Mechanical design and characterization of a resonant magnetic field microsensor with linear response and high resolution

作者：Herrera May A L^*; Garcia Ramirez P J; Aguilera Cortes L A; Figueras E; Martinez Castillo J; Manjarrez E; Sauceda A; Garcia Gonzalez L; Juarez Aguirre R

来源：Sensors and Actuators A: Physical , 2011, 165(2): 399-409.

DOI：10.1016/j.sna.2010.07.005

• Lorentz force
• Magnetic field microsensor
• Macaulay's method
• MEMS technology
• Piezoresistive sensing
• Rayleigh method

A resonant magnetic field microsensor based on Microelectromechanical Systems (MEMS) technology including a piezoresistive detection system has been designed, fabricated, and characterized. The mechanical design for the microsensor includes a symmetrical resonant structure integrated into a seesaw rectangular loop (700 mu m x 450 mu m) of 5 mu m thick silicon beams. An analytical model for estimating the first resonant frequency and deflections of the resonant structure by means of Rayleigh and Macaulay's methods is developed. The microsensor exploits the Lorentz force and presents a linear response in the weak magnetic field range (40-2000 mu T). It has a resonant frequency of 22.99 kHz, a sensitivity of 1.94 VT-1, a quality factor of 96.6 at atmospheric pressure, and a resolution close to 43 nT for a frequency difference of 1 Hz. In addition, the microsensor has a compact structure, requires simple signal processing, has low power consumption (16 mW), as well as an uncomplicated fabrication process. This microsensor could be useful in applications such as the automotive sector, the telecommunications industry, in consumer electronic products, and in some medical applications.

• 出版日期2011-2