scholarly journals Highly Porous Platinum Electrodes for Dry Ear-EEG Measurements

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3176 ◽  
Author(s):  
Max Eickenscheidt ◽  
Patrick Schäfer ◽  
Yara Baslan ◽  
Claudia Schwarz ◽  
Thomas Stieglitz
Keyword(s):  
Silver Chloride ◽  
Signal To Noise Ratio ◽  
Auditory Attention ◽  
Platinum Electrodes ◽  
Effective Surface Area ◽  
Effective Surface ◽  
Transmission Properties ◽  
Silver Silver ◽  
Silver Silver Chloride ◽  
Highly Porous

The interest in dry electroencephalography (EEG) electrodes has increased in recent years, especially as everyday suitability earplugs for measuring drowsiness or focus of auditory attention. However, the challenge is still the need for a good electrode material, which is reliable and can be easily processed for highly personalized applications. Laser processing, as used here, is a fast and very precise method to produce personalized electrode configurations that meet the high requirements of in-ear EEG electrodes. The arrangement of the electrodes on the flexible and compressible mats allows an exact alignment to the ear mold and contributes to high wearing comfort, as no edges or metal protrusions are present. For better transmission properties, an adapted coating process for surface enlargement of platinum electrodes is used, which can be controlled precisely. The resulting porous platinum-copper alloy is chemically very stable, shows no exposed copper residues, and enlarges the effective surface area by 40. In a proof-of-principle experiment, these porous platinum electrodes could be used to measure the Berger effect in a dry state using just one ear of a test person. Their signal-to-noise ratio and the frequency transfer function is comparable to gel-based silver/silver chloride electrodes.

scholarly journals Highly Porous Platinum Electrodes for Dry Ear-EEG Measurements

2020 ◽  
Author(s):  
Max Eickenscheidt ◽  
Patrick Schäfer ◽  
Yara Baslan ◽  
Claudia Schwarz ◽  
Thomas Stieglitz
Keyword(s):  
Growth Form ◽  
Silver Chloride ◽  
Auditory Attention ◽  
Platinum Electrodes ◽  
Effective Surface Area ◽  
Effective Surface ◽  
Transmission Properties ◽  
Silver Silver ◽  
Silver Silver Chloride ◽  
Highly Porous

The interest in dry EEG electrodes has increased in recent years and especially as everyday suitability earplugs for measuring drowsiness or focus of auditory attention. However, the challenge is still the need for a good electrode material, which is reliable and can be easily processed for highly personalized applications. Laser processing as used here is a fast and very precise method to produce personalized electrode configurations that meet the high requirements of in-ear EEG electrodes, for example. The arrangement of the electrodes on the very flexible and compressible mats allows an exact alignment of the electrodes to the ear mold and contributes to a high wearing comfort, as no edges or metal protrusions are present. For better transmission properties, an adapted coating process for surface enlargement of platinum electrodes is used, which allows easy control of the thickness and growth form of the porous layer. The porous platinum-copper alloy is chemically very stable, shows no exposed copper residues and enlarges the effective surface area by 40. In a proof-of-principle experiment, these porous platinum electrodes could be used to measure the Berger effect in a dry state using just one ear of a test person. Their signal-to-noise ration and frequency transfer function is comparable to gel-based silver/silver chloride electrodes.

scholarly journals Development of Washable Silver Printed Textile Electrodes for Long-Term ECG Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6233
Author(s):  
Abreha Bayrau Nigusse ◽  
Benny Malengier ◽  
Desalegn Alemu Mengistie ◽  
Granch Berhe Tseghai ◽  
Lieva Van Langenhove
Keyword(s):  
Silver Chloride ◽  
Signal To Noise Ratio ◽  
Polyester Fabric ◽  
Signal Quality ◽  
Ecg Monitoring ◽  
Textile Electrodes ◽  
Elastic Strap ◽  
Silver Silver ◽  
Silver Silver Chloride

Long-term electrocardiography (ECG) monitoring is very essential for the early detection and treatment of cardiovascular disorders. However, commercially used silver/silver chloride (Ag/AgCl) electrodes have drawbacks, and these become more obvious during long-term signal monitoring, making them inconvenient for this use. In this study, we developed silver printed textile electrodes from knitted cotton and polyester fabric for ECG monitoring. The surface resistance of printed electrodes was 1.64 Ω/sq for cotton and 1.78 Ω/sq for polyester electrodes. The ECG detection performance of the electrodes was studied by placing three electrodes around the wrist where the electrodes were embedded on an elastic strap with Velcro. The ECG signals collected using textile electrodes had a comparable waveform to those acquired using standard Ag/AgCl electrodes with a signal to noise ratio (SNR) of 33.10, 30.17, and 33.52 dB for signals collected from cotton, polyester, and Ag/AgCl electrodes, respectively. The signal quality increased as the tightness of the elastic strap increased. Signals acquired at 15 mmHg pressure level with the textile electrodes provided a similar quality to those acquired using standard electrodes. Interestingly, the textile electrodes gave acceptable signal quality even after ten washing cycles.

scholarly journals Reexamination of Electrical Stimulation on Sarcoplasmic Reticulum Fragments In Vitro

