MEMS-based magnetic sensor with a Lorentz force actuator used as force feedback

摘要

A magnetic sensor utilizes a MEMS device that has at least one vibrating member and at least one conductive path integral with the vibrating member so that a current flows along the vibrating member and in the presence of a magnetic field interaction of the magnetic field and the point charges in the current on the conductive path due to the Lorentz force causes a change in vibration of the vibrating member. That change can be used to provide a measure of the magnetic field.

主权项

1. A magnetic sensor comprising:
a MEMS device including,
a member configured to vibrate responsive to a drive force;at least one conductive path integral with the member to allow a current to flow into and out of the member and configured to exert a Lorentz force on the member when a current flows through the conductive path in the presence of a magnetic field having at least a portion of the magnetic field orthogonal to the conductive path;wherein an apparent quality factor (Q) of the MEMS device is changed in the presence of the magnetic field acting on the current flowing through the conductive path that creates the Lorentz force; an oscillator including the MEMS device, the oscillator including a control loop to maintain output of the oscillator constant and wherein a value of the magnetic field is reflected in a control signal of the control loop used to maintain the output constant.