Vigilant windows

Mar 17, 2009
The invisible light of a UV lamp "illuminates" the window panes and generates fluorescent radiation in the coating. This radiation is detected by sensors in the edges of the window. (c) Fraunhofer IAP

Is someone sneaking around in front of the window trying to break in? Windows and doors are now being sensitized to suspicious movements: they can detect whether and how quickly something is moving. If it is a person, the system sounds an alarm.

It is 6 p.m. and the museum is closing down for the night. The building's alarm system is switched on and the security guard does his rounds. A novel motion sensor developed by the Fraunhofer Institutes for Applied Research IAP in Potsdam-Golm and for Computer Architecture and Software Technology FIRST in Berlin could provide even more security in future, enabling window panes and glass doors to detect movements thanks to a special . If anything changes in front of the pane, or someone sneaks up to it, an is sent to the security guard.

"The glass is coated with a fluorescent material," explains IAP group manager Dr. Burkhard Elling. "The coating contains nanoparticles that convert into ." The principle is as follows: The invisible light of a "illuminates" the window panes and generates fluorescent radiation in the coating. This radiation is channeled to the edges of the window, where it is detected by sensors. Simple applications require only one sensor. Similarly to a light barrier, if someone steps into the light of the lamp 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. Its size, too, can 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 instance do not trigger an alarm.

Likewise, the sensors do not react to light from passing cars, as the researchers at FIRST have developed a that can interpret different light signals. This enables the system to easily distinguish between the frequency of the UV lamp and the slowly changing light from a passing headlight. The system has further advantages: it does not infringe on anybody's personal rights, as it only detects the change in radiation, and not who triggered it. It is also cost-efficient, because the coating can be sprayed onto the by airbrush or glued on as a film. A demonstrator system already exists, and the researchers now plan to optimize the dyes and their concentration in the coating.

Source: Fraunhofer-Gesellschaft (news : web)

Explore further: Comfortable climate indoors with porous glass

add to favorites email to friend print save as pdf

Related Stories

Electronic nose sniffs out false alarms

Dec 14, 2005

An electronic nose is so sensitive that it can distinguish between cigarette smoke and smoke from an office or factory fire. Developed by a European research consortium the device will help to end the vast ...

As fast as a shark in water

Dec 15, 2006

With the help of tiny ridge-like structures in their scales, sharks are able to minimize drag when swimming. A new coating system takes advantage of this “riblet effect” to improve the aerodynamics of vehicles and aircraft.

Noise-absorbing windows

Apr 03, 2007

The noise of aircraft taking off, road traffic or a booming discotheque often drive inhabitants of the neighborhood to a nervous frenzy. The first-ever windows with active sound insulation offer much-needed ...

Recommended for you

Comfortable climate indoors with porous glass

19 minutes ago

Proper humidity and temperature play a key role in indoor climate. In the future, establishing a comfortable indoor environment may rely on porous glass incorporated into plaster, as this regulates moisture ...

Crash-testing rivets

39 minutes ago

Rivets have to reliably hold the chassis of an automobile together – even if there is a crash. Previously, it was difficult to predict with great precision how much load they could tolerate. A more advanced ...

Customized surface inspection

59 minutes ago

The quality control of component surfaces is a complex undertaking. Researchers have engineered a high-precision modular inspection system that can be adapted on a customer-specific basis and integrated into ...

Sensors that improve rail transport safety

1 hour ago

A new kind of human-machine communication is to make it possible to detect damage to rail vehicles before it's too late and service trains only when they need it – all thanks to a cloud-supported, wireless ...

Tiny UAVs and hummingbirds are put to test

17 hours ago

Hummingbirds in nature exhibit expert engineering skills, the only birds capable of sustained hovering. A team from the US, British Columbia, and the Netherlands have completed tests to learn more about the ...

User comments : 0