Electrostatic Detection Research Articles

Electrostatic Bursts Generated by the Ion–Ion Acoustic Instability with Solar Wind Plasma Parameters

This study is motivated by recent observations from the Parker Solar Probe (PSP) mission, which have been identified as ion-acoustic waves from 15 to 25 solar radii. These observations reveal characteristic sequences of narrowband, high-frequency bursts exceeding 100 Hz embedded into a slower evolution around 1 Hz, persisting for several hours. To explore the potential role of the ion-acoustic instability (IAI) in these phenomena, we begin by reviewing classical findings on the IAI within the framework of linear kinetic theory. Focusing on proton distributions comprising both a core and a beam component, we analyze the IAI instability range and growth rates within the parameter regime relevant to PSP observations. Our findings indicate that the IAI can indeed occur in this regime, albeit requiring electron-to-core and beam-to-core temperature ratios slightly different from reported values during electrostatic burst detection. Furthermore, employing one-dimensional kinetic plasma simulations, we validate the growth rates predicted by linear theory and observe the saturation behavior of the instability. The resultant nonlinear structures exhibit trapped proton beam populations and oscillatory signatures comparable to those observed, both in terms of timescales and amplitude.

Design of Low-Cost Simulation Space Micro Debris Launch Device

The high cost and low emission frequency of microparticle launchers have resulted in a long lead time for the development of detectors for micro-debris in space. In this paper, two low-cost, high-emission-frequency, small-size, millimeter-sized particle launchers are designed using the principles of gas expansion and surge propulsion by a high-speed air stream. Electrostatic detection is utilized to determine the emission velocity of the microbeads and their deviation from a specific position on the flight trajectory. The emission rate and accuracy of both methods were experimentally evaluated, along with the deviation of the detection system. Both devices emitted microbeads to simulate micro-debris, providing experimental data for the development of a space debris detector and establishing research conditions for studying the impact of micro-debris.

Centimeter-level 2D ultra-small interdigital sensor for ESD detection of spacecraft

The spacecraft in geosynchronous orbit interacts with the space plasma environment, which is prone to electrostatic discharge and affects the safe operation of the spacecraft. In order to realize simple, accurate and reliable electrostatic discharge detection in space environment, based on the energy spectrum characteristics of spacecraft electrostatic discharge electromagnetic radiation electromagnetic pulse and the electromagnetic pulse sensing principle of interdigital electrode, a centimeter-level two-dimensional planar ultra-small interdigital sensor with a size of only 4 cm × 3 cm × 0.01 cm is developed. The impedance matching circuit is established to greatly improve the transmission efficiency of electromagnetic pulse, which is 59.34 % higher than that before the matching circuit is added. Finally, a spacecraft vacuum electrostatic discharge simulation experiment platform is built to test the frequency response characteristics of the sensor. The results show that the frequency response characteristics of the electromagnetic pulse signal perceived by the sensor developed in this paper are consistent with the main frequency characteristics of the spacecraft electrostatic discharge radiation electromagnetic pulse energy spectrum, which can be used for spacecraft electrostatic discharge detection in space environment.

Quantifying squeeze film damping in four-leaf clover-coupled micro-resonators: A comprehensive study under variable vacuum degrees

The squeeze film effect has a significant impact on the performance of micro-resonators when utilizing the electrostatic excitation and capacitive detection technique, due to the narrow air gaps present. It becomes the most critical damping effect that needs to be addressed. However, when micro-resonators are encapsulated in vacuum or rarefied air, squeeze film damping analysis can become considerably complex due to high-quality factors. In this study, we systematically investigate the squeeze film damping of a widely-used four-leaf clover-coupled micro-resonator under different vacuum degrees. The characteristic frequencies of micro-resonators are determined by applying the principle of mode superposition. Subsequently, the energy transfer theory is utilized to derive the theoretical formula for the quality factor caused by squeeze film damping, for varying levels of vacuum. Finite element analysis is then conducted to simulate the characteristic behavior and squeeze film damping of the resonator, confirming the accuracy of the proposed theory. In the experiment, a novel four-leaf silicon micro-resonator is fabricated using bulk anisotropic wet etching and other micromachining technologies. An experimental platform is established to study the squeeze film damping of the micro-resonator under various vacuum degrees, where the micro-resonator is excited electrostatically and detected capacitively. The frequency response and quality factor of the resonator under different vacuum degrees are measured using a house-made modal test circuit board. The experimental results demonstrate excellent agreement with the theoretical and simulated results, indicating that the proposed method can be a reliable and precise guide for understanding the squeeze film damping effect in advance, once the primary model of a micro-resonator has been designed.

