CAD-CAM for nanotechnology manufacturing
A team of U.S. researchers has used a computer aided design and manufacturing (CAD-CAM) process to guide an atomic force microscope (AFM). According to them, this automated technique is 'paving the way for a nanotechnology's industrial revolution.' And their results look very promising. If they're confirmed -- and adopted by the industry -- this suggests that 'the nanotechnology factories of the future might not operate so differently from existing manufacturing plants.' In fact, using CAD-CAM tools already mastered by today's engineering workforce would probably be very beneficial to the emerging nanotechnology industry.
You can see above an example of CAD design and its application to replicate specific nanostructures: "(a) CAD design of desired features; (b) to (d) contact AFM height images of resulting structures." (Credit: Matthew Johannes, Daniel Cole and Robert Clark)
This project has been led by Robert Clark, Thomas Lord Professor and acting dean of Duke University's Pratt School of Engineering. The other researchers for this project are Matthew Johannes, who recently received his doctoral degree at Duke, and Daniel Cole of the University of Pittsburgh.
So how did the scientists proceed? "The feat was accomplished by using the traditional computing language of macroscale milling machines to guide an atomic force microscope (AFM). The system reliably produced 3-D, nanometer-scale silicon oxide nanostructures through a process called anodization nanolithography, in which oxides are built on semiconducting and metallic surfaces by applying an electric field in the presence of tiny amounts of water."
And here is one comment from Clark. "That's the key to moving from basic science to industrial automation," Clark said. "When you manufacture, it doesn't matter if you can do it once, the question is: Can you do it 100 million times and what's the variability over those 100 million times" Is it consistent enough that you can actually put it into a process""
So what's next? Is this really possible to use today's engineers to manufacture nanoscle products? "If you can take prototyping and nanomanufacturing to a level that leverages what engineers know how to do, then you are ahead of the game," Clark said. "Most engineers with conventional training don't think about nanoscale manipulation. But if you want to leverage a workforce that's already in place, how do you set up the future of manufacturing in a language that engineers already use to communicate" That's what we're focused on doing here."
This research work has been published in the online version of the Nanotechnology journal under the name "Three-dimensional design and replication of silicon oxide nanostructures using an atomic force microscope" (Volume 18, Issue 34, Article 345304, August 29, 2007).
For your convenience, here is the abstract. "Atomic force microscope (AFM) based local anodic oxidation of metallic and semiconducting layers has emerged as a powerful tool for nanoscale fabrication. A unique nanoscale patterning technique has been created that couples computer aided design (CAD) with the lithographic capabilities of the AFM. Target nanostructures to be deposited on a silicon substrate are rendered as a three-dimensional model. Using AFM based local anodic oxidation on a silicon substrate, the features are duplicated at the nanoscale using voltage bias, probe speed, and humidity modulation, as prescribed by the model. The work presented herein highlights the advantages when three-dimensional modeling is linked with nanolithography; nanoscale features can be precisely replicated from a design plan."
And if you want more information, here is a link to the full text of the article (PDF format, 7 pages, 2.05 MB, free registration needed). The above figure has been extracted from this document.
Sources: Duke University news release, August 1, 2007; and various websites
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