Friday, December 18, 2009

This week in nanotechnology, Dec 18, 2009

A team led by Yale University researchers has used nanosensors to measure cancer biomarkers in whole blood for the first time. Their findings could dramatically simplify the way physicians test for biomarkers of cancer and other diseases. The team demonstrated nanowire sensors to detect and measure concentrations of two specific biomarkers: one for prostate cancer and the other for breast cancer.

In another nanomedicine development, researchers have created a single nanoparticle that can be tracked in real time with MRI as it homes in on cancer cells, tags them with a fluorescent dye and kills them with heat. The all-in-one particle is one of the first examples from a growing field called "theranostics" that develops technologies physicians can use to diagnose and treat diseases in a single procedure.

A new microscopic system could provide a novel method for moving tiny objects inside a microchip, and could also provide new insights into how cells and other objects are transported around within the body. Inside organs such as the trachea and the intestines, tiny hair-like filaments called cilia are constantly in motion, beating in unison to create currents that sweep along cells, nutrients, or other tiny particles. The new research uses a self-assembling system to mimic that kind of motion, providing a simple way to move particles around in a precisely controlled way.

Scientists at Georgia Tech have developed a nanolithographic technique that can produce high-resolution patterns of at least three different chemicals on a single chip at writing speeds of up to one millimeter per second. The chemical nanopatterns can be tailor-designed with any desired shape and have been shown to be sufficiently stable so that they can be stored for weeks and then used elsewhere.

Not quite nanotechnology but still amazing: scientists use bacteria to power simple machines. ave discovered that common bacteria can turn microgears when suspended in a solution, providing insights for design of bio-inspired dynamically adaptive materials for energy. The gears are a million times more massive than the bacteria. The ability to harness and control the power of bacterial motions is an important requirement for further development of hybrid biomechanical systems driven by microorganisms.

Scientists film photons with electrons. Techniques recently invented by researchers at the California Institute of Technology – which allow the real-time, real-space visualization of fleeting changes in the structure of nanoscale matter – have been used to image the evanescent electrical fields produced by the interaction of electrons and photons, and to track changes in atomic-scale structures.

Friday, December 11, 2009

This week in nanotechnology, Dec 11, 2009

Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper. Simply coating a sheet of paper with ink made of carbon nanotubes and silver nanowires makes a highly conductive storage device. Like batteries, capacitors hold an electric charge, but for a shorter period of time. However, capacitors can store and discharge electricity much more rapidly than a battery.

Nanoscale machines expected to have wide application in industry, energy, medicine and other fields may someday operate far more efficiently thanks to important theoretical discoveries concerning the manipulation of famous Casimir forces. The groundbreaking research, conducted through mathematical simulations, revealed the possibility of a new class of materials able to exert a repulsive force when they are placed in extremely close proximity to each other. The repulsive force, which harnesses a quantum phenomenon known as the Casimir effect, may someday allow nanoscale machines to overcome mechanical friction.

University of Wisconsin-Madison researchers have achieved a nanoscale laser structure they anticipate will produce semiconductor lasers in the next two years that are more than twice as efficient as current continuous-wave lasers emitting in the mid-infrared. These next-generation lasers could benefit a wide range of industries, as they could be used in biomedical devices, environmental monitoring devices, missile avoidance systems and even food packaging processes.

All existing forms of electronics are built on the two-dimensional, planar surfaces of either semiconductor wafers or plates of glass. Mechanically flexible circuits based on organic semiconductors are beginning to emerge into commercial applications, but they can only be wrapped onto the surfaces of cones or cylinders – they cannot conform to spheres or any other type of surface that exhibits non-Gaussian curvature. Applications that demand conformal integration, e.g. structural or personal health monitors, advanced surgical devices, or systems that use ergonomic or bio-inspired layouts, etc., require circuit technologies in curvilinear layouts like the ones developed by the Rogers Group at the University of Illinois.

molecular dynamics simulation of a protein embedded in water

Silicon circuit mesh wrapped onto a pyramidal substrate. (Image: Rogers Group, University of Illinois)

Scientists have developed a way to rapidly manipulate and sort different cells in the blood using magnetizable liquids. Ferrofluids are comprised of magnetic nanoparticles suspended throughout a liquid carrier. They have been used in industrial applications for years, including in hard disk drives and loudspeakers. Now, a biocompatible ferrofluid – one with the right pH level and salinity so that human cells can survive in it for several hours – and a device with integrated electrodes that generate a magnetic field pattern, allowing researchers to manipulate and separate red blood cells, sickle cells and bacteria contained in this unique solution.

Using a nanoparticle from corn, a Purdue University scientist has found a way to lengthen the shelf life of many food products and sustain their health benefits by successfully modifying the phytoglycogen nanoparticle, a starchlike substance that makes up nearly 30 percent of the dry mass of some sweet corn. The modification allows the nanoparticle to attach to oils and emulsify them while also acting as a barrier to oxidation, which causes food to become rancid.

Friday, December 4, 2009

This week in nanotechnology, Dec 4, 2009

Researchers in Europe and Australia have succeeded in building a working single-atom transistor, whose active region composes only of a single phosphorus atom in silicon. The working principles of the device are based on sequential tunneling of single electrons between the phosphorus atom and the source and drain leads of the transistor. The tunneling can be suppressed or allowed by controlling the voltage on a nearby metal electrode with a width of a few tens of nanometers.

Single-walled nanotubes – cylinders of carbon about a nanometer in diameter – have been highly touted for potential applications such as ultrastrong fibers, electrical wires in molecular devices, or hydrogen storage components for fuel cells. Thanks to a new development , you can add one more application to the list: detection and destruction of an aggressive form of breast cancer.

An important new study raises the curtain on the hidden lives of proteins at the atomic level. The study reports that for the first time, researchers used x-ray crystallography and nuclear magnetic resonance (NMR) techniques to directly visualize protein structures essential for catalysis at the rare high-energy state. The study also showed how the motions of these rare, or hidden, structures collectively, directly contribute to enzyme catalysis.

Researchers at Rensselaer Polytechnic Institute have discovered a new, more precise method for measuring how much – or how little – nanoscale interfaces love water. This new method for measuring hydrophobicity at the nanoscale could have important applications for the future of drug discovery.

molecular dynamics simulation of a protein embedded in water

The above snapshot from a molecular dynamics simulation shows a protein (center) embedded in water.

A new understanding about nanoparticle behavior in sewage treatment plants could improve the environmental management of nanoparticle wastes from foods, cosmetics, medicines, cleaning and personal care products. Scientists have now studied how certain nanoparticles behave in wastewater and have now identified a way to potentially help remove them during primary sewage treatment.

Nanotechnology catalytical techniques are having a profound impact on clean energy research and development, ranging from hydrogen and liquid fuel production to clean combustion technologies. In this area, catalyst stability is paramount for technical application, and remains a major challenge, even for many conventional catalysts. Researchers have now overcame a major hurdle in developing more efficient nanoparticle catalysts by demonstrating high-temperature stability in metallic nanoparticles.