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Applied scientists at Harvard University in collaboration with researchers from the German universities of Jena, Gottingen, and Bremen, have developed a new technique for fabricating nanowire photonic and electronic integrated circuits that may one day be suitable for high-volume commercial production.

Fabrication technique could yield low-cost, scalable nanowire photonic and electronic circuits

Spearheaded by graduate student Mariano Zimmler and Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering, both of Harvard’s School of Engineering and Applied Sciences (SEAS), and Prof. Carsten Ronning of the University of Jena, the findings will be published in Nano Letters. The researchers have filed for U.S. patents covering their invention.

Continue reading ‘Scientists Demonstrate Method for Integrating Nanowire Devices Directly onto Silicon’ »

Future nanomanufacturing processes will rely on two basic principles: a combination of chemical synthesis and self-assembly on one hand and robotic nanofabrication on the other. While the former is a controlled ‘natural’ process relying on chemistry and self-organization principles of nature (read more: How falling spaghettis could lead to more complex nanotechnology self-assembly), the latter will be an industrial process similar in concept to today’s automated manufacturing assembly lines.

Micromanufacturing

Continue reading ‘A Gripping Tale for Nanomanufacturing’ »

Engineers and applied physicists from Harvard University have demonstrated the first room-temperature electrically-pumped semiconductor source of coherent Terahertz (THz) radiation, also known as T-rays. The breakthrough in laser technology, based upon commercially available nanotechnology, has the potential to become a standard Terahertz source to support applications ranging from security screening to chemical sensing.Spearheaded by research associate Mikhail Belkin and Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering, both of Harvard’s School of Engineering and Applied Sciences (SEAS), the findings will be published in the May 19 issue of Applied Physics Letters. The researchers have also filed for U.S. patents covering the novel device.

Using lasers in the Terahertz spectral range, which covers wavelengths from 30 to 300å, has long presented a major hurdle to engineers. In particular, making electrically pumped room-temperature and thermoelectrically-cooled Terahertz semiconductor lasers has been a major challenge. These devices require cryogenic cooling, greatly limiting their use in everyday applications.

Continue reading ‘Engineers Demonstrate First Room-Temperature Semiconductor Source Of Coherent Terahertz Radiation’ »

Microcantilever actuators made from carbon nanotube (CNT)-polymer composites could dramatically improve the performance of microelectromechanical systems, according to scientists in Taiwan. The researchers from National Tsing Hua University have developed an easy to actuate material that rapidly suppresses unwanted oscillations thanks to a low quality factor.

“Lightweight and highly flexible CNT-composites provide fast electrothermo-actuation at low power,” Weileun Fang told nanotechweb.org. “Moving the actuator from its original position to its pull-in position can be employed to define two different states such as 0/1 or on/off, which suits many applications in communications and displays.”

The group’s nanocomposite device has a pull-in voltage of just 50?V for a full deflection of 560?µm. As Fang explains, this value is very low compared with existing microcantilevers, which can demand at least 500?V to achieve a similar displacement. The researchers believe that CNT-based field amplification is responsible for the low pull-in voltage.

Continue reading ‘Nanocomposite offers MEMS upgrade’ »

In response to the electronics industry’s rallying cry of “smaller and faster,” the next breakthroughs in the electronics size barrier are likely to come from microchips and data storage devices created out of novel materials such as organic molecules and polymers. With innovative measurement techniques and new ways to position the molecules, NIST researchers reported at the March Meeting of the American Physical Society how they have improved manipulation of so-called block copolymers—polymers made of a mixture of two or more different molecule building blocks that are tethered at a junction point—which can form arrays of tiny dots that could be used as the basis for electronic components that pack terabytes (1000 gigabytes) of memory in something as small as a pack of gum.

One of the challenges in polymer nanotechnology is how to control their self-assembly—a hard-to-control process for materials which require precision. An important recent NIST accomplishment has been in developing accurate measurements of thin film polymeric nanostructure in 3-D. (Ironically, while determining atomic structure is well-established, measuring the slightly larger internal structure of the polymers—on the order of 10 to 20 nanometers—is much harder.) Ron Jones, together with colleagues from NIST, the University of Maryland and IBM, has used NIST’s neutron scattering and reflectivity facility to deflect neutrons off block copolymer films from many different angles. By combining the many 2-D neutron scattering pictures into a single composite scattering pattern, this technique provides the first quantitative method for imaging the 3-D internal structure of thin film polymeric nanostructures using neutron scattering—a crucial tool to see if the nanoscale polymer structures are in their required positions.

NIST researchers also have developed new insights on how best to nudge these self-assembling material into those positions. August Bosse will report on computer simulations that model how the polymers assemble when they are placed on templates lined with troughs separated by crests. When a heated zone is swept across the template, the polymer molecules assemble into almost defect free, well-aligned lines faster over the entire template, an important feature for nanotech manufacturing applications. Sangcheol Kim (working with a team that included researchers from the University of Maryland and IBM) has found that changing the surface chemistry of the template by making some parts hydrophillic and some parts hydrophobic also can elegantly control the dimension of the block-copolymer pattern relative to the chemical template.

