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Goal: Transcutaneous coupling scheme for wireless powering and signal in active implants are known for more than a decade. This study aimed to investigate the in vivo behavior of this approach to drive multiple channels of an implanted peripheral nerve interfaces. Methods: The stimulation signals were transmitted through the skin over two contacts to an intracorporeal counterpart which was connected to a cuff electrode with two channels. EMG after stimulation was measured to establish recruitment curves. Results: Limitations of transcutaneous coupling were found in the feasible complexity of the system. High electrical crosstalk in a multi-channel system reduces this approach to low channel applications, such as pain treatment. No significant influence of the pulse width or extracorporeal stimulation amplitude on the electrical crosstalk was observed. Conclusions: The study's findings provide insight into the behavior of the transcutaneous coupling scheme in vivo and highlight the limitations and areas of application. Our results indicate that transcutaneous coupling schemes are a promising alternative approach for wireless powering of implants, as it does not require complex implanted electronics, expensive sophisticated electronics, and hermetic enclosures. Physical constraints, however, limit the use in highly selective nerve stimulation scenarios.

Epidural spinal cord stimulation (ESCS) is a potential treatment for the recovery of the motor function in spinal cord injury (SCI) patients. Since the mechanism of ESCS remains unclear, it is necessary to study the neurophysiological principles in animal experiments and standardize the clinical treatment. In this paper, an ESCS system is proposed for animal experimental study. The proposed system provides a fully implantable and programmable stimulating system for complete SCI rat model, along with a wireless charging power solution. The system is composed of an implantable pulse generator (IPG), a stimulating electrode, an external charging module and an Android application (APP) via a smartphone. The IPG has an area of ${25} \times {25}$ mm2 and can output 8 channels of stimulating currents. Stimulating parameters, including amplitude, frequency, pulse width and sequence, can be programmed through the APP. The IPG was encapsulated with a zirconia ceramic shell and two-month implantable experiments were carried out in 5 rats with SCI. The main focus of the animal experiment was to show that the ESCS system could work stably in SCI rats. The IPG implanted in vivo can be charged through the external charging module in vitro without anesthetizing the rats. The stimulating electrode was implanted according to the distribution of ESCS motor function regions of rats and fixed on the vertebrae. The lower limb muscles of SCI rats can be activated effectively. The two-month SCI rats needed greater stimulating current intensity than the one-month SCI rats The results indicated that the stimulating system provides an effective and simplified tool for studying the ESCS application in motor function recovery for untethered animals.

Epidural spinal cord stimulation (ESCS) is a potential treatment for the recovery of the motor function in spinal cord injury (SCI) patients. Since the mechanism of ESCS remains unclear, it is necessary to study the neurophysiological principles in animal experiments and standardize the clinical treatment. In this paper, an ESCS system is proposed for animal experimental study. The proposed system provides a fully implantable and programmable stimulating system for complete SCI rat model, along with a wireless charging power solution. The system is composed of an implantable pulse generator (IPG), a stimulating electrode, an external charging module and an Android application (APP) via a smartphone. The IPG has an area of ${25} \times {25}$ mm2 and can output 8 channels of stimulating currents. Stimulating parameters, including amplitude, frequency, pulse width and sequence, can be programmed through the APP. The IPG was encapsulated with a zirconia ceramic shell and two-month implantable experiments were carried out in 5 rats with SCI. The main focus of the animal experiment was to show that the ESCS system could work stably in SCI rats. The IPG implanted in vivo can be charged through the external charging module in vitro without anesthetizing the rats. The stimulating electrode was implanted according to the distribution of ESCS motor function regions of rats and fixed on the vertebrae. The lower limb muscles of SCI rats can be activated effectively. The two-month SCI rats needed greater stimulating current intensity than the one-month SCI rats The results indicated that the stimulating system provides an effective and simplified tool for studying the ESCS application in motor function recovery for untethered animals. [ABSTRACT FROM AUTHOR]

