Cytotoxicity test based on electrochemical impedance measurement of HepG2 cultured in microfabricated cell chip

2005 ◽  
Vol 341 (2) ◽  
pp. 308-315 ◽  
Author(s):  
Ju Hun Yeon ◽  
Je-Kyun Park
Keyword(s):  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Cytotoxicity Test ◽  
Cell Chip

scholarly journals Impact of Relaxation Time on Electrochemical Impedance Spectroscopy Characterization of the Most Common Lithium Battery Technologies—Experimental Study and Chemistry-Neutral Modeling

2021 ◽  
Vol 12 (2) ◽  
pp. 77
Author(s):  
Md Sazzad Hosen ◽  
Rahul Gopalakrishnan ◽  
Theodoros Kalogiannis ◽  
Joris Jaguemont ◽  
Joeri Van Mierlo ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Nonlinear Behavior ◽  
Lithium Ion ◽  
Health Condition ◽  
Battery Cell ◽  
Rest Time

In electrified vehicle applications, understanding the battery characteristics is of great importance as it is the state-of-art principal energy source. The key battery parameters can be identified by one of the robust and nondestructive characterization techniques, such as electrochemical impedance spectroscopy (EIS). However, relaxing the battery cell before performing the EIS method is crucial for the characterization results to be standardized. In this study, the three most common and commercially available lithium-ion technologies (NMC/graphite, LFP/graphite, NCA/LTO) are investigated at 15–45 °C temperature, in the range of 20–80% state of charge (SoC) and in fresh and aged state of health (SoH) conditions. The analysis shows that the duration of the relaxation time before impedance measurement has an impact on the battery’s nonlinear behavior. A rest time of 2 h can be proposed, irrespective of battery health condition, considering neutral technology-based impedance measurement. An impedance growth in ohmic and charge transfer characteristics was found, due to aging, and the effect of rest periods was also analyzed from an electrochemical standpoint. This experimental data was fitted to develop an empirical model, which can predict the nonlinear dynamics of lithium technologies with a 4–8% relative error for longer rest time.

Effect of Co-Content on the Corrosion of High Performance Stainless Steels in Simulated Bio-Solutions

2007 ◽  
Vol 342-343 ◽  
pp. 585-588
Author(s):  
Y.R. Yoo ◽  
H.H. Cho ◽  
S.G. Jang ◽  
K.Y. Lee ◽  
H.Y. Son ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
High Performance ◽  
316L Stainless Steel ◽  
Impedance Measurement ◽  
Cytotoxicity Test ◽  
Polarization Test ◽  
Acidic Chloride Solution ◽  
Acidic Chloride ◽  
Test Result

This work focused on the effect of Co content on the corrosion resistance of high pitting resistance equivalent (PRE), super ferritic, Ni-free stainless steels in simulated biosolutions. The effect of Co in Ni-free alloys was evaluated by cytotoxicity test. Anodic polarization test and AC impedance measurement were performed to evaluate the effect of Co on corrosion resistance of the alloys. The cytotoxicity test result for 4 experimental alloys shows non-cytotoxic but mild cytotoxic for 316L stainless steel due to relatively poor corrosion resistance. However, the effect of Co on the passivity was positive in bio-solution but it was negative in acidic chloride solution.

Corrosion Inhibition of Mild Steel by Electrodeposited Poly(M-Aminophenol) Coating

2021 ◽  
Vol 317 ◽  
pp. 498-505
Author(s):  
Sabrina M. Yahaya ◽  
Mohamad Kamal Harun ◽  
Ismaliza Ismail ◽  
Rosmamuhamadani Ramli
Keyword(s):  
Mild Steel ◽  
Steel Surface ◽  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Barrier Properties ◽  
Electrical Circuit ◽  
Significant Drop ◽  
Mild Steel Surface ◽  
Barrier Resistance ◽  
And Performance

