Experimental investigation of parametric and externally forced motion in resonant MEMS sensors

Abstract

In this paper an excitation method employing both harmonic forcing and parametric excitation is applied to a resonant MEMS sensor in order to investigate and characterize the phenomena of parametric resonance and parametric amplification. The motivation for this research is that parametric excitation may be used to significantly reduce the total damping in MEMS sensors in a controllable manner. This is extremely pertinent to devices where the Q-factor is a principal factor in determining sensor performance. In this paper it is shown that, by adjusting the parametric excitation parameters (frequency, amplitude and phase) of an electrostatically actuated and sensed device, the gain of the frequency response function of a mode of vibration may be amplified. The amplification is quantified by the gain factor which is characterized experimentally. The instability regions defining the regions for parametric resonance are also characterized experimentally and compared to theoretical predictions. The boundaries of these instability regions define the thresholds for parametric resonance and play a crucial role in the design of the parametric amplifier.

High gain parametric amplification applied to the micro ring gyroscope

“…From the tests conducted in [3] it was shown that the threshold voltage for parametric resonance was experimentally determined to be of the order V . Experimental tests were performed with a series of different forcing levels to determine the validity of the linear model and to determine the minimum level of forcing that may be used practically with this experimental setup.…”

“…the forcing voltage f V must be considerably reduced from the value of 100 mV used in the low gain experiments reported in [3]. Attenuation of the harmonic forcing signal was performed via a resistor network after the signal generation to avoid distortion and to provide impedance matching between signal generator, digitizer and the MEMs device.…”

“…This is referred as parametric amplification. It is only recently that the application of parametric excitation to MEMs/NEMs has been investigated [1][2][3][4].…”

“…The MEMS device investigated was a micro-ring resonator and has applications as a rate gyroscope. Previous work on this device reported in [3] was restricted to parametric amplification of an order of magnitude. Figure 1 illustrates the MEMS resonator used in the investigation.…”

Thermal Effect on Free Vibration and Buckling of a Double-Microbeam System

“…With the rapid development of technology, functionally graded (FG) beams and plates are often used in MEMS/NEMS, such as the components in the shape of memory thin films alloy with a global thickness in the micro/nano scale, atomic force microscopes (AFMs), and electrically actuated MEMS devices [1][2][3][4][5][6][7][8]. As opposed to the strain theories which were introduced by Mindlin and Eshel [9], with five constants besides the Lamé constants, Lam et al [1] presented a modified theory consisting of only three non-classical constants.…”