TechBlog

Energy now lost as heat during the production of electricity could be harnessed through the use of silicon nanowires synthesized via a technique developed by researchers with the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley.

 

 The far-ranging potential applications of this technology include DOE’s hydrogen fuel cell-powered “Freedom CAR,” and personal power-jackets that could use heat from the human body to recharge cell-phones and other electronic devices.

Continue reading ‘Researchers Make Thermoelectric Breakthrough In Silicon Nanowires’ »

Hailed as the world’s most powerful transmission electron microscope, TEAM 0.5 is living up to expectations. Using TEAM 0.5 (TEAM stands for Transmission Electron Aberration-corrected Microscope), researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have produced stunning images of individual carbon atoms in graphene, the two-dimensional crystalline form of carbon that is highly prized by the electronics industry. These first time ever images were recorded at Berkeley Lab’s National Center for Electron Microscopy (NCEM), a DOE national user facility that is a premier center for electron microscopy and microcharacterization. TEAM 0.5, its newest instrument, is capable of producing images with half-angstrom resolution, which is less than the diameter of a single hydrogen atom. “Simply put, TEAM 0.5 is the best transmission electron microscope in the world, representing a quantum leap forward in instrumentation,” said physicist Alex Zettl who led this research. “Having the ability to see, basically in real time, each and every individual atom in a sample is unbelievably useful and the images we can now see have been jaw-dropping for even the most seasoned electron microscopists. TEAM 0.5 is pushing transmission electron microscopy to a new level.” Zettl holds joint appointments with Berkeley Lab’s Materials Sciences Division (MSD) and the Physics Department at the University of California’s Berkeley campus, where he is the director of the Center of Integrated Nanomechanical Systems. Collaborating with him on this graphene imaging project were Jannik Meyer, also with Berkeley Lab’s Materials Sciences Division, and Christian Kisielowski, Rolf Erni and Marta Rossell of NCEM. Their results were published in the journal Nanoletters, in a paper entitled: “Direct imaging of lattice atoms and topological defects in graphene membranes.” The properties of solid materials stem from the arrangement of their constituent atoms in the solid’s crystal structure. While technologies such as electron and x-ray crystallography can reveal the atomic geometry of a crystal, they do not identify the precise location and position of each individual atom. When the dimensions of a material shrink to the nanoscale, the location and position of each individual atom becomes critically important, as Zettl explains. “Think of the steel re-bars on a three-dimensional structure, like a jungle gym,” he said. “If a small piece of re-bar is rusted out somewhere in the center of the gym, it won’t likely have much affect on the overall properties of the structure. In a two-dimensional structure, however, a rusted out segment becomes a much bigger problem, and in a one-dimensional structure, i.e., a single re-bar, a rusted out segment can be catastrophic, causing the entire structure to fail.

On a nanoscale crystal, one missing atom or some other defect in the arrangement can result in catastrophic failure.” Graphene is especially sensitive to defects in its atomic structure. Consisting of a single-layered sheet of carbon atoms arranged in hexagons, like a sheet of chicken wire with an atom at each nexus, graphene features extraordinary electrical, mechanical and thermal properties that could enable it to serve in a broad array of carbon-based electronic devices. For the enormous promises of graphene to be fulfilled, however, scientists need a much better understanding of how specific types of defects in the crystal structure, including those that change location over time, affect its properties.

Continue reading ‘Closest Look Ever At Graphene’ »

A CubeSat is a type of space research picosatellite with dimensions usually of 10×10×10 centimetres (i.e., a volume of exactly one litre), weighing no more than one kilogram, and typically using commercial off-the-shelf electronics components.

Developed through joint efforts, California Polytechnic State University and Stanford University introduced the CubeSat to academia as a way for universities throughout the world to enter the realm of space science and exploration.

Currently, a large number of universities and some companies and other organizations around the world are actively developing CubeSats. One of these companies Clyde-Space, has just developed an ‘off-the-shelf’ website with information and resources for various sized cubesats and their subsystems. Other suppliers such as ISIS and GomSpace are also offering products and services through their websites.
With their relatively small size, CubeSats can be made and launched for an estimated US$65,000–80,000 each (2004 US dollars). This low price tag, as compared to most satellite launches, has made Cubesat a viable option for schools and universities across the world.

Continue reading ‘Researchers And Students To Develop Small CubeSat Satellites, the Size of a Loaf of Bread’ »

Acoustic waves play many everyday roles – from communication between people to ultrasound imaging. Now the highest frequency acoustic waves in materials, with nearly atomic-scale wavelengths, promise to be useful probes of nanostructures such as LED lights.

However, detecting them isn’t so easy.

Continue reading ‘Visualizing Atomic-Scale Acoustic Waves In Nanostructures’ »

This undated handout photo provided by IBM and the Feature Photo Service shows lead engineer Don Grice of IBM inspecting the world’s fastest computer, nicknamed “Roadrunner”, in the company’s Poughkeepsie, N.Y. plant. Scientists unveiled the world’s fastest supercomputer on Monday, June 9, 2008, a $100 million machine that for the first time has performed 1,000 trillion calculations per second in a sustained exercise. The technology breakthrough was accomplished by engineers from the Los Alamos National Laboratory and the IBM Corp. on a computer to be used primarily on nuclear weapons work, including simulating nuclear explosions. (AP Photo/IBM, Feature Photo Service)

 

Continue reading ‘Scientists develop fastest computer’ »

The U.S. Air Force Research Laboratory has authorized Raytheon Company to demonstrate target recognition technology designed to increase protection for ground forces without compounding risk to an aircraft stalking enemies who threaten those forces.

