A High Sensitivity Electric Field Microsensor Based on Torsional Resonance

Abstract

This paper proposes a high sensitivity electric field microsensor (EFM) based on torsional resonance. The proposed microsensor adopts torsional shutter, which is composed of shielding electrodes and torsional beams. The movable shielding electrodes and the fixed sensing electrodes are fabricated on the same plane and interdigitally arranged. Push–pull electrostatic actuation method is employed to excite the torsional shutter. Simulation results proved that the torsional shutter has higher efficiency of charge induction. The optimization of structure parameters was conducted to improve its efficiency of charge induction further. A micromachining fabrication process was developed to fabricate the EFM. Experiments were conducted to characterize the EFM. A good linearity of 0.15% was achieved within an electrostatic field range of 0–50 kV/m, and the uncertainty was below 0.38% in the three roundtrip measurements. A high sensitivity of 4.82 mV/(kV/m) was achieved with the trans-resistance of 100 MΩ, which is improved by at least one order of magnitude compared with previously reported EFMs. The efficiency of charge induction for this microsensor reached 48.19 pA/(kV/m).

An Electric Field Microsensor with Mutual Shielding Electrodes

“…When the electrode width or the electrode gap decreases, the number of mutual shielding electrode groups increases in a certain area. This paper uses parameter B [ 30 ] to illustrate the simulation results, B is given by …”

“…In the recent three decades, with the development of micromachining technology, a variety of EFMs have been reported [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], which have advantages of small volume, batch producibility and low power consumption. Most of them are charge–induction-based ones, whose sensing structures mainly consist of fixed sensing electrodes and grounded movable shielding electrodes.…”

Design, Fabrication and Characterization of a MEMS-Based Three-Dimensional Electric Field Sensor with Low Cross-Axis Coupling Interference

“…In the last two decades, with the rapid development of Micro-electro-mechanical Systems (MEMS) technology, much literature on electric field sensor chips (EFSCs) has emerged, providing various EFSCs with the advantages of low power cost, small size, high integration, and convenience for batch production. These EFSCs can be classified into three categories according to their working principles, namely, induction charge [ 7 , 8 , 9 , 10 , 11 , 12 ], electrostatic force [ 13 , 14 ], and steered-electrons [ 15 ]. These EFSCs focus on direct current (DC) and low-frequency alternating current (AC) electric field measurement.…”

Research on a Novel MEMS Sensor for Spatial DC Electric Field Measurements in an Ion Flows Field

“…Recently, a serious of new type EFSs have been proposed. Chu proposed a new type based on torsional resonance [ 16 ], and Andò designed a ferroelectric-capacitor-based quasistatic EFS [ 17 ]. Kainz et al used the AC electric field to generate the driving force which makes the optical shutter of the MEMS structure periodically shielding the light and changes the light flux received by the photodetector, so as to realize the detection of the low-frequency AC electric field and DC electric field [ 18 ].…”

“…Comparisons of different EFS are listed in Table 1 . However, the measuring result cannot be assumed to be equal to the original value due to the redistribution of the charged particles and electric field distortion when the sensor is placed in an ion flow field [ 16 , 17 , 18 , 19 ]. Thus far, no effective method has been developed to measure the space synthetic field in an ionized field.…”