Friday, October 29, 2010

This week in nanotechnology - October 29, 2010

Researchers at the University of Pennsylvania have developed a new electronic method for detecting microRNA isolated from living cells. MicroRNAs are a class of small biomolecules that control gene expression into proteins, the "workers" of the cell. MicroRNAs act by binding to specific messenger RNAs that code for proteins, and, by doing so, inhibit protein synthesis.

Bone consists of fibers of collagen in which calcium phosphate is deposited in the form of nanocrystals. Researchers at Eindhoven University of Technology have for the first time succeeded in mimicking the process of bone formation in the laboratory, and in visualizing the process in great detail.

EU research initiative called 'Steeper'aims to increase electronic device efficiency by 10x and eliminate power consumption of devices in standby mode. Scientists collaborating on the project will apply their expertise and research to tunnel field effect transistors (TFETs) and semiconducting nanowires to improve the efficient use of energy in electronics. To explain the challenge, consider a leaky water faucet -- even after closing the valve as far as possible water continues to drip -- this is similar to today's transistor, in that energy is constantly "leaking" or being lost or wasted in the off-state. In Steeper, scientists not only hope to contain the leak by using a new method to close the valve or gate of the transistor more tightly, but also open and close the gate for maximum current flow with less turns, i.e. less voltage for maximum efficiency.

Researchers from North Carolina State University have found a way to optimize the development of DNA self-assembling materials, which hold promise for technologies ranging from drug delivery to molecular sensors.

buckyballs in space

And some fun fact at the end: Astronomers have discovered bucket loads of buckyballs in space. They used NASA's Spitzer Space Telescope to find the little carbon spheres throughout our Milky Way galaxy – in the space between stars and around three dying stars. What's more, Spitzer detected buckyballs around a fourth dying star in a nearby galaxy in staggering quantities – the equivalent in mass to about 15 of our moons.

Friday, October 22, 2010

This week in nanotechnology, October 22, 2010

Scientists have captured the first direct images of magnetic monopoles which were theoretically conceived by the British-Swiss physicist Dirac in the early 1930s who showed that their existence is consistent with the ultimate theory of matter – quantum theory.

For the first time scientists have been able to watch nanoparticles grow from the earliest stages of their formation. Nanoparticles are the foundation of nanotechnology and their performance depends on their structure, composition, and size. Researchers will now be able to develop ways to control conditions under which they are grown. The breakthrough will affect a wide range of applications including solar-cell technology and chemical and biological sensors.
bacterial nanowire

This image shows nanoparticles growing.

Photonic crystals are exotic materials with the ability to guide light beams through confined spaces and could be vital components of low-power computer chips that use light instead of electricity. Cost-effective ways of producing them have proved elusive, but researchers have recently been turning toward a surprising source for help: DNA molecules. The researchers demonstrated that tiny particles of gold and balls of protein known as virus-like particles, both with strands of DNA attached to them, would spontaneously organize themselves into a lattice-like structure. Although the materials themselves aren't useful for making photonic crystals, the distances between the particles are exactly those that would enable a photonic crystal to guide light in the visible spectrum.

Nature has one very big advantage over any human research team: plenty of time. Billions of years, in fact. And over all that time, it has produced some truly amazing materials — using weak building blocks that human engineers have not yet figured out how to use for high-tech applications, and with many properties that humans have yet to find ways to duplicate. But now a number of researchers have begun to unravel these processes at a deep level, not just finding out how the materials behave but what the essential structural and chemical characteristics are that give them their unique properties. In the future, they hope to mimic those structures in ways that produce even better results.

Twisting spires, concentric rings, and gracefully bending petals are a few of the new three-dimensional shapes that University of Michigan engineers can make from carbon nanotubes using a new manufacturing process. The process is called "capillary forming", and it takes advantage of capillary action, the phenomenon at work when liquids seem to defy gravity and travel up a drinking straw of their own accord.
bacterial nanowire

Twisting spires are one of the 3D shapes researchers were able to develop using a new manufacturing process.

