Innovation and Technology Weekly – No. 30, 2009

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Issue 30, 2009

This week's headlines:

US scientists levitate mice to study low gravity
September 10, 2009

With the aid of a strong magnetic field, mice have been made to levitate for hours at NASA's Jet Propulsion Laboratory (JPL). The method works because a strong magnetic field distorts the movement of electrons in water molecules, which in turn produces a magnetic field that opposes the one applied. The net result is a repulsive effect which, if suitably oriented and strong enough, can overcome the pull of gravity.

The scientists used a purpose-built levitation device containing a coil of wire cooled to a few degrees above absolute zero so that it became superconducting. Running a current through the wire creates a magnetic field of 17 teslas, ten thousand times as strong as a typical fridge magnet and 10 million times that of the Earth.

The magnetic field varies along the length of the coil. A water- containing object placed at the base of the coil develops an opposing magnetic field that generates a force twice that of Earth's gravity at the bottom, Earth-like gravity in the middle, and zero gravity at the top. The system can levitate water-based objects for days at a time.

The levitating mice could provide a testing ground for studying the effects of space travel on humans, such as bone and muscle loss, and changes in blood flow. The machine is better suited to such experiments than the 'vomit comet' planes that simulate microgravity, or the International Space Station. It makes it possible to dial in anything between Earth and zero gravity for as long as needed, and at lower cost.

Full story: New Scientist Back to top

Google plans new mirror for cheaper solar power
September 10, 2009

Google is disappointed with the lack of breakthrough investment ideas in the green technology sector but the company is working to develop its own new mirror technology that could reduce the cost of building solar thermal plants by a quarter or more.

Google in late 2007 said it would invest in companies and do research of its own to produce affordable renewable energy within a few years. The company's engineers have been focused on solar thermal technology, in which the sun's energy is used to heat up a substance that produces steam to turn a turbine. Mirrors focus the sun's rays on the heated substance. Google is looking to cut the cost of making heliostats, the fields of mirrors that track the sun, by at least a factor of two.

Google hopes to have a viable technology to show internally in a couple of months. It will need to do accelerated testing to show the impact of decades of wear on the new mirrors in desert conditions.

Another technology that Google is working on is gas turbines that would run on solar power rather than natural gas, an idea that has the potential of further cutting the cost of electricity, the company says.

Full story: Reuters Back to top

Robot to be controlled by human brain cells
September 09, 2009

A robot controlled by human brain cells could soon be trundling around a British lab. Researchers at the University of Reading, UK, have already used rat brain cells to control a simple wheeled robotMovie Camera.

Some 300,000 rat neurons grown in a nutrient broth and producing spikes of electrical activity were connected to the output of the robot's distance sensors. The neurons proved capable of steering the robot around a small enclosure.

The team say that observing how their neuron culture responds to stimulation could improve our understanding of neurological conditions such as epilepsy. For instance, the way large numbers of neurons sometimes spike in unison – a phenomenon known as 'bursting' – may be similar to what happens during an epileptic seizure. If that behaviour can be altered by changing the culture chemically, electrically or physically, it might hint at potential therapies.

To make the system a better model of human disease, a culture of human neurons will be connected to the robot once the current work with rat cells is completed. This will be the first instance of human cells being used to control a robot. One aim is to investigate any differences in the behaviour of robots controlled by rat and human neurons.

Full story: New Scientist Back to top

Ultra-strong Velcro-like fastener inspired by birds
September 08, 2009

Researchers have created a new type of Velcro-like fastener system made from steel that may be useful in a range of settings, including hospitals and the aviation industry. Borrowing its design from nature, the new material comprises a series of hooks in the shape of birds' heads that feed into a series of tiny loops along a perforated strip.

Velcro can seal with a relatively tight grip but still be released with minimal effort. The trouble, however, with these fasteners is that their gripping mechanism tends to break down when exposed to harsh conditions such as high temperatures and aggressive cleaning chemicals. This limitation leads to problems in industrial and applications.

