Trends In Nanotechnology Research Articles

Nanotechnology - An Opportunity of Building Materials’ Development

After a few years of lots of researchers working for nanotechnology, and with enormous amounts of money invested in its research and development, the impact of nanotechnology on every walk of life becomes profound. In this study, it is demonstrated that the traditional industries, such as building materials industry may have a good opportunity to develop. Furthermore, nano-cement and nano-paint are introduced as the outstanding representations to prove the above point. And the predicted trend of nanotechnology using in building materials is presented.

Editorial: Trends in Nanotechnology (TNT2005)

AbstractThis special issue of physica status solidi (a) presents representative contributions describing the main topics covered at the sixth “Trends in Nanotechnology” (TNT2005) International Conference, held in Oviedo (Spain), 29 August–2 September 2005.During the last years many international or national conferences have emerged in response to the growing awareness of the importance of nanotechnology as key issue for the future scientific and technological development. Among these, the conference series “Trends in Nanotechnology” has become one of the most important meeting points in the nanotechnology field: it provides fresh organisation ideas, brings together well known speakers, and promotes a suitable environment for discussions, exchanging ideas, enhancing scientific and personal relations among participants. TNT2005 was organised in a similar way to the five prior TNT conferences, with an impressive scientific programme including 40 Keynote lectures and two Nobel prizes, without parallel sessions, covering a wide spectrum of Nanotechnology research. In 2005, more than 360 scientists worldwide attended this event and contributed with more than 60 oral contributions and 250 posters, stimulating discussions about their most recent research.The aim of the conference was to focus on the applications of Nanotechnology and to bring together, in a scientific forum, various worldwide groups belonging to industry, universities and government institutions. TNT2005 was particularly effective at transmitting information and establishing contacts among workers in this field. Graduate students attending such conferences have understood the importance of interdisciplinary skills to afford their future research lines. 76 graduate students received a grant allowing them to present their work. 28 prizes to the best posters were awarded during this event. We would like to thank all the participants for their assistance, as well as the authors for their written contributions.TNT2005 is the successful consequence of a coordinated effort among several organising Institutions: PHANTOMS Foundation, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Universidad Carlos III de Madrid, Universidad Complutense de Madrid, Universidad de Oviedo, Donostia International Physics Center, Nanomaterials Laboratory‐NIMS, CEA/LETI and CEA/DSM/DFRMC, University of Purdue and Georgia Institute of Technology. In addition, we are indebted to the following institutions, companies and government agencies for their help and financial support: NASA, Air Force Office of Scientific Research, iNANO, NSERC/CRSNG (Nano Innovation Platform), Sociedad de Microscopía Española (SME), Wiley‐VCH, Raith GmbH, The European Office of Aerospace Research and Development (EOARD), The Office of Naval Research International Field Office (ONRIFO), World Scientific and Imperial College Press, Ministerio de Educación y Ciencia, Parque Científico de Barcelona, Parque Científico de Madrid, Tyndall National institute, Nanoquanta, GDR‐E Nano‐E, Minatec, Dupont, Physica Status Solidi, Zeiss, Ayuntamiento de Oviedo, Gobierno de Principado de Asturias, Asturiana de Zinc, cajAstur, Aleastur, Aceralia‐Grupo Arcelor, Saint‐Gobain Cristaleria, Mediadores Asociados Asturianos and Inderscience Publishers.We would like also to thanks the following companies for their participation: NanoTec, Raith GmbH, Scientec, NT‐MDT, Schaefer Techniques, Suss Microtec, Carl Zeiss, Biometa, Wiley‐VCH, World Scientific and Imperial College Press and Atomic Force.We invite readers of this special issue to join us in Grenoble (France), where the next “Trends in Nanotechnology” 2006 edition will take place (http://www.tnt2006.org).

