According to laws of quantum mechanics a physical entity may possess either particle-like or wave-like properties. A particle exhibits wave properties when one cannot tell the path the particle may take among different paths available. Once the path information is obtained, however, the wave-like properties of a particle are supposed to disappear. In any case, it is not possible to observe both the wave and particle properties simultaneously, which is known as complementarity of a physical entity. In early days around the advent of quantum mechanics the concept of complementarity was considere..
The invention of the scanning tunnel microscope (STM) opened the door to nanoworld, enabling humankind to actually touch and feel the individual atoms at the surface of a material. It has inspired a series of inventions such as the atomic force microscope (AFM), the lateral force microscope (LFM), the magnetic force microscope (MFM), etc. Recently, the scanning probe microscope (SPM), which encompasses all these inventions, has evolved into the millipede technology which has a potential to make competing data storage technologies obsolete. A common denominator of these exciting developments is..
A research team of Department of Life Science’s Center for Biomolecular Recognition and Division of Molecular and Life Science, consisting of Professor Byung-Ha Oh, Doctor Jae-Sung Woo, and Doctor Jae-Hong Lim, has solved secrets of the ring-shaped molecular structure of the MukBEF condensin, the key mediator of chromosome condensation.In eukaryotic organisms, chromosomes are found in the nucleus of every cell. Before cell division, chromosomes are condensed, and the two replicated copies of the chromosomes are partitioned into the two daughter cells. In prokaryotic organisms, chromosome..
Direct printing of functional electronic materials may provide a promising route to low-cost fabrication of integrated circuits. From this point of view, ink-jet printing has received special attention as a direct patterning technique for the cost-effective fabrication of organic electronic devices such as organic thin-film transistors (OTFTs) (Figure 1) and organic photovoltaic cells. Professor Kilwon Cho and Ms. Jung Ah Lim of the Department of Chemical Engineering have succeeded in fabricating high-performance OTFTs by inkjet printing of organic semiconductor. This result entitled “Se..
X-ray imaging shows in real-time and in in-vivo that intensive irradiation of x-rays significantly decreases the surface tension of water in droplets and capillary tubes. X-rays are used in a variety of experimental studies of liquids, in particular, of water. The present synchrotron sources allow intense irradiation, possibly enabling to alter the basic property of surface tension. In spite of its potential impact, this issue has been still unexplored. In 1896 Wilson roughly showed that x-rays ionized the air molecules, and the electrons and ions created cloud nuclei in a cloud chamber. His c..
The way to prevent intra-operative awareness has been paved by joint efforts of medical science and physics. Intra-operative awareness, familiarized through some thriller movies, is a unique physiological phenomenon which causes the patient under general anesthesia to recover consciousness during surgery. The patient experiencing intra-operative awareness may feel the pain or pressure of surgery, hear conversations, or feel as if he cannot breathe, but may be unable to communicate any distress because he has been given a paralytic or muscle relaxant.Professor Seunghwan Kim (Department of Physi..
Professor Kilwon Cho and Doctor Ho Sun Lim of the Department of Chemical Engineering discovered the smart surface that can switch reversibly from extreme water-hating (superhydrophobic) to dramatic water-loving (superhydrophilic) via exposure to ultraviolet or visible light (J. Am. Chem. Soc., 2006, 128, 14458). Recently, this smart surface was introduced with the subject, “Self-Cleaning Materials: Lotus Leaf-Inspired Nanotechnology” in a hot issue of materials science field in Scientific American. The lotus grows in muddy water, but its leaves, when they emerge, are seemingly neve..
Spin-valve devices are a key component of a magnetoresistive random access memory. Mr. Woo Youn Kim and Professor Kwang Soo Kim of Department of Chemistry of POSTECH predicted supermagnetoresistance in a graphene nanoribbon device, the article of which has appeared in Nature Nanotech (3, 408-412, 2008). The reported graphene nanoribbon spin-valve device shows extremely large magnetoresistance (ten thousand times larger than that of conventional devices), which promises high speed access, and good sensitivity. The striking enhancement originates from the peculiar symmetry of band structures of ..
Professor Seung-Hoon Jhi and Ph.D. Candidate Seon-Myeong Choi, both of the Department of Physics, in their study of metal doped graphene nanoribbons, discovered that the adsorbed metal atoms form atomic chains which can be used as reagents to identify the edge atomic structures of the graphene nanoribbons and also as gate-driven spin valves to control the spin current in graphene nanoribbons. Graphene, the basic structural element of all graphitic materials including graphite, carbon nanotubes and fullerenes, is a one-atom-thick planar sheet of carbon atoms that are densely packed in a honeyco..
Ultrahigh density arrays of conducting polymer nanorods have been fabricated through a joint research project by Professors Jin Kon Kim and Su-Moon Park of Pohang University of Science and Technology (POSTECH), Dr. Jae-Woong Yu of Korea Institute of Science and Technology (KIST), and Professor Thomas P. Russell of the University of Massachusetts at Amherst, U.S.A., as reported in Nano Letters, vol. 8, 2315-2320 (2008). Nanoporous templates, for instance, track-etched polymer membrane and anodized aluminum oxide (AAO) membrane, have been widely used to prepare conducting polymer nanotubes, nano..