More Like this

1. Electrokinetic Streaming-Current Methods to Probe the Electrode–Electrolyte Interface under Applied Potentials

   https://doi.org/10.1021/acs.jpcc.9b03430  

   Saha, Prantik; Nam, Changwoo; Hickner, Michael A.; Zenyuk, Iryna V. (July 2019, The Journal of Physical Chemistry C)
2. Electrokinetic Streaming Current Method to Probe Polycrystalline Gold Electrode-Electrolyte Interface Under Applied Potentials

   https://doi.org/10.1149/1945-7111/abf4aa  

   Saha, Prantik; Zenyuk, Iryna V. (April 2021, Journal of The Electrochemical Society)

   We developed a method, by combining electrochemical and electrokinetic streaming current techniques to study ion distribution and ionic conductivity in the diffuse part of electrochemical double layer (EDL) of a metal-electrolyte interface, when potential is applied on the metal by a potentiostat. We applied this method to an electrochemically clean polycrystalline gold (poly Au)-electrolyte interface and measured zeta potential for various applied potentials, pH, and concentration of the electrolyte. Specific adsorption of chloride ions on poly Au was studied by comparing measurements of zeta potential in KCl and KClO₄electrolytes. In absence of specific adsorption, zeta potential was found to increase linearly with applied potential, having slope of 0.04–0.06. When Cl⁻adsorption occurs, zeta potential changes the sign from positive to negative value at ∼750 mV vs Ag/AgCl applied potential. Complementary cyclic voltammetry and X-ray photoelectron spectroscopy studies were conducted to determine a degree of chloride ion adsorption on a poly Au. A correlation was observed between the applied potential at which zeta potential is zero and potential of zero charge for poly Au. Ion-distribution and ionic conductivity in the diffuse layer were calculated from the measured zeta potential data using nonlinear Poisson-Boltzmann distribution. 

   more » « less
3. Feedback-based Electrode Rehydration for High Quality, Long Term, Noninvasive Biopotential Measurements and Current Delivery

   https://doi.org/10.1109/BIOCAS.2019.8919026  

   Krishnan, Ashwati; Weigle, Harper; Kelly, Shawn K; Grover, Pulkit (January 2019, IEEE Biomedical Circuits and Systems)

   null (Ed.)
4. 1024-Electrode Hybrid Voltage/Current-Clamp Neural Interface System-on-Chip with Dynamic Incremental-SAR Acquisition

   https://doi.org/10.1109/VLSICircuits18222.2020.9162837  

   Wang, Jun; Paul, Akshay; Zhang, Dinghong; Wu, Jiajia; Xu, Yuchen; Zou, Yimin; Kim, Chul; Cauwenberghs, Gert (June 2020, 2020 IEEE Symposium on VLSI Circuits (VLSI-Circuits))

   We present a neural interface system-on-chip (NISoC) with 1,024 channels of simultaneous electrical recording and stimulation for high-resolution high-throughput electrophysiology. The 2mm  2mm NISoC in 65nm CMOS integrates a 32  32 array of electrodes vertically coupled to analog front-ends supporting both voltage and current clamping through a programmable interface, ranging over 100dB in voltage and 120dB in current, with 0.82mW power per channel at 5.96mVrms input-referred voltage noise from DC to 12.5kHz signal bandwidth. This includes onchip acquisition with a back-end array of 32 dynamic incremental SAR ADCs for 25Msps 11-ENOB acquisition at 2fJ/level FOM. 

   more » « less
5. Investigation of Electrode Kinetics of Porous La-Sr-Co-Fe-oxide (LSCF) Electrodes on Yttria-Stabilized Zirconia (YSZ) Electrolyte Using Alternating Current (AC) and Direct Current (DC) Methods

   https://doi.org/10.1149/1945-7111/ac0946  

   Lei, Chong; Simpson, Michael F; Virkar, Anil V (June 2021, Journal of The Electrochemical Society)

   Lanthanum strontium cobalt iron oxide (LSCF) is commonly used as a cathode in solid oxide fuel cells (SOFCs), because it is a mixed ionic-electronic conductor with reasonable oxygen ion conductivity and high electronic conductivity. Yttria stabilized zirconia (YSZ) is used as an electrolyte in SOFCs with good oxygen ion conductivity. AC techniques are used to test the performance of SOFCs. But electrode processes at the cathode and the anode cannot be studied separately using 2-probe electrical impedance spectroscopy (EIS). To overcome this problem, 2-probe EIS with three probes and DC tests were conducted. An LSCF/8YSZ/LSCF symmetrical bar-shaped cell was made, and platinum strip electrodes were applied as probes for EIS and DC measurements. Impedance spectra across the cathode and the platinum strip electrode and across the anode and the platinum strip electrode were measured separately. The sum was evaluated to see if it matches the EIS spectra across the cathode and the anode. The polarity was switched to study how it affects the electrode processes. The polarization resistances of the electrodes were also measured by a DC method separately. EIS and DC measurements are in good agreement. Results indicate the two electrodes need not be identical. 

   more » « less