need to make considerable efforts to achieve their synthesis, purification, large-scale production, and ultimately their integration into relevant devices. Furthermore, we are still unable to produce uniform samples of carbon nanotubes with identical properties. 　　9. Soft Etching Soft etching technology actually makes use of a simple old method – printing patterns based on a reusable stamp. This technology can be applied to many different substrates, whether they are flat, curved, or flexible. More importantly, this technology is inexpensive, can achieve a resolution as precise as nanometers, and can be applied to emerging fields such as bioprocessing. The original microcontact printing technology was developed in 1993 in the laboratory of Joe Zhi-Whitesides at Harvard University. Using this technology, we can print out precise molecular patterns – with components as small as 30 nanometers – while also enabling the transfer of organic molecules. Furthermore, microcontact printing technology can also be used to directly print solid materials, thereby extending its applications into the field of nanofabrication. Since 1993, microcontact printing has evolved into a complete set of printing, molding, and embossing techniques, vividly referred to as \"soft etching\". All of these methods require the use of a flexible stamp to reproduce the pattern of the master plate. 　　10. Metamaterials: An exciting development at the beginning of the new millennium was the discovery that materials with a negative refractive index actually exist – these are what we call “metamaterials”. In the 1960s, Soviet scientist Fislag predicted that materials with both negative permeability and negative permittivity could possess a negative refractive index. Today, this prediction has become a reality: as light or microwaves pass through metamaterials, they bend in the “wrong direction”. The first type of supermaterial is a composite made up of metal wires and open loops, installed on a printed circuit board lattice; it is an artificial structure composed of repeating micro-components, designed to possess special properties. It is crucial that, even if the structure of a supermaterial is much smaller than the wavelength of light, we can still use Maxwell’s electromagnetic theory to describe its electromagnetic responses: the structure of fine metal wires generates negative electrical responses at gigahertz frequencies ； The open-loop structure generates a negative magnetic response. In 2000, David Smith, Willie Padilla, and Sherry Scutts from the University of California, San Diego, combined these structures for the first time to create metamaterials with a negative refractive index. This post was last edited by QXZ-1966 on 2009-2-7 22:46.]