Volume 10 Issue 2, February 2011

By combining gene cloning and amplification techniques, a new one-pot, parallel synthesis method for the generation of long, repetitive genes is realized. The method promises to open up the discovery of protein polymer biomaterials.

A knot-containing protein is found to fold reversibly at biologically relevant timescales despite not having naturally evolved for this ability.

Bodies in relative motion, separated by nanometres of vacuum, experience a tiny friction force. Experiments involving a conductor–superconductor transition provide essential information for distinguishing the contribution of electrons from that of lattice vibrations in this non-contact form of friction.

Metallic glasses are strong but can be brittle. The discovery of a metallic glass that also shows a high toughness against fracture is remarkable, and establishes metallic glasses, at least those based on noble metals, as materials with the highest known damage tolerance.

Single dopants in semiconductors have an atom-like electron-energy spectrum whose discrete character gives them the potential for applications such as quantum information or transistors. This Review describes the marked advances in the past decade towards observing, controllably creating and manipulating single dopants, as well as their application in devices.

The control over phase transitions in complex oxides offers the possibility to control their electronic and structural properties. The discovery of a new route to ultrafast photoswitching of manganites via high-energy ‘hidden’ excited states offers the possibility of phase transitions free from thermal effects.

Skyrmions are vortex-like arrangements of spin magnetic moments, which so far have been observed in only a few compounds, and only at low temperatures. The discovery that skyrmions can be stabilized by thin magnetic films close to room temperature promises their use in spintronic devices.

Plasmon lasers can operate at dimensions well below the diffraction limit. Their small size promises uses in nanophotonic circuits and for other size-critical applications. The demonstration of a sub-diffraction-limited plasmon laser with low losses, which enables its room-temperature operation, takes a significant step towards realizing the potential of these lasers.

Considerable attention has been given in the past few years to two-dimensional electron gases formed at the interface between two bulk insulators. It is now shown that a similar electronic system can be created on the surface of an oxide insulator simply by exposure to UV light.

Is friction dominated by electrons or by lattice vibrations? A nano-contact experiment shows that on a Nb surface friction drops by a factor of three when crossing the superconductivity transition, showing that it has essentially an electronic nature in the metallic state, whereas the phononic contribution dominates in the superconducting state.

Metallic glasses are strong but at the same time are brittle once they yield. A new Pd-based metallic glass now shows significantly enhanced fracture toughness. The unique combination of yield strength and toughness makes this glass comparable to the toughest as well as strongest materials known.

Phase-change materials are key components in rewritable optical disks and are promising for non-volatile electronic memories. The very different structure and ultrafast recrystallization dynamics of another class of phase-change materials, Sb–Te-based alloys, now suggests their use in future memory applications.

Devices that can field-ionize gas molecules at low bias voltages are promising for selective gas-sensing applications and for ion-mobility spectrometry. Field ionization is now observed at very low voltage on semiconducting whiskered silicon nanowires.

A one-pot, high-throughput method for the recombinant polymerization of monomer DNA sequences is reported. The method enables the rapid synthesis of diverse libraries of artificial repetitive polypeptides, exemplified by the isolation of protease-responsive polymers and a family of polypeptides with reversible thermally responsive behaviour.

A polymeric hydrogel coating shows impressive antimicrobial activity against both bacteria and fungi. The biocompatible and reusable coating, formed of a polycationic nanoporous hydrogel, is thought to act by drawing anionic sections of phospholipids on bacterial cell membranes into its pores, causing membrane disruption and cell death.