Mar 29, 2011 09:27 GMT  ·  By
Schematic of coaxial probe for imaging a carbon nanotube (left) and chemical map of carbon nanotube with chemical and (right) topographical information at each pixel
   Schematic of coaxial probe for imaging a carbon nanotube (left) and chemical map of carbon nanotube with chemical and (right) topographical information at each pixel

Investigators from the US Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) announce the development of a new chemical mapping method. The approach shows great promise for analyzing objects at the nanoscale.

This new technique, pioneered by experts at the Berkeley Lab Molecular Foundry, moves past traditional static imaging methods. In the past, investigating nanoscale objects was limited to snapping a photo of the phenomena as they were happening, but at only one point in time.

Using the maps enabled by the latest technology, experts will now be able to make consdierable headway in areas of research including artificial photosynthesis, biofuels production and light-harvesting applications.

Deciphering mysteries related to molecular chemistry and the interactions materials develop at the nanoscale will also become considerably easier, the Molecular Foundry team explains.

“This new technique allows us to capture very high-resolution images of nanomaterials with a huge amount of physical and chemical information at each pixel,” explains Alexander Weber-Bargioni.

“Usually when you take an image, you just get a picture of what this material looks like, but nothing more. With our method, we can now gain information about the functionality of a nanostructure with rich detail,” he says further.

Weber-Bargioni holds an appointment as a postdoctoral scholar in the Molecular Foundry Imaging and Manipulation of Nanostructures Facility. He explains that the new approach was only made possible by the fact that the expert and his team had access to the focused ion beam tool at the Facility.

What the team did was basically design and construct a coaxial antenna capable of focusing light at the nanoscale with tremendous precision. The antenna itself is made out of a silicon nitride atomic force microscope tip, that is coated with gold atoms.

“Fabricating reproducible near-field optical microscopy probes has always been a challenge,” explains the acting facility director of the Nanostructures Facility, Frank Ogletree,

“We now have a high-yield method to make engineered plasmonic probes for spectroscopy on a variety of surfaces,” he goes on to say. The expert explains that maps examining nanomaterial are critical to scientists because they show locations where local surface chemistry and interfaces dominate behavior.

“We’re very excited – this new nano-optics capability enables us to explore previously inaccessible properties within nanosystems,” says Facility staff scientist Jim Schuck.

“The work reflects a major strength of the Molecular Foundry, where collaboration between scientists with complementary expertise leads to real nanoscience breakthroughs,” he concludes.