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]