Carbon fibre makes discount displays

researchers are replacing silicon components in microelectromechanical systems (MEMS) with carbon fibre, which is stronger and more flexible and could be used in video devices.

For decades, researchers have been trying to make video displays using tiny mirrors mounted on silicon oscillators, but silicon cannot oscillate fast enough or bend far enough.

Shahyaan Desai, a Cornell graduate student who has been to create a practical MEMS video display device, decided to try carbon fibre, which is twice as stiff as silicon but 10 times more flexible.

Desai first showed that micrometre-scale carbon fibres can bend like tiny fishing rods by more than 90 degrees and can be made to vibrate billions of times without breaking down.

He then built an optical scanner consisting of a tiny rectangular mirror measuring 400 by 500 microns, supported by two carbon-fibre hinges about 55 microns across. Made to oscillate at 2.5kHz, the tiny mirror caused a laser beam to scan across a range of up to 180 degrees, corresponding to a 90-degree bend by the carbon fibres.