MEMS approach for making a low cost, high sensitivity magnetic sensor

An approach based on electromechanical systems (MEMS) technology will be presented that essentially eliminates the problem of 1/f noise in small magnetic sensors. The sensor based on this approach, the MEMS flux concentrator sensor, should outperform all other high sensitivity vector magnetometers in terms of cost, power consumption, and sensitivity. The method for achieving this improvement is to employ flux concentrators on MEMS structures that are near the magnetic sense element. The motion of the flux concentrators modulates the magnetic field and shifts the operating frequency of the sensor to higher frequencies where 1/f noise is unimportant. The data presented here provides our first evidence that the MEMS flux concentrator improves the signal to noise ratio at low frequencies.