Friday, April 1, 2011

This week in nanotechnology - April 1, 2011

How would you like to store all the films ever made on a device the size of an I-phone? Magnets made of just a few metallic atoms could make it possible to build radically smaller storage devices and have also recently been proposed as components for spintronics devices. There's just one obstacle on the way. Nano-sized magnets have only been seen to work at temperatures a few hairs above absolute zero. Now a chemistry student at the University of Copenhagen has demonstrated that molecular magnets using the metals ruthenium and osmium retain their magnetic properties at higher temperatures.

Scientists at Berkeley Lab's Molecular Foundry have pioneered a new chemical mapping method that provides unprecedented insight into materials at the nanoscale. Moving beyond traditional static imaging techniques, which provide a snapshot in time, these new maps will guide researchers in deciphering molecular chemistry and interactions at the nanoscale—critical for artificial photosynthesis, biofuels production and light-harvesting applications such as solar cells. This new technique allows the capture of very high-resolution images of nanomaterials with a huge amount of physical and chemical information at each pixel.
coaxial probe for imaging a carbon nanotube
Schematic of coaxial probe for imaging a carbon nanotube (left) and chemical map of carbon nanotube with chemical and topographical information at each pixel (right).


A Harvard bioengineer and an MIT aeronautical engineer have created a new device that can detect single cancer cells in a blood sample, potentially allowing doctors to quickly determine whether cancer has spread from its original site. The carbon nanotube-based microfluidic device is about the size of a dime, and could also detect viruses such as HIV. It could eventually be developed into low-cost tests for doctors to use in developing countries where expensive diagnostic equipment is hard to come by.

Stanford researchers have developed a battery that takes advantage of the difference in salinity between freshwater and seawater to produce electricity. As an indicator of the battery's potential for producing power, the research team calculated that if all the world's rivers were put to use, their batteries could supply about 2 terawatts of electricity annually – that's roughly 13 percent of the world's current energy consumption.

Researchers from North Carolina State University have investigated the viability of a technique called "spincasting" for creating thin films of nanoparticles on an underlying substrate – an important step in the creation of materials with a variety of uses, from optics to electronics. Spincasting, which utilizes centrifugal force to distribute a liquid onto a solid substrate, already has a variety of uses. For example, it is used in the electronics industry to deposit organic thin films on silicon wafers to create transistors.