First in a laboratory and then aloft, the company expects to show how its Air-to-Ground Radar Imaging II program would permit aircraft at a safe distance to detect, track and target hostile forces in motion on the ground.

The laboratory demonstration is expected in autumn 2008, followed by a flight next spring aboard a Raytheon test aircraft.

Continue reading ‘Raytheon Develops Technology To Help Aircraft Protect Ground Forces’ »

The concept of wireless sensing is a fascinating and promising area. The potential for industrial, commercial and consumer uses boggles the mind and in some cases sounds like something from a futuristic movie.

Because of the vastness of potential applications, the hype at the introductory stages of this technology to some degree exceeds the level of technology available now in the real world. While some manufacturers have ventured forth with solutions for specific industrial applications, other organizations (including sensor manufacturers, the government and academia) are doing research and development on the bleeding edge of the vision for wireless sensor networks.

Wireless sensors are used in a variety of industrial and commercial applications such as machine condition monitoring, structural health monitoring, process control/discrete manufacturing control, biomedical, heating and ventilation air conditioning (HVAC) controls, logistics and agriculture. This is by no means an exhaustive list, but it demonstrates the already wide array of uses being investigated for wireless technology.

Continue reading ‘Wireless develops extrasensory vision of future’ »

The National Institute of Standards and Technology (NIST) has issued its first reference standards for nanoscale particles targeted for the biomedical research community—literally “gold standards” for labs studying the biological effects of nanoparticles. The three new materials, gold spheres nominally 10, 30 and 60 nanometers in diameter, were developed in cooperation with the National Cancer Institute’s Nanotechnology Characterization Laboratory (NCL).

Nanosized particles are the subject of a great deal of biological research, in part because of concerns that in addition to having unique physical properties due to their size, they also may have unique biological properties. On the negative side, nanoparticles may have special toxicity issues. On the positive side, they also are being studied as vehicles for targeted drug delivery that have the potential to revolutionize cancer treatments. Research in the field has suffered from a lack of reliable nanoscale measurement standards, both to ensure consistency of data from one lab to the next and to verify the performance of measurement instruments and analytic techniques.

False color scanning electron micrograph (250,000 times magnification) showing the gold nanoparticles created by NIST and the National Cancer Institute’s Nanotechnology Characterization Laboratory for use as reference standards in biomedical research laboratories.The new NIST reference materials are citrate-stabilized nanosized gold particles in a colloidal suspension in water. They have been extensively analyzed by NIST scientists to assess particle size and size distribution by multiple techniques for dry-deposited, aerosol and liquid-borne forms of the material. Dimensions were measured using six independent methods—including atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential mobility analysis (DMA), dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS). At the nanoscale in particular, different measurement techniques can and will produce different types of values for the same particles.

Continue reading ‘NIST Reference Materials Are ‘Gold Standard’ For Bio-Nanotech Research’ »

Berkeley, CA — As structures made of metal get smaller — as their dimensions approach the micrometer scale (millionths of a meter) or less — they get stronger. Scientists discovered this phenomenon 50 years ago while measuring the strength of tin “whiskers” a few micrometers in diameter and a few millimeters in length. Many theories have been proposed to explain why smaller is stronger, but only recently has it become possible to see and record what’s actually happening in tiny structures under stress.Andrew Minor, of the Materials Sciences Division in the Department of Energy’s Lawrence Berkeley National Laboratory, with colleagues from Hysitron Incorporated and the General Motors Research and Development Center, used the In Situ Microscope at the National Center for Electron Microscopy (NCEM) to record what happens when pillars of nickel with diameters between 150 and 400 nanometers (billionths of a meter) are compressed under a flat punch made of diamond. The transmission electron microscope is equipped so that samples can be stressed, measured, and videotaped while being observed under the electron beam.

“What controls the deformation of a metal object is the way that defects, called dislocations, move along planes in its crystal structure,” Minor says. “The result of dislocation slip is plastic deformation. For example, bending a paper clip causes its trillions of dislocations per square centimeter to tangle up and multiply as they run into one another and slide along numerous slip planes.”

In general, mechanical deformation tends to increase the number of dislocations in a material. But for small-scale structures, with a much greater proportion of surface area to volume, the process can be very different. The videotaped images from the electron microscope helped the researchers understand why nanoscale nickel pillars are so strong by allowing them to observe changes in the microstructure of the pillars during deformation — including a never-before-seen process the researchers dubbed “mechanical annealing.” (In bulk materials, annealing, a treatment that reduces the density of defects, is usually accomplished by heating.)

Continue reading ‘Smaller Is Stronger — Now Scientists Know Why’ »

Berkeley, CA — Energy now lost as heat during the production of electricity could be harnessed through the use of silicon nanowires synthesized via a technique developed by researchers with the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley. The far-ranging potential applications of this technology include DOE’s hydrogen fuel cell-powered “Freedom CAR,” and personal power-jackets that could use heat from the human body to recharge cell-phones and other electronic devices.

“This is the first demonstration of high performance thermoelectric capability in silicon, an abundant semiconductor for which there already exists a multibillion dollar infrastructure for low-cost and high-yield processing and packaging,” said Arun Majumdar, a mechanical engineer and materials scientist with joint appointments at Berkeley Lab and UC Berkeley, who was one of the principal investigators behind this research.

“We’ve shown that it’s possible to achieve a large enhancement of thermoelectric energy efficiency at room temperature in rough silicon nanowires that have been processed by wafer-scale electrochemical synthesis,” said chemist Peidong Yang, the other principal investigator behind this research, who also holds a joint Berkeley Lab and UC Berkeley appointment.

Continue reading ‘Feeling The Heat: Berkeley Researchers Make Thermoelectric Breakthrough In Silicon Nanowires’ »