Patent ID: 8549922
Filing Date: 2013-10-08
Classification: A63F,G01B,G01P

Abstract:
1. A micro-electromechanical motion sensor for sensing motion of a device to which the sensor is attached, the motion sensor comprising a capacitor having first and second capacitor plates spaced from one another, the first and second plates having different work functions and being electrically connected with each other, wherein the plates are movable with respect to one another such that a spacing between the plates changes in response to a force from motion of the device to which the sensor is attached, a current through the capacitor being representative of a rate of change in the spacing between the plates at a given time, the motion sensor further comprising a reference capacitor having third and fourth capacitor plates spaced from one another, the third and fourth capacitor plates having different work functions, wherein the third and fourth capacitor plates are fixed with respect to one another such that a spacing between the plates is maintained in response to the force to provide a reference current through the reference capacitor.