Differential MEMS quartz resonant accelerometer has significant technological innovations

Under the background of the rapid development of micro-electromechanical systems (MEMS) technology, accelerometer sensor, as one of its important applications, are constantly breaking through technical bottlenecks and achieving a higher performance goals. Recently, Xi'an Jiaotong University developed a new differential MEMS quartz resonant accelerometer. This device has broken through many performance limits of traditional accelerometers and attracted industry attention with its high resolution and low noise characteristics.

The working principle of MEMS quartz resonant accelerometer is based on the piezoelectric effect of single crystal quartz. By placing electrodes on its surface and applying AC voltage, the resonator oscillates in a specific mode. This design makes the device more compact while improving the quality factor (Q) and linear operating range. In recent years, MEMS quartz resonant accelerometers have attracted widespread attention due to their superior performance and broad application prospects, but relevant research on their high-resolution characteristics is still relatively scarce.

In the new research, Xi'an Jiaotong University 's differential MEMS quartz resonant accelerometer has significant technological innovations. A novel low-noise oscillator readout circuit is used, which not only optimizes the operation of the resonator but also overcomes the traditional trade-off between gain, bandwidth and noise. Its unique bandpass front-end design achieves a gain of 14.5M and a phase drift of 0.04° at the oscillation frequency, while maintaining an input-referred current noise of 30.5fA/√Hz, greatly improving the bias instability of the accelerometer. and resolution.

In addition, the research team also introduced an anti-aliasing phase shifter to further adjust the loop bandwidth and compensate for phase drift, thereby improving the frequency resolution. The test results show that it has achieved a frequency resolution of 14μHz/√Hz and a bias instability of 32μHz. Combining these advantages, the full scale of the accelerometer is ±70g, the scale factor is 54.5Hz/g, and the bandwidth is 552Hz.

In order to more clearly demonstrate the effectiveness of this technology, the research team designed and manufactured a sensitive element, which includes two resonators, connected to the calibration mass block through a force amplification lever, to achieve accurate measurement of acceleration. When acceleration acts on the two resonators, their resonant frequencies change in the opposite direction, and the resulting frequency gap is the basis for measuring acceleration.

The study shows that the MEMS quartz resonant accelerometer performs well in practical applications. In the test of the vibration generator, the device can robustly respond to vibration signals of different frequencies, and the output resonance peak is consistent with the theoretical prediction, verifying its reliability in practical scenarios.

With the continuous advancement of MEMS technology, the application potential of this differential MEMS quartz resonant accelerometer in inertial guidance, earthquake detection, wearable devices and intelligent robots will be fully released. The breakthrough of this technology not only reflects China's research strength in the field of MEMS, but also lays a solid foundation for future scientific and technological progress.

In addition, the main results of the research team have been published in the journal "Microsystems & Nanoengineering". The relevant paper has made an in-depth explanation of the development and application of MEMS resonant accelerometers. Interested readers can learn more about the technology through the paper link.

In the wave of rapid social and technological development, innovative technology has always been the driving force for the development of the industry. How to make reasonable use of these technologies will be a problem that professionals in multiple fields need to think about together. In the evening reflections of the researchers, perhaps more people will see the infinite possibilities that new technologies bring to human future exploration.