Fringe Field Research Articles

Analytical Winding Loss and Inductance Models for Gapped Inductors With Litz or Solid Wires

In gapped inductors, the fringing field of the air gaps causes additional eddy current losses in the windings and an increase of the inductance. Since this impact of the fringing field is very significant, calculating the additional eddy current losses and the inductance increase is important in the design of inductors. This article proposes analytical formulas to accurately calculate the inductance and the additional eddy current losses in gapped inductors with solid round wire and Litz wire windings. The analytical formulas are verified by measurements, showing that the proposed models are accurate over a wide-frequency range.

Solution Properties of a New Dynamic Model for MEMS with Parallel Plates in the Presence of Fringing Field

In this paper, starting from a well-known nonlinear hyperbolic integro-differential model of the fourth order describing the dynamic behavior of an electrostatic MEMS with a parallel plate, the authors propose an upgrade of it by formulating an additive term due to the effects produced by the fringing field and satisfying the Pelesko–Driscoll theory, which, as is well known, has strong experimental confirmation. Exploiting the theory of hyperbolic equations in Hilbert spaces, and also utilizing Campanato’s Near Operator Theory (and subsequent applications), results of existence and regularity of the solution are proved and discussed particularly usefully in anticipation of the development of numerical approaches for recovering the profile of the deformable plate for a wide range of applications.

Radially symmetric stationary solutions for a MEMS type reaction–diffusion equation with fringing field

Radially symmetric stationary solutions for a micro-electro-mechanical system (MEMS) type reaction–diffusion equation with fringing field are considered. This equation arises in the study of the MEMS devices. This paper is devoted to the study of the existence of these solutions, information about their shape, and their asymptotic behaviour. These are studied by applying the framework that combines Poincaré type compactification, classical dynamical systems theory, and geometric methods for desingularization of vector fields called the blow-up technique.

Development and optimization a miniature Mattauch-Herzog mass analyzer

With the advancement of space exploration in China, mass spectrometers are becoming increasingly important in space missions. A miniature Mattauch-Herzog double focusing mass spectrometer was developed for mass analysis. Based on the study of the fringing field of the analyzer, the ion optical lens software SIMION8.1 was used to simulate the focusing performance of the ion beam. The 90° magnetic analyzer with asymmetric structure is adopted, which has a magnetic flux density of 0.85T. The experiment shows that the ion current is actually affected by the fringing field of electrostatic analyzer which is basically consistent with the simulation results. Besides, the performance indicators of the miniature MS are tested, the mass resolution of N2 is 75.7, the sensitivity of N2 is 4.13 × 105 V/Pa and the minimum detectable partial pressure of N2 is 2.81 × 10−7Pa.

Study on the fringe field effect of quadrupoles for CSNS MEBT

Study on the fringe field effect of quadrupoles for CSNS MEBT

Design and Analysis of a Unique Electrode Configuration Targeting Fringing Field Utilization for Improved Chemicapacitor Sensitivity

A novel electrode configuration is proposed in this article that targets fringing field utilization as a critical design parameter to enhance sensitivity. In this work, the electrode architecture is the cornerstone in enhancing the chemicapacitor sensitivity as compared to existing literature that often use the sensing material as the primary focus to achieve low-level detection. The proposed electrode configuration consists of multiple dimple-shaped interdigitated electrodes (IDEs). The results obtained from the finite element analysis (FEA) conducted in this work reveal that it is possible to increase fringing field utilization by up to 82% by adopting this unique electrode geometry. The proposed design along with the conventional sensor designs is micromachined using PolyMUMP-fabricated electrodes, and a PVA polymer sensing material is used to measure the output capacitance as a proof of concept. When exposed to 40%–85% humidity in the same controlled environment, the proposed design offers a 76–149 times greater sensitivity compared to the conventional designs. As such, the findings of this research suggest a means to ameliorate chemicapacitor gas sensors for low-level detection, which can be implemented in agricultural greenhouses to monitor the controlled plant-growing environment, among many other applications.

Suppressing the polarization aberrations by combining reflection and refraction optical groups.

