|
University of Pennsylvania engineers discover natural 'workbench' for nanoscale construction
July 18, 2007PHILADELPHIA -- Engineers at the University of Pennsylvania have taken a step toward simplifying the creation of nanostructures by identifying the first inorganic material to phase separate with near-perfect order at the nanometer scale. The finding provides an atomically tuneable nanocomposite "workbench" that is cheap and easy to produce and provides a super-lattice foundation potentially suitable for building nanostructures.
The findings appear in the August issue of Nature Materials.
Alerted by an unusual diffraction effect of a common ceramic material, researchers used imaging to identify a two-phase structural pattern ideal as the first step towards nanodevice construction. Practical application of nanotechnology will rely upon engineering's ability to manipulate atoms and molecules into long-range order to produce materials with desired functionalities. The Penn findings provide a simpler method for the ordering of composite parts on the nanometer scale, which is integral to the incorporation of nano-objects such as particles and wires that make up nanodevices.
The material used in the Penn study is an ionically- conductive, crystalline ceramic (Nd2/3-xLi3x)TiO3 that engineers observed with transmission electron microscopy. The powdered perovskite exhibited two distinct patterns at the atomic scale with identical periodicity: a nanoscale chessboard pattern and a diamond pattern that indicated periodic separation into two phases within the structure. This spontaneous separation of phases could present a new foundation on which to build nanodevice technology. This material - made using standard and easily reproducible ceramic processing methods - represents the formation of a spontaneous microscopic surface controlled on the nanoscale with atomic precision.
Further study revealed that the separation of the structure into two distinct phases was a result of the oxide separating into lithium rich squares and lithium poor stripes. By varying the amount of lithium and neodymium, two ingredients in the ceramic powder, engineers controlled the length and spacing of the alternating phases, thereby tuning the workbench upon which nanodevices could be built.
On a larger-than-atomic scale, the research extends science's knowledge of the properties of a most common oxide structure type, currently used for superconducting materials, magnetoresistive materials and ferroelectrics.
"This study represents great potential for the use of standard ceramic processing methods for nanotechnology," said Peter K. Davies, chair of the Department of Materials Science and Engineering at Penn. "The phase separation occurs spontaneously, providing two phases whose dimensions both extend into the nanometer scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers."
University of Pennsylvania
The material used in the Penn study is an ionically- conductive, crystalline ceramic (Nd2/3-xLi3x)TiO3 that engineers observed with transmission electron microscopy. The powdered perovskite exhibited two distinct patterns at the atomic scale with identical periodicity: a nanoscale chessboard pattern and a diamond pattern that indicated periodic separation into two phases within the structure. This spontaneous separation of phases could present a new foundation on which to build nanodevice technology. This material - made using standard and easily reproducible ceramic processing methods - represents the formation of a spontaneous microscopic surface controlled on the nanoscale with atomic precision.
Further study revealed that the separation of the structure into two distinct phases was a result of the oxide separating into lithium rich squares and lithium poor stripes. By varying the amount of lithium and neodymium, two ingredients in the ceramic powder, engineers controlled the length and spacing of the alternating phases, thereby tuning the workbench upon which nanodevices could be built.
On a larger-than-atomic scale, the research extends science's knowledge of the properties of a most common oxide structure type, currently used for superconducting materials, magnetoresistive materials and ferroelectrics.
"This study represents great potential for the use of standard ceramic processing methods for nanotechnology," said Peter K. Davies, chair of the Department of Materials Science and Engineering at Penn. "The phase separation occurs spontaneously, providing two phases whose dimensions both extend into the nanometer scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers."
University of Pennsylvania
Nanostructures News and Current Nanostructures Events RSSNew paper offers insights into 'blinking' phenomena
A new paper by a team of researchers led by University of Notre Dame physicist Bolizsár Jankó provides an overview of research into one of the few remaining unsolved problems of quantum mechanics.
Researchers untangle quantum quirk
Quantum computing has been hailed as the next leap forward for computers, promising to catapult memory capacity and processing speeds well beyond current limits. Several challenging problems need to be cracked, however, before the dream can be fully realized.
Nanoparticles assemble by millions to encase oil drops
In a development that could lead to new technologies for cleaning up oil spills and polluted groundwater, scientists at Rice University have shown how tiny, stick-shaped particles of metal and carbon can trap oil droplets in water by spontaneously assembling into bag-like sacs.
Are nanobots on their way?
The first real steps towards building a microscopic device that can construct nano machines have been taken by US researchers. Writing in the peer-reviewed publication, International Journal of Nanomanufacturing from Inderscience Publishers, researchers describe an early prototype for a nanoassembler.
Promising new nanotechnology for spinal cord injury
A spinal cord injury often leads to permanent paralysis and loss of sensation below the site of the injury because the damaged nerve fibers can't regenerate. The nerve fibers or axons have the capacity to grow again, but don't because they're blocked by scar tissue that develops around the injury.
Self-Assembled Materials Form Mini Stem Cell Lab
Imagine having one polymer and one small molecule that instantly assemble into a flexible but strong sac in which you can grow human stem cells, creating a sort of miniature laboratory.
Strengthening Fluids With Nanoparticles
Researchers at Rensselaer Polytechnic Institute have demonstrated that liquids embedded with nanoparticles show enhanced performance and stability when exposed to electric fields. The finding could lead to new types of miniature camera lenses, cell phone displays, and other microscale fluidic devices.
Chemists measure copper levels in zinc oxide nanowires
Chemists at the National Institute of Standards and Technology (NIST) have been the first to measure significant amounts of copper incorporated into zinc oxide (ZnO) nanowires during fabrication.
MIT creates gecko-inspired bandage
MIT researchers and colleagues have created a waterproof adhesive bandage inspired by gecko lizards that may soon join sutures and staples as a basic operating room tool for patching up surgical wounds or internal injuries.
Fiber-based nanotechnology in clothing could harvest energy from physical movement
Nanotechnology researchers are developing the perfect complement to the power tie: a "power shirt" able to generate electricity to power small electronic devices for soldiers in the field, hikers and others whose physical motion could be harnessed and converted to electrical energy.
More Nanostructures News Articles
 | Roark's Formulas for Stress and Strain by Warren C. Young, Richard Budynas |
 | Nanotechnology For Dummies (For Dummies (Math & Science)) by Richard D. Booker, Earl Boysen |
 | Schaum's Outline of Strength of Materials 4th Edition by William Nash |
 | Engines of Creation: The Coming Era of Nanotechnology by Eric Drexler |
 | Ubiquity: Why Catastrophes Happen by Mark Buchanan |
 | Nanofuture: What's Next For Nanotechnology by J. Storrs Hall |
 | Principles of Nano-Optics by Lukas Novotny, Bert Hecht |
 | Electronic Structure: Basic Theory and Practical Methods by Richard M. Martin |
 | Atomic and Electronic Structure of Solids by Efthimios Kaxiras |
 | Soft Machines: Nanotechnology and Life by Richard A. L. Jones |
| © 2008 BrightSurf.com |