David Kirkpatrick

November 2, 2010

Cool nanotech image — growing nanowires

Cool image and interesting process

nanotechnology image
In the growth of sapphire nanowires using the vapor-liquid-solid method, scientists have observed that a facet at the liquid-solid interface alternately grows and shrinks, which promotes nanowire growth. These images are from the video below. Image credit: Sang Ho Oh, et al.

From the link:

Nanowires can be grown in many ways, but one of the lesser-understood growth processes is vapor-liquid-solid (VLS) growth. In VLS, a vapor adsorbs onto a liquid droplet, and the droplet transports the vapor and deposits it as a crystal at a liquid-solid interface. As the process repeats, a nanowire is built one crystal at a time. One advantage of the VLS process is that it allows scientists to control the nanowire’s growth in terms of size, shape, orientation, and composition, although this requires understanding the growth mechanisms on the atomic scale. In a new study, scientists have investigated the steps involved in VLS growth, and have observed a new oscillatory behavior that could lead to better controlled nanowire growth.

Hit the link for a video of the process.

June 11, 2010

Nanoscale circuits on graphene

Via KurzweilAI.net — For all those fresh graduates out there, one word — graphene.

Simple way to create nanocircuitry on graphene developed
KurzweilAI.net, June 11, 2010

method of drawing nanoscale circuits onto atom-thick sheets of graphene has been developed by researchers at the U.S. Naval Research Laboratory, Georgia Institute ofTechnology, and the University of Illinois at Urbana-Champaign.

(University of Illinois at Urbana-Champaign)

The simple, quick one-step process for creating nanowires, based on thermochemical nanolithography (TCNL), tunes the electronic properties of reduced graphene oxide, allowing it to switch from being an insulating material to a conducting material.

Scientists who work with nanocircuits are enthusiastic about graphene because electrons meet with less resistance when they travel along graphene compared to silicon and because today’s silicon transistors are nearly as small as allowed by the laws of physics. Graphene also has the edge due to its thickness – it’s a carbon sheet that is a single atom thick.

However, no one knew how to produce graphene nanostructures with such a reproducible or scalable method until now.

More info: Georgia Institute of Technology

February 3, 2010

The latest in display tech — multitouch skin

Filed under: Business, Media, Science, Technology — Tags: , , , , — David Kirkpatrick @ 2:25 pm

Via KurzweilAI.net — Like almost all announcements of this type of product, I’ll  be much more interested when this is available on the open market with practical applications. Of course, it’s still pretty cool to contemplate.

Multitouch ‘Skin’ Transforms Surfaces Into Interactive Screens
Physorg.com, Feb. 2, 2010

A new large-format multi-touch technology launched today by DISPLAX will transform any non-conductive flat or curved surface, such as glass, plastic or wood, into a multitouch screen.

DISPLAX Multitouch Technology uses a controller that works by processing multiple input signals it receives from a grid of nanowires embedded in the film attached to the enabled surface. Each time a finger is placed on the screen or a user blows on the surface, a small electrical disturbance is caused. The microprocessor controller analyzes this data and decodes the location of each input on that grid to track the finger and air-flow movements.
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September 18, 2009

The future of technology looks pretty bright

Filed under: Business, Science, Technology — Tags: , , , , — David Kirkpatrick @ 6:23 pm

I’ve blogged on all three of the technologies — OLEDs and nanowires pretty extensively — but this is a very nice thumbnail sketch of what’s at the edge of the real-world horizon, if not already here.

From the last link:

Have a look at just three technologies that have the ability to completely revolutionize IT from the ground up: memristors, nanowires and OLEDS.

Memristors are transistor-like devices made out of titanium dioxide that can remember voltage state information. They hold the potential for completely revolutionizing storage and processing technologies because they erase the distinction between processing and storage (you can do both/and on the same chip). More prosaically, they make it possible to create storage devices that require no power. How will that affect your data center?

Then there are nanowires: tiny wires no more than a single nanometer in width that can be conductors, insulators or semiconductors (albeit with weird quantum properties). These can form the basis for embedded intelligent networks — sensor and control networks that are actually built into the materials and devices they control. (Take that, smart grids!)