Assessing the Stability of Human Gait Based on a Human Electrostatic Field Detection System

Assessing the Stability of Human Gait Based on a Human Electrostatic Field Detection System

Electrostatic detection and electric signalling in plants: do flowers act as antennas?

Flying insect pollinators are electrically charged. As bumblebees (Bombus terrestris) and honeybees (Apis mellifera) are almost always positively charged, they present a static electric field that is modulated by the harmonic motion of their wings. Previous research has demonstrated that as a bee approaches a flower, there is a change in the stem potential of the plant, even before the bee lands, suggesting a capacity for flowers to sense the approaching bee through its electric field. Using a combination of laboratory and field studies, we explore the potential for flowers to act as receiving antennas for electrical signals, and to transmit these signals to neighbouring plants. Results show that flowers can detect non-contact electric stimuli, presumably by charge induction, and appear not to be tuned to a specific frequency. In the field, non-contact electric stimuli can also be detected in neighbouring flowers that did not receive the aerial stimulus. This evidence demonstrates the ability of flowers to capture local, aerial electrical signals, and the plant to then transmit signals through the soil to neighbouring plants. This work highlights the significance of environmental electric fields in pollination biology.

Compact Archimedean spiral antenna with high gain for electrostatic discharge detection

AbstractA compact Archimedean spiral antenna with high gain for electrostatic discharge (ESD) detection is investigated. A frustum‐shaped cavity proposed in this work is formed to optimise the maximum antenna gain. Additionally, a helix arm is loaded to enhance antenna gain in lower band. The measured results demonstrate that the proposed antenna, which employs a unidirectional radiation mode, exhibits a maximum antenna gain ranging from −0.74 dBi to 9.46 dBi and a voltage standing wave ratio less than 3 across a frequency range of 0.65–5 GHz. A test system consisted of proposed antenna and a commercial ESD detection antenna is established. The verified results indicate that the proposed antenna has a performance close to the commercial antenna, so that proposed antenna with compact size is preferred to be utilised for ESD detection.

Analysis of influencing factors of electrostatic detection system based on double electrode

This study aims to explore the influence of various factors of the electrostatic induction system on the object information of double-electrode electrostatic detection. Based on the principle of electrostatic induction, we first establish a system model and a mathematical model for single-electrode electrostatic detection. We analyze the effect of various factors on the target information of single-electrode electrostatic detection. On this basis, a novel double-electrode electrostatic detection model is introduced, and detection rational is explained in detail. A comparative study using theory and computer simulation is conducted. The results show that the novel double-electrode electrostatic detection system performs significantly better than its single-electrode counterpart. We also observe that the vertical detection distance has a greater impact on the detection performance compared to the interval between the two electrodes. Moreover, we find that the vertical detection distance and the interval between the two electrodes have a much more substantial influence on the electrostatic detection performance than other intrinsic factors.

A passive optical fibre sensor based on Fabry‐Perot interferometry for bipolar electrostatic monitoring of insulating dielectrics

AbstractThe measurement of the surface charge on the insulating dielectrics is critical to estimate the insulation strength of electrical equipment in operation. Unavoidable interactions with the electromagnetic field, however, generally result in distortion measurement of active sensor. Thus, it is of great significance to investigate a passive sensor for monitoring the deposited charge. Here, a passive optical fibre electrostatic sensor is developed on the principle of Fabry–Perot interference to quantify the surface potential of the insulating dielectrics. The sensitivity of quantifying the electrostatic charge is explored in terms of the wavelength shift in the interference spectrum, and the linear correlation is 0.99. Meanwhile, the sensor can identify a negative quadratic trend with the increase of the surface roughness of the insulating dielectrics. The merits of the proposed sensor such as passive monitoring, bipolar electrostatic detection, and the excellent ability of anti‐electromagnetic interference are highlighted in the results. Hence, this sensor can serve as an effective tool to monitor the electrostatic charge in the fields of smart electrical equipment, fuel transportation, aerospace, integrate circuit etc.

