An improved computer tomography system, a multitouch display that recognizes hand gestures, and a method to simultaneously measure terahertz transmission and reflection have earned their creators Hugo Geiger Prizes from Fraunhofer Gesellschaft. The prizes are awarded annually for outstanding application-oriented doctoral theses or dissertations written at, or related to, Fraunhofer Gesellschaft institutes. They were selected on the basis of scientific quality, industrial or economic relevance, novelty and interdisciplinary approach. Anika Brahm from the Fraunhofer Institute for Applied Optics and Precision Engineering in Jena, Germany, was awarded third place for a terahertz measuring system that makes it possible to determine transmitted and reflected light in a single measuring sweep. Stefan Hebele (left) has received the Hugo Geiger Prize for the development of a compact x-ray tomography system; Anika Brahm placed third for her work on terahertz scanning. (Image: Fraunhofer IOS) Terahertz radiation, which is in the range between infrared and microwave radiation, can penetrate materials such as wood, textiles and plastics. Current processes irradiate components, packages or other objects and measure how much radiation penetrates the object or how much is being reflected by it. Both methods contain identical information, but some materials can be examined better by one version than another. For example, metals do not allow terahertz pulses to penetrate them, but layers affixed to them can be examined by means of reflection. “Since we are able to utilize transmission as well as reflection with the measuring system we developed, we are more flexible in the examination,” Brahm said. Not only does the system help to find structural defects or other material defects, but it also examines the characteristic frequency spectrum. Such a spectrum tells the researchers what kind of material they are dealing with. For example, they are able to detect explosives in packages this way. For the first time, the machine can determine the spectral information in three dimensions, so we can state exactly what kind of material is scanned, Brahm said. X-ray tomography, in which numerous scans are combined into cross-sectional images, is handy for inspecting products and structures for production errors and other flaws. However, the instruments usually weigh up to several tons, with even the lightest ones approximately 50 kg. Stefan Hebele of the Development Center for X-Ray Technology of the Fraunhofer Institute for Integrated Circuits in Erlangen, Germany, developed a micro CT scanner that weighs only 19 kg and measures just 350 × 300 × 230 mm. “It is the first computer tomograph that, according to occupational safety law, may be carried by a single person, without reservation,” said Hebele, who achieved second place in the Hugo Geiger Prizes. The operation could not be simpler: Turn it on, connect a USB cable, open the cover, put the sample in it and start it. “The device is so handy that it can also be used for mobile applications. For example, it would be possible to offer mobile services. Instead of sending out samples of new materials or prototypes, companies could then simply have the service provider come on-site with its device. The results are available more quickly, and it is more likely that confidentiality will be maintained than would be the case if the sample is sent out,” he said. Gesture recognition systems have received a lot of attention in recent years, in part because they are already available in simplified form in the computer games industry. But there is still plenty of scope for developing this kind of interaction with computers further. Georg Hackenberg of Fraunhofer FIT has taken gesture control a step further: He developed a multitouch interface that uses a 3-D camera system to recognize gestures down to the movements of each finger and process them in real time. This represents a significant advance in gesture recognition technology, since precise hand movements and signals play such an integral part in human gestural communication. Hackenberg’s invention, for which he was awarded first place in the competition, has stirred great interest in the media and among industry partners. The first-place winner received €5000; the second-place winner, €3000; and the third-place winner, €2000. For more information, visit: www.iof.fraunhofer.de