Volume 7 Issue 7, July 2008

Although the Internet has fundamentally changed the way we communicate, science publishing is remarkably hesitant in making full use of the potential offered by new technology.

The American Physical Society is the largest publisher in physics. Nature Materials talks to Gene Sprouse, Editor-in-Chief of APS publications.

Nanoparticles with alternating striations of hydrophobic and hydrophilic ligands cross the cell membrane by a direct mechanism — a route that delivers them to the main compartment of the cell while leaving the membrane undisrupted.

The observation of metallic conductivity at interfaces between layers of organic insulators opens the way to the realization of a wide range of electronic systems that cannot be prepared in bulk organic materials.

A blend of ferroelectric and semiconducting polymers provides a potential route to a memory technology compatible with low-cost printed electronics.

Materials that respond to their external environment require creative molecular design — much inspiration comes from the natural world.

One-dimensional metals are predicted to exhibit charge-order fluctuations and become insulators at low temperature. Experiments on silicide nanowires grown on silicon reveal that fluctuations in the narrowest wires determine the electronic properties, and can be exploited in nanoelectronic devices.

Metamaterials enable a number of intriguing photonic functionalities from superlensing to cloaking. The demonstration of truly three-dimensional metamaterials by a direct laser writing process offers the possibility of complex photonic functionalities at optical frequencies.

Although ferroelectric polarization is of interest for the development of non-volatile memories, the read-out of the polarization state is destructive. The blending of semiconducting and ferroelectric polymers in a phase-separated network achieves non-volatile memory arrays that can be read out non-destructively.

The occupation of specific crystallographic sites by tetrahedrally coordinated aluminium atoms in zeolites has a strong influence on their catalytic and separation performance. X-ray standing waves are now used to directly and unambiguously determine the distribution and ordering of aluminium on active sites in a microporous scolecite system.

Cooled liquids that fail to reach their thermodynamic ground state either form gels or glasses. Their formation is thought to be promoted by stable local atomic structures. The role of these local structures has now been verified in experiments that also show that their structural variety is much larger than expected.

Relaxor ferroelectrics, which show a strong dependence of electric polarization on the applied electric field, are promising for applications such as sensors and actuators. Neutron-scattering experiments now establish a direct link between the unique piezoelectric properties of relaxors and local clusters of randomly oriented polarization specific to these materials.

Nanomagnets are very promising structures for magnetic data storage. However, it is found that during exposure to ambient oxygen for processing, a nanomagnet develops a sidewall oxide layer that is detrimental for its magnetic properties. The problem can be solved by deposition of a metal layer (aluminium) that reduces and almost eliminates the problem.

The electronic properties of interfaces between two different solids can differ strikingly from those of the constituent materials, as demonstrated by the high conductivity at the interface between insulating perovskite oxide layers. Metallic conductivity is now observed at the interface between organic insulators, which promises new scientific developments for organic electronics.

Fabrication of complex two-dimensional patterns is now possible using ‘rails’ as a guiding mechanism for the self-assembly of microstructures within fluidic channels. The method is efficient, and heterogeneous systems, for example patterns of different living cells for tissue engineering, can be made with high precision.

The structural organization of surface groups on nanoparticles is proven to be important for cell membrane penetration. Nanoparticles coated with alternating ribbon-like arrangements of hydrophobic and anionic ligands penetrate membranes without causing disruption. These design rules may have implications for toxicity issues and drug delivery applications of nanomaterials.