Design and numerical performance analysis of a microgravity accelerometer with quasi-zero stiffness

Abstract

We report a nonlinear electrothermal-loaded accelerometer for microgravity measurement, achieving quasi-zero stiffness nearby its static equilibrium position. The high mechanical sensitivity is attributed to the compression of the spring, in addition to the geometric parameters matched with quasi-zero stiffness characteristic. To make the spring compressed effectively, a V-shape electrothermal actuator was adopted in the design. The FEA results in multiphysics clearly show the different performance of the accelerometer when it is at applied voltage or not, verifying that the electrothermal-loaded mechanism has an effective influence on the sensitivity of accelerometer. At the applied voltage of 22.3 V, the natural frequency of the accelerometer decreases from 501.95 Hz to 8.24 Hz, while the other two higher mode frequencies remain above 500 Hz. In addition, this mechanism realizes a quasi-zero stiffness approximately of 0.007 N m −1 within a linear working range of ±400 µg and the stiffness becomes larger beyond this range protecting the device being overloaded.

Optical Interferometric MEMS Accelerometers

“…Based on this, researchers proposed nonlinear springs, spring tandem, spring tuning, and additional mass to reduce the accelerometer's resonant frequency. Yuxing Duan et al designed a spring-tuned device based on an electrothermal actuator (Figure 32a), [125] reducing the resonant frequency from 501.95 Hz to 8.24 Hz. Wenjie Wu et al designed a MEMS chip with a resonant frequency of 0.7 Hz based on the nonlinear effect of the curved spring (Figure 32b).…”

Optical Accelerometers for Detecting Low-Frequency Micro-Vibrations

“…In summary, optical accelerometers based on optical intensity modulation are similar to those based on optical path modulation, with a simple structure and lower cost. This type of optical accelerometers can achieve extremely high sensitivity by using a highly sensitive mechanical sensing unit [46][47][48]. However, the measurement accuracy of light intensity-modulated accelerometers is directly dependent on the stability of light intensity and has high requirements for the light source and its driver.…”

Acceleration Sensors: Sensing Mechanisms, Emerging Fabrication Strategies, Materials, and Applications

“…The sensor achieved a high-sensitivity range of 8 μGal/√Hz and wide dynamic range of 8000 mGal . An electrothermal-loaded accelerometer for microgravity measurement that has quasi-zero-stiffness characteristic was reported by Duan et al In order to achieve high mechanical sensitivity, the spring was compressed and geometric parameters were matched with the quasi-zero-stiffness characteristic of the sensor …”

“…135 An electrothermal-loaded accelerometer for microgravity measurement that has quasi-zero-stiffness characteristic was reported by Duan et al In order to achieve high mechanical sensitivity, the spring was compressed and geometric parameters were matched with the quasi-zerostiffness characteristic of the sensor. 136 Multiple literature contributions demonstrate liquid metal based accelerometers used for vibration monitoring applications. One example shown by Zeng and Zhao is of a liquid marble based accelerometer designed for vibration monitoring which was fabricated by placing a liquid marble in a curved channel and sealed with SU-8 polymer such that the liquid marble can move in the channel.…”