Micromechanical Magnetometer using an all-silicon nonlinear torsional resonator

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

APPLIED PHYSICS LETTERS

Año: 2009 vol. 95 p. 133505 - 133508

0003-6951

In this work, a micromagnetometer employing a nonlinear torsional resonator with a high qualityfactor Q is presented experimentally. Oscillatory rotation of a conducting plate in the sensedmagnetic field H induces eddy currents that dissipate energy. Due to the nonlinear response of theoscillator, the resulting mechanical damping originates frequency shifts in the resonance curve thatdepend on H. Nonlinearity results from the electrostatic detection, which introduces high orderelectrical spring constants. The device is fabricated with a standard silicon process and does notincorporate ferromagnetic materials. An analytical nonlinear model that correctly describes thedevice is also introduced.