Polarization remote sensing technology expands the dimensions of the target and enriches its basic information over traditional remote sensing methods. During the imaging process, polarization imaging changes the polarization information of the target by the modulation of the optical system, affecting the detection accuracy. We term the modulation of the polarization state of light by an optical system as polarization aberration, and we found that a lens group combined with mirrors is beneficial in suppressing polarization aberrations. This study analyzed the principles of suppression and the polarization aberration of the optical system before and after suppression. Simulation results show that the diattenuation's average value is reduced by 51.1% and the retardance's average value is reduced by 26.3% after suppression. The corrected polarization cross-coupled energy is reduced by 73.18% in the central field of view and by 69.80% in the fringe field of view. Adding a lens group also effectively suppresses traditional aberrations and expands the field of view.

Non-ohmic electrical fringe field selective to biofilm suitable for addressing biofouling in wastewater treatment

The non-ohmic electrical fringe field has been shown to be a viable approach for addressing biofouling in wastewater treatment. Existing attached growth systems require periodic mechanical- or chemical-based maintenance or part replacement to regulate excessive biofilm formation. The proposed electrical approach uses a non-ohmic fringe field at a low voltage of 10 V and a low frequency of 100 kHz, where bacterial biofilm growth is noticeably reduced. The fringe field was generated by insulated interdigitated electrodes embedded below the surface on which the biofilm grew. Electric field simulation showed field strength of 15.2 and 12.3 V/cm at 0.05 and 1 mm from the surface, respectively, which are sufficient to reduce biofilm growth. As the biofilm grows, the fringe field passing through it becomes denser (hence, higher field strength) owing to the difference in relative permittivity. It selectively targeted biofilms in water. The optical density measurements showed that the presence of fringe field was able to reduce the biofilm by ∼10.1 % as compared to the control. Adenosine triphosphate measurements suggested that the effect of fringe field on bacterial viability was even more pronounced at ∼20.6 % reduction. This is an efficient approach with no moving parts suitable for uninterrupted biofilm growth regulation in wastewater treatment.

Nonlinear damping in micromachined bridge resonators

This study presents a thorough theoretical and experimental investigation on the nonlinear damping of in-plane micromachined electromechanical resonators. More specifically, experiments are conducted on an electrically actuated bridge resonator, and the primary resonance response of the system is obtained at various AC and DC voltages. A nonlinear theoretical model is developed using the Euler–Bernoulli beam theory while accounting for the geometric, electrostatic (including fringing field effect), and damping nonlinearities. Two damping models are considered in the theoretical model: the Kelvin–Voigt model, which for this system is a nonlinear damping model due to the presence of geometric nonlinearities. The second damping model consists of linear, quadratic, and cubic damping terms. A high-dimensional discretisation is performed, and the nonlinear dynamics of the resonator are examined in detail in the primary resonance regime by constructing the frequency response diagrams at various AC and DC voltages. Thorough comparisons are conducted between the experimental data and the theoretical results for different damping conditions. It is shown that the microresonator displays strong nonlinear damping. Detailed calibration procedures for the nonlinear damping models are proposed, and the advantages and disadvantages of each nonlinear damping model are discussed.

Nonlinear dielectric properties of polyimide in high AC electric field

The nonlinear dielectric properties of polyimide (PI) films, excited by high-intensity, AC electric fields, have been measured. This work highlights that nonlinear DC conduction is a component of the AC conductivity and dielectric loss response when surpassing a certain threshold field strength. An additional Poole–Frenkel polarization, induced by high-intensity, high-frequency fields, also contributes to the nonlinearity. This increases the dielectric losses through a charge de-trapping process, the so-called “jacking-up” effect. A novel expression that captures the large signal behavior of the complex permittivity is introduced using the Cole–Cole format. Finally, it is shown that the dielectric properties and power dissipation density in PI films remain fully linear and frequency-independent up to an AC electric field of EPF ∼100 Vrms/μm and more conservatively below a threshold field of EX ∼ 45 V/μm (i.e., end of the ohmic region). Consequently, polyimide-based insulated electronic devices that are designed to continuously operate below this threshold field (including both uniform and fringe fields) will remain immune to a frequency-dependent electrical aging. Their lifetime should not be affected in any way.

