Molecular Rectification Based on Asymmetrical Molecule−Electrode Contact

2010 ◽  
Vol 114 (9) ◽  
pp. 4135-4141 ◽  
Author(s):  
Jianwei Zhao ◽  
Cui Yu ◽  
Nan Wang ◽  
Hongmei Liu
Keyword(s):  
Molecular Rectification ◽  
Electrode Contact

scholarly journals Textile Electrodes: Influence of Knitting Construction and Pressure on the Contact Impedance

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1578
Author(s):  
Luisa Euler ◽  
Li Guo ◽  
Nils-Krister Persson
Keyword(s):  
Smooth Surface ◽  
Research Field ◽  
Uneven Surface ◽  
Contact Impedance ◽  
Dry Electrodes ◽  
Textile Electrodes ◽  
Human Forearm ◽  
Wet Condition ◽  
Electrode Contact ◽  
Influencing Parameters

Textile electrodes, also called textrodes, for biosignal monitoring as well as electrostimulation are central for the emerging research field of smart textiles. However, so far, only the general suitability of textrodes for those areas was investigated, while the influencing parameters on the contact impedance related to the electrode construction and external factors remain rather unknown. Therefore, in this work, six different knitted electrodes, applied both wet and dry, were compared regarding the influence of specific knitting construction parameters on the three-electrode contact impedance measured on a human forearm. Additionally, the influence of applying pressure was investigated in a two-electrode setup using a water-based agar dummy. Further, simulation of an equivalent circuit was used for quantitative evaluation. Indications were found that the preferred electrode construction to achieve the lowest contact impedance includes a square shaped electrode, knitted with a high yarn density and, in the case of dry electrodes, an uneven surface topography consisting of loops, while in wet condition a smooth surface is favorable. Wet electrodes are showing a greatly reduced contact impedance and are therefore to be preferred over dry ones; however, opportunities are seen for improving the electrode performance of dry electrodes by applying pressure to the system, thereby avoiding disadvantages of wet electrodes with fluid administration, drying-out of the electrolyte, and discomfort arising from a “wet feeling”.

Properties of perpendicular-anisotropy magnetic tunnel junctions fabricated over the bottom electrode contact

2015 ◽  
Vol 54 (4S) ◽  
pp. 04DM06 ◽  
Author(s):  
Sadahiko Miura ◽  
Hiroaki Honjo ◽  
Keizo Kinoshita ◽  
Keiichi Tokutome ◽  
Hiroaki Koike ◽  
...  
Keyword(s):  
Bottom Electrode ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Perpendicular Anisotropy ◽  
Electrode Contact

scholarly journals Prediction of Behavioral T/C Levels in Cochlear Implant Patients Based Upon Analysis of Electrode Impedances

2021 ◽  
Author(s):  
A. Molisz ◽  
A. Zarowski ◽  
E. Cardinael ◽  
A. Vermeiren ◽  
T. Theunen ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Objective Measure ◽  
Analysis Data ◽  
Case Review ◽  
Data Collection And Analysis ◽  
Compound Action Potentials ◽  
Subjective Threshold ◽  
Electrode Contact ◽  
Maximum Comfort

Abstract Background Fitting cochlear implants in babies and noncooperative patients is cumbersome and time consuming. Therefore, objective parameters have been sought in order to predict the subjective threshold (T) and maximum comfort (C) levels. Measurements of the electrically evoked compound action potentials (ECAPs) have been widely used for this purpose, yet the correlation between these objective measures and the subjective T/C levels is weak to moderate. Purpose This article aims (1) to evaluate correlations between the subjective parameters of the fitting maps such as thresholds (T level) and maximum comfort levels (C level), the impedance of the electrode contacts, and the ECAP thresholds, and (2) to compare the value of the electrode impedances and the ECAP measures for prediction of the T/C levels. Research Design Case review study in a quaternary otologic referral center. Study Sample Ninety-eight consecutive CI patients were enrolled. The average age of the patients was 49 years. All patients were users of the Nucleus 24RECA (Freedom, Contour Advance-of-Stylet electrode) cochlear implant. Data Collection and Analysis Data on impedance of the electrode contacts and the behavioral T/C levels at the first fitting session (2–5 weeks after surgery) and at the 5th fitting session (4–6 months after surgery) have been retrospectively collected in 98 consecutive CI patients. Additionally, the intraoperative impedance values and the ECAP thresholds (tNRT) have been recorded. Results Impedances of electrode contacts show significant strong negative correlations with the stabilized T/C levels at 4 to 6 months after implantation and are an important predictor for the behavioral T/C levels. They can explain R 2 = 28 to 41% of the variability of the behavioral T/C levels. In multiple regression analysis electrode contact impedances can explain twice as much of the variability of the stabilized T/C levels than the tNRT values. The electrode impedances together with the tNRT values are able to explain R 2 = 37 to 40% of the global variability of the T/C levels while the tNRT thresholds solely are able to explain only R 2 = 5 to 14% of the T/C levels variability. Conclusion Impedances of electrode contacts correlate strongly with the stabilized behavioral T/C levels and may be used as an objective measure for fitting of cochlear implants.