Finally, there are organic LEDs, which have the interesting property that they can be printed onto things such as wallpaper at relatively low cost. Sony has developed OLED monitors, and GE is looking into OLED wallpaper. So in a couple of years, your new office (or home office) may come equipped with wallpaper that, at the touch of a button, can turn into a floor-to-ceiling high-resolution display. (Think of the bandwidth requirements).

Each of these technologies holds the possibility of completely reshaping IT within the next few years. And the conjunction of all three could make the conjunction of the transistor and fiber optics look like a warm-up act.

April 23, 2009

Nanotech improves transistor chips

Nanotechnology offers fairly regular breakthroughs in chip tech. Here’s the latest.

The release:

Self-assembled nanowires could make chips smaller and faster

CHAMPAIGN, Ill. — Researchers at the University of Illinois have found a new way to make transistors smaller and faster. The technique uses self-assembled, self-aligned, and defect-free nanowire channels made of gallium arsenide.

In a paper to appear in the IEEE (Institute of Electrical and Electronics Engineers) journal Electron Device Letters, U. of I. electrical and computer engineering professor Xiuling Li and graduate research assistant Seth Fortuna describe the first metal-semiconductor field-effect transistor fabricated with a self-assembled, planar gallium-arsenide nanowire channel.

Nanowires are attractive building blocks for both electronics and photonics applications. Compound semiconductor nanowires, such as gallium arsenide, are especially desirable because of their better transport properties and versatile heterojunctions. However, a number of challenges – including integration with existing microelectronics – must first be overcome.

“Our new planar growth process creates self-aligned, defect-free gallium-arsenide nanowires that could readily be scaled up for manufacturing purposes,” said Li, who also is affiliated with the university’s Micro and Nanoelectronics Laboratory and the Beckman Institute. “It’s a non-lithographic process that can precisely control the nanowire dimension and orientation, yet is compatible with existing circuit design and fabrication technology.”

The gallium-arsenide nanowire channel used in the researchers’ demonstration transistor was grown by metal organic chemical vapor deposition using gold as a catalyst. The rest of the transistor was made with conventional microfabrication techniques.

While the diameter of the transistor’s nanowire channel was approximately 200 nanometers, nanowires with diameters as small as 5 nanometers can be made with the gold-catalyzed growth technique, the researchers report. The self-aligned orientation of the nanowires is determined by the crystal structure of the substrate and certain growth parameters.

In earlier work, Li and Fortuna demonstrated they could grow the nanowires and then transfer-print them on other substrates, including silicon, for heterogeneous integration. “Transferring the self-aligned planar nanowires while maintaining both their position and alignment could enable flexible electronics and photonics at a true nanometer scale,” the researchers wrote in the December 2008 issue of the journal Nano Letters.

In work presented in the current paper, the researchers grew the gallium-arsenide nanowire channel in place, instead of transferring it. In contrast to the common types of non-planar gallium arsenide nanowires, the researchers’ planar nanowire was free from twin defects, which are rotational defects in the crystal structure that decrease the mobility of the charge carriers.

“By replacing the standard channel in a metal-semiconductor field-effect transistor with one of our planar nanowires, we demonstrated that the defect-free nanowire’s electron mobility was indeed as high as the corresponding bulk value,” Fortuna said. “The high electron mobility nanowire channel could lead to smaller, better and faster devices.”

Considering their planar, self-aligned and transferable nature, the nanowire channels could help create higher performance transistors for next-generation integrated circuit applications, Li said.

The high quality planar nanowires can also be used in nano-injection lasers for use in optical communications.

The researchers are also developing new device concepts driven by further engineering of the planar one-dimensional nanostructure.




The work was supported by the National Science Foundation.

July 29, 2008

Nanowire lawns sense images

Filed under: Science, Technology — Tags: , , , — David Kirkpatrick @ 1:00 pm

From KurzweilAI.net — another nanotech breakthrough from researchers at the University of California at Berkeley.