University of Virginia chemical engineers have uncovered the key features that control the high reactivity of gold nanoparticles in a process that oxidizes alcohols in water. The research is an important first step in unlocking the potential of using metal catalysts for developing biorenewable chemicals.

Scientists take first step toward electronically interfacing microbes with inorganic materials. The Terminator. The Borg. The Six Million Dollar Man. Science fiction is ripe with biological beings armed with artificial capabilities. In reality, however, the clunky connections between living and non-living worlds often lack a clear channel for communication. Now, scientists with the Berkeley Lab have designed an electrical link to living cells engineered to shuttle electrons across a cell's membrane to an external acceptor along a well-defined path. This direct channel could yield cells that can read and respond to electronic signals, electronics capable of self-replication and repair, or efficiently transfer sunlight into electricity.

Friday, October 15, 2010

This week in nanotechnology - October 15, 2010

Scientists have developed a novel nano-tomography method, which uses X-rays to allow doctors to produce three-dimensional (3D) detailed imaging of fragile bone structures. This method could lead to the development of better therapeutic approaches to tackle the brittle bone disease osteoporosis, one of the most common disorders among older people.

Some bacteria grow electrical hair that lets them link up in big biological circuits, according to a University of Southern California biophysicist and his collaborators. The finding suggests that microbial colonies may survive, communicate and share energy in part through electrically conducting hairs known as bacterial nanowires.
bacterial nanowire

Like human hair, a bacterial nanowire consists mostly of protein.

Rice University research that capitalizes on the wide-ranging capabilities of graphene could lead to circuit applications that are far more compact and versatile than what is now feasible with silicon-based technologies. Triple-mode, single-transistor amplifiers based on graphene -- the one-atom-thick form of carbon that recently won its discoverers a Nobel Prize -- could become key components in future electronic circuits.

Researchers at the Georgia Institute of Technology and Emory University have developed a novel approach for delivering small bits of genetic material into the body to improve the treatment of inflammatory bowel diseases. Delivering short strands of RNA into cells has become a popular research area because of its potential therapeutic applications, but how to deliver them into targeted cells in a living organism has been an obstacle. The team encapsulated short pieces of RNA into engineered particles called thioketal nanoparticles and orally delivered the genetic material directly to the inflamed intestines of animals.

Tyndall National Institute, UCC announced the development of a new nanomaterial that will dramatically reduce the operating temperature of silicon chip components and circuits, thereby enhancing the reliability and lifetime of electronics in products ranging from smart phones to automotive electronics.

Friday, October 8, 2010

This week in nanotechnology, October 8, 2010

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2010 to Andre Geim and Konstantin Novoselov, University of Manchester, "for groundbreaking experiments regarding the two-dimensional material graphene".

In recent years, studies have shown that for many types of cancer, combination drug therapy is more effective than single drugs. However, it is usually difficult to get the right amount of each drug to the tumor. Now researchers at MIT and Brigham and Women's Hospital have developed a nanoparticle that can deliver precise doses of two or more drugs to prostate cancer cells.

The enigmatic Möbius strip has long been an object of fascination, appearing in numerous works of art, most famously a woodcut by M.C. Escher, in which a tribe of ants traverses the form's single, never-ending surface. Scientists have now reproduced a nanoscale Möbius strip, joining up braid-like segments of DNA to create Möbius structures measuring just 50 nanometers across—roughly the width of a virus particle. Eventually, researchers hope to capitalize on the unique material properties of such nano-architectures, applying them to the development of biological and chemical sensing devices, nanolithography, drug delivery mechanisms pared down to the molecular scale and a new breed of nanoelectronics.
nanoscale DNA Möbius strip
This is the design for the DNA Möbius strip. Single-stranded viral DNA is used as scaffolding and 164 short segments of DNA are used as staple strands, to create the nanostructure. The Möbius form is composed of eleven double helices, assembled in parallel (left). Each double-helical length contains a twist of 180 degrees along its central axis, before it seamlessly reconnects with itself. The central helix, (seen in red) circles around the length of the strip once. The other helices circle twice, while also twisting around the core helix by 180 degrees before reconnecting to close the Möbius loop. (Center) A small segment of the strip with the details of the helices shown. Scaffold strands are seen in blue and staple strands are different colors. To create the Möbius, 20.5 units like this were used, with the precise folding pattern pre-programmed through the design of appropriate nucleotide base-pairing. (Right) Atomic Force Microscopy image.

