Extremely Sensitive PZT-based MEMS Magnetometer for Use as an Orientation Sensor.

摘要

The objective of this project was to develop a sensitive MEMS-based magnetometer for use as an orientation sensor on spinning projectiles. The magnetometer was derived from the JHU/APL resonating xylophone bar with sensitivity linearly proportional to the drive current, mechanical Q at resonance, and the magnetic field. Polysilicon magnetometers demonstrated the size effects expected for such devices. Their sensitivity was limited by the relatively high sheet resistivity that restricted the drive current. A custom designed capacitive sense chip was developed and tested. PZT-based magnetometers (processed at ARL, Adelphi) were shown, at the current state of development, to be unsuitable for this application because of low Q's, asymmetric conducting layers, and high residual stress levels. The most promising technology appears to be based on CMOS-MEMS, although more development is required to produce practical devices. Even more recent advances in silicon-on-sapphire (SOS) technologies may make it possible to replace standard capacitive transduction schemes with much more sensitive optical ones. Studies have shown that a MEMS-based magnetometer would have important applications in addition to orientation sensing.