Nanowire lawns make for sheets of image sensors
New Scientist news service, July 28, 2008

University of California, Berkeley researchers are growing a mixed “lawn” of two kinds of nanowires to make a new kind of cheap, high-quality image sensor array that could be made in meter-scale sheets.

The arrays are reliable, flexible and easy to scale up. They could be grown to form rolls of tape several meters in diameter with all the needed components to do active sensing, translate the data, and transmit it wirelessly.

Read Original Article>>

July 8, 2008

Medical nanotech, picowatt processor and a 400 gig disc

From KurzweilAI.net — nanosensors that constantly monitor patient’s blood markers, here’s a tiny picowatt processor and a 16-layer, 400 gigabyte optical disc from Pioneer.

Nanosensors for Medical Monitoring
Technology Review, July 8, 2008Vista Therapeutics is developing sensitive devices for continuous bedside monitoring of blood biomarkers for detecting organ failure and other problems in seriously injured or ill patients, such as those in the ICU after suffering a heart attack or traumatic injuries from a car accident.The devices use silicon nanowires developed by Harvard University chemist Charles Lieber. When a single protein binds to an antibody along the wire, the current flowing through the wire changes. Arrays of hundreds of nanowires, each designed to detect a different molecule in the same sample, can be arranged on tiny, inexpensive chips. The changes can be monitored continuously as molecules bind and unbind, making it possible to detect subtle trends over time, without requiring multiple blood draws.

Because nanowires are so sensitive and inexpensive, they could also find their way into home tests for cancer.

Read Original Article>>

A Picowatt Processor
Technology Review, July 8, 2008University of Michigan have made a processor (the Phoenix) that measures just one millimeter square with a power consumption so low (2.8 picojoules of energy per computing cycle) that emerging thin-film batteries of the same size could power it for 10 years or more.At this scale, it could be feasible to build the chip into a thick contact lens and use it to monitor pressure in the eye, which would be useful for glaucoma detection. It could also be implanted under the skin to sense glucose levels in subcutaneous fluid. It could also be used in environmental sensors that monitor pollution, or structural health sensors, for instance.

Read Original Article>>

Pioneer Develops World’s First 16-Layer Optical Disc
PhysOrg.com, July 7, 2008Pioneer Corporation has developed a 16-layer read-only optical disc with a capacity of 400 gigabytes.
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June 27, 2008

Nanowire circuits and tracking asteroids

From KurzweilAI.net, the House passed a bill to begin tracking potential Earth-strike asteroids, and a new low-cost, high-volume method of integrating nanowires onto silicon has been developed.

House passes bill mandating a plan for asteroid warning and deflection
KurzweilAI.net, June 27, 2008

In recently passed H.R.6063, The U.S. House of Representatives would direct the NASA Administrator to develop plans for a low-cost spacemission to rendezvous with the Apophis asteroid and attach a tracking device (subject to Senate approval).

The Apophis is expected to pass at a distance from Earth that is closer than geostationary satellites in 2029.

The bill would also require the Director of the White House’s Office of Science and TechnologyPolicy (OSTP) to develop a policy within two years for notifying Federal agencies and relevant emergency response institutions of an impending near-Earth objectthreat. And the OSTP would be required to recommend a Federal agency (or agencies) to be responsible for protecting the Nation from any near-Earth object anticipated to collide with Earth, and for implementing a deflection campaign.


Researchers develop new technique for fabricating nanowire circuits
Nanowerk News, June 26, 2008

Scientists at Harvard University and German universities of Jena, Gottingen, and Bremen have developed a reproducible, high-volume, low-cost fabrication methodfor integrating nanowire devices directly onto silicon.

The method incorporates spin-on glass technology, used in silicon integrated circuits manufacturing, and photolithography, transferring a circuit pattern onto a substrate with light. These devices can then function as light-emitting diodes, with the color of light determined by the type of semiconductor nanowire used.

Because nanowires can be made of materials commonly used in electronics and photonics, they hold great promise for integrating efficient light emitters, and could lead to the development of a completely new class of integrated circuits, such as large arrays of ultra-small nanoscale lasers that could be designed as high-density optical interconnects or used for on-chip chemical sensing.

