Innovation & Technology Weekly Roundup

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This week's headlines:

'Optical fibre' made out of thin air
July 23, 2014

Scientists from the University of Maryland say they have turned thin air into an 'optical fibre' that can transmit and amplify light signals without the need for any cables. The team created an 'air waveguide' that could one day be used as an instantaneous optical fibre to any point on earth, or even into space.

Lasers lose intensity and focus with increasing distance as photons spread apart and interact with atoms and molecules in the air. Fibre optics solves this problem by beaming the light through glass cores with a high refractive index, which is good for transmitting light. The core is surrounded by material with a lower refractive index that reflects light back in to the core, preventing the beam from losing focus or intensity. Fibre optics, however, are limited in the amount of power they can carry and the need for a physical structure to support them.

The researchers made the equivalent of an optical fibre out of thin air by generating a laser with its light split into a ring of multiple beams forming a pipe. They used very short and powerful pulses from the laser to heat the air molecules along the beam extremely quickly. Such rapid heating produced sound waves that took about a microsecond to converge to the centre of the pipe, creating a high-density area surrounded by a low-density area left behind in the wake of the laser beams.

The lower density region of air surrounding the centre of the air waveguide had a lower refractive index, keeping the light focused. Once the team created their air waveguide, they used a second laser to spark the air at one end of the waveguide turning it into plasma. An optical signal from the spark was transmitted along the air waveguide, over a distance of a metre to a detector at the other end. The signal collected by the detector was strong enough to allow the team to analyse the chemical composition of the air that produced the spark.

Full story: ABC Net / Optica Back to top

Browser 'fingerprints' help track users
July 22, 2014

Web users are being warned about a novel tracking system that watches what they do online and frustrates tools designed to prevent them being tracked. The warning comes from researchers who have found the tracking system being used on thousands of websites. The system exploits features of the web's underlying code to generate unique identifiers for each visitor. Government portals, online shops and pornography sites were all found to be using the tracking system.

The team, made up of researchers at Princeton University in the US and University of Leuven in Belgium, analysed tracking techniques on the top 100,000 websites. They found that many sites had turned away from well-known systems such as 'cookies' in favour of more subtle methods. More than 5% of the sites they surveyed had turned to a technique known as 'canvas fingerprinting' to identify visitors.

This technique forces a web browser to create a hidden image. Subtle differences in the set-up of a computer mean almost every machine will render the image in a different way enabling that device to be identified consistently. Many web browsing programs now include tools that let people manage or stop their activity being tracked across the sites they visit. Many advertisers are keen to find out these browsing histories to better target ads.

The team also studied ways to stop canvas fingerprinting but said none of the browsers it tested had stopped the system being used. Only the Tor browser did a good job of spotting the fingerprinting technique was being used and asking people if they were happy for it to operate.

Full story: BBC News Back to top

Cell phone towers monitor African rains
July 18, 2014

While not always noticeable, cell phones get worse reception during rainstorms. Raindrops garble specific frequencies in radio signals, an effect compensated for by cell phone companies.

Scientists realised these tainted transmissions could be used to reconstruct rain patterns near cell phone towers and since 2006 have successfully implemented the technique in developed countries such as the United States.

Some have proposed that the method's most important use could be in Africa, where weather-monitoring infrastructure has fallen into disrepair. Tracking weather has become particularly important in the face of climate change, which can exacerbate rain-related hazards such as floods and droughts.

Geoscientists of the University of Ouagadougou in Burkina Faso partnered with a telecommunications company to conduct the first cell phone tower rainfall monitoring in West Africa. The team crunched data transmitted during the 2012 monsoon season between two transmission towers separated by 29 kilometres. The researchers report that they detected 95% of rainy days and measured rainfall as well as weather satellites did, or better.

As Africa's wireless networks expand coverage, the team hopes the technique can provide cheap rainfall tracking.

Full story: ScienceNews / Geophysical Research Letters Back to top

An easier way to turn plant scraps to plastics
July 23, 2014

A new way of turning vegetable waste directly into bioplastics could make such materials even more environmentally friendly.

Current bioplastics are created by processing plant material to create short molecules called monomers, which link up to create long polymer molecules that make up plastics. Although the resulting material is usually biodegradable, making it a greener alternative to regular plastic, the way it is produced has come under criticism. Making bioplastics takes multiple steps, requiring more energy, and often uses crops that could otherwise be used for food, like corn or potatoes.