Early detection is critical for improving cancer survival rates. Yet, one of the deadliest cancers in the United States, lung cancer, is notoriously difficult to detect in its early stages. Now, researchers have developed a method to detect lung cancer by merely shining diffuse light on cells swabbed from patients' cheeks. Nanoscale disturbances in cheek cells indicate the presence of lung cancer. Regular microscopy looking at chromatin, the genetic material inside a cell's nucleus, will not reveal significant dissimilarities between the cheek cells of a healthy person and those of a lung cancer patient. However, a new technique called partial wave spectroscopic microscopy (PWS) zeroes in on smaller-than-microscopic disturbances at the nano-level, which are harbingers of trouble.

Cornell researchers have developed a new method to create a patterned single-crystal thin film of semiconductor material that could lead to more efficient photovoltaic cells and batteries. The "holy grail" for such applications has been to create on a silicon base, or substrate, a film with a 3-D structure at the nanoscale, with the crystal lattice of the film aligned in the same direction (epitaxially) as in the substrate. Doing so is the culmination of years of research into using polymer chemistry to create nanoscale self-assembling structures.

Friday, October 1, 2010

This week in nanotechnology - October 1, 2010

A 'forest' of molecules holds the promise of turning waste heat into electricity. What do a car engine, a power plant, a factory and a solar panel have in common? They all generate heat – a lot of which is wasted. University of Arizona physicists have discovered a new way of harvesting waste heat and turning it into electrical power. Unlike existing heat-conversion devices such as refrigerators and steam turbines, the new devices of require no mechanics and no ozone-depleting chemicals. Instead, a rubber-like polymer sandwiched between two metals acting as electrodes can do the trick.

Researchers at IBM have added a new measurement method to their toolkit to capture ultra-fast phenomena on individual nano-objects. The ability to measure nanosecond-fast phenomena opens a new realm of experiments for scientists, since they can now add the dimension of time to experiments in which extremely fast changes occur.

In a major physics breakthrough with international significance, scientists have developed a technique to consistently isolate and capture a fast-moving neutral atom – and have also seen and photographed this atom for the first time. The researchers used laser cooling technology to dramatically slow a group of rubidium 85 atoms. A laser-beam, or "optical tweezers", was then deployed to isolate and hold one atom - at which point it could be photographed through a microscope.

Graphene may hold key to speeding up DNA sequencing - researchers from Harvard University and MIT have demonstrated that graphene, a surprisingly robust planar sheet of carbon just one-atom thick, can act as an artificial membrane separating two liquid reservoirs. By drilling a tiny pore just a few-nanometers in diameter, called a nanopore, in the graphene membrane, the researchers were able to measure exchange of ions through the pore and demonstrate that a long DNA molecule can be pulled through the graphene nanopore just as a thread is pulled through the eye of a needle.

A layer of graphene is shown with a tiny nanopore drilled into its surface

A layer of graphene is shown with a tiny nanopore drilled into its surface. Researchers at Harvard and MIT say the membrane holds potential for speeding up DNA sequencing due to its extreme thinness.

Getting an inside look at the center of a cell can be as easy as a needle prick, thanks to University of Illinois researchers who have developed a tiny needle to deliver a shot right to a cell's nucleus. The team developed a nanoneedle that also served as an electrode that could deliver quantum dots directly into the nucleus of a cell – specifically to a pinpointed location within the nucleus.

Scientists report the first successful assembly of 3-D multi-component nanoscale structures with tunable optical properties that incorporate light-absorbing and -emitting particles. This work, using synthetic DNA as a programmable component to link the nanoparticles, demonstrates the versatility of DNA-based nanotechnology for the fabrication of functional classes of materials, particularly optical ones, with possible applications in solar-energy conversion devices, sensors, and nanoscale circuits.