Read Original Article>>

May 15, 2008

Nanowire solar cells and black holes

From KurzweilAI.net, nanotech that may boost solar efficiency and black holes may have an escape hatch of sorts

Nanowires may boost solar cell efficiency, engineers say
PhysOrg.com, May 14, 2008

University of California, San Diego electrical engineers have created experimental solar cells spiked with nanowires that could lead to highly efficient thin-film solar cells of the future.

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Physicists Demonstrate How Information Can Escape From Black Holes
PhysOrg.com, May 14, 2008

Physicists at Penn State and the Raman Research Institute in India have discovered such a mechanism by which information can be recovered from black holes.

They suggest that singularities do not exist in the real world. “Information only appears to be lost because we have been looking at a restricted part of the true quantum-mechanical space-time,” said Madhavan Varadarajan, a professor at the Raman Research Institute. “Once you consider quantum gravity, then space-time becomes much larger and there is room for information to reappear in the distant future on the other side of what was first thought to be the end of space-time.”

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May 7, 2008

Display nanowires, ultramicroelectrodes, more affordable solar news

From KurzweilAI.net — Upright copper nanowires may be key to better flat panel displays, single-walled carbon nanotubes form ultramicroelectrodes, more news on solar electricity that rivals fossil fuels in cost.

Nanowires for Displays
Technology Review, May 6, 2008

Researchers at the University of Illinois in Urbana Champaign have developed a simple process to grow upright copper nanowires on different surfaces.

The nanowire arrays could find use in field-emission displays, a new type of display technology that promises to provide brighter, more vivid pictures than existing flat-panel displays.

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Nanotube production leaps from sooty mess in test tube to ready formed chemical microsensors
PhysOrg.com, May 6, 2008

University of Warwick chemists have produced single-walled carbon nanotubes that instantly form ultramicroelecrodes that could be used to create biocompatible, ultrasensitive sensors with high signal-to-noise ratios and fast response times.

The research team is exploring how these ultramicroelecrodes could be used to measure levels of neurotransmitters and catalysis in fuel cells.

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Focusing on Solar’s Cost
Technology Review, May 7, 2008

Solar startup Sunrgi says that it will soon be able to produce electricity from the sun at costs that are competitive with fossil-fuel generation.

The company has created a concentrated photovoltaic system that uses a lens to focus sunlight up to 2,000 times sun concentration onto tiny solar cells that can convert 37.5 percent of the sun’s energy into electricity. Stronger concentrations of sunlight allow engineers to use much smaller solar cells, making it more economical to use higher-efficiency–but higher-cost–cells.

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May 2, 2008

Nanotrees and nanomotors

From KurzweilAI.net, nanotrees are a new type of nanowire and Arizona State researchers have created the fastest nanomotor.

Spiraling nanotrees offer new twist on growth of nanowires
PhysOrg.com, May 1, 2008

University of Wisconsin-Madison researchers have discovered a new way of growing nanowires that leads to “nanopines”–elaborate pine-tree-shaped nanowires–caused by a “screw” dislocation, or defect, in their crystal structure.

Dislocations are fundamental to the growth and characteristics of all crystalline materials, but this is the first time they’ve been shown to aid the growthof one-dimensional nanostructures.

Engineering these dislocations may allow scientists to create more elaborate nanostructures, and to investigate the fundamental mechanical, thermal and electronic properties of dislocations in materials.

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Revving up the world’s fastest nanomotor
PhysOrg.com, May 1, 2008

Arizona State University researchers have developed a new generation of nanomotors with an average speed of 60 micrometers per second.

Tracks left by various types of speeding nanomotors (American Chemical Society)

Existing catalytic nanomotors–made with gold and platinum nanowires and fueled with hydrogen peroxide–have top speeds of about 10 micrometers per second.

The new design adds carbon nanotubes to the platinum (boosting the average speed) and spikes the hydrogenperoxide fuel with hydrazine to increase the nanomotor’s top speed to 200 nanometers per second.

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