Researchers from the Italian Institute of Technology in Genova, Italy were looking at the process for creating cellophane, which involves passing cellulose, the material that makes up plant cell walls, through multiple acid and alkali baths. They discovered that dissolving cellulose from cotton and hemp in trifluoroacetic acid, a common chemical, converted it directly from its naturally crystalline form to an amorphous form suitable for moulding into plastic without the need for any further processing.

Next they tried the process on vegetable waste products, including rice hulls, cocoa pod husks and spinach and parsley stems. They could all be easily converted into useful bioplastics, with different properties based on the starting material: rubbery for spinach, but firmer for rice hulls. The new materials have a different combination of stiffness and stretchiness compared to both existing bioplastics and traditional plastics. They can also inherit the properties of the original plant, meaning parsley plastic could have antioxidant properties, or cinnamon plastic could be antibacterial.

Full story: New Scientist / Macromolecules Back to top

Nanomaterial cloaks the sense of touch
July 21, 2014

A real invisibility cloak may still be the stuff of fantasy, but scientists have figured out a way to hide objects from touch.

Two years ago, researchers at the Karlsruhe Institute of Technology (KIT) in Germany successfully created pentamodes, or mechanical metamaterials. Now, researchers have found a fascinating property in the metamaterial: the ability to hide or 'cloak' the existence of foreign objects hidden within it. It's a discovery that could lead to making everything from more comfortable camping gear to shoes that make you feel like you're walking on air.

Built at a millimetre scale, this polymer-based, scaffold-like structure can shape itself around a object - say, a tiny hard tube - and disperse pressure in such a way that human touch can't detect its existence.

While this is purely a research project, the KIT researchers do envision an interesting nanomaterial future. The discovery could, for example, eventually be used to make more comfortable sleeping bags that shield the user from feeling rocks or pebbles on the ground or rugs that hide the bumps of bad flooring and cables.

Full story: CNN / Nature Communications Back to top

Liquid bits could brim with data in future computers
July 23, 2014

Don't drink that, it's my hard drive! A future form of computing could see information stored on clusters of microscopic particles suspended in liquid.

Clusters of spheres can arrange themselves around a central sphere in a limited number of ways, similar to how a Rubik's cube can only be twisted in certain ways around the central point. Researchers at the University of Michigan realised these states could represent information.

To test the idea, the team created a cluster of five spheres in a liquid and watched them naturally switch between two states, like the 0s and 1s of traditional computing bits. Next, they plan to create clusters that can be locked into a particular state to store a bit of data, and unlocked again to rewrite it, using a central sphere made from gel that can swell and shrink.

In theory, a terabyte of data could be stored in a tablespoon of clusters - though it might be hard to scale up. Klaus-Peter Zauner at the University of Southampton, UK, notes that there is no obvious way to read and write data to large numbers of clusters floating in a liquid. Instead, he suggests that individual clusters could be used to guide self-assembling materials on a microscopic scale.

Full story: New Scientist / Soft Matter Back to top

Art by algorithm: Computer evolves new artworks
July 24, 2014

A new breed of art has evolved. A computer program has been built that creates digital artworks using algorithms that mimic natural selection. Researchers from Nagoya University in Japan built the software after learning how artistic methods are passed down through generations.

Paintings that have remained to the present were painted by scaling, rotating and combining motifs that had already existed, they found. This appeared to echo the process of biological evolution, in which traits are inherited and altered from parent to child.

To use the program, a person first indicates the style of art that they like. Then they select a picture from a few preloaded images to feed into an algorithm, which mutates the image in different ways. The resulting images are either culled or kept depending on how closely they adhere to the user's initial stylistic choices, and the process repeats. The person can stop the process at any time and select an image they like. Finally, the person adds colour to the image, as the program currently manipulates the images in black and white.

The team tested its program with different sets of preferences and starting images, letting it run for up to 4800 generations at a time. This resulted in several images, including one called 'A witch who looks to the distance', which began with a picture of a four-leaf clover. Another that started with a sketch of a pair of scissors became a hazy depiction of a woman in profile, lifting one hand to her face.

The team is interested in incorporating colour into the program. They are also exploring whether they can evolve pieces that look similar to paintings by renowned artists. Using an original Michelangelo as the starting image, for example, the team could evolve pictures that capture the style of the Renaissance master.

Full story: New Scientist Back to top