Roguish Pentagon kill-nerds have decided to spend more than $6m on a miraculous handheld scanner along the lines of a Star Trek Tricorder or Aliens Colonial Marine motion-tracker. The through-walls people detector will work in the same way as the mysterious brain-slime electrofield senses of sharks and manta rays.

Now we just need a gizmo that foreshadows the dramatic necessity for us to die one by one.

The new technology has been dubbed E-FED, or Electric Field Detector, by those behind it. The idea would be to detect the bioelectrical fields produced by all living things using sensitive electronics. This would offer detection and tracking through walls or other barriers, and allows a sensor to easily work in three dimensions.

Such methods are already employed in real life, by elasmobranches (sharks and rays). Slime-filled canals in the creatures' heads - known as the "ampullae of Lorenzini" - let them sniff out the electric field of bottom-feeding flatfish concealed in mud or sand, leading to a tasty treat for the prowling elasmobranch.

Other applications of electrofield detection have already been made by human technology, perhaps most famously by the eccentric researchers of MIT's Media Lab. They have proposed (and built prototypes of) so-called "Taufish" or "Lazyfish" devices. These can detect a human hand situated above a sensor, allowing a "3D mouse" gesture based computer interface.