Ultra sensitive lorentz force MEMS magnetometer with pico-tesla limit of detection

Author

Kumar, Varun ; Mahdavi, Mohammad ; Xiaobo Guo ; Mehdizadeh, Emad ; Pourkamali, Siavash

Author_Institution

Electr. Eng. Dept., Univ. of Texas at Dallas, Richardson, TX, USA

fYear

2015

fDate

18-22 Jan. 2015

Firstpage

204

Lastpage

207

Abstract

This work presents ultra-high sensitivities for Lorentz Force resonant MEMS magnetometers enabled by internal thermal-piezoresistive vibration amplification. Up to 2400X increase in sensitivity has been demonstrated by tuning the resonator bias current to maximize its internal amplification factor boosting the effective Quality Factor (Q) from its intrinsic value of 680 to 1.14×10⁶ (1675X amplification). For a bias current of 7.245mA, where the sensitivity of the device is maximum (2.107mV/nT), the noise floor is measured to be as low as 2.8 pT/√Hz. This is by far the most sensitive MEMS Lorentz force magnetometer demonstrated to date.

Keywords

Q-factor; magnetic sensors; magnetometers; micromechanical resonators; vibrations; MEMS Lorentz force magnetometer; current 7.245 mA; device sensitivity; effective quality factor; internal amplification factor; internal thermal-piezoresistive vibration amplification; noise floor; pico-tesla detection limit; resonator bias current tuning; ultrahigh-sensitivities; ultrasensitive Lorentz force MEMS magnetometer; Lorentz covariance; Magnetic field measurement; Magnetic resonance; Magnetic sensors; Magnetometers; Sensitivity;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems (MEMS), 2015 28th IEEE International Conference on

Conference_Location

Estoril

Type

conf

DOI

10.1109/MEMSYS.2015.7050922

Filename

7050922