Volume 14 Issue 7, July 2015

Exchange bias is a magnetic phenomenon that has facilitated the ever-increasing storage density of magnetic recording systems. The finding of high tunable exchange bias in certain Heusler alloys indicates new routes for the design of rare-earth-free hard magnetic materials.

A growing body of evidence suggests that nucleation of a first dislocation in a pristine crystal is associated with a diffusion-controlled process. Understanding this is critical for strain-engineered devices at ultrahigh stresses.

Imaging the dynamics of local phenomena in materials with resolution down to the individual grain level is poised to transform our understanding of material behaviour.

Ultrathin and conformal piezoelectric transducers enable high-resolution mapping of the mechanical properties of human skin.

DNA spacing within hexagonal bundles of DNA and polycationic peptides correlates with interferon production in dendritic cells.

Microgel particle precursors bearing peptide substrates for human enzymes crosslink in wound sites to produce bioactive scaffolds in situ that rapidly recruit cells and promote dermal healing.

Researchers develop a simple and low-cost fabrication method for the production of large-scale all-dielectric metasurfaces, which exhibit near-perfect reflectivity in the telecommunications spectral window.

Thermal vibrations in materials can be controlled via interference (in a similar way to light propagating in layered structures) to produce a thermal bandgap, an approach promising for thermoelectric applications.

In the superconducting phase of niobium nitride the spin Hall effect is mediated by quasiparticles. Decreasing the spin injection current causes the inverse spin Hall signal to become 2,000 times larger in this phase than in the normal state.

An approach to design compensated ferrimagnetic Heusler alloys is established. A small lack of compensation produces giant exchange bias and large coercivity. This effect is observed for alloys that have the magnetic transition above room temperature.

A design rule to synthesize organic molecules with a phosphorescence lifetime longer than 1 second is presented. The molecules form H aggregates that promote the stabilization of triplet excitons and persistent luminescence under ambient conditions.

An in situ X-ray nanodiffraction technique allows for the real-time study of the photoinduced chemical reaction to produce Ag from AgBr, and can spatially resolve structural changes at the submicrometre scale with a time resolution of 5 ms.

Liquid-crystalline arrangements of complexes of DNA and antimicrobial peptides can lead to multivalent electrostatic interactions that drastically amplify TLR9-mediated immune responses.

Clinical translation of transcription factor therapeutics is limited by delivery problems. Now, an oligonucleotide that can bind and deliver transcription factors with high in vivo efficiency and treat acetaminophen-induced liver injury is reported.

A detailed study is performed of dislocation nucleation at the surface of defect-free crystalline nanowhiskers, including the effect of sample size, temperature and strain rate, via in situ mechanical testing.

Sub-ångström-resolution indentation measurements and semi-analytical methods indicate that, for few-layer-thick films, the elasticity perpendicular to the plane is sensitive to the films’ structure and the presence of intercalated molecules.

Manipulating strain states to modulate ionic conduction in micro energy devices has proved difficult. Effective net strain is now used to control oxygen ionic transport kinetics in ceria-based electrolyte membranes.

Piezoelectric sensors and actuators are embedded in pliable devices that conform to human skin and organ surfaces. These devices enable rapid characterization of the mechanical properties of soft tissues under various clinical conditions.

Injectable microporous scaffolds assembled from annealed microgel building blocks whose properties can be tailored by microfluidic fabrication facilitate rapid wound healing in vivo.