Segmented, or slow-wave electrodes have emerged as an index-matching solution to improve bandwidth of traveling-wave Mach Zehnder (MZM) and phase modulators on the thin-film lithium niobate on insulator platform. However, these devices require the use of a quartz handle or substrate removal, adding cost and additional processing. In this work, a high-speed dual-output electro-optic intensity modulator in the thin-film silicon nitride and lithium niobate material system that uses segmented electrodes for RF and optical index matching is presented. The device uses a silicon handle and does not require substrate removal. A silicon handle allows the use of larger wafer sizes to increase yield, and lends itself to processing in established silicon foundries that may not have the capability to process a quartz or fused silica wafer. The balanced MZM has an interaction region of 10 mm, shows a DC half wave voltage of 3.75 V with a 92 mW $\text{P}\pi $ , an ultra-high extinction ratio of roughly 45 dB consistent with previous work, and a fiber-to-fiber insertion loss of 7.47 dB with a 95 GHz 3 dB bandwidth. [ABSTRACT FROM AUTHOR]

We propose a design method for liquid crystal lens with positive-negative tunable focal length and rectangular aperture. The designed electrodes produce a parabolic profile of voltage difference over the lens aperture. Parabolic phase profile is then obtained by controlling the voltage difference within the linear response range of liquid crystal materials, and high-quality performance liquid crystal lens can be realized. The principle of the design is described and the lens is demonstrated experimentally. [ABSTRACT FROM AUTHOR]

Objective: Chronic neural implants require energy and signal supply. The objective of this work was to evaluate a multichannel transcutaneous coupling approach in an ex vivo split-concept study, which minimizes the invasiveness of such an implant by externalizing the processing electronics. Methods: Herein, the experimental work focused on the transcutaneous energy and signal transmission. The performance was discussed with widely evaluated concepts of neural interfaces in the literature. Results: The performance of the transcutaneous coupling approach increased with higher channel count and higher electrode pitches. Electrical crosstalk among channels was present, but acceptable for the stimulation of peripheral nerves. Conclusions: Transcutaneous coupling with extracorporeal transmitting arrays and subcutaneous counterparts provide a promising alternative to the inductive concept particularly when a fully integration of the system in a prosthetic shaft is intended. The relocation of the electronics can potentially prevent pressure sores, improve accessibility for maintenance and increase lifetime of the implant.

The rated current of ±800kV Ultra High Voltage Direct Current (UHVDC) Transmission system can be up to 6250A, so that the influence of the DC grounding current of electrode is enormous. It is of great significance to understand the distribution characteristics of DC earth potential near the grounding electrodes and the influence of the grounding current to propose prevention and controlling schemes. According to the needs of Shanghaimiao-to-Shandong UHVDC terminal grounding electrode DC bias treatment project, a three-dimensional (3D) earth resistance model of 310km depth is established by the data of shallow earth resistance measurement and deep magnetotelluric data of 1°×1° longitude and latitude measurement point. The distribution of earth surface potential in the total area of 204.3 thousand square kilometers under 6250A DC is calculated by the finite element method. The results show that the larger the current entering the grounding electrode, the larger the influence range. Additionally, the distribution of equipotential lines were relatively dense in the area 80 kilometers away from coastline under the influence of coast effect and sparse in the area with high earth resistance.

Cr/Al/Ti/Au stacks with two thicknesses of Al layers were employed as reflective n-type electrodes for 274 nm AlGaN-based flip-chip deep ultraviolet light-emitting diodes (DUV LEDs). Large bulges arose in the annealed n-type electrode with 120-nm-thick Al layer, resulting in cracks within the upper rugged SiO2 passivation layer after burn-in test. Sn atoms from solder paste migrated along the cracks and served as leakage current channels, which accelerated device degradation. In contrast, the annealed n-type electrode with 60-nm-thick Al layer retained uniform morphology. And the DUV LEDs with such n-type electrode exhibited good reliability and normalized optical power of 86.8% after burn-in test of 1000 h. This study provides insight into electrode defects related degradation behavior and helps to improve the reliability of AlGaN-based flip-chip DUV LEDs with reflective electrode. [ABSTRACT FROM AUTHOR]

