Conventional shaped glass lenses are limited in their ability to redirect incoming light beams and have them meet at a precise point. However, a team at Singapore’s A*STAR Institute of High Performance Computing has shared an innovative approach to ‘superlens’ technology.

To develop the design, the team used numerical modelling. By concentrating radiation into a smaller volume, the interaction between light and matter is enhanced. It is expected that this concept could be useful in very sensitive sensors of the future.

As a type of wave, light consists of oscillating electric and magnetic fields. The distance travelled by a wave in one oscillation cycle is its wavelength and this involves a direct limit on the minimum size to which it is possible to focus light. However, this limit is not relevant to small distances that can be compared to the wavelength – otherwise known as the near-field regime.

The use of a ‘superlens’ (and restriction of light into intense ‘hot spots’) may prove advantageous for optical detection systems. The concept is currently targeted at biomedical and chemical sensing applications.

Source:  http://www.sciencedaily.com/releases/2013/08/130831110653.htm

Researchers from the Institute of Molecular Biotechnology in Vienna, Austria, have used stem cells to grow a three-dimensional, self-organising model of a developing human brain.

This system could potentially be used to model neurological diseases in a real human brain, offering advantages over the use of animal models that may not develop in the same way.

The researchers refer to the model created as a ‘cerebral organoid’. It has features that mimic the early developing human brain and specific regions are present, including the dorsal cortex, the ventral forebrain and an immature retina.

To date, this is the most complex in vitro human brain tissue. Early signs of the cortical layers can be identified, although the complete six-layer human cortex and all its complexities cannot be developed.

Embryonic stem cells and induced pluripotent stem cells (derived from adult human skin or blood cells) were used to grow the organoids. Most grow to a size of three or four millimetres, which is approximately the same size as the brain of an embryonic human at 9 weeks gestation.

Juergen Knoblich, the coordinator of the study, said that despite its appearance being similar to brain tissue in the early stages of development and despite the presence of active neurons, the organoid does not replicate naturally developing tissue. He likened the project to building a car with wheels and an engine, but with the engine on the roof: the car wouldn’t be driveable, but you could still analyse how it worked.

Cerebral organoids may be used to better understand diseases such as microcephaly and, potentially, disorders such as schizophrenia and autism.

Source:  http://www.popsci.com.au/science/whoa-scientists-grow-a-brain-in-a-dish

Crystals can jump – that’s what a team of scientists from Russia and the United Arab Emirates have discovered recently. After a systematic examination of how crystals behave in response to light, the team have presented the first quantitative kinematic analysis of jumping crystals, published in the journal Angewandte Chemie.

The crystals move thanks to a phenomenon called the ‘photosalient effect’: when irradiated by UV light, the crystals move around. The size of the crystals are micrometre or millimetre in size and of the cobalt coordination complex [Co(NH3)5(NO2)]Cl(NO3).

The effect has the crystals ‘jumping’ distances thousands of times larger than their size. According to the scientists, this happens because the irradiation process breaks the bond between the nitrite ligand (NO2) and the central cobalt ion.

As a result, the ligand ends up rotating in order to use one of its oxygen atoms to bind to the cobalt, resulting in a strain in the crystal and forcing it to jump and fracture, and sometimes explode.

The scientists used a microscope-mounted high-speed camera to capture the phenomenon. They observed that the distance covered by the crystal’s movement depends on how long it is exposed to irradiation and how intense the light is.

They also found that there is a lag stage between exposure and movement, as the stress caused by the irradiation builds up. The findings could be useful for the design of materials and technical components.

Source: http://phys.org/news/2013-07-crystals-kinematic-analysis-light-induced.html

A special rubber-like protein that enables insects to jump, flap their wings, and chirp could have wide applications in medical science, according to research published in ACS Macro Letters.

While scientists discovered resilin half a century ago, it is only in recent years that scientists have begun to look at the potential medical and scientific applications of the protein.

Resilin is found in the wing hinges of locusts and tendons of dragonflies. Scientist Kristi Kiick says that the natural protein is unmatched by even the best synthetic rubbers that are currently available. Resilin can be stretched to three times its original dimensions and still spring back to its original shape without any loss of elasticity, even when stretched and relaxed many times.

Scientists have already created resilin-based products that could be used in diagnostics, cartilage replacement, cardiovascular applications, and traditional polymer applications. Resilin products could be used in nanosprings, biosensors, and biorubbers in the future.

Source: http://phys.org/news/2013-07-insect-inspired-super-rubber-medicine.html

A team of eight scientists led by David C. Johnson of the University of Oregon has invented a new technique for rapidly synthesizing compounds with very low thermal conductivity and other unique properties.  The new method is a major breakthrough, as the traditional method is more time-consuming and limited in its application to only a few compounds that are thermodynamically stable.

The technique involves lightly warming a design of layered elemental precursors. Having been exposed to warmer temperatures, these automatically assemble into 18 new metastable and nano-sized compounds.

The new technique is revolutionary and has been described as paradigm changing. The traditional method for synthesising crystalline materials (in solid-state inorganic chemistry) has been limited in scope and application. This was largely due to the time and amount of heating required.

As Johnson states, it is now possible to make 20,000 compounds rather than only three. Johnson adds that the technique is possible because his team has found a way to control local compositions and diffusion distances of precursors.

Kimberly Andres Espy, the University of Oregon’s vice president of research and innovation, says that the new approach developed by Johnson and his team could potentially help create a more sustainable future for the world. This is because the technique has the potential to change how critical products are manufactured and delivered.

Source: http://phys.org/news/2013-07-team-game-materials.html

A team of scientists of the University of California Berkeley has created a flexible plastic skin that could be used to make touch-sensitive robots. The electronic skin, dubbed ‘e-skin’ has an inbuilt sensor network that lights up when touched. The stronger the pressure, the brighter the light.

Ali Javey, Associate Professor at the university and leader of the research team, says that the e-skin can be wrapped around different objects. Javey adds that it is a system rather than a device. The device has a broader application than robotics; it could be used for wallpapers that also function as touchscreen displays, controllable dashboards in cars, and bandages as health monitors, says the study’s co-lead author Chuan Wang.

The e-skin is made from polymer, silicon, and electronic components. Javey says the technology will be easy and relatively inexpensive to commercialise.

Wang says it is the interactivity of the e-skin sensor system that makes it something new as an invention. The flexibility of the skin means it can be applied to many different surfaces. The team is now focusing their efforts on making the e-skin responsive to temperature and light.

Source: http://www.sciencedaily.com/releases/2013/07/130721161716.htm

Scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the University of New South Wales have discovered a formation mechanism of nanocrystalline CeO2 particles.

The findings will have a fundamental impact on current methods for producing CeO2 nanocrystals and is likely to simplify the production methods that are currently available. The scientists used a multi-spectroscopic technique to observe the nanocrystal evolution process.

Current methods of synthesising nanocrystalline CeO2 particles are based on sol-gel and thermal treatments or by adding accelerant reagents. The new study has enabled a better understanding of how the metal nanocrystal particles are formed at the atomic scale, in an aqueous solution.

The study found that it is possible to produce uniformly sized nanoparticles of CeO2 in a size suitable for industrial application. The technique involves pH adjustment of tetravalent cerium in an aqueous solution, in the absence of any chemical or heat treatment afterwards.

Dr Christoph Hennig, one of the scientists involved in the study, said that the multi-spectroscopic technique is applicable to other types of research on metal nanocrystals. Nanocrystalline CeO2 particles are used in a variety of industrial and medical applications.

Source: http://www.sciencedaily.com/releases/2013/06/130625121155.htm