Geometrical Optimization of Printed Interdigitated Electrode Sensors to Improve Soil Moisture Sensitivity

Printing electronics allows us to fabricate low-cost, simple sensor networks. Distributed soil moisture sensors in agriculture industry will result in better water management practices; however, price and reliability do not allow for ubiquitous availability. Here, we demonstrate the fabrication of low-cost, flexible, interdigitated electrode (IDE) soil moisture sensors with the electrode widths of 537, 877, 1055, 1204, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1916~\mu \text{m}$ </tex-math></inline-formula> on polyimide (PI) substrates using a silver nanoparticle (Ag NP) ink. The sensors were tested in sandy textured soil with a volumetric water content ranging from 0.05 to 0.25 m3/m3. Analytically, the sensitivities of all the sensors are expected to be equal, as the proposed mechanisms dictate that the capacitance should depend linearly on the dielectric constant of the moist soil. However, we found the sensitivity for the widest IDE, which measured <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1916~\mu \text{m}$ </tex-math></inline-formula> to be 442 pF/H2O volumetric percentage, whereas the sensitivity for the sensor with 537- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -wide electrodes to be only 221 pF/H2O volumetric percentage. We hypothesized that the increase in sensitivity can be directly related to the increase in the capacitive fringing field height, which results in increased sensing volume for the widest IDE. The increased sensing volume leads to increased water molecule polarization, increasing the overall capacitance change with respect to changing water content. To validate the hypothesis, we conducted electric fringing field experiments to observe the trend between the maximum fringing field height and the electrode width of an IDE. Results confirmed that increased sensing volume was caused by the increased fringing field height of the electrode in an IDE.

Impact of sidewall spacer materials and gate underlap length on negative capacitance double-gate tunnel field-effect transistor (NCDG-TFET)

In this study, a negative capacitance double-gate tunnel field-effect transistor (NCDG-TFET) with sidewall spacer engineering is proposed and its electrical characteristics are examined by technology computer-aided design (TCAD) simulation for lower subthreshold swing (SS) and higher on–off current ratio (Ion/Ioff) than conventional planar TFET. In detail, the dielectric constant (κ) and length of sidewall spacer (Lspc) which determine gate-to-source/drain underlap are optimized for an enhanced device performance. The simulation study shows that the sidewall spacers at source and drain underlap need to be designed differently for high Ion and low ambipolar current (Iamb). In case of source underlap, the HfO2 3 nm-Lspc can enhance outer fringing field and Ion. On the other hand, the SiO2 15 nm-Lspc at drain underlap can alleviate Iamb due to low outer fringing field. As a result, the asymmetric structure shows ∼ 1.5 times larger Ion and ∼ 4 orders lower Iamb with smaller SS and turn-on voltage (Von) than the conventional NCDG-TFET without sidewall spacer.

40.3: Fast Fringe‐field‐effect Free Continuous 2.25π Phase Modulation Based on Non‐linear Kerr Effect of Vertical Aligned Deformed Helix Ferroelectric Liquid Crystal

40.3: Fast Fringe‐field‐effect Free Continuous 2.25π Phase Modulation Based on Non‐linear Kerr Effect of Vertical Aligned Deformed Helix Ferroelectric Liquid Crystal

P‐5.6: Analysis of ITO Residue in 4mask process applied in Extra large‐size FFS LCDs

Indium tin oxide (ITO) residue is a serious problem in 4mask process applied in Fringe Field Switching (FFS) mode LCDs. In this paper, we analyzed the composition and structure of the residues and the reasons for their formation. ITO grains grow with increasing temperature during copper sputtering. As a result, it is hardly etched in the subsequent wet etching process, resulting in residues.

P‐1.4: Analysis of the Hump Characteristics in Poly‐Si Thin Film Transistor &amp; Process a method to suppress hump effect

In this study, we investigate the transfer characteristics of low‐temperature polycrystalline silicon(LTPS) thin film transistors(TFTs) often show a “hump” in subthreshold region. This effect can be attributed to the presence of an enhanced electrical field at edges of the active layer. To reduce the hump effect which is one of the critical issues in ploy‐Si TFT, we focus on crowding of gate fringing field at channel edge and suggest a modified structure of channel edge. Using dry etching process, change the polysilicon layer at the edge of the channel from a steep profile to a slightly flat profile. And we confirmed that the severity of the hump effect is directly related to the edge profile of the polysilicon.