Improving the stability of electrostatic induction dust concentration detection using kalman filtering algorithm aided by machine learning

The suspended dust produced in the production of process industry may cause damage to occupational health and even trigger explosion accidents. To accurately detect the dust concentration, and to reduce the noises and standard deviation volatility of the inductive signal of characterized dust concentration generated when applying the electrostatic induction method, the study designs the Kalman filter based on a machine learning algorithm and realizes secondary processing of the standard deviation of inductive signal. Firstly, this study designs the dust concentration detection device using the electrostatic induction method, realizing an effective extraction and amplification of the dust inductive signal, confirming a positive correlation between the volatility of the inductive signal and dust concentration. A data processing procedure for the inductive signal is also designed. To eliminate the standard deviation volatility of inductive signal, the Kalman filter aided by machine learning is selected to process mathematical models. By comparing the conventional sliding filter algorithm, median filter algorithm and Kalman filtering aided by machine learning, it is confirmed that Kalman filtering aided by machine learning has a better effect on reducing the standard deviation of inductive signal. The standard deviation can be quickly converged to the target value through short-term iteration, effectively eliminating the fluctuation of the standard deviation value of the inductive signal, and improving the stability of the standard deviation value of the inductive signal.

試験ダクト設備を用いた煙道用ダスト計の性能評価

This paper describes the configuration and performance of the developed duct for evaluation tests and examples of evaluation measurements. In addition, the equivalence with the gravimetric measurement that cannot be accurately evaluated for the electrostatic detection type dust meter, which was a pending issue when the JIS standard was established, is discussed. As a result, the charging of dust in the test duct was confirmed and was assumed to be caused by triboelectrification with obstacles such as agitator plates and rectifying wire mesh. And since an exponentially decreasing relationship appeared between the dust concentration in the duct and the dust charge, this change in dust charge disrupted the linear relationship between the dust meter readings and the gravimetric measurements, making evaluation difficult. This indicates that when conducting equivalency tests using test ducts, dust charging should be fully considered, and in some cases, dust charge should be measured and appropriately corrected.

Development of a Coal Dust Concentration Sensor Based on the Electrostatic Induction Method.

In order to solve the problems of easy blockage and difficult maintenance of the current coal dust concentration sensor, a coal dust concentration sensor based on the electrostatic induction method was designed. Based on the analysis of the principle of electrostatic induction dust concentration detection, an electrostatic induction dust concentration sensor composed of a electrostatic detection electrode, a dust extraction fan, an induction signal processing circuit, an insulator, a shield, and other parts was designed. The influence of the length and width of the electrostatic detection electrode and the particle flow rate on the standard deviation of the induction signal was analyzed through experiments to optimize them. The induction signals on the electrostatic detection electrode at different dust concentrations were determined in tests, and the mathematical relationship between the standard deviation of the induction signal and the dust concentration was obtained. According to segment multiple-curve height fitting, the maximum deviation between the detected value and actual dust concentration does not exceed 10%.

Effects of Molecular Size on Resolution in Charge Detection Mass Spectrometry.

