Friday, January 7, 2011

This week in nanotechnology - January 7, 2011

An entirely new type of nanomaterial developed at Rensselaer Polytechnic Institute could enable the next generation of high-power rechargeable lithium (Li)-ion batteries for electric automobiles, as well as batteries for laptop computers, mobile phones, and other portable devices. The new material, dubbed a "nanoscoop" because its shape resembles a cone with a scoop of ice cream on top, can withstand extremely high rates of charge and discharge that would cause conventional electrodes used in today's Li-ion batteries to rapidly deteriorate and fail. The nanoscoop's success lies in its unique material composition, structure, and size.

A quick look at new Cornell research hints at colorful patchwork quilts, but they are actually pictures of graphene -- one atom-thick sheets of carbon stitched together at tilted interfaces. Researchers have unveiled striking, atomic-resolution details of what graphene "quilts" look like at the boundaries between patches, and have uncovered key insights into graphene's electrical and mechanical properties.
A false-color microscopy image overlay depicting the shapes and lattice orientations of several grains in graphene

A false-color microscopy image overlay depicting the shapes and lattice orientations of several grains in graphene.

Researchers are creating a new type of solar cell designed to self-repair like natural photosynthetic systems in plants by using carbon nanotubes and DNA, an approach aimed at increasing service life and reducing cost. The design exploits the unusual electrical properties of single-wall carbon nanotubes, using them as molecular wires in light harvesting cells.

A promising approach for making solar cells that are inexpensive, lightweight and flexible is to use organic (that is, carbon-containing) compounds instead of expensive, highly purified silicon. But one stubborn problem has slowed the development of such cells: Researchers have had a hard time coming up with appropriate materials for the electrodes to carry the current to and from the cells. Now, a team of MIT researchers has come up with a practical way of using a possible substitute made from graphene.

Nanotechnologists at the University of Texas at Dallas have invented a broadly deployable technology for producing weavable, knittable, sewable, and knottable yarns containing up to 95 weight percent of otherwise unspinnable guest powders and nanofibers. The researchers describe the use of biscrolling to solve these problems, and demonstrate the feasibility of using their biscrolled yarns for applications ranging from superconducting cables and electronic textiles to batteries and fuel cells containing flexible woven electrodes.