Permanent magnet force rebalance micro accelerometer

Claim 1

A micromachined monolithic structure adapted for use in inertial acceleration sensing comprising: a monolithic body of an etchable structural material and having an etched cavity with a bottom therein; said monolithic body including a resiliently supported element suspended in said cavity above said bottom and having attachments to said body forming resilient supports for said element which permits said element to rotate about a first axis which passes through said supports; said resiliently supported element including an opening between first and second segments coupled to said resilient supports, said first and second segments of said resiliently supported element coupled by a crosspiece extending parallel to and laterally displaced from said first axis; said element and supports having etch resistant dopants therein, and formed in the same structural material as said monolithic body by selectively etching portions of said body; an electrical conductor extending in a direction parallel to said axis across a portion of a surface of said crosspiece of said element; a permanent magnet including first and second pole portions disposed on either side of said crosspiece of said element, said first and second pole portions supported to direct magnetic field lines orthogonal to the direction of said conductor where it crosses a portion of said surface of said crosspiece of said element such that rotation of said crosspiece of said element about said axis will cause said conductor to pass through a maximum of magnetic field lines from said permanent magnet; and means for imparting electrical conductivity to said bottom of said body.