Instrumental resolution of Fourier transform-charge detection mass spectrometry instruments with electrostatic ion trap detection of individual ions depends on the precision with which ion energy is determined. Energy can be selected using ion optic filters or from harmonic amplitude ratios (HARs) that provide Fellgett's advantage and eliminate the necessity of ion transmission loss to improve resolution. Unlike the ion energy-filtering method, the resolution of the HAR method increases with charge (improved S/N) and thus with mass. An analysis of the HAR method with current instrumentation indicates that higher resolution can be obtained with the HAR method than the best resolution demonstrated for instruments with energy-selective optics for ions in the low MDa range and above. However, this gain is typically unrealized because the resolution obtainable with molecular systems in this mass range is limited by sample heterogeneity. This phenomenon is illustrated with both tobacco mosaic virus (0.6-2.7 MDa) and AAV9 (3.7-4.7 MDa) samples where mass spectral resolution is limited by the sample, including salt adducts, and not by instrument resolution. Nevertheless, the ratio of full to empty AAV9 capsids and the included genome mass can be accurately obtained in a few minutes from 1× PBS buffer solution and an elution buffer containing 300+ mM nonvolatile content despite extensive adduction and lower resolution. Empty and full capsids adduct similarly indicating that salts encrust the complexes during late stages of droplet evaporation and that mass shifts can be calibrated in order to obtain accurate analyte masses even from highly salty solutions.

Fused Quartz Dual-Shell Resonator Gyroscope

This paper introduces a 3-D fused quartz dual-shell microstructure, discussing its design, simulation, fabrication, and instrumentation as a Microelectromechanical System (MEMS) gyroscope. The dual-shell was realized from plastic deformation of fused quartz using triple-stack wafer bonding and high-temperature micro-glassblowing processes. The fabrication process was developed and dual-shell prototypes with different design parameters were fabricated. A Finite Element (FE) model was presented to simulate the deformation of viscous fused quartz during the micro-glassblowing process. The model was utilized to predict the final 3-D geometry from the design process parameters. A modeling framework based on FE simulations was presented for designing the resonators as well as predicting the resonator’s response to transient excitation, such as shock and vibrations. Fused quartz dual-shell resonator prototype with Q-factors as high as 1.83 million and amplitude ringdown time of 120 seconds was demonstrated. An electrode substrate was designed and integrated with the dual-shell resonator for electrostatic excitation and detection of the vibration modes, as well as 3-D packaging and vacuum encapsulation of the sensing element. An open-loop angular rate gyro operation with electrostatic excitation and capacitive detection was demonstrated on the dual-shell resonator. The Allan deviation of zero rate output bias revealed Angle Random Walk (ARW) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.058 \deg /\sqrt {hr}$ </tex-math></inline-formula> and in-run bias instability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.4 \deg /hr$ </tex-math></inline-formula> without temperature control on the dual-shell resonator gyroscope. The proposed structure can be instrumented to operate as a resonator, a gyroscope, or other vibratory sensors, and is anticipated to have advantages for precision operation in a harsh environment.

Evolution of charged particles in jet combustion chamber

The combustion process in the combustion chamber of the engine will change the electrostatic field characteristics of the jet aircraft, thereby affecting the accuracy of the electrostatic field information obtained by the electrostatic detector. Based on the quantitative analysis of the evolution of charged particles in the combustion chamber, this study further analyses the effect of different surface materials in the combustion chamber on the charging process of combustion products. The combustion chamber is divided into burning zone, intermediate zone and dilution zone, and the evolution model of charged particles in the combustion chamber is constructed under the time constraint. Finally, the variation curve of the charged particle concentration when the surface materials in the combustion chamber are metal materials and non-metal materials are calculated by simulation, and the influence of the conductivity of the surface materials in the combustion chamber on the combustion charging process is analyzed. This study provides the analytical basis for the application of electrostatic detection technology in jet aircraft.

Peak-tracking scanning capacitance force microscopy with multibias modulation technique

