This may look look like an incredibly simple little device—because, well, it is—but don't be fooled. This laser-powered nanosensor can spot the movement of the tiniest of objects, and it could help us identify extra-terrestrial life.
In fact, it's a simple cantilever which contains a laser motion sensor. As bacteria pass through it, they cause tiny vibrations in the device which are captured by the lasers as a sign of life. Kill the bacterium by some means, and the motion should stop. Simple.
The device has been developed by scientists in France, and a single sensor can accept about 500 bacteria. As you might expect, the device has potential Earth-bound applications: determining whether drugs effectively kill diseased cells, say.
In space, scientists usually use chemical sensors to detect signs of life. But given that doesn't detect motion—and, for all we know, life could take unusual chemical forms elsewhere in the Universe—this kind of bacteria-sized motion detector could just do the trick. [PNAS via Physorg via Engadget]