1973 ◽  
Vol 62 (6) ◽  
pp. 773-786 ◽  
Author(s):  
H. Miyamoto ◽  
M. Kasai
Keyword(s):  
Electrical Stimulation ◽  
Sarcoplasmic Reticulum ◽  
Silver Chloride ◽  
Electrical Response ◽  
Platinum Electrodes ◽  
Irreversible Denaturation ◽  
Ca Uptake ◽  
Silver Silver ◽  
Silver Silver Chloride

The effect of direct electrical stimulation on suspensions of sarcoplasmic reticulum membrane fragments (SRF) was carefully re-examined using the method of Lee et al. (1966) J. Gen. Physiol. 49:689. Inhibition of Ca++ uptake or release by electrical stimulation was observed. When platinum electrodes were used as stimulating electrodes, the effect was dependent on the total current passed through the suspension. On the contrary, when silver-silver chloride electrodes were used, no effect was observed even if voltage and current were the same as in the case of the platinum electrodes. In addition, apparent re-uptake of Ca++ after cessation of electrical stimulation using platinum electrodes was shown to be due to a binding of Ca++ to denatured SRF which did not require an energy supply such as ATP, although such re-uptake had been taken as strong evidence of electrical response of SRF in Lee's paper. Finally, it was concluded that the effect of electrical stimulation on SRF was attributable to the irreversible denaturation of SRF due to the oxidation caused by the chlorine generated at the platinum electrode.

scholarly journals Textile-based electrode for electrocardiography monitoring

2020 ◽  
Vol 9 (6) ◽  
pp. 2311-2318
Author(s):  
Syaidah Md Saleh ◽  
Nurul Ashikin Abdul-Kadir ◽  
Fauzan Khairi Che Harun ◽  
Dedy H. B. Wicaksono
Keyword(s):  
Cotton Fabric ◽  
Silver Chloride ◽  
Promising Result ◽  
Signal To Noise Ratio ◽  
Vertical Position ◽  
Ecg Signal ◽  
Increasing Demand ◽  
Silver Silver ◽  
Silver Silver Chloride ◽  
Coated Cotton

The increasing demand of smart garment for monitoring people’s health is due to comfortability, lightweight and flexibility properties of the textile could offer to the user. The textile-based electrocardiography (ECG) electrode is an alternative of commercially available silver/silver chloride (Ag/AgCl) electrode which could cause skin allergies to certain users and is not suitable for long-term monitoring electrode. In this paper, we report the performance of reduced graphene oxide (rGO) coated cotton fabric electrode to the effect of longevity and temperature. The ECG waveform and signal-to noise ratio (SNR) of the rGO-coated cotton electrodes were compared to that the performance of Ag/AgCl electrodes. The reliability characterization confirmed the rGO-coated cotton fabric conductance maintain at more than 80% even after 100 days of fabrication and the conductance measurement is increasing with respect to the temperature applied. The electrode shows lower in impedance value and the performance in acquiring ECG signal is comparable with the Ag/AgCl electrode. The vertical position rectangle-shaped electrode is recommended in measuring ECG signals. In conclusion, the rGO-coated cotton electrode with flexible dry-type electrode and excellent performance especially reliability and in capturing ECG signal had shown a promising result for further development.

scholarly journals A Novel Highly Durable Carbon/Silver/Silver Chloride Composite Electrode for High-Definition Transcranial Direct Current Stimulation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1962
Author(s):  
Lingjun Li ◽  
Guangli Li ◽  
Yuliang Cao ◽  
Yvonne Yanwen Duan
Keyword(s):  
Service Life ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Silver Chloride ◽  
Cycling Performance ◽  
High Definition ◽  
Silver Silver ◽  
Sintered Ag ◽  
Silver Silver Chloride

High-definition transcranial direct current stimulation (HD-tDCS) is a promising non-invasive neuromodulation technique, which has been widely used in the clinical intervention and treatment of neurological or psychiatric disorders. Sintered Ag/AgCl electrode has become a preferred candidate for HD-tDCS, but its service life is very short, especially for long-term anodal stimulation. To address this issue, a novel highly durable conductive carbon/silver/silver chloride composite (C/Ag/AgCl) electrode was fabricated by a facile cold rolling method. The important parameters were systematically optimized, including the conductive enhancer, the particle size of Ag powder, the C:Ag:PTFE ratio, the saline concentration, and the active substance loading. The CNT/Ag/AgCl-721 electrode demonstrated excellent specific capacity and cycling performance. Both constant current anodal polarization and simulated tDCS measurement demonstrated that the service life of the CNT/Ag/AgCl-721 electrodes was 15-16 times of that of sintered Ag/AgCl electrodes. The much longer service life can be attributed to the formation of the three-dimensional interpenetrating conductive network with CNT doping, which can maintain a good conductivity and cycling performance even if excessive non-conductive AgCl is accumulated on the surface during long-term anodal stimulation. Considering their low cost, long service life, and good skin tolerance, the proposed CNT/Ag/AgCl electrodes have shown promising application prospects in HD-tDCS, especially for daily life scenarios.

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