Volume 3 Issue 8, August 2008

A new technology will only be successful if those promoting it can show that it is safe, but history is littered with examples of promising technologies that never fulfilled their true potential and/or caused untold damage because early warnings about safety problems were ignored. The nanotechnology community stands to benefit by learning lessons from this history.

Is nanotechnology an example of a new approach to science and technology, or have commercial considerations always played a major role in decisions about funding research? Richard Jones looks at both sides of the argument.

Its economy might be dominated by agriculture and tourism, but Thailand is investing heavily in nanotechnology, although a shortage of scientists and engineers remains a problem, as Adarsh Sandhu reports.

Polymer scaffolds reinforced with carbon nanotubes can improve the growth of bone tissue in rabbits.

The unique electronic band structure of graphene has led to a number of exotic effects that have fascinated fundamental researchers and may also lead to improvements in the performance of electronic devices.

A dislocation running through the trunk of a nanowire offers a new twist to the growth of chiral branched nanostructures, producing beautiful tree-like structures in the process.

Cotton is an important raw material for producing soft textiles and clothing. Recent discoveries in functionalizing cotton fibres with nanotubes may offer a new line of tough, wearable, smart and interactive garments.

A superconducting detector can count photons and measure their energy with an accuracy that could be good enough for space-based far-infrared telescopes.

Conventional atomic force microscopy probes only the surface of specimens. A related technique called scanning near-field ultrasonic holography can now image nanoparticles buried below the surfaces of cells, which could prove useful in nanotoxicology.

Understanding how nature's nanomotors achieve the assembly of complex molecules and the intracellular transport of cargo will enable their future application in non-natural settings and provide inspiration for the development of purely synthetic systems.

The electrical, optical and mechanical properties of nanowires depend on their morphology. Nanowires that possess both chirality and a branched structure may therefore possess new material properties. Such nanowires can be formed by vapour–liquid–solid branching from a central PbSe nanowire with an axial screw dislocation.

Quantum co-tunnelling through a single-electron transistor limits its performance for many applications. Researchers have now built a nanomechanical single-electron shuttle driven by ultrasound waves in which co-tunnelling is suppressed. This approach could lead to the development of high-performance nanomechanical single-electron devices. (Summary revised 8 July 2008)

Scanning photocurrent microscopy has revealed that metal contacts lead to potential steps that act as transport barriers in graphene devices. The formation of p-type conducting edges surrounding a central n-type channel has also been observed at low carrier densities.

The novel electronic properties of graphene can be compromised when it is supported on an insulating substrate. However, suspended graphene samples can display low-temperature mobility values that cannot be attained in semiconductors or non-suspended graphene, and the conductivity approaches ballistic values at liquid-helium temperatures.

By carefully controlling the heat capacity and other thermal properties of a superconducting hot-electron nanobolometer, researchers have built a device that is sufficiently sensitive to detect single terahertz photons, making it suitable for use in a future space-based terahertz telescope.

Scanning near-field ultrasonic holography has been used to probe inside cells taken from the lungs of mice that had been exposed to carbon nanohorns, and provides evidence that these particles can enter the cells. The ability to detect nanoparticles below the cell surface could make this technique useful for studying toxicity of nanomaterials.

Aqueous dispersions of nanoparticles of Triclosan — a commercial antimicrobial agent — display better biocidal activity than organic solutions of the same agent. The nanoparticles are produced by a combination of modified emulsion-templating and freeze-drying.

Elastomeric proteins similar to those found in many biological tissues have been engineered so that they can behave as springs or shock absorbers.