Micromechanical magnetometer using an all-silicon nonlinear torsional resonator

ANTONIO, D.; DOLZ, M.; PASTORIZA, H.

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Año: 2009 vol. 95 p. 133505 - 133505

0003-6951

In this work, a micromagnetometer employing a nonlinear torsional resonator with a high quality factor Q is presented experimentally. Oscillatory rotationof a conducting plate in the sensed magnetic field H induces eddy currents that dissipate energy. Due to the nonlinearresponse of the oscillator, the resulting mechanical damping originates frequency shifts in the resonance curve that depend on H. Nonlinearity results from the electrostatic detection, which introduces high order electrical spring constants. The device is fabricated with a standard silicon process and does not incorporate ferromagnetic materials. An analytical nonlinear model that correctly describes the device is also introduced.