In this study, we report the use of graphene-coated fabrics as textile electrodes in surface electromyography (sEMG) acquisition. Their performance was compared with that of wet silver/silver chloride (Ag/AgCl) electrodes for the signals that were taken from three different muscle groups. Comparisons were performed in terms of the skin-electrode impedance (SEI), signal-to-noise ratio (SNR) and cross correlation. SEI values of graphene textile electrodes ($\sim 90\text{k}\Omega $) were found to be well within the range of commercial Ag/AgCl electrodes ($\sim 50\text{k}\Omega $). At 2 kg load, SNR values of 19.23 dB from triceps brachii, 27.18 dB from biceps brachii, and 28.13 dB from quadriceps femoris muscles were obtained, respectively; which showed that performance of graphene textile electrodes in static settings is at minimum 94% of clinical signal quality both in terms of SNR and similarity of signal morphologies in terms of cross correlation. After benchmarking the electrode performance, a proof of concept fully textile elastic band and a mobile acquisition circuit were combined to further validate the feasibility of surface electromyography with wearable graphene textiles through a step counter application, where the implemented wearable graphene textile-based step counter achieved on average a success rate above 90% for varying speed levels and up to a maximum of ~98%. Results suggests that graphene textiles could be a viable alternative to gelled Ag/AgCl electrodes and can be used to develop wearable, smart garment applications. [ABSTRACT FROM AUTHOR]

Continuous monitoring of vital bio-signals is crucial to track the well-being of patients and to allow for timelymedical intervention in cases of emergency. This paper presents a compact and wearable electrocardiogram (ECG) sensor using graphene-elastomer electrodes, which were characterised, first using an electronic patient simulator, then on a human subject. We demonstrate that the proposed electrodes are highly conductive, flexible and ultralight (weighing less than 10 mg). Their skin-impedance values are significantly lower than existing electrodes including other graphene-based sensors. In addition, we demonstrate that they can be applied on the skin in dry form without needing an intermediate gel layer, or excessivemechanical pressures, overcoming an important challenge for long term monitoring applications. The proposed configuration enables the design ofwearable devices that can outperformwell-refined commercial sensors, providing great potential for electronic/mobile health applications. [ABSTRACT FROM AUTHOR]

This study focuses on the analysis and early detection of freeze-damage in tangerines using a specific double-needle sensor and Electrochemical Impedance Spectroscopy (EIS). Freeze damage may appear in citrus fruits both in the field and in postharvest processes resulting in quality loss and a difficult commercialization of the fruit. EIS has been used to test a set of homogeneous tangerine samples both fresh and later frozen to analyze electrochemical and biological differences. A double-needle electrode associated to a specifically designed electronic device and software has been designed and used to send an AC electric sinusoidal signal 1 V in amplitude and frequency range [100Hz to 1MHz] to the analyzed samples and then receive the electrochemical impedance response. EIS measurements lead to distinct values of both impedance module and phase of fresh and frozen samples over a wide frequency range. Statistical treatment of the received data set by Principal Components Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) shows a clear classification of the samples depending on the experienced freeze phenomenon, with high sensitivity (1.00), specificity (≥ 0.95) and confidence level (95%). Later Artificial Neural Networks (ANN) analysis based on 20-3-1 architecture has allowed to create a mathematical prediction model able to correctly classify 100% of the analyzed samples (CCR =100% for training, validation and test phases, and overall classification), being fast, easy, robust and reliable, and an interesting alternative method to the traditional laboratory analyses. [ABSTRACT FROM AUTHOR]