3.3: Fast Continuous &gt;2π Phase Modulation without Fringe Field Effect based on Kerr Effect of Vertical Aligned Ferroelectric Liquid Crystal

3.3: Fast Continuous &gt;2π Phase Modulation without Fringe Field Effect based on Kerr Effect of Vertical Aligned Ferroelectric Liquid Crystal

1.3: Active‐matrix Addressed High Brightness and Ultra‐high PPI Field‐Sequential‐Color Display based on Deformed Helix Ferroelectric Liquid Crystal for VR/AR

Barriers exits regarding increasing brightness and pixel density for various display technologies, be it, LCD, LED and OLED. In this paper, we proposed a defect‐free high‐contrast fast (~100μ) active‐matrix addressed DHFLC with a theoretical 11500 PPI due to its nature of no fringe field effect (FFE) and high capacitance, shedding a light on the barriers. For the realization, the no‐storage‐capacitor AM‐DHFLC display device is fabricated as preliminary demo with both optimizations in the DHFLC alignment and pixel design. Innovatively, the no‐storage‐capacitor characteristic, which is impossible for NLC, not only rockets efficiency and aperture ratio from 57% to 83% with high brightness, but also reveals the potential in reducing the pixel size for higher resolution. Moreover, fast response around 100μs at 360 Hz for FSC display and no‐FFE strengthen the promising potential of DHFLC in various modern display technologies, be it VR/AR, high PPI display, micro display, and high‐resolution hologram.

Magnetic field measurements on the mini-ICAL detector using Hall probes

The magnetised 51 kton Iron Calorimeter (ICAL) detector proposed to be built at INO is designed with a focus on detecting 1–20 GeV muons. The magnetic field will enable the measurement of the momentum of the μ - and μ + generated from the charge current interactions of atmospheric νμ and ν̅μ separately within iron in the detector, thus permitting the determination of the neutrino mass ordering/hierarchy, among other important goals of ICAL. Hence it is important to determine the magnetic field as accurately as possible. The mini-ICAL detector is an 85-ton prototype of ICAL, which is operational at Madurai in South India. We describe here the first measurement of the magnetic field in mini-ICAL using Hall sensors. A set-up was developed to calibrate the Hall probe sensors using an electromagnet. The readout system has been designed using an Arduino Nano board for selection of channels of Hall probes mounted on the PCB and the output voltage was measured. The magnetic field has been measured in the small gaps (provided for the purpose) between iron plates in the top layer of mini-ICAL as well as in the air just outside the detector. A precision of better than 3% was obtained, with a sensitivity down to about 3 mT when measuring the small fringe fields outside the detector.

Frequency-Dependent Inductance and Winding Loss Model for Gapped Foil Inductors

For comprehensively optimizing high-frequency foil inductors, calculating the increased inductance and the additional eddy current losses due to a two-dimensional magnetic fringing field caused by air gaps in the center leg is mandatory. This article proposes an analytical model that accurately calculates the inductance and the additional eddy current losses in gapped inductors with foil windings. The analytical field expressions are combined into closed-form winding loss and inductance formulas and verified by measurements. Furthermore, the frequency dependency of the inductance due to the shielding effect of the foil conductors is being discussed.

Finite Differences for Recovering the Plate Profile in Electrostatic MEMS with Fringing Field

Global existence and uniqueness conditions for a dimensionless fourth-order integro-differential model for an electrostatic-elastic MEMS device with parallel plates and fringing field contribution were recently achieved by the Authors. Moving from this work, once the dielectric profile of the deformable plate according with experimental setups has been assigned, some technical conditions of applicability for the intended use of the device as well as the mechanical tension of the deformable plate are presented and discussed. Then, highlighting the link between the fringing field and the electrostatic force, finite differences were exploited for recovering the deformable plate profile according both global existence and uniqueness conditions. Moreover, the influence of the electro-mechanical properties of the deformable plate on both the numerical approach and on the intended uses of the device is discussed, comparing the results with experimental setups regarding pull-in voltage and electrostatic pressure.