In this study, poly(m-aminophenol) (PMAP) coating was electrochemically synthesized by cyclic voltammetry (CV) on mild steel surface to investigate the effects of its barrier protection within the scope of its electrochemical impedance towards further oxidation of the mild steel substrates. The developed PMAP coating were characterized by Fourier Transform Infrared (FTIR) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). The barrier resistance ability of PMAP coating towards corrosion of mild steel was determined in 0.5 M aqueous sodium chloride solution (NaCl) at various immersion times by the electrochemical impedance spectroscopy (EIS). The barrier properties were interpreted through impedance measurement using Nyquist and Bode plots. Equivalent electrical circuit models derived from the plots were employed to describe the coating barrier behaviour and performance. Data obtained showed that, the oxidation peak of PMAP coating were observed at potential +1.0 V (Ag/AgCl). The micrograph of FESEM indicates the formation of a dense and continous PMAP coatings. In FTIR analyses, the presence of peak around 1082 cm-1 ascribed to C–O–C etheric linkage which supported the formation of electro polymerized PMAP coating on mild steel surface. EIS measurement revealed that, PMAP coatings experienced a significant drop in total impedance values with time followed by the development of an electrochemical reactions on coating/metal interface, which indicates the gradual degradation of the barrier resistance ability of the PMAP coatings.

scholarly journals Transfer Printing of Conductive Thin Films on PDMS with Soluble Substrates for Flexible Biosensors

2020 ◽  
Vol 2 (1) ◽  
pp. 47
Author(s):  
Steffen Hadeler ◽  
Sebastian Bengsch ◽  
Maren S. Prediger ◽  
Marc Christopher Wurz
Keyword(s):  
Physical Vapor Deposition ◽  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Impedance Measurement ◽  
Water Soluble ◽  
Electrode Spacing ◽  
Conductive Layer ◽  
Electrode Structure ◽  
Neural Implants ◽  
The Individual

The resolution of commercially available electrocorticography (ECoG) electrodes is limited due to the large electrode spacing and, therefore, allows only a limited identification of the active nerve cell area. This paper describes a novel manufacturing process for neural implants with higher spatial resolution combining micro technological processes and Polydimethylsiloxane (PDMS) as the flexible, biocompatible material. The conductive electrode structure is deposited on a water-soluble transfer substrate by Physical Vapor Deposition (PVD) processes. Subsequently, the structure is contacted. Finally, the transfer to PDMS and dissolution of the transfer substrate takes place. In this way, high-resolution conductive structures can be produced on the PDMS. Transferred gold structures exhibit higher adhesion and conductivity than transferred platinum structures. The adhesion was improved by applying a silica surface modification to the conductive layer prior to transferring. Furthermore, the conductive layer is flexible, conductive up to an elongation of 10%, and resistant to sodium chloride solution, mimicking brain fluids. Using the introduced production process, an ECoG electrode was manufactured and characterized for its functionality in an electrochemical impedance measurement. Furthermore, the electrodes are flexible enough to adapt to different shapes. The transfer process can also be carried out in a three-dimensional mold to produce electrodes tailored to the individual patient.

scholarly journals Broadband Impedance Measurement of Lithium-Ion Battery in the Presence of Nonlinear Distortions

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2493
Author(s):  
Jussi Sihvo ◽  
Tomi Roinila ◽  
Daniel-Ioan Stroe
Keyword(s):  
Electrochemical Impedance ◽  
Equivalent Circuit Model ◽  
Impedance Measurement ◽  
Lithium Ion ◽  
Li Ion Battery ◽  
Third Order ◽  
Impedance Measurements ◽  
Nonlinear Distortions ◽  
Measured Impedance ◽  
Li Ion

The impedance of a Lithium-ion (Li-ion) battery has been shown to be a valuable tool in evaluating the battery characteristics such as the state-of-charge (SOC) and state-of-health (SOH). Recent studies have shown impedance-measurement methods based on broadband pseudo-random sequences (PRS) and Fourier techniques. The methods can be efficiently applied in real-time applications where the conventional electrochemical-impedance spectroscopy (EIS) is not well suited to measure the impedance. The techniques based on the PRS are, however, strongly affected by the battery nonlinearities. This paper presents the use of a direct-synthesis ternary (DST) signal to minimize the effect caused by the nonlinearities. In such a signal, the second- and third-order harmonics are suppressed from the signal energy spectrum. As a result, the effect of the second- and third-order nonlinearities are suppressed from the impedance measurements. The impedance measurements are carried out for a nickel manganese cobalt Li-ion battery cell. The performance of the method is compared to the conventional EIS, as well as to other PRS signals which are more prone to battery nonlinearities. The Kronig–Kramers (K–K) transformation test is used to validate the uniqueness of the measured impedance spectra. It is shown that the measurement method based on the DST produces highly accurate impedance measurements under nonlinear distortions of the battery. The method shows a good K–K test behavior indicating that the measured impedance complies well to a linearized equivalent circuit model that can be used for the SOC and SOH estimation of the battery. Due to the good performance, low measurement time, and simplicity of the DST, the method is well suited for practical battery applications.

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