In recent years, several experimental approaches have been adopted to study and understand the mechanism and improve the ferroelectricity of fluorite-type hafnia-based ferroelectric materials. In this regard, significant efforts have been made to elucidate the role of top electrode and bottom electrode (TE and BE) materials in defining the ferroelectricity in such systems, especially in terms of induced mechanical tensile stress by these materials during the process of annealing. However, the effect of the electrode material was not investigated both at TE and BE, and despite numerous efforts, there is still a lack of accurate and systematic understanding. In this report, we have carried out a systematic investigation on the effect of TE and BE materials having different coefficient of thermal expansion (CTE), by changing the electrode material one at a time, both at the top and bottom. The influence of the TE was confirmed using [TE/Hf0.5Zr0.5O2(HZO)/TiN] structure in which the BE was fixed as TiN, and the influence of the BE was confirmed using [TiN/HZO/BE] structure by fixing TiN as the TE. As revealed by polarization versus electric field and residual stress analysis, smaller CTE of the electrode was found to result in higher tensile stress in the HZO films during the annealing process, facilitating the formation of higher ferroelectric o-phase and thereby resulting in greater ferroelectricity. Although the influence of TE and BE on the ferroelectric property of HZO films was found to show similar trends according to the CTE value of the electrodes, the influence of TE on the ferroelectric property of the HZO capacitors is found to be mainly due to the variation in the induced mechanical tensile stress; pulse switching measurement and X-ray photoelectron spectrometer (XPS) analysis suggest that in case of BE, both the induced mechanical tensile stress and the interfacial dead layer were found to play a significant part. As a result, BE was found to have a greater influence on ferroelectricity of the HZO capacitors when compared with that of TE. The highest remnant polarization of 48.2 and 58.7 μC/cm2 was obtained for W with the lowest of CTE of 4.5 × 10-6/°C in both the configurations. The results obtained in this article are expected to provide a new way out to optimize the interface quality and ferroelectricity in HZO-based capacitors. [ABSTRACT FROM AUTHOR]

Continuous electroencephalogram (EEG) recording is vital for brain science research, monitoring pathological and physiological conditions, and the diagnosis of brain disease. Conventional wet electrodes require skin preparation and a gel electrolyte to reduce electrode–skin interface impedance (EII), which limits its further application in long-term EEG signal recording. Microneedle-array electrodes (MAEs) have been employed in EEG recording, as they can be used directly without skin preparation or the gel electrolyte. However, most microneedles used in MAE are rigid and have a high aspect ratio; thus, they can break easily. Hence, we developed a novel bendable MAE for EEG recording. It is made of a flexible polydimethylsiloxane (PDMS) pillar array with rigid microneedle tips. The PDMS pillar array could help the MAE pass through hair and enable the microneedle tips to penetrate a stratum corneum layer into a scalp, thus reducing the EII. Moreover, the PDMS pillar array is bendable, which prevents the microneedles tips from breaking. The MAE can record EEG signals well in a BIOPAC system and an Emotiv EPOC+ device. The bendable MAE may be an alternative electrode for long-term EEG recording. [ABSTRACT FROM AUTHOR]

Measurement of the flow rate of any conductive liquid plays as one of the major roles in any process industry. Generally, electromagnetic flow meters are mostly used to measure the flow rate but electrode polarization impedance-based flow sensors can be a very good replacement of it due to its simple construction and low cost. In this sensing technique, four metal electrodes are inserted in a nonconductive flowline of the conductive liquid. The flow sensor is driven by a small ac voltage supplied through two electrodes and another two electrodes serve as pick-up ones to measure the output voltage. According to the flow rate, the output voltage is changed due to the change in polarization impedance. Simultaneously, there are other factors also, such as electrode size and material, current density, and excitation frequency, which effect the impedance polarization. The effect of the position of electrodes inside the pipe plays as a very crucial effecting factor to the sensor’s performance. In this article, to analyze the effect, an experiment is performed with three different arrangements for placing the electrodes, whereas the third arrangement is a novel one. The third arrangement also increases the sensitivity of the sensing unit and uses a new equivalent model to make analysis theoretically. Equivalent electrical models for three arrangements are analyzed and experimental results are also compared to make a proper evaluation to get a clear idea of the influence of the electrodes’ position. [ABSTRACT FROM AUTHOR]

This article explores hybrid energy storage devices in which an individual electrode is composed of a mixture of the active materials used in lithium-ion batteries and ultracapacitors, allowing them to exhibit characteristics of both device types. In order to explore the breadth of options between a pure battery electrode and a pure ultracapacitor electrode, seven different electrode compositions containing mixtures of lithium iron phosphate (LiFePO4) and activated carbon have been investigated. The hybrid electrodes have been implemented in an aqueous lithium sulfate electrolyte with single-electrode measurements using a reference electrode. The hybrid pulse power characterization (HPPC) test profile has been employed to characterize the energy and power capability of each electrode composition. An approach for converting single-electrode cycling results to full cell predictions suitable for the HPPC analysis procedure is presented. By executing this procedure, battery scale factors representing estimates of the quantity of active material required to achieve a set of energy storage target requirements have been calculated. Models of full 18650-format hybrid cells are developed to extend results to optimize a tailored energy storage system on the basis of total cell mass and volume. These results show that the required amount of active materials, total mass, or total volume of an energy storage system can be minimized for a given application by using a hybrid electrode and adjusting the constituent fraction of battery and ultracapacitor materials. [ABSTRACT FROM AUTHOR]