Modeling the influence of two terminal electrode contact geometry and sample dimensions in electro‐materials

2018 ◽  
Vol 102 (6) ◽  
pp. 3609-3622 ◽  
Author(s):  
Richard A. Veazey ◽  
Amy S. Gandy ◽  
Derek C. Sinclair ◽  
Julian S. Dean
Keyword(s):  
Contact Geometry ◽  
Electrode Contact

scholarly journals Numerical Modeling of the Effects of Electrode Spacing and Multilayered Concrete Resistivity on the Apparent Resistivity Measured Using Wenner Method

2020 ◽  
Author(s):  
Karthick Thiyagarajan ◽  
Parikshit Acharya ◽  
Lasitha Piyathilaka ◽  
sarath kodagoda
Keyword(s):  
Contact Area ◽  
Apparent Resistivity ◽  
Resistivity Measurement ◽  
Gaussian Process Regression ◽  
Electrode Spacing ◽  
Electrical Resistivity Measurement ◽  
Resistivity Measurements ◽  
Electrode Contact ◽  
Concrete Resistivity ◽  
Moisture Conditions

Smart Sensing technologies can play an important role in the conditional assessment of concrete sewer pipe linings. In the long-term, the permeation of acids can deteriorate the pipe linings. Currently, there are no proven sensors available to non-invasively estimate the depth of acid permeation in real-time. The electrical resistivity measurement on the surface of the linings can indicate the sub-surface acid moisture conditions. In this study, we consider acid permeated linings as a two resistivity layer concrete sample, where the top resistivity layer is assumed to be acid permeated and the bottom resistivity layer indicates normal moisture conditions. Firstly, we modeled the sensor based on the four-probe Wenner method. The measurements of the developed model were compared with the previous studies for validation. Then, the sensor model was utilized to study the effects of electrode contact area, electrode spacing distance and two resistivity layered concrete on the apparent resistivity measurements. All the simulations were carried out by varying the thickness of top resistivity layer concrete. The simulation study indicated that the electrode contact area has very minimal effects on apparent resistivity measurements. Also, an increase in apparent resistivity measurements was observed when there is an increase in the distance of the electrode spacing. Further, a machine learning approach using Gaussian process regression modeling was formulated to estimate the depth of acid permeated layer

scholarly journals Electrochemical Characteristics Based on Skin-Electrode Contact Pressure for Dry Biomedical Electrodes and the Application to Wearable ECG Signal Acquisition

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jinzhong Song ◽  
Tianshu Zhou ◽  
Zhonggang Liang ◽  
Ruoxi Liu ◽  
Jianping Guo ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Electrode Pair ◽  
Electrochemical Characteristics ◽  
Polarization Voltage ◽  
Skin Electrode ◽  
Textile Electrodes ◽  
Biomedical Electrodes ◽  
Electrode Contact ◽  
Evaluation Platform ◽  
Electrochemical Evaluation

Based on one simulated skin-electrode electrochemical interface, some electrochemical characteristics based on skin-electrode contact pressure (SECP) for dry biomedical electrodes were analysed and applied in this research. First, 14 electrochemical characteristics including 2 static impedance (SI) characteristics, 11 alternating current impedance (ACI) characteristics and one polarization voltage (PV), and 4 SECP characteristics were extracted in one electrochemical evaluation platform, and their correlation trends were statistically analysed. Second, dry biomedical electrode samples developed by the company and the laboratory, including textile electrodes, Apple watch, AMAZFIT rice health bracelet 1S, and stainless steel electrodes, were placed horizontally and vertically on the “skin” surface of the electrochemical evaluation platform, whose polarization voltages were quantitatively analysed. Third, electrocardiogram (ECG) collection circuits based on an impedance transformation (IT) circuit for textile electrodes were designed, and a wearable ECG acquisition device was designed, which could obtain complete ECG signals. Experimental results showed SECP characteristics for dry electrodes had good correlations with static impedance and ACI characteristics and the better correlation values among 2-10 Hz. In addition, polarization voltages in vertical state were smaller in horizontal state for dry biomedical electrodes, and polarization voltage of electrode pair (PVEP) values for Apple watch bottom was always smaller than ones for Apple watch crown and LMF-2 textile electrode. And the skin-electrode contact impedance of IT textile electrodes was less than the traditional textile electrodes.

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