New nanotech applications may be made possible by the demonstration of a force generated from light that differs from the more familiar radiation pressure, and that is more versatile because it does not require a reflective surface. This force can be used to make light drive nanoscale machinery on a silicon chip. From Yale University, via AAAS EurekAlert “Harnessing light to drive nanomachines“

…a team led by researchers at the Yale School of Engineering & Applied Science has shown that the force of light indeed can be harnessed to drive machines — when the process is scaled to nano-proportions.

Their work opens the door to a new class of semiconductor devices that are operated by the force of light. They envision a future where this process powers quantum information processing and sensing devices, as well as telecommunications that run at ultra-high speed and consume little power.

The research, appearing in the November 27 issue of Nature [abstract], demonstrates a marriage of two emerging fields of research — nanophotonics and nanomechanics — which makes possible the extreme miniaturization of optics and mechanics on a silicon chip.…

“While the force of light is far too weak for us to feel in everyday life, we have found that it can be harnessed and used at the nanoscale,” said team leader Hong Tang, assistant professor at Yale. “Our work demonstrates the advantage of using nano-objects as “targets” for the force of light — using devices that … match the size of today’s typical transistors.”

Until now light has only been used to maneuver single tiny objects with a focused laser beam — a technique called “optical tweezers.” Postdoctoral scientist and lead author, Mo Li noted, “Instead of moving particles with light, now we integrate everything on a chip and move a semiconductor device.”

“When researchers talk about optical forces, they are generally referring to the radiation pressure light applies in the direction of the flow of light,” said Tang. “The new force we have investigated actually kicks out to the side of that light flow.”

While this new optical force was predicted by several theories, the proof required state-of-the-art nanophotonics to confine light with ultra-high intensity within nanoscale photonic wires. The researchers showed that when the concentrated light was guided through a nanoscale mechanical device, significant light force could be generated — enough, in fact, to operate nanoscale machinery on a silicon chip.

—Jim

Dr. David Baker, who with Dr. Brian Kuhlman was awarded the 2004 Foresight Nanotech Institute Feynman Prize for Theory, will be one of three winners of the 2008 Raymond and Beverly Sackler International Prize in Biophysics. Dr. Baker has been featured on Nanodot posts this year for inviting online gamers to aid in protein design and for the design of protein catalysts for non-natural chemical reactions. From the University of Washington, via AAAS EurekAlert “Protein folding researcher David Baker to receive Sackler Prize in Biophysics“

Dr. David Baker, University of Washington (UW) professor of biochemistry and an investigator at the Howard Hughes Medical Research Institute, has been selected to receive the 2008 Raymond & Beverly Sackler International Prize in Biophysics, along with Dr. Martin Gruebele of the University of Illinois, Urbana-Champaign, and Dr. Jonathan Weissman of the University of California, San Francisco.

The field for this year’s prize was the physics of structure formation and self-assembly of proteins and nucleic acids. The award will be presented to the three scientists Dec. 15 at Israel’s Tel Aviv University.…

Baker is being honored for his seminal contributions to computer-based studies of the manner and the speed in which chains of amino acids fold into protein molecules. Anyone who has tried to put together a cardboard box knows the importance of proper folding to get a useful product. The same is true when the body manufactures proteins.

Creating computer models of protein-folding is essential for figuring out how genetic information directs protein formation, how proteins work, and how misfolded, misshapen, and malfunctioning proteins might underlie serious degenerative diseases.

Baker has developed computer programs to predict protein structures from amino acid sequences in DNA. His program, Rosetta, is among the most accurate. He has combined data from nuclear magnetic resonance imaging and X-ray defraction [sic] imaging with his computer modeling to more quickly delineate protein molecule structures. He also researches the ways that molecular configurations of proteins determine their functions in biochemical reactions.

In addition, Baker and his team have developed new protein folds and have designed and built functional enzymes, and engineered protein interactions, that previously did not exist in nature. His group has also contributed new ways of studying proteins in membranes — the thin fatty covering that separates the inside of the cell from the external environment. These transmembrane proteins include molecular channels that permit the flow of calcium into and out of the cell, and that are responsible for the passage of neural impulses and communication between cells. The Baker group was able to apply the Rosetta program to these unusual proteins by treating the membranes as a series of layers with different protein folding requirements.

Baker has involved people of all ages and backgrounds from around the world in helping with protein folding research. People donate their idle computer time to a project called Rosetta@home (http://boinc.bakerlab.org/rosetta/). The combined computing power of thousands of home computers around the globe (called “distributed computing”) allows for lengthy, complicated analysis of the data needed to study how proteins are assembled. Watch a YouTube video on Rosetta@home: http://ie.youtube.com/watch?v=GzATbET3g54.

Baker and his team have also created Fold-It, a Web-based protein folding and design game (http://fold.it/portal/)for scientists and non-scientists alike to play to study protein formation.

