Temperature fluctuations seriously damage the performance of resonant accelerometers. Two approaches have been proposed in this paper to address this problem. In structural design, electrostatic softening spring is utilized to modulate the external acceleration on the frequency of resonator’s anti-phase modal without any stress transmission, and thus improve the thermal robustness of the accelerometer. In control circuit, continuous ring-down technique is employed for real-time quality factor (utilized as a virtual thermometer) monitoring, which attenuates measuring hysteresis and improves the precision of temperature compensation. A prototype is implemented to verify the proposed approaches. Experiments show that this accelerometer is insensitive to stress and has better performance of temperature compared with vibration beam resonant accelerometer. The bias stability of acceleration output was improved from 35.2mg to 0.08mg with real-time quality factor compensation ranging from −40°C to +40°C.

High-quality-factor Micro-Electro-Mechanical System (MEMS) resonators have been widely used in sensors and actuators to obtain great mechanical sensitivity. The frequency drift of resonator with temperature is a problem encountered practically. The paper focuses on the resonator frequency distribution law in the temperature range of—40 to 60 °C. The four-layer models were established to analyze thermal stress caused by temperature due to the mismatch of thermal expansion coefficients. The temperature variation leads to the transformation of stress, which leads to the shift of resonance frequency. The paper analyzes the influence of hard and soft adhesive package on the temperature coefficient of frequency. The resonant accelerometer was employed for the frequency measurements in the paper. In experiments, three types of adhesive dispensing patterns were implemented. The results are consistent with the simulation well. The optimal packaging method achieves −24.1 ppm/°C to −30.2 ppm/°C temperature coefficient of the resonator in the whole temperature range, close to the intrinsic property of silicon (−31 ppm).

Phononic crystals/metamaterials are attracting increasing interest because of their large variety of applications at both the macro and micro scales. In this work, a new metamaterial plate (metaplate) composed of innovative phononic crystal unit-cells is presented, numerically studied, fabricated at the microscale and experimentally tested. Numerical simulations and experimental tests demonstrate a complete 3D phononic bandgap that guarantees a complete vibration isolation in a certain range of frequency. Moreover, its compatibility with Micro Electro Mechanical Systems (MEMS) fabrication processes suggests applications for vibration isolation of MEMS resonant devices. The measured transmission diagram shows a -30 dB attenuation level, which is in good agreement with numerical predictions. The proposed design opens up new perspectives for the development of vibration isolation applications for MEMS resonators. [2020-0069].

Due to material mismatch, silicon differential resonant accelerometers (SDRA) experience unpredictable thermal stress that is challenging to account for. An SDRA with a stress-isolated frame that is co-faced with the sensitive structural layer is shown in this study. Analytical construction is used to create the stress transmission model of SDRA, which incorporates the equivalent stiffness of a stress-isolated frame. It offers a technique to balance the scale factor of the device with thermal stress resistance. Then, from -40°C to 85°C, the proposed SDRA devices’ temperature behavior with and without a stress-isolated frame were examined theoretically, numerically, and experimentally. The measured temperature sensitivities of the device with the stress-isolated structure were around -1.15Hz /°C, 0.19mg/°C, and 37.23ppm /°C for the frequency, bias, and scale factors, respectively. The bias instability of the novel device is 0.72μg. Under the identical experimental conditions, each of these metrics outperformed the device without stress isolation by one to two orders of magnitude, demonstrating the efficiency of the novel stress-isolated structure.

In this work the nonlinear dynamic behaviour under varying temperature conditions of the resonating beams of a differential resonant accelerometer is studied from the theoretical, numerical and experimental points of view. A complete analytical model based on the Hamilton’s principle is proposed to describe the nonlinear behaviour of the resonators under varying temperature conditions and numerical solutions are presented in comparison with experimental data. This provides a novel perspective to examine the relationship between temperature and nonlinearity, which helps predicting the dynamic behaviour of resonant devices and can guide their optimal design.

A novel and sensitive electrochemical method was proposed for the determination of Sunset yellow (SY) using an expanded graphite paste electrode (EGPE). The EGPE was prepared by mixing expanded graphite (EG) with solid paraffin. EG was characterized with scanning electron microscopy. Compared with flake graphite paste and carbon paste electrode, the EGPE showed a higher electrocatalytic activity toward the oxidation of SY. The EGPE exhibited wide linear response of 5.0 × 10⁻⁸−2.0 × 10⁻⁶ mol/L with a detection limit down to 5.0 nmol/L (S/N = 3) and good accuracy, precision, reproducibility. The proposed method was successfully applied in the determination of SY in jelly and fruit juice.