Volume 13 Issue 4, April 2014

Winds of change blow through research centres and universities operating in the Middle East.

The Middle East is rich in human and natural resources, but many of its countries need a cultural and scientific transformation to reach worldwide recognition in education, research and economic productivity. Several institutions are making a positive impact, kindling hope for a successful 'science spring'.

Jean M. J. Fréchet, vice-president for research at the King Abdullah University of Science and Technology (KAUST), talked to Nature Materials about the achievements of this institution since its foundation in 2009 and its contribution to shaping research attitudes in Saudi Arabia.

The macroscopic alignment of dilute dispersions of graphene oxide can be controlled, with extremely large optical sensitivity, through the application of weak electric fields.

In spite of their promise, practical applications of high-temperature cuprate superconductors have been hard to come by. The development of a method to fabricate round wires of the cuprate system Bi-2212 may begin to change this.

Cracks and defects induced during the transfer of large-area graphene on insulating substrates impair its excellent electronic properties. A defect-free transfer can now be obtained thanks to capillary bridges that anchor the graphene film to the substrate while the underlying growth layer is etched away.

Chloroplasts with extended photosynthetic activity beyond the visible absorption spectrum, and living leaves that perform non-biological functions, are made possible by localizing nanoparticles within plant organelles.

Electric fields prompt epithelial cell populations to make coordinated movements such as U-turns.

Microimaging techniques, such as interference and infrared microscopy, can be used as a tool to directly monitor guest profiles within nanoporous materials. Observation of the variation in these profiles leads to unprecedented insight into transport phenomena, including intracrystalline diffusion and surface permeation.

Electric-field-induced switching of material’s magnetization is a promising approach for achieving energy-efficient memory devices. By taking advantage of the strong magnetoelectric coupling with a BaTiO₃ substrate, a small electric field is used to switch a FeRh thin film from anti- to ferromagnetic above room temperature.

In addition to controlling the propagation of light, metamaterials have also received attention for controlling sound. Now, a device that can act as a broadband and omnidirectional acoustic cloak is experimentally demonstrated.

Quantum spin liquids are a state of magnetic order that, in analogy with ordinary liquids, is characterized by fluctuating, disordered spins. By means of specific heat measurements, the frustrated Kondo system Pr₂Ir₂O₇ is shown to undergo a transition to such a state in zero magnetic field.

Spin currents form the basis of spintronics as a viable approach for future memory and information storage devices. Now, it is shown that a thermal spin current can be induced and controlled by applying a voltage.

Magnetic memory devices are typically based on ferromagnetic materials. Now, a memory resistor based on the antiferromagnetic alloy FeRh is demonstrated at room temperature.

Cuprate superconductors have found limited application for high-field magnets because of difficulties related to grain boundaries. Now, this issue is partially overcome and round wires suitable for magnetic coils are fabricated from Bi₂Sr₂CaCu₂O_8−x.

Optical amplifiers based on erbium ions typically require high pump power densities to produce gain. Now, an organic optical amplifier material composed of erbium ions and a zinc-based organic chromophore is demonstrated to reach population inversion using low-power visible light.

The energy density of supercapacitors can be enhanced by using ionic liquids and electrodes with subnanometre pores, but this tends to reduce their power density. The mechanisms of charging subnanometre pores with ionic liquids are now clarified and molecular simulations suggest that charging of such ionophilic pores is a diffusive process.

Although dispersions of aligned graphene oxide flakes are particularly attractive for electro-optic devices, controlling the alignment of the flakes by using electric fields has proved difficult. It is now shown that the macroscopic alignment of graphene oxide liquid crystals can be controlled through the application of weak electric fields when interflake interactions are sufficiently small, giving rise to the largest Kerr coefficient in a molecular liquid crystal.

Imparting non-native functions to living plants using nanoparticles opens the possibility of creating synthetic materials that can grow and repair themselves using sunlight, water and carbon dioxide. It is now shown that, both in plant extracts and living leaves, carbon nanotubes traverse and localize within the lipid envelope of plant chloroplasts, enhance their photosynthetic activity, and enable near-infrared fluorescence monitoring of nitric oxide.

The collective migration of epithelial cells arises from the interplay between intercellular forces and cellular signalling networks. It is now shown that the migration of an epithelium can be controlled by applying electric fields that bias the signalling networks, and that such galvanotactic control can prompt cell populations to make coordinated U-turns, undergo divergent or convergent migration, or move against an obstacle.

The use of persistent luminescence nanoparticles for in vivo optical imaging commonly requires ex vivo activation before systemic administration, hampering longer-term imaging capabilities. Now, it is shown that near-infrared emitting nanoprobes based on chromium-doped zinc gallate can be activated in vivo using low-energy red light and used for tumour-targeted imaging and cell tracking experiments.

Research in the Middle East struggles to achieve worldwide recognition, but the recent encouraging trends in scientific productivity suggest that something is changing. In this focus issue, the positive impact of some Middle Eastern research centres and universities, as well as the institutional and cultural changes required to foster the scientific renaissance of the Arab world are discussed.