Bio-signal recording is vital for human condition monitoring and early disease diagnosis. An electrode is a biosensor for bio-signal collection. The conventional wet electrode is not suitable for long-term bio-signal recording owing to the gradual drying of the electrolytic gel and increase in the electrode-skin interface impedance. Microneedle array electrode is a dry electrode that can painlessly pierce skin, form a contact interface between the microneedles and skin tissue, eliminate the high impedance of stratum corneum, weaken the motion artifact, and accurately record bio-signals without skin preparation and application of electrolytic gel. This review focuses on the recently developed fabrication techniques, the mechanical performance, and bio-signal recording performance of microneedle array electrode. The microneedle array electrode is a potential electrode for long-term bio-signal recording, although progress is required in terms of safety and scaled-up manufacture. [ABSTRACT FROM AUTHOR]

This report presents characterizations of in vivo neural recordings performed with a CMOS multichannel neural recording chip that uses rapid multiplexing directly at the electrodes, without any pre-amplification or buffering. Neural recordings were taken from a 16-channel microwire array implanted in rodent cortex, with comparison to a gold-standard commercial bench-top recording system. We were able to record well-isolated threshold crossings from 10 multiplexed electrodes and typical local field potential waveforms from 16, with strong agreement with the standard system (average SNR = 2.59 and 3.07 respectively). For 10 electrodes, the circuit achieves an effective area per channel of 0.0077 mm2, which is >5x smaller than typical multichannel chips. Extensive characterizations of noise and signal quality are presented and compared to fundamental theory, as well as results from in vivo and in vitro experiments. By demonstrating the validation of rapid multiplexing directly at the electrodes, this report confirms it as a promising approach for reducing circuit area in massively-multichannel neural recording systems, which is crucial for scaling recording site density and achieving large-scale sensing of brain activity with high spatiotemporal resolution. [ABSTRACT FROM AUTHOR]

A multilayer sweat-absorbable flexible textile dry electrode for EEG measurement in forehead site was presented in this paper. With the development of BCI and wearable healthcare devices, the demand for long-term EEG monitoring, especially in the forehead site, has been increasing. However, current EEG electrodes cannot fulfill this demand, as wet electrodes need complex operations and conductive gels, and majorities of dry electrodes exhibit unacceptable high impedances. On the other hand, in motion or hot and moisture environment, the human body inevitably produces sweat that leads to short circuits or crosstalk interferences between neighboring electrodes, while current electrodes cannot deal with this situation effectively. To address the above-mentioned issues, a novel flexible dry electrode is designed using multilayer textile materials, including conductive fabrics and sweat absorption acceleration layer, which is able to absorb sweat effectively and further take the sweat as an electrolyte to enhance the conductivity. It also exhibits excellent conductivity with an electrode-scalp impedance superior to the wet electrode and other major electrodes in the literature. A good long-term stability in impedance was observed among current electrodes. A series of tests proved that the electrode was suitable for forehead EEG monitoring in daily life activities with a convenient and quick setup procedure as well as advantages of lightweight, adequate flexibility, and wearing comfort. [ABSTRACT FROM AUTHOR]

The optoelectrode arrays can modulate the neuron precisely with high time resolution and good reversibility compared to electrical stimulation. However, the integrated light-emitting diode (LED) or laser diode (LD) will introduce noise from the surroundings and affects the signal quality recording by the electrodes. Here, we present a polyimide (PI)-based flexible optoelectrode for low-noise neural recording. Compared with traditional electrode, this low-noise optoelectrode has a metal shield between the recording part and LED part which can isolate the electromagnetic noise from the active devices and Poly (3, 4-ethylenedioxythiophene) - poly (styrenesulfonate) (PEDOT: PSS) is electroplated to further increase the quality of the signal. It has been proved that the transient impulse aroused by turning ON/OFF the LED is eliminated in vitro bench test. In vivo, the electrode with metal shield has less high-frequency noise and 50 Hz power noise is suppressed compared with the electrode without shield. [ABSTRACT FROM AUTHOR]

