Friday, April 23, 2010

This week in nanotechnology - April 23, 2010

A new biosensor can measure whether neurons are performing correctly when communicating with each other, giving researchers a tool to test the effectiveness of new epilepsy or seizure treatments. The novel sensor exploits conductive carbon nanotubes and is only 2 micrometers in diameter, or about 50 times smaller than the diameter of a human hair.

Researchers have developed nano-sized cantilevers for atomic force microscopes whose gentle touch could help discern the workings of living cells and other soft materials in their natural, liquid environment. Used in combination with a revolutionary detection mechanism, this new imaging tool is sensitive enough to investigate soft materials without the limitations present in other cantilevers.

IBM scientists have created a 3D map of the earth so small that 1,000 of them could fit on one grain of salt. The scientists accomplished this by means of a new, breakthrough technique that uses a tiny, silicon tip with a sharp apex — 100,000 times smaller than a sharpened pencil — to create patterns and structures as small as 15 nanometers at greatly reduced cost and complexity. This patterning technique opens new prospects for developing nanosized objects in fields such as electronics, future chip technology, medicine, life sciences, and opto-electronics.

nanoscale world map

The world just got a little smaller. IBM scientists have created a complete 3D map of the world measuring only 22 by 11 micrometers. The nano-world was “written” – on a polymer - at this size 1000 world maps could fit on a grain of salt. In the relief, one thousand meters of altitude correspond to roughly eight nanometers. It is composed of 500,000 pixels, each measuring 20 nm2 and was created in only 2 minutes and 23 seconds.

New research demonstrates that a vaccine delivered by a Nanopatch induces a similarly protective immune response as a vaccine delivered by needle and syringe, but uses 100 times less vaccine. This discovery has implications for many vaccination programs in both industrialised and developing nations, which must overcome issues with vaccine shortages and distribution. Being both painless and needle-free, the nanopatch offers hope for those with needle phobia, as well as improving the vaccination experience for young children.

Mimicking the human nervous system for bionic applications could become a reality with the help of a method developed to process carbon nanotubes. While these nanostructures have electrical and other properties that make them attractive to use as artificial neural bundles in prosthetic devices, the challenge has been to make bundles with enough fibers to match that of a real neuron bundle. With current technology, the weight alone of wires required to match the density of receptors at even the fingertips would make it impossible to accommodate. Now, by adapting conventional glass fiber drawing technology to process carbon nanotubes into multichannel assemblies, researchers believe they are on a path that could lead to a breakthrough.

Scientists take first step toward controlling the growth of nanomaterials without catalysts. The question of how one-dimensional crystals grow sometimes without catalysts has been troublesome for scientists and engineers who need to produce large amounts of nanomaterials for specific applications. Working with zinc oxide, a common semiconductor widely used as a nanomaterial, researchers now demonstrated a new understanding of the subject by showing that nanotubes can be formed solely due to the strain energy and screw dislocations that drive their growth.

If you think that building an artificial human brain is science fiction, you are probably right – for now. But don't think for a moment that researchers are not working hard on laying the foundations for what is called neuromorphic engineering – a new interdisciplinary discipline that includes nanotechnologies and whose goal is to design artificial neural systems with physical architectures similar to biological nervous systems. One of the key components of any neuromorphic effort is the design of artificial synapses. The human brain contains vastly more synapses than neurons – by a factor of about 10,000 – and therefore it is necessary to develop a nanoscale, low power, synapse-like device if scientists want to scale neuromorphic circuits towards the human brain level. New research now suggests that memristor devices are capable of emulating the biological synapses with properly designed CMOS neuron components.