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Advances in technology across industry

Fast building inspection from the air Saving lives in a burning skyscraper

Quietly humming, the flying robot hovers up outside the high-rise. The miniature aircraft equipped with eight rotors slowly whirls upwards to the 11th floor. It examines the façade for damage, such as cracks, defective joints, or chipped and crumbling concrete. At a distance of two metres from the building, the octocopter scans the masonry. Also on board is a high-resolution, digital camera that takes detailed images of each part of the building. In addition, the material tester is equipped with sensors that adjust for wind gusts, maintaining stable attitudes and avoiding collisions with the building. As the remote-controlled robot works its way forward metre by metre, it is carefully monitored by Christian Eschmann. He is a researcher at the Fraunhofer Institute for Non-Destructive Testing IZFP in Saarbrücken, Germany, where he develops and adapts micro-aircraft for building inspections.

Compared to many conventional methods, the inspection is more convenient, thanks to the assistance of an aerial robot, and can occur at shorter intervals. In addition, inspection time can be significantly shortened, usually without impeding use of the buildings. “For a 20 by 80 metre-wide façade, a test engineer needs about two to three days. Our octocopter needs three to four hours for this,” says Christian. Cracks and other flaws can now be digitally photographed in high resolution. This permits quick conclusions about the state of a building’s structure. If necessary, the octocopter can also be equipped with a thermal imaging camera, to check such things as building insulation. Visit: christian.eschmann@izfp.fraunhofer.de Residents and workers in skyscrapers and other tall buildings are often trapped in case of a fire, as 9/11 has demonstrated. The newly developed Evacuator offers a last resort, allowing them to slowly and safely descend on a steel cable at the outside of the building. Worldwide the device can save thousands of lives, from residents in tall buildings to mechanics in wind turbines.

Dutch inventors Eugene Verstegen and Joris Veeger came up with the idea when they saw people fall to their death from the Twin Towers in New York. Together with a professional engineering company they developed a fireproof steel winch, which is guaranteed to work at all times, even when electricity is down. The device allows four persons at the same time to descend 50, 140 or 300 metres. They automatically descend in a safety harness on a steel cable, at a speed of one metre per second. The Evacuator is people’s last resort if elevators are switched off, emergency exits are filled with smoke and firemen can’t reach them. Visit: www.evacuator.com

New catalyst gives hope for more cost-efficient metal-air batteries and fuel cells

Chemists at the Ruhr-Universität Bochum have made a decisive step towards more costefficient regenerative fuel cells and rechargeable metal-air batteries. They developed a new type of catalyst on the basis of carbon, which can facilitate two opposite reactions: electrolysis of water and combustion of hydrogen with oxygen. A catalyst of this kind might make the storage of wind and solar energy and the manufacture of cost-efficient batteries, for example for electric cars, possible.

When energy is supplied, the so-called bi-functional catalysts can split water into hydrogen and oxygen – referred to as electrolysis. They can then store the energy in the chemical bonds of the thus formed hydrogen. The same catalysts can also have their polarity reversed to become fuel cells; they combust hydrogen with oxygen to water, generating electricity at the same time. So far, researchers have been using noble-metal catalysts for this purpose. However, these catalysts have the disadvantage of being either good for electrolysis or good for combustion, but not for both.

The novel catalysts from Bochum are made from manganese-oxide or cobalt-oxide nano particles which are embedded in specially modified carbon, into which the researchers have integrated nitrogen atoms in specific positions. Visit: wolfgang.schuhmann@rub.de