—Jim

A new multi-disciplinary collaboration will focus on developing computing technology that mimics the human brain in being able to solve a wide variety of problems. One of the difficulties that the researchers will confront is making a nanoscale material that can mimic the synapses connecting neurons by forming connections that will get stronger or weaker depending on the signals passing through them. From “IBM plans ‘brain-like’ computers“, by BBC News science and technology reporter Jason Palmer:

IBM has announced it will lead a US government-funded collaboration to make electronic circuits that mimic brains.

Part of a field called “cognitive computing”, the research will bring together neurobiologists, computer and materials scientists and psychologists.

As a first step in its research the project has been granted $4.9m (£3.27m) from US defence agency Darpa.

The resulting technology could be used for large-scale data analysis, decision making or even image recognition.

“The mind has an amazing ability to integrate ambiguous information across the senses, and it can effortlessly create the categories of time, space, object, and interrelationship from the sensory data,” says Dharmendra Modha, the IBM scientist who is heading the collaboration.

“There are no computers that can even remotely approach the remarkable feats the mind performs,” he said.

“The key idea of cognitive computing is to engineer mind-like intelligent machines by reverse engineering the structure, dynamics, function and behaviour of the brain.”

IBM will join five US universities in an ambitious effort to integrate what is known from real biological systems with the results of supercomputer simulations of neurons. The team will then aim to produce for the first time an electronic system that behaves as the simulations do.

The longer-term goal is to create a system with the level of complexity of a cat’s brain.

…Free from the constraints of explicitly programmed function, computers could gather together disparate information, weigh it based on experience, form memory independently and arguably begin to solve problems in a way that has so far been the preserve of what we call “thinking”.

—Jim

A new microscope may facilitate nanotech developments by combining nanometer scale spatial resolution with temporal resolution in the millisecond to femtosecond range. ScienceDaily brings us this news release from Caltech: “Caltech 4D Microscope Revolutionizes the Way We Look at the Nano World“:

More than a century ago, the development of the earliest motion picture technology made what had been previously thought “magical” a reality: capturing and recreating the movement and dynamism of the world around us. A breakthrough technology based on new concepts has now accomplished a similar feat, but on an atomic scale–by allowing, for the first time, the real-time, real-space visualization of fleeting changes in the structure and shape of matter barely a billionth of a meter in size.

Such “movies” of atomic changes in materials of gold and graphite, obtained using the technique, are featured in a paper appearing in the November 21 issue of the journal Science [abstract]. (4D microscopy videos can be viewed at http://ust.caltech.edu/movie_gallery/.) A patent on the conceptual framework of this approach was granted to the California Institute of Technology (Caltech) in 2006.

The new technique, dubbed four-dimensional (4D) electron microscopy, was developed in the Physical Biology Center for Ultrafast Science and Technology, directed by Ahmed Zewail, the Linus Pauling Professor of Chemistry and professor of physics at Caltech, and winner of the 1999 Nobel Prize in Chemistry.

Zewail was awarded the Nobel Prize for pioneering the science of femtochemistry, the use of ultrashort laser flashes to observe fundamental chemical reactions–atoms uniting into molecules, then breaking apart back into atoms–occurring at the timescale of the femtosecond, or one millionth of a billionth of a second. The work “captured atoms and molecules in motion,” Zewail says, akin to the freeze-frame stills snapped by 19th-century photographer Eadweard Muybridge of a galloping horse (which proved for the first time that a horse does indeed lift all four hooves off the ground as it gallops) and other moving objects.

Snapshots of molecules in motion “gave us the time dimension,” Zewail says, “but what we didn’t have was the dimensions of space, the structure. We didn’t know what the horse looked like. Did it have a long tail? Beautiful eyes? My dream since 1999 was to come up with a way to look not just at time but also at the spatial domain; to see the architecture of a complex system at the atomic scale, as it changes over time, be it for physical or biological matter.”

…As reported in the Science paper, Zewail and colleagues applied their new 4D electron microscopy to observe the behavior of the atoms in superthin sheets of gold and graphite. Graphite, the material in pencils, consists of layers of carbon atoms locked into a sheet-like array. The atoms move in a unique and coherent way on the femtosecond timescale.

However, the researchers found that on a slightly longer, picosecond (one thousandth of a billionth of a second) scale, the graphite nanosheets produce sound waves. In the images, they directly visualized the elastic movements of the sheets and determined the force holding them together, which is described by a stress-strain property known as “Young’s modulus.” The 4D movies produced from the frames revealed the behavior in space and time.

In a second paper in the current issue of the journal Nano Letters [abstract], Zewail and his colleagues described their visualization of the changes in a nanometer-thick graphite membrane on a longer time scale, up to a thousandth of a second. The researchers first blasted the sample with a pulse of heat. The heated carbon atoms began to vibrate in a random, nonsynchronized fashion. Over time, however, the oscillations of the individual atoms became synchronized as different modes of the material locked in phase, emerging to become a heartbeat-like “drumming.” Digital video, slowed down more than a billion times, illustrates this nano-drumming mechanical phenomenon, which displays a well-defined resonance that is nearly 100 times higher than can be detected by the human eardrum.

—Jim