High-altitude electric fields are a critical parameter of electricity in the atmosphere. Due to such drawbacks as their bulk and high cost, traditional electric field mills are not available for daily atmospheric sounding purposes. This paper introduces a highly sensitive and robust electric field sounding sensor based on an existent micro-electro-mechanical systems chip and a new protective package that augments sensor sensitivity. To gain high sensitivity, an innovative external metal electrode connects to the electric field microchip's package cap, hangs down out of the guardian foam, and effectively enhances the local electric field near the microchip due to the distortion effect. This distortion regularity was studied during a series of finite element simulations, calibrations, and comparison experiments. With a 1.5-meter-long external electrode, the sensitivity of the sensor reached 465 mV/kV/m with a resolution that was better than 10 V/m in an actual long-term ground comparison test. Furthermore, the microsensor chip and its circuit are protected inside a foam while the metal electrode is exposed outside, therefore gaining a robust stability during harsh environments such as low temperature, rainfall, etc. To examine the performances, we built an electric field sounding system, including the electric field sensor, a radiosonde, and a receiving antenna, and measured high-altitude electric fields in various weather conditions. Intended for atmospheric electricity research, our innovative electric field sounding sensor would be especially propitious if integrated with a radiosonde and applicable to daily sounding services.

A non-interference AC voltage measurement system based on a resonant electric field microsensor is proposed. The equivalent circuit of the proposed system is established, which shows that the frequency response function is only related to the capacitances of the system structure in the kHz low-frequency range. Furthermore, the sensitivity analysis and experiments demonstrate that the amplitude sensitivity is independent of the frequency of an unknown AC voltage. Therefore, this technique is very suitable for measuring arbitrary waveform voltage. A functional prototype was developed and tested to acquire AC power-line voltages. The prototype responded well to the transient waveform of the AC input signal, yet with a phase delay of 177.24°. The output of the system was linear in the range of 0–1000 V_rms at 50-Hz and the linearity was 0.54%, whereas the maximum relative deviation of the rms voltage measurements above 10 V was −0.83%. Finally, the shielding ability of the system against interference and noise was verified through the AC interference voltage measurement.

Electric field sensors (EFSs) are widely used in various fields, particularly in accurately assessing atmospheric electric fields and high-voltage power lines. Precisely detecting electric fields enhances the accuracy of weather forecasting and contributes to the safe operation of power grids. This paper comprehensively reviews the development of micro-electromechanical system (MEMS) resonant EFSs, including theoretical analysis, working principles, and applications. MEMS resonant EFSs have developed into various structures over the past decades. They have been reported to measure electric field strength by detecting changes in the induced charge on the electrodes. Significant advancements include diverse driving and sensing structures, along with improved dynamic range, sensitivity, and resolution. Recently, mode localization has gained attention and has been applied to electric field sensing. This paper reviews the performances and structures of MEMS resonant EFSs over recent decades and highlights recent advances in weakly coupled resonant EFSs, offering comprehensive guidance for researchers.

Electrostatic field microsensors (EFMs) are widely used in many fields, and the environmental adaptability is one of the major concerns for EFMs development. This paper proposes a resonant EFM with self-compensation for sensitivity drift, which is suitable for outdoor applications. The proposed EFM sensitive structure mainly consists of sensing electrodes and reference electrodes, where the sensing electrodes are designed to measure the electrostatic field, and the reference electrodes are used to detect the vibration amplitude and phase of the movable structure. With the reference electrodes output, the EFM can track the resonant frequency by phase-locked loop circuit automatically and correct the sensing output signal in real time. Experimental results demonstrated that the proposed EFM reached a linearity of 0.21% and a total uncertainty of three round trips within 1.34% in the electrostatic field range of ±18 kV/m, and achieved a sensitivity drift within 3.0% in the temperature range of -40~70 °C, which means that it realized a good self-compensation performance.

Electrostatic voltage is a vital parameter in industrial production lines, for reducing electrostatic discharge harms and improving yields. Due to such drawbacks as package shielding and low resolution, previously reported electric field microsensors are still not applicable for industrial static monitoring uses. In this paper, we introduce a newly designed microsensor package structure, which enhances the field strength inside the package cavity remarkably. This magnification effect was studied and optimized by both theoretical calculation and ANSYS simulation. By means of the digital synthesizer and digital coherent demodulation method, the compact signal processing circuit for the packaged microsensor was also developed. The meter prototype was calibrated above a charged metal plate, and the electric field resolution was 5 V/m, while the measuring error was less than 3 V, from −1 kV to 1 kV in a 2 cm distance. The meter was also installed into a production line and showed good consistency with, and better resolution than, a traditional vibratory capacitance sensor.

High-resolution and sensitive MEMS DC electric field sensors offer the possibility for the integration of detection in multiple fields, such as atmospheric electricity, power grids and biomedical sciences. In this work, a mode-localized sensor prototype based on a double-ended tuning fork design (DETF) is presented. The theoretical derivations and lumped model simulations reveal the key performance enhancements regarding the wide measurement range and high resolution of such a coupled resonator structure. A prototype is fabricated using Silicon-On-insulator (SOI) approaches, which is further tested to achieve a sensitivity of $\mathrm{0.016 /(kV/m)}$ , a resolution of $\mathrm{21.3~V/m}$ , a measurement range of $\mathrm{200 kV/m}$ and a bias instability of $\mathrm{0.29~V/m}$ . The metrics are improved compared to the traditional Euler beam designs and the micro-machined counterparts. This shows the capability to meet the demands for electric field sensing in modern atmospheric electricity, power grids and biomedical sciences, with enhanced sensitivity, measurement range and stability. 2024-0154