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. 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.