Continue reading ‘Copolymers Block Out New Approaches To Microelectronics’ »

Advances made in the field of nanotechnology could be applied in the development of a new generation of chemical and biological weapons, writes Andy Oppenheimer.

Current and future developments in nanotechnology—science and engineering on the scale of nanometres or billionths of a metre—may pave the way for new types of weapons. The new technology will have a profound impact on new materials, electronic devices, chemical, biological and mechanical systems and provides the potential for future weapons development. Previous articles on Janes Chem-Bio Web discussed the potential of nanotechnology being used for a fourth generation of nuclear weapons. This article deals with its potential to enable future production of novel chemical and biological weapons (CBW).

Dual-use medical advances

Nanotechnology has great potential in the fields of biotechnology and medicine. Bio-nanotechnology is concerned with molecular-scale properties and production of materials and devices including tissue and cellular engineering scaffolds, molecular motors and biomolecules for sensors and drug delivery. While bio-nanotechnological products are seen as around 10 years off, medical application is promising, with intense research being conducted in disease diagnosis, drug delivery and molecular imaging. Medical-related products containing nanoparticles are currently on the market in the US. DNA-based geometrical structures (including artificial crystals) and functioning DNA-based nanomachines are currently being fabricated.

Continue reading ‘Nanotechnology paves way for new weapons’ »

As a step toward advanced nanotechnology, general methods for producing complex nanoscale structures in three dimensions are useful stepping stones from current nanotech to atomically precise functional nanosystems. Although the nanomaterials and nanostructures produced are far from atomically precise, a recently developed method of using a micropipette and rapidly drying ink to draw long fibers and complex 3D structures is an important advance.

Excerpts from a University of Illinois at Urbana-Champaign news release “New process makes nanofibers in complex shapes and unlimited lengths“

The continuous fabrication of complex, three-dimensional nanoscale structures and the ability to grow individual nanowires of unlimited length are now possible with a process developed by researchers at the University of Illinois.

Continue reading ‘A nanotechnology based upon writing in 3D produces long fibers and complex structures’ »

An ambitious government plan seeks to make Korea one of the top three countries for nanotechnology by 2020.

The Science and Technology Ministry announced Tuesday (Jan. 15) its “National Nanotechnology Roadmap (2007-2020)” for research and development in the field.

The Korea Nanotechnology Research Society drew up the plan, and will also hold a public hearing on the roadmap Thursday.

Continue reading ‘Korea - Ambitious nanotechnology plan released’ »

System is invisible to the immune system, preventing response
News source: University of California - Los Angeles, via AAAS EurekAlertUsing nanotechnology, scientists from UCLA and Northwestern University have developed a localized and controlled drug delivery method that is invisible to the immune system, a discovery that could provide newer and more effective treatments for cancer and other diseases.

…The researchers used nanoscale polymer films, about four nanometers per layer, to build a sort of matrix or platform to hold and slowly release an anti-inflammatory drug. The films are orders of magnitude thinner than conventional drug deliver coatings, said Genhong Cheng, a researcher at UCLA’s Jonsson Comprehensive Cancer Center and one of the study’s authors…

“Using this system, drugs could be released slowly and under control for weeks or longer,” said Cheng, a professor of microbiology, immunology and molecular genetics. “A drug that is given orally or through the bloodstream travels throughout the system and dissipates from the body much more quickly. Using a more localized and controlled approach could limit side effects, particularly with chemotherapy drugs.” Continue reading ‘Copolymeric Nanofilm Platform for Controlled and Localized Therapeutic Delivery’ »

Researchers at Children’s Hospital Boston have developed a new “nanobiotechnology” that enables magnetic control of events at the cellular level. They describe the technology, which could lead to finely-tuned but noninvasive treatments for disease, in the January issue of Nature Nanotechnology.

Don Ingber, MD, PhD, and Robert Mannix, PhD, of Children’s program in Vascular Biology, in collaboration with Mara Prentiss, PhD, a physicist at Harvard University, devised a way to get tiny beads — 30 nanometers (billionths of a meter) in diameter — to bind to receptor molecules on the cell surface. When exposed to a magnetic field, the beads themselves become magnets, and pull together through magnetic attraction. This pull drags the cell’s receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. This clustering, in turn, activates the receptors, triggering a cascade of biochemical signals that influence different cell functions.

The technology could lead to non-invasive ways of controlling drug release or physiologic processes such as heart rhythms and muscle contractions, says Ingber, the study’s senior investigator. More importantly, it represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules.

Continue reading ‘An “Attractive” Man-Machine Interface: Researchers Use Magnetic Fields, Rather Than Drugs, To Control Cellular Signaling’ »