Analysis of Frequency Stability and Thermoelastic Effects for Slotted Tuning Fork MEMS Resonators

Valentina Zega; Attilio Frangi; Andrea Guercilena; Gabriele Gattere

doi:10.3390/s18072157

Analysis of Frequency Stability and Thermoelastic Effects for Slotted Tuning Fork MEMS Resonators

Sensors ◽

10.3390/s18072157 ◽

2018 ◽

Vol 18 (7) ◽

pp. 2157 ◽

Cited By ~ 6

Author(s):

Valentina Zega ◽

Attilio Frangi ◽

Andrea Guercilena ◽

Gabriele Gattere

Keyword(s):

Tuning Fork ◽

Frequency Stability ◽

Mems Resonators ◽

Thermoelastic Effects

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Dynamic behaviours of the Double-end tuning fork based comb-driven microelectromechanical resonators for modulating the magnetic flux synchronously

Journal of Micromechanics and Microengineering ◽

10.1088/1361-6439/ac388e ◽

2021 ◽

Author(s):

Zhenxi Liu ◽

Jiamin Chen ◽

Wuhao Yang ◽

Tianyi Zheng ◽

Qifeng Jiao ◽

...

Keyword(s):

Detection Limit ◽

Magnetic Flux ◽

Resonance Frequency ◽

Tuning Fork ◽

Paper Making ◽

Initial Space ◽

Mems Resonator ◽

Mems Resonators ◽

Mems Fabrication ◽

First Time

Abstract MEMS resonators have been widely used in the magneto-resistive (MR) sensor for modulating the magnetic flux to enhance the detection limit. However, the manufacturing tolerances in MEMS fabrication processes make it challenging to fabricate the identical resonators with the same vibration frequency, which greatly decreases the detection limit of the MR sensor. To synchronize the MEMS resonators and improve the performance of the MR sensor, the double end tuning fork (DETF) based comb-driven MEMS resonators is proposed in this paper, making the system operate at the out-of-phase mode to complete the synchronization. The dynamic behaviour of the resonators is investigated through theoretical analysis, numerical solution based on MATLAB code and Simulink, and experimental verification. The results show that the transverse capacitances in the comb will significantly affect the resonance frequency due to the second-order electrostatic spring constant. It is the first time to observe the phenomenon that the resonant frequency increases with the increase of the bias, and it can also decrease with increasing the bias through adjusting the initial space between the fixed finger and the moving mass, they are different from the model about spring softening and spring hardening. Besides, the proposed DETF-based comb-driven resonators can suppress the in-phase and out-of-phase mode through adjusting the driving and sensing ports, and sensing method, meanwhile make the magnetic flux modulation fully synchronized, and maximize the modulation efficiency, and minimize the detection limit. These characteristics are appropriate for the MR sensor, even other devices that need to adjust the resonance frequency and vibration amplitude. Furthermore, the model and the design can also be extended to characteristic the single end tuning fork (SETF) based MEMS resonator and other MEMS-based MR sensors.

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Vertical MEMS Resonators for Real-Time Clock Applications

Journal of Sensors ◽

10.1155/2010/362439 ◽

2010 ◽

Vol 2010 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

A. Pomarico ◽

A. Morea ◽

P. Flora ◽

G. Roselli ◽

E. Lasalandra

Keyword(s):

Real Time ◽

High Performance ◽

Large Scale ◽

Low Cost ◽

Frequency Stability ◽

Equivalent Resistance ◽

Real Time Clock ◽

Mems Resonator ◽

Mems Resonators ◽

Frequency Tunable

MEMS resonators are today widely investigated as a desirable alternative to quartz resonators in real-time clock applications, because of their low-cost, integration capability properties. Nevertheless, MEMS resonators performances are still not competitive, especially in terms of frequency stability and device equivalent resistance (and, then, power consumption). We propose a new structure for a MEMS resonator, with a vertical-like transduction mechanism, which exhibits promising features. The vertical resonator can be fabricated with the low-cost, high performance THELMA technology, and it is designed to be efficiently frequency tunable. With respect to the commonly investigated lateral resonators, it is expected to have lower equivalent resistances and improved large-scale repeatability characteristics.

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