Unlike X-ray machines or radar instruments, the sensor doesn't have to generate a signal to detect objects – it spots them based on how brightly they reflect the natural radiation that is all around us every day.
There is always a certain amount of radiation – light, heat, and even microwaves – in the environment. Every object – the human body, a gun or knife, or an asphalt runway – reflects this ambient radiation differently.
The Ohio State sensor isn't the only ambient radiation sensor under development, but it is...compatible with silicon – a feature that makes it relatively inexpensive and easy to work with.
The team that is making the antimonide sensor has succeeded in combining it with a camera system; the pictures look a lot like X-ray images, with bodies and clothing appearing as dim outlines and metal objects such as guns standing out in sharp relief.
Posted by Cieciel at August 24, 2005 10:03 AM