March 19, 2009

Scientists create protective windows

German scientists say they have created windows and doors that can detect suspicious movements before a crime is committed and, if necessary, sound an alarm.

A motion sensor developed at the Fraunhofer Institutes for Applied Polymer Research in Potsdam and by Computer Architecture and Software Technology in Berlin can enable window panes and glass doors to detect movements thanks to a special coating.

The glass is coated with a fluorescent material, said IAP group manager Burkhard Elling. The coating contains nanoparticles that convert light into fluorescent radiation.

He said an ultraviolet lamp illuminates the window panes and generates fluorescent radiation in the coating that is channeled to the edges of the window, where it is detected by sensors. If someone steps into the light, less light reaches the coating and less fluorescent radiation is produced. If several sensors are installed on all four sides of the window frame, conclusions can be drawn from the data as to how fast and in what direction an object is moving.

Elling said size can also be estimated by the sensors. Is it a small creature such as a bird or is it a person? The threshold for the alarm can be set, so that moving objects the size of birds, for example, do not trigger an alarm.

A demonstrator system already exists, and the researchers now say they plan to refine the technology.