Carbon nanotubes and nucleic acids: tools and targets

AbstractNucleic acids are playing an important role in the rapid development of nanotechnologies. Our Editor's Choice [1] discusses the use of nucleic acids to disperse and sort single walled carbon nanotubes (SWNTs). The cover picture shows a two‐dimensional photoluminescence (PL) spectrum of highly purified (6,5) SWNT:DNA hybrids. The fine resolution of the PL peaks displays photo‐excited intermediates in a range of energies between ES22 and ES11 transitions revealing for the first time specific phonon‐assisted optical absorption and energy relaxation mechanisms.The first author, Bibiana Onoa, has been working on carbon nanotubes and nucleic acids in the molecular electronics group of Dupont Central Research and Development. Her current research focuses on the development of nanotechnologies that allow fast and economical detection of pathogens.This special issue of physica status solidi (a) presents representative contributions and main topics on “Trends in Nanotechnology” from the TNT2005 International Conference in Oviedo (Spain).

Numerical simulation of ballistic magnetoconductance and magnetic focusing in strainedSi–SiGe cavities

We present numerical simulations of the transport properties of a ballistic cavity connectedto two leads in the presence of a finite degree of decoherence. The cavity is obtainedby realizing a ‘quantum chicane’, i.e., by shifting a short section of a quantumwire defined by etching on a SiGe heterostructure. We compare our results withexperiments by Scappucci et al (2004 Trends in Nanotechnology (Segovia, Spain,Sept. 2004) unpublished) and show that the magnetoconductance features can bereproduced if we use a recently developed model that includes decoherence with aphenomenological statistical description. Otherwise, simulations based on completelycoherent transport would provide a much richer structure of magnetoconductance, that inexperiments is smoothed out by dephasing processes. In particular, we recoverexperimental features of the magnetoconductance such as magnetic focusing andShubnikov–de Haas oscillations. By computing the local partial density of states of thesystem at different values of the external field we recover the semiclassical orbits.

Status and trends of nanotechnology R&D in Japan.

Intense competition exists in the realm of research and development in nanotechnology. The government of Japan, one of the countries most advanced in this field, has been actively promoting this form of R&D in cooperation with industrial and academic circles. The hope is that success in nanotechnology will also revitalize Japan's economy. Here, we outline the current status of national projects and future trends of nanotechnology in Japan.

Response to Comment on "Single Crystals of Single-Walled Carbon Nanotubes Formed by Self-Assembly"

