HOW can image sensors - the most complicated and expensive part of a digital camera - be made cheaper and less complex? Easy: take the lid off a memory chip and use that instead.

As simple as it sounds, that pretty much sums up a device being developed by a team led by Edoardo Charbon, of the Technical University of Delft, in the Netherlands. In a paper presented at an imaging conference in Kyoto, Japan, this week, the team say that their so-called "gigavision" sensor will pave the way for cellphones and other inexpensive gadgets that take richer, more pleasing pictures than today's devices. Crucially, Charbon says the device performs better in both very bright light and dim light - conditions which regular digital cameras struggle to cope with.

While Charbon's idea is new and has a patent pending, the principle behind it is not. It has long been known that memory chips are extremely sensitive to light: remove their black plastic packages to let in light, and the onrush of photons energises electrons, creating a current in each memory cell that overwhelms the tiny stored charge that might have represented digital information. "Light simply destroys the information," says Martin Vetterli, a member of the EPFL team.