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What is Nanomanufacturing?
Posted On Friday, November 21, 2008 at at 1:17 PM by Yongan HuangNanomanufacturing is the controllable manipulation of materials structures, components, devices, and systems at the nanoscale (1 to 100 nanometers) in one, two, and three dimensions for large-scale reproducibility of value-added components and devices. Nanomanufacturing remains the essential bridge between the discoveries of the nanosciences and real-world nanotechnology products.
Advancing nanotechnology from the laboratory into high-volume production ultimately requires careful study of manufacturing system issues including product design, reliability and quality, process design and control, shop floor operations and supply chain management. Nanomanufacturing encompasses bottom-up directed assembly, top-down high resolution processing, molecular systems engineering, and hierarchical integration with larger scale systems. As dimensional scales of materials and molecular systems approach the nanoscale, the conventional rules governing the behavior and properties of these components, devices, and systems change significantly. As such, the behavior of the final product is enabled by the collective performance of the nanoscale building blocks.
More disscussion can be found in http://www.mechscience.com/?q=node/87.
Research Challenges
The challenges facing nanomanufacturing systems integration represents an inherently multi-disciplinary set of problems addressing issues for working with structures in the 0.1-100 nm regime that must combine the range of top-down and bottom-up processes available in order to provide multi-scale systems integration. To achieve the necessary economy of scale for large-scale production, new concepts and principles must be envisioned providing revolutionary approaches, thereby extending the capabilities of existing manufacturing and infrastructure. A cross-section of scientific disciplines is contributing to the greater understanding and control of nanoscale phenomena—physics, chemistry, biology, material and information sciences, engineering, and polymer science. The collective knowledge of these disciplines will redefine the relationships between materials, processes and property phenomena, allowing for the creation of revolutionary nanomanufacturing techniques. Those techniques will help to bridge the manufacturing gap between the innovations of the research laboratory and the economic viability of nanotechnology.
The critical challenges for nanomanufacturing are the need to control assembly of three-dimensional heterogeneous systems; to process nanoscale structures in high-rate/high-volume applications without compromising their inherent properties; and to ensure the long-term reliability of nanostructures through testing and metrics. These challenges reflect the need for research in the characterization of nanomaterials and nanoparticles as the building-blocks of nanostructures, and in the fabrication and synthesis of both top-down and bottom-up processes. Further, they require advanced instrumentation to characterize and measure nanostructures, to provide predictive simulation of nanostructure behavior, and to contribute to the design and integration of nanodevices and systems. Finally, knowledge sharing and outreach is a challenge to be overcome to enable technology transfer and to contribute to public awareness of nanotechnologies.
Context
Much of the momentum for nanomanufacturing emanates from the semiconductor industry, where the push to create smaller, faster, and more efficient microprocessors has heralded the creation of circuitry less than 100 nanometers in size.
Federally, the National Nanotechnology Initiative (NNI) is a cross-departmental program that has been working since 2001 to support and advance the development of nanotechnologies in the United States. The NNI has identified nanomanufacturing as one of seven Program Component Areas and, in 2006, earmarked $47 million for research in this domain. Also since 2001, the National Science Foundation (NSF) has funded four Nanoscale Science and Engineering Centers explicitly focused on manufacturing.
With nearly 60 federally funded research centers under NNI governance and over 1200 nanotech companies based in the USA as of 2006, the drive to move nanotechnology from laboratory to marketplace is strong.
Areas of application for nanomanufacturing include:
Electronics and Semiconductor Industries
IT and Telecommunications
Aerospace and Automotive Industries
Energy and Utilities
Materials and Chemical Industries
Forest and Paper Products
Food Industries
Pharma, Biomed and Biotechnology
Environment and National Security
Clothing and Personal Care
References
Busnaina, Ahmed. Nanomanufacturing Handbook. Boca Raton, FL: CRC Press/Taylor & Francis; 2007, 1-31.
Biscarini, Fabio, et al. “Nanomanufacturing and Processing—Research, Education, Infrastructure, Security, Resource.” Journal of Manufacturing Science and Engineering 124 (2002) 489-490.
Haris Doumanidis. “The Nanomanufacturing Programme at the National Science Foundation.” Nanotechnology 13 (2002) 248-252.
NSET Subcommittee, Committee on Technology. The National Nanotechnology Initiative: Research and Development Leading to a Revolution in Technology and Industry—Supplement to the President’s 2006 Budget. National Nanotechnology Initiative. March 2005.
Karen F. Schmidt. Nanofrontiers: Visions for the Future of Nanotechnology. Woodrow Wilson International Center for Scholars Project on Emerging Nanotechnologies. March 2007.