Amorphous indium–gallium–zinc oxide (IGZO) is one of the most promising oxide semiconductors for thin-film transistors and it has started to replace amorphous silicon in display drivers. However, attempts to use IGZO in resistive random access memories (ReRAMs) are still scarce. This work investigates the bipolar resistive switching properties of crossbar-ReRAM devices based on IGZO thin film. Aluminum bottom electrode and two different top electrodes (i.e., Al and Ag) were tested in the devices. It was discovered that an oxygen plasma treatment (OPT) on the bottom electrode could significantly improve the surface roughness of the bottom electrode, the ON/OFF ratio, and the switching uniformity. After the OPT, the endurance of ReRAMs was enhanced. The ON/OFF current ratios reached ~104 and 105 within 100 endurance cycles for Al and Ag top electrode devices, respectively. Furthermore, the ReRAMs memory window remained nearly constant during a retention test of 105 s. The conduction mechanisms of the two device structures were examined using Schottky emission and space-charge-limited-current pictures, and the memory effect was explained by the formation and the interruption of filaments. [ABSTRACT FROM AUTHOR]

The cycle operation was performed on 1325 phase change memory (PCM) cells, and 4% of these cells could not be RESET to the high-resistance state after 106 cycles. The grown grains have been found in the TEM images, and the heat electron contact (HEC) has laterally diffused. The energy-dispersive X-ray spectroscopy profiles of HEC expound that Si and O elements have both multiplied. Thus, the HEC resistance has increased, resulting in insufficient RESET current. According to measurement, the HEC resistance increased from 4.6 to 7.2 $\text{K}{\Omega }$ after 106 cycles, which would decrease the RESET current from 0.7 to 0.45 mA. Compared with the endurance characteristics of the HEC and PCM device, the PCM device, with an increased HEC resistance, cannot be fully operated. When the HEC resistance is large enough to reduce the RESET current to 0.55 mA, the PCM device would be stuck to set. [ABSTRACT FROM AUTHOR]

The development of a single carbon fiber electrode has been investigated as a potential non-enzymatic sensor capable of quantifying peroxide. Electrodeposition of palladium is shown to create nanostructured deposits with a nanoneedle and nano-rod like morphology. The electrode modification is shown to be facile, and the resulting sensors exhibit a high sensitivity toward the oxidation ($388~\mu \text{A} \cdot {\mathrm {mM}}^{-1} \cdot {\mathrm {cm}}^{-2}$) and the reduction of peroxide. Interference from uric acid has been investigated, and the use of Nafion shown to greatly reduce its influence without unduly compromising the sensitivity of the sensors toward peroxide. [ABSTRACT FROM AUTHOR]

Flexible sheet electrode can record electrocorticography signals without penetrating the blood-brain barrier. However, the attachment between the cortex and the electrode influences the quality of the signal directly. Here, we present a 3-D ultrathin bioelectrode with elastic electrode sites to achieve conformal coverage on brain tissue and increase the flexibility of the electrode. Inspired by kirigami, the micro-warping elastic structures on the electrode can increase the conformality significantly when compared with the conventional planar electrodes. It has been proved that the warping structure has an excellent springback curve and maintains at least one week under the maximum stress of 7.5 kPa. Furthermore, the electrode sites were modified with platinum black to improve the electrochemical performance, and electrochemical characterization was performed. The electrode was compared with a plane onein vitro, which demonstrated the prominent attachment performance from the surface with sulci. Finally, the local field potential was recordedin vivo. [2018-0088] [ABSTRACT FROM AUTHOR]

