A microelectromechanical (MEM) device is disclosed that includes a shuttle
suspended for movement above a substrate. A plurality of permanent
magnets in the shuttle of the MEM device interact with a metal plate
which forms the substrate or a metal portion thereof to provide an
eddy-current damping of the shuttle, thereby making the shuttle
responsive to changes in acceleration or velocity of the MEM device.
Alternately, the permanent magnets can be located in the substrate, and
the metal portion can form the shuttle. An electrical switch closure in
the MEM device can occur in response to a predetermined acceleration-time
event. The MEM device, which can be fabricated either by micromachining
or LIGA, can be used for sensing an acceleration or deceleration event
(e.g. in automotive applications such as airbag deployment or seat belt
retraction).