Microscopic microscope

Researchers at the California Institute of Technology have developed a super-compact high-resolution microscope small enough to fit on a fingertip.

The 'microscopic microscope' could be used in the field to analyse blood samples for malaria or check water supplies for pathogens. Better yet, the researchers claim it could be mass-produced for as little as $10 (£5).

The new microscope, which works without using lenses, combines traditional computer-chip manufacturing technology with microfluidics - the channeling of fluid at small scales. The entire optofluidic microscope chip is about the size of a 10 pence piece, although the part of the device that images objects is smaller still.

The fabrication of the microscopic chip is disarmingly simple. A layer of metal is coated onto a grid of charge-coupled device (CCD) sensors (the same sensors that are used in digital cameras). Then, a line of tiny holes, less than one-millionth of a metre in diameter, is punched into the metal, spaced five micrometres apart. Each hole corresponds to one pixel on the sensor array.