Now, a team at the Technical University of Munich may have found a solution to this problem. They have created a new hook-and-loop fastener using steel, chosen for its high resistance to mechanical loads and chemical corrosion. Steel can also deform significantly under high stresses without fracturing and breaking the grip.

In developing the fastener, which is dubbed 'Metaklett', the researchers tested a range of different hook designs. After combining laboratory testing with computer simulations, the researchers settled on two specific designs, both of which are resistant to chemicals and remain fastened up to 800 °C.

Full story: PhysicsWorld Back to top

Harnessing bacteria to make fuel cells more efficient
September 10, 2009

Bacteria that generate significant amounts of electricity could be used in microbial fuel cells to provide power in remote environments or to convert waste to electricity. Researchers at the University of Massachusetts isolated bacteria with large numbers of tiny projections called pili which were more efficient at transferring electrons to generate power in fuel cells than bacteria with a smooth surface.

The researchers isolated a strain of Geobacter sulfurreducens that grew prolifically on the graphite anodes of fuel cells. The bacteria formed a thick biofilm on the anode surface, which conducted electricity. The team found large quantities of pilin, a protein that makes the tiny fibres that conduct electricity through the sticky biofilm. The pili on the bacteria's surface seemed to be primarily for electrical conduction rather than to help them to attach to the anode.

Microbial fuel cells could be used in monitoring devices in environments where it is difficult to replace batteries if they fail but to be successful they need to have an efficient and long-lasting source of power.

Full story: ScienceDaily Back to top

'NanoPen' may write new chapter in nanotechnology manufacturing
September 08, 2009

Researchers in California are reporting development of a so-called 'NanoPen' that could provide a quick, convenient way of laying down patterns of nanoparticles - from wires to circuits - for making futuristic electronic devices, medical diagnostic tests, and other much-anticipated nanotech applications.

In the new study, the team point out that researchers have already developed several different techniques for producing patterns of nanoparticles, which are barely 1/50,000th the width of a human hair. But current techniques tend to be too complex and slow. They require bulky instrumentation and take minutes or even hours to complete. These techniques also require the use of very high temperatures to apply the nanostructures to their target surfaces. Such limitations prevent widespread application of such techniques.

The scientists say their NanoPen solves these problems. In lab studies, the researchers used it to deposit various nanoparticles into specific patterns in the presence of relatively low light and temperature intensities. The process, which requires the use of special 'photoconductive' surfaces, takes only seconds to complete. Manufacturers can adjust the size and density of the patterns by adjusting the voltage, light intensity, and exposure time applied during the process, the researchers say.

Full story: Science Daily / Nano Letters Back to top

Cement's basic molecular structure finally decoded
September 09, 2009

In the 2,000 years since the Romans employed a naturally occurring form of cement to build a vast system of concrete aqueducts and other large edifices, researchers have analysed the molecular structure of natural materials and created entirely new building materials such as steel, which has a well-documented crystalline structure at the atomic scale.

Oddly enough, the 3D crystalline structure of cement hydrate - the paste that forms and quickly hardens when cement powder is mixed with water - has eluded scientific attempts at decoding, despite the fact that concrete is the most prevalent man-made material on earth.

Scientists have long believed that at the atomic level, cement hydrate closely resembles the rare mineral tobermorite, which has an ordered geometry consisting of layers of infinitely long chains of three-armed silica molecules (called silica tetrahedra) interspersed with neat layers of calcium oxide. But the MIT team found that the calcium-silica-hydrate in cement is not really a crystal but a hybrid that shares some characteristics with crystalline structures and some with the amorphous structure of frozen liquids, such as glass or ice.

With a validated molecular model the chemical structure can be manipulated to design concrete for strength and environmental qualities, such as the ability to withstand higher pressure or temperature, according to the researchers.

Full story: MIT Back to top