Sunday, October 18, 2009

US Patent 7602097 - Elastic nanotube shaft for MEMS

A variety of designs for micromirror hinges have been proposed for applications in digital displays and optical switching networks. However, the repeated torsional deformation of these micromirrors cause fatigue in the hinge structure which reduces the reliable life expectancy of the device. This patent from Fujitsu teaches forming the deformable shaft of a MEMS device from carbon nanotubes to reduce the problem of fatigue. Claim 1 reads:

1. A movable device provided with

bottom electrodes and a basic conductive layer fixed to a substrate,

an elastic shaft of a carbon nanotube with a bottom end fixed on said basic conductive layer and standing up, and

a top structure including a top electrode spaced away from said bottom electrode and fixed to a top end of said elastic shaft,

wherein when applying voltage between a said bottom electrode and said top electrode, said top electrode displaces relatively to said bottom electrodes within an allowable range of elastic deformation of said elastic shaft.