Scientists are developing a cheap microscopic "pinhead" camera which they claim could soon revolutionise a host of applications ranging from surgeries to robotics.

Researchers at Cornell University in New York produced a working prototype which is 100th of a millimetre thick and just half a millimetre across.

The device, which is small enough to fit on the head of a pin and contains no lenses or moving parts, is able to resolve 20 pixel images using a clever piece of mathematics and some fast computing, the researchers said.

It is created from pieces of silicon doped to make them sensitive to light at different angles, they said. "It's not going to be a camera with which people take family portraits, but there are a lot of applications out there that require just a little bit of dim vision,"Dr Patrick Gill, who led the research team, was quoted as saying by the Daily Mail.

According to the researchers, the camera could be used to help brain surgeons image neurons, or be a component in any cheap electronic system. For example, it could be fitted to devices that detect the angle of the sun, or micro-robots that require a simple visual system to navigate.

The camera was invented in the lab of Alyosha Molnar, assistant professor of electrical and computer engineering at Cornell, and developed by a group led by Gill, a postdoctoral associate.

The scientists, who detailed online in the journal Optics Letters, call their camera a Planar Fourier Capture Array (PFCA) because it uses the principles of the Fourier transform -- a mathematical tool that allows multiple ways of capturing the same information.