This work proposes, analyzes, designs, and validates superior topologies of UHGH converters that are capable of supporting extremely large conversion ratios up to ∼2000× and output voltage up to ...∼4–12 kV for future mobile soft robots from an input voltage as low as the range of a 1-cell battery pack. Thus, the converter makes soft robots standalone systems that can be untethered and mobile. The extremely large voltage gain is enabled by a unique hybrid combination of a high-gain switched magnetic element (HGSME) and a capacitor-based voltage multiplier rectifier (CVMR) that, together, achieve small overall size, efficient operation, and output voltage regulation and shaping with simple duty-cycle modulation. With superior performance, power density, and compact size, the UHGH converters prove to be a promising candidate for future untethered soft robots.
Electroadhesion device allows one to pick up almost all of the objects regardless of their shape or type of materials by means of the electrostatic Maxwell force, which is developed due to the ...dielectric-induced polarization on the subject surface. In this study, we propose the modeling methodology and its experimental verification that could maximize the lifting shear force of the electroadhesive device to reach well over the human-finger grip force, say, ca. 8.9 kPa, which has not been achieved yet in this device system. In this study, we maximized the lifting force up to 33.05 kPa for paper objects by scaling down the electrode pitches in the scale of micrometers while avoiding the voltage breakdown using the boundary-edge-length modeling methodology Choi, K. ; ACS Omega 2019, 4, 7994−8000. The developed model equation expressed adhesion lifting force as a function of the boundary edge length, applied voltage, and impedance, demonstrating that the model equation agreed well with the experimental output of our device and allowed the lifting force well over the human-finger grip. The in situ charge-transfer resistance measurement value of the impedance analysis (R CT), indicating the amount of polarization, was decreased in the order of paper and glass, and it was clearly related to the enhanced lifting force of the two types of objects (23.9 and 50.0 kPa, respectively). Hence, the impedance analysis could quantify the magnitude of polarizations and the amount of induced charges of objects while in contact with the device.
Biological membranes are essential components of the living systems and processes occurring with their participation are related mainly to electric phenomena, such as signal transduction, the ...existence of membrane potentials, and transport through the membrane. It is well known that the universal model of the cell membrane structure is the lipid bilayer, which constitutes the environment for integral and surface membrane proteins. Thus, much attention has been given to the study of the organization and properties of these structures concerning both experimental and theoretical aspects. As systematic examinations are impeded by the complexity of the natural membranes, the best approach to conducting detailed physical and chemical studies of biological membranes is to use simplified well-defined model lipid membranes. Among the most commonly used are liposomes, planar lipid membranes, membranes on solid substrates, and lipid monolayers on the free surface.Studies of the electrical properties of model lipid membranes have been carried out for many years. However, there are still many issues that have not been verified experimentally and for which the existing results are incomplete or inconsistent. Therefore, the main objective of this book was to collect recent scientific and review articles on the electrical properties of model lipid membranes. This objective has been successfully achieved, for which I express heartfelt appreciation to all authors and reviewers for their excellent contributions.
Multistage depressed collectors (MDCs) play a vital role in efficiency enhancement of traveling-wave tubes for various strategic and communication applications. Design of a highly efficient MDC is no ...longer a tough challenge due to the availability of large number of efficient numerical simulation tools. However, still an established technique for the development of such MDCs to address their thermal as well as high-voltage breakdown issues has not been published. In this paper, we have exercised different development techniques in the light of specified meritorious aspects with respect to actual dimensional accuracies, thermal dissipation, and high-voltage withstanding capability. We have made use of an analytical method to estimate the proper braze alloy quantity and holding time during brazing operation to ensure optimum brazing, thereby, yielding minimum thermal impedance and improved high-voltage breakdown strength.