Our study ( [1][1] ) described a new technique that allowed for the precise targeting of chemical precursors to specific surface sites with nanometer-range accuracy. One of our aims was to control both the site and growth process of single-walled carbon nanotubes (SWCNTs) by depositing controlled mixtures of C60 and metal catalyst through a moveable shadow mask, followed by annealing to form single-walled nanotubes (SWNTs), a growth process with proven efficacy. We applied the technique to a number of substrates including molybdenum grids to allow for transmission electron microscopy (TEM) and electron energy loss studies. Although anticipating that the molybdenum would further catalyze the SWNT growth, we did not anticipate the degree to which the surface chemistry of the grids would dominate the resultant structures. Shortly after the publication of ( [1][1] ), we recognized the problems associated with the Mo grids on the interpretation of our data, having carried out a detailed high-resolution energy loss and Raman study of the growth process. We reported the results of this study widely ( [2][2] – [5][3] ). The comment by Chisholm et al . ( [6][4] ) independently confirms our previous findings, and we are able to add some further detail as a result of our subsequent studies. We followed the growth process by varying both temperature and time of annealing of the C60/nickel structures, recording Raman spectra and electron energy loss spectra. The former provided the greater insight. Briefly, Raman spectra were taken with two laser energies, 2.41 eV and 1.58 eV. During the very early stages of growth after the exfoliation of the C60, all the characteristic vibrational modes expected for SWCNTs were observed. The first-order features consisted of a G peak around 1590 cm–1, corresponding to the high-energy (∼ 0.2 eV) tangential modes (TM) of SWCNTs, and a D peak around 1300 cm–1, consistent with a disorder mode in SWCNTs. The G mode was very narrow, with a full-width at half maximum (FWHM) of about 13 cm–1. The low-energy radial breathing modes (RBM) of SWCNTs were not resolvable because the chemically complex substrates gave contributions in this frequency range of the Raman spectra. Their presence was, however, indirectly demonstrated by their involvement in combination modes in the second-order spectra. Raman spectra consistent with SWCNTs were, however, observed only fleetingly during the growth process, so that the combination modes involving the RBM modes were rapidly lost, while the others—the D and G modes and their overtones—transformed into their nanocrystalline graphite (nc-C) counterparts. Thus, the resultant structures obtained on Mo grids after annealing at the times and temperatures reported in the original paper were based not on SWNTs but on a complex of molybdenum, as detailed by Chisholm et al . ( [6][4] ). The only area in which we would take issue with the Chisholm et al . comment is in the origin of the carbon edge in the energy loss spectrum as originally reported, which we would argue is at least partially residual carbon as inferred by the Raman study above. Although the shadow mask technique remains a unique method to fabricate nanostructures at controlled surface sites, including the growth of CNTs, we accept that our conclusion of the growth of single crystals containing SWCNTs was mistaken. In particular, in the case of the Mo substrates the complex surface chemistry resulting from the manufacturing process dominates the final nanostructures observed. 1. [↵][5] R. R. Schlittler et al ., Science 292, 1136 (2001). [OpenUrl][6][Abstract/FREE Full Text][7] 2. [↵][8] A. Ilie, C. Durkan, M. S. M. Saifullah, M. E. Welland, J. K. Gimzewski, paper presented at Trends in Nanotechnology, Segovia, Spain, 3 to 6 September 2001. 3. J. W. Seo, paper presented at XVI International Winterschool on Electronic Properties of Novel Materials, Kirchberg, Austria, 2 to 9 March 2002. 4. C. Durkan, A. Ilie, M. S. M. Saifullah, M. E. Welland, Appl. Phys. Lett. 80, 4244 (2002). [OpenUrl][9] 5. [↵][10] J. W. Seo, H. Siegwart, L. Forro, American Physical Society March Meeting 2003, Austin, Texas, 3 to 7 March 2003, abstract A26.008. 6. [↵][11] M. S. Chisholm et al ., Science 300, 1236 (2003); [www.sciencemag.org/cgi/content/full/300/5623/1236b][12]. [OpenUrl][13] [1]: #ref-1 [2]: #ref-2 [3]: #ref-5 [4]: #ref-6 [5]: #xref-ref-1-1 View reference 1 in text [6]: {openurl}?query=rft.jtitle%253DScience%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.1057823%26rft_id%253Dinfo%253Apmid%252F11292859%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [7]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIyOTIvNTUxOS8xMTM2IjtzOjQ6ImF0b20iO3M6MjU6Ii9zY2kvMzAwLzU2MjMvMTIzNi4zLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ== [8]: #xref-ref-2-1 View reference 2 in text [9]: {openurl}?query=rft.jtitle%253DAppl.%2BPhys.%2BLett.%26rft.volume%253D80%26rft.spage%253D4244%26rft.atitle%253DAPPL%2BPHYS%2BLETT%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [10]: #xref-ref-5-1 View reference 5 in text [11]: #xref-ref-6-1 View reference 6 in text [12]: http://www.sciencemag.org/cgi/content/full/300/5623/1236b [13]: {openurl}?query=rft.jtitle%253DScience%26rft.volume%253D300%26rft.spage%253D1236%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx

Space and terrestrial photovoltaics: synergy and diversity

AbstractA historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the 1970s and 1980s, 1990s and beyond. The synergy of both communities, both at the beginning and in the present, and hopefully in the future, are highlighted, with examples of the important features in each program. The space community which was impressed by the light weight and reliability of photovoltaics drove much of the early development. Even today, nearly every satellite and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems was only a small fraction of the satellite and launch cost, the use of much of this technology in the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advances, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost nonexistent. Recent work by both communities have focused on the development thin‐film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in III–V materials and thin‐film materials. Basic photovoltaics research, including these current trends in nanotechnology, provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars. Published in 2002 by John Wiley & Sons, Ltd.

欧米におけるナノテクノロジーの動向

欧米におけるナノテクノロジーの動向