Scanning capacitance force microscopy (SCFM) is a good method for capacitance measurements using electrostatic force detection. However, to obtain an entire capacitance–voltage (C–V) curve by SCFM, a sweep of a direct current (DC) bias voltage is required at a certain fixed point on a sample surface during scan suspension, and thus the measurements become very time-consuming when we want to observe some types of image related with C–V characteristics. In this paper, we propose peak-tracking scanning capacitance force microscopy (PTSCFM) for the purpose of extracting the main feature of the C–V curve without DC voltage sweep. In PT-SCFM, alternating current voltages at three different angular frequencies, ω 1, ω 2, and , are applied together with DC voltage, , to generate an electrostatic force, and high-order components at the angular frequencies of and , which represent a voltage derivative of a capacitance () and a second-order derivative of the capacitance (), respectively, are extracted from the electrostatic force. Then, a DC voltage, , giving the peak of is determined from to be adjusted to nullify the component using a feedback controller. From the obtained values of and at , the C–V curve can be outlined. In PT-SCFM, the distributions of those values are simultaneously imaged together with a topography without sweep, and when we operate PT-SCFM under various modulation frequency conditions, analyses similar to those based on the frequency dependence of the C–V property are realized. We have applied the PT-SCFM to a microcrystalline material to discuss the effects of surface depletion and deep-level states, from which the validity of PT-SCFM has been examined.

Evaluation of the performance of erasable marker pen ink for the development of indentations on documents upon surface charging by electrostatic detection device

Indented impressions can be left on the surface beneath a document when it is written on. In the absence of this document, electrostatic detection devices can be used to reveal the underneath previously written information. However, there are instances where the toner used to develop these indentations has to be substituted with alternative application, under unexpected circumstances, such as the supply chain disruption during the ongoing global pandemic. This study aimed to verify the use of erasable marker pen ink as an alternative application for the development of indentations. The procedure was optimized and evaluated, and its performance in deciphering indented impressions from 11 different underlying surfaces was compared to a conventional electrostatic detection device that applied toner to develop indentation. Electrostatic device with toner application using cascade developer method has successfully developed indented impressions from all surfaces, except for the coated glossy paper. In contrast, the application of erasable marker pens revealed indentation successfully from not only the coated glossy paper but also six other common writing surfaces. While the toner is a reliable application for deciphering indentations, the application of erasable marker ink pen can be used in the event when toners are unavailable but also on surfaces such as glossy paper, where application of toners to develop indentation may not provide satisfactory results.

Detection of plant virus particles with a capacitive field-effect sensor

Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.

Electrostatic Signal analysis of rotor UAV

With the rapid growth of unmanned aerial vehicle(UAV) market, incidents of small UAV flying without license or without permission frequently occur, which bring serious hidden dangers to the security of civil airports, sensitive targets and major activities. Rapid and accurate detection and recognition of small UAVs is the basis and premise of countermeasures against small UAVs. However, due to the fact that the production materials of small UAVs are mostly composite materials with good wave-absorbing and wave-penetrating properties and small size, the existing detection technologies such as radar and laser cannot effectively detect the signals of UAVs, so the detection accuracy is very low and the amount of information that can be obtained is small. In this paper, the most typical type of small UAV, rotor UAV, is taken as the research object to study the electrostatic signal of rotor UAV, which provides a theoretical basis for the electrostatic detection of rotor UAV.

Non-destructive DNA recovery from handwritten documents using a dry vacuum technique.

Investigations of many crimes such as robberies, kidnappings, and terrorism are often associated with the recovery of a paper document which has been written by the perpetrator. Paper can provide a variety of forensic evidence such as DNA, latent fingermarks, and indented writing. The focus of this study was DNA recovery from handwritten notes through a vacuum suction device while preserving the other evidence types and the integrity of the document. Copy paper was used to create handwritten documents and sheets with deliberate fingerprints, and indentations. The homemade vacuum device consists of a glass pipette blocked with a moistened swab and attached to a vacuum source. The method collected sufficient DNA amounts for DNA typing analysis with 80% of the 11 copy paper samples tested giving probative DNA profiles with five being eligible for DNA database entry. DNA recovery was also tested on other commonly encountered paper types. DNA quantities would have been sufficient for STR typing for approximately 50% of manila envelopes and notebook paper samples, but not for magazine pages and bank deposit slips. Deliberate sebaceous and eccrine latent fingermarks placed onto copy paper and developed with magnetic fingerprint developer or 1,2 indanedione were not affected by the vacuum swabbing technique. Simulated robbery notes with indented writing and processed using an Electrostatic Detection Apparatus (ESDA) demonstrated no interference through the DNA collection. This vacuum-based collection method enables laboratories to reverse the current questioned document workflow and start with DNA collection.