Soft robots have the potential to fundamentally change interactions between robots and the surrounding environment, and between robots and animals, and robots and humans in ways that today's hard ...robots are incapable of doing. However, to realize this potential, soft robot actuators require extremely high voltage supplies of more than 4 kV. The electronics that can satisfy this need currently are either too large and bulky or unable to achieve the high power efficiency required for mobile systems. To meet this challenge, this paper conceptualizes, analyzes, designs, and validates a hardware prototype of an ultra-high gain (UHG) converter that can support extremely large conversion ratios up to ∼1000× to provide up to 5 kV output voltage from an input voltage of ∼5-10 V. This converter is demonstrated to be able to drive HASEL (Hydraulically Amplified Self-Healing Electrostatic) actuators, a promising candidate to realize future soft mobile robotic fishes, from an input voltage range of a 1-cell battery pack. The circuit topology employs a unique hybrid combination of a high-gain switched magnetic element (HGSME) and a diode and capacitor-based voltage multiplier rectifier (DCVMR) to enable compact magnetic elements, efficient soft-charging in all flying capacitors, and adjustable output voltage capability with simple duty-cycle modulation. Achieving an efficiency of 78.2% at 15 W output power, while providing 3.85 kV output from 8.5 V input, the proposed UGH converter proves to be a promising candidate for future untethered soft robots.
In this paper, an AIGaN/GaN metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT) device is realized. The device shows normal ON characteristics with a maximum current of 570 mA/mm ...at a gate-to-source voltage of 3 V, an on-state resistance of 7.3 Ω·mm and breakdown voltage of 500 V. The device has been modeled using numerical simulations to reproduce output and transfer characteristics. We identify, via experimental results and TCAD simulations, the main physical mechanisms responsible for the premature breakdown. The contribution of the AlN/Silicon substrate interface to the premature off-state breakdown is pointed out. Vertical leakage in lateral GaN devices significantly contributes to the off-state breakdown at high blocking voltages. The parasitic current path leads to premature breakdown before the appearance of avalanche or dielectric breakdown. A comparative study between a MOS-HEMT GaN on a silicon substrate with and without a SiNx interlayer at the AlN/Silicon substrate interface is presented here. We show that it is possible to increase the breakdown voltages of the fabricated transistors on a silicon substrate using SiNx interlayer.
This study reports on subnanosecond breakdowns initiated on high pressure nitrogen by a runaway electron beam in an inhomogeneous electric field. It is shown that a diffuse discharge with a duration ...of ≥1 ns is formed in the gas diode. Data are reported for the first time on collector measurements of a supershort avalanche electron beam downstream of an anode foil at a nitrogen pressure of 0.5–1.2 MPa. The beam pulsewidth at these pressures is ∼90 ps. At a nitrogen pressure of 1.2 MPa, the number of electrons with an energy >70 keV recorded by the collector is 4 × 106/cm2.
New Development of BIRD model Spada, E.; De Lorenzi, A.; Lotto, L. ...
2020 29th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV),
2021-Sept.-27
Conference Proceeding
The possibility that the flow of electrons emitted by a cathode at high dc voltage is essentially due to local emission of a covering dielectric layer is at the basis of the BIRD (Breakdown Induced ...by Rupture of Dielectric) model. This model assumes that, in the presence of a sufficient electric field, the electrons trapped in the polarization structures of the dielectric layer are extracted by the quantum tunnel effect. Because of the layer electron depletion, the electric field inside the dielectric layer increases and the rupture (breakdown) of the layer itself can occur, provided certain conditions met. In order to investigate the features of this model the High Voltage Short Gap Test Facility (HVSGTF) has recently been built in Padua. The experimental dark current measured at different electrode configurations permits us to test the correctness of the model predictions. In particular, we consider the trend of the current as a function of time and its dependence on the characteristic properties of the dielectric layer. From the theoretical side, we investigate the consistency between a semi-classical model and a simple quantum model.
Marine switchboards are manufactured to specifications similar to industrial switchboards but sustain arcing faults more frequently. Thus, the marine environment can serve to accelerate aging, ...showing what industrial switchboards will experience over time. U.S. Navy data are used to show that faulty connections are the primary cause of arcing faults in marine switchboards. Various approaches to arc detection and to the prevention of arcing failures will be examined. The approaches which were integrated into an automatic arc fault protection system for the Navy will be discussed. The historical effectiveness of arc fault protection systems on Navy ships will be discussed. The authors believe that the success achieved in this harsh marine environment is statistically significant and holds lessons for the deployment of arc fault protective systems in critical land-based power distribution systems.
We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled ...off using a CMOS compatible process from a standard bulk mono-crystalline silicon substrate. A lifetime projection is extracted using statistical analysis of the ramping voltage (Vramp) breakdown and time dependent dielectric breakdown data. The obtained flexible MOSCAPs operational voltages satisfying the 10 years lifetime benchmark are compared to those of the control MOSCAPs, which are not peeled off from the silicon wafer.
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