Friday, September 17, 2010

This week in nanotechnology - September 17, 2010

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, they were able to measure exchange of ions through the pore and demonstrated that a long DNA molecule can be pulled through the graphene nanopore just as a thread is pulled through the eye of a needle.

artificial e-skin with nanowire active matrix circuitry covering a hand
An artist's illustration of an artificial e-skin with nanowire active matrix circuitry covering a hand. The fragile egg illustrates the functionality of the e-skin device for prosthetic and robotic applications.

Engineers make artificial skin out of nanowires. Engineers at UC Berkeley, have developed a pressure-sensitive electronic material from semiconductor nanowires that could one day give new meaning to the term "thin-skinned." A touch-sensitive artificial skin would help overcome a key challenge in robotics: adapting the amount of force needed to hold and manipulate a wide range of objects.

Using carbon nanotubes, MIT chemical engineers have found a way to concentrate solar energy 100 times more than a regular photovoltaic cell. Such nanotubes could form antennas that capture and focus light energy, potentially allowing much smaller and more powerful solar arrays.

Molecular machines can be found everywhere in nature, for example, transporting proteins through cells and aiding metabolism. To develop artificial molecular machines, scientists need to understand the rules that govern mechanics at the molecular or nanometer scale. To address this challenge, a research team at UC Riverside studied a class of molecular machines that 'walk' across a flat metal surface. They considered both bipedal machines that walk on two 'legs' and quadrupedal ones that walk on four.

aregions on a cathode surface display varying electrochemical behaviors when probed with ESM
This 1 micron x 1 micron composite image demonstrates how regions on a cathode surface display varying electrochemical behaviors when probed with ESM.

As industries and consumers increasingly seek improved battery power sources, cutting-edge microscopy performed at the Department of Energy's Oak Ridge National Laboratory is providing an unprecedented perspective on how lithium-ion batteries function. They have developed a new type of scanning probe microscopy called electrochemical strain microscopy (ESM) to examine the movement of lithium ions through a battery's cathode material.

A Florida State University engineering professor's innovative research with nanomaterials could one day lead to a new generation of hydrogen fuel cells that are less expensive, smaller, lighter and more durable. Working with carbon nanotubes, he has designed a membrane that could reduce the need for expensive platinum components in hydrogen fuel cells.

quantum tornado
A flat wave (left) meets the specially shaped grid screen, which converts the electron beam into right-rotating and left-rotating vortex beams (top and bottom), and a middle beam that does not rotate. Similar to in a tornado, the rotation of the electron current is low internally.

Manipulating materials with rotating quantum particles: a team from the University of Antwerp and TU Vienna has succeeded in producing what are known as vortex beams - rotating electron beams, which make it possible to investigate the magnetic properties of materials. In the future, it may even be possible to manipulate the tiniest components in a targeted manner and set them in rotation.

Researchers at Oregon State University have reported the successful loading of biological molecules onto "nanosprings" - a type of nanostructure that has gained significant interest in recent years for its ability to maximize surface area in microreactors. Nanosprings are a little like a miniature version of an old-fashioned, curled-up phone cord. They make a great support on which to place reactive catalysts, and there are a variety of potential applications.

The ability of phase-change materials to readily and swiftly transition between different phases has made them valuable as a low-power source of non-volatile or "flash" memory and data storage. Now an entire new class of phase-change materials has been discovered that could be applied to phase change random access memory (PCM) technologies and possibly optical data storage as well. The new phase-change materials – nanocrystal alloys of a metal and semiconductor – are called "BEANs," for binary eutectic-alloy nanostructures.