Nanovip.com, the International Nanotechnology Business Directory. Accessed 7/26/07 http://www.nanovip.com/.
Come from InterNano
Study Produces Road Map for Nanomanufacturing
Researchers have taken an important step toward high-volume production of new nanometer-scale structures with the first systematic study of growth conditions that affect production of one-dimensional nanostructures from the optoelectronic material cadmium selenide (CdSe).
Using the results from more than 150 different experiments in which temperature and pressure conditions were systematically varied, nanotechnology researchers at the Georgia Institute of Technology created a “road map” to guide future nanomanufacturing using the vapor-liquid-solid (VLS) technique.
The results, reported this month in the journal Advanced Materials (Vol. 17, pp.1-6), join earlier Georgia Tech work that similarly mapped production conditions for nanostructures made from zinc oxide – an increasingly important nanotechnology material. Together, the two studies provide a foundation for large-scale, controlled synthesis of nanostructures that could play important roles in future sensors, displays and other nanoelectronic devices.
The research was supported by the National Science Foundation (NSF), the NASA Vehicle Systems Program, the Department of Defense Research and Engineering (DDR&E) and the Defense Advanced Research Projects Agency (DARPA).
“For the future of nanomanufacturing, we needed a systematic map to show the best conditions for producing these structures reproducibly with high yield,” explained Zhong Lin Wang, director of Georgia Tech’s Center for Nanoscience and Nanotechnology. “This information will be necessary for scaling up the production of these interesting structures for the applications that will be developed.”
In work that required more than a year to complete, Wang and collaborator Christopher Ma collected information on more than 45 separate combinations of growth conditions governing the production of cadmium selenide nanostructures. In their experimental set-up, powdered cadmium selenide was heated to hundred of degrees Celsius in a simple horizontal tube furnace under the flow of nitrogen gas, using gold as a catalyst.
The technique produced three different types of nanostructures:
• “Nanosaws/nanocombs,” unusual structures that form with “teeth” on one side and a smooth surface on the other;
• “Nanobelts,” which are ribbon-like structures, and
• “Nanowires” that resemble grass and grow vertically from the substrate.
The researchers varied the temperature at the cadmium selenide source, the temperature of the silicon substrate where the structures grew, and the gas pressure inside the furnace. They repeated each experimental condition three times, each time determining where the structures grew on the substrate and counting the number of nanosaws/nanocombs, nanobelts and nanowires in samples that were examined with electron microscopy.
“These three different structures are all produced using the same general experimental conditions, but somehow you get different percentages of each,” Wang said. “Our goal was to determine how to control the conditions to learn how to get close to 100 percent yield of each structure. This required a systematic study of the experimental conditions.”
Each experiment required approximately two days to produce the structures and analyze the samples.
Based on their experimental work, Wang and Ma mapped the optimal conditions for producing each of the three structures – and learned more about the fabrication process. For instance, they found that growth of the nanostructures is primarily controlled by the nitrogen gas pressure inside the chamber and the temperature of the substrate where the structures are deposited. They also learned where each type of structure was likely to be deposited on the substrate under each set of conditions.
Cadmium selenide nanosaws and nanocombs are the most finicky to grow. At the other end of the scale, nanowires can be produced from cadmium selenide at a broad range of temperature and pressure conditions. Specifically, the researchers reported:
• Lower temperatures at the source material (630 degrees C), higher pressures (600 millibars) and substrate temperatures of approximately 575 degrees C produce the highest percentage of nanosaws and nanocombs.
• Lower temperatures at the source material (700 degrees C), lower chamber pressures (4 millibars) and substrate temperatures of approximately 575 degrees C produce the highest percentage of nanobelts.
• Growth of nanowires can be carried out at a broad range of temperatures and pressures, with higher source temperatures favoring the growth of nanowires over nanosaws.
“If other groups want to produce these structures, they can use our plots to determine the pressures that will be required, the temperatures and the locations within the chamber where they will grow,” Wang said. “Until now, researchers have had to determine these parameters by trial and error.”
Cadmium selenide has been studied for applications in optoelectronics, luminescent materials, lasing materials and biomedical imaging. It is perhaps best known as the basis for quantum dots that have applications in biomedical imaging.
Zinc oxide is a semiconducting, piezoelectric and optical material with potential applications in sensors, resonators and other nanoelectronic structures. The systematic study of growth parameters for these structures involved more than 100 experiments and was published in the Journal of Physical Chemistry (B, Vol. 109 (2005) 9869-9872).
“Now that we have determined the optimal requirements for growth, it should be straightforward to scale up the production of these structures,” Wang concluded. “We have a lot of ideas for potential applications.”
Source: Georgia Institute of Technology