Dual-type corona electrodes, consisting of a thin ionizing wire attached to a larger radius metallic cylinder, both connected to the same high-voltage supply, are widely used to generate corona discharges in several electrostatic processes such as charging granular materials in electrostatic separation and charging of fibrous media in the manufacturing processes of industrial air filters. The principal aim of this work is to experimentally investigate the effect of geometric dimensions (width and height) of a ground-shielded wire-type dual electrode on the current to a nearby metallic plate. The experimental results of this work clearly show that the current intensity generated by the corona electrode is higher using a narrower shield width. Otherwise, as long as the lower limits of the shield exceed the horizontal axis of the ionizing wire, the shield height does not affect significantly the current intensity produced by the discharge. These experimental results are validated by a series of corona-charging tests of insulating granules in the belt-type electrostatic separator. The quantities of particles recovered in the electro-separator are higher in presence of the shield, with well-chosen dimensions producing the highest possible corona current. These results may help to formulate some recommendations concerning the design of this type of electrode configuration. As the shield increases the output current of the electrode and broadens the ionized field, the proposed arrangement may be very useful for various industrial electrostatic processes. [ABSTRACT FROM PUBLISHER]

We compare electrical capacitance tomography (ECT) and displacement-current phase tomography (DCPT) results for non-invasive imaging of lossy media. ECT is based on mutual capacitance measurements between electrode pairs surrounding the region of interest (RoI), whereas DCPT is a relatively less mature sensing modality that utilizes the phase information inherent in the displacement current measured by such electrode pairs excited by time-harmonic voltages (in the electroquasistatic regime). DCPT and ECT can be implemented using basically the same hardware components and used alongside to provide complementary information for imaging purposes or separately to reconstruct the spatial distribution of the loss tangent or the permittivity within the RoI, respectively. We show that the (nonlinear) relationship between the measured phase in DCPT and the conductivity distribution in the RoI has a more extended linear range than the nonlinear relationship between the measured capacitances in ECT and the permittivity distribution in the RoI. Of note, DCPT does not require electrical contact with the RoI in contrast to electrical impedance tomography. To illustrate the potential of DCPT, we evaluate its performance using both numerical examples and experiment results. [ABSTRACT FROM PUBLISHER]

Kilohertz electrical stimulation (KES) induces repeatable and reversible conduction block of nerve activity and is a potential therapeutic option for various diseases and disorders resulting from pathological or undesired neurological activity. However, successful translation of KES nerve block to clinical applications is stymied by many unknowns, such as the relevance of the onset response, acceptable levels of waveform contamination, and optimal electrode characteristics. We investigated the role of electrode geometric surface area on the KES nerve block threshold using 20- and 40-kHz current-controlled sinusoidal KES. Electrodes were electrochemically characterized and used to characterize typical KES waveforms and electrode charge characteristics. KES nerve block amplitudes, onset duration, and recovery of normal conduction after delivery of the KES were evaluated along with power requirements for effective KES nerve block. Results from this investigation demonstrate that increasing electrode geometric surface area provides for a more power-efficient KES nerve block. Reductions in block threshold by increased electrode surface area were found to be KES-frequency-dependent, with block thresholds and average power consumption reduced by greater than two times with 20-kHz KES waveforms and greater than three times for 40-kHz KES waveforms. [ABSTRACT FROM AUTHOR]

Several electrode arrangements have been proposed to enhance the efficiency of insulating materials charging by corona discharge. Recent studies pointed out that the presence of a grounded metallic shield in the proximity of the high-voltage corona electrode increases, the total current measured at the surface of the collecting electrode decreases the corona onset voltage value and enlarges the reparation of current density and the surface potential as well. The aim of the present paper is to analyze the effect of replacing the shield by two parallel grounded strips located in the horizontal plan of the ionizing wire. The experimental results obtained show that the presence of the shield or the two parallel strips in the proximity of the dual wire electrode increases in the same way the corona current at the surface of the plate electrode. Varying the height of the strips and the wire-strips distance could modify significantly the behavior of the corona discharge in such electrode arrangements for both polarities. The characterization of this new electrode configuration could be very useful to the corona charging of different insulating materials in various electrostatic processes. These experiments are discussed in relation with the results of the numerical analysis of the electric field generated by the various electrode configurations. The equipotential lines plots and the electric field lines orientation explain the peculiarities of the corona discharge generated by this electrode arrangement. [ABSTRACT FROM PUBLISHER]