Model chi6054e

To determine the electrical properties of the three types of electrodes used, we measured the impedance of each electrode (hydrogel, dry polymer nanocomposite, and dry carbon rubber) using electrochemical impedance spectroscopy (EIS) with an electrochemical analyzer (Model CHI6054E, CH Instruments, USA). The experimental setup consisted of a three-electrode configuration with one sample connected to the working electrode, a second sample connected to the counter electrode, and a third sample connected to the reference electrode while placed on a single subject’s forearm (female, age 30). The parameters used were a sine wave with a peak amplitude of 0.01 V and a frequency range from 1 Hz to 1 MHz. For comparison, this procedure was performed on samples with a 5 × 5 cm square shape design. In addition, the average surface resistivity of the samples was measured using a digital multimeter (34401A Multimeter, Agilent, USA).

Electrochemical impedance spectroscopy (EIS) was performed using an electrochemical analyzer (Model CHI6054E, CH Instruments, United States) to measure the electrodes’ impedance. A three-electrode configuration was used with a silver/silver chloride (Ag/AgCl) reference electrode (CHI111, CH Instruments, United States), a platinum counter electrode (CHI221, CH Instruments, United States), and the device wires as a working electrode. A 0.9% saline solution at room temperature was used as the electrolyte in a 642.62 cm³ (7.1 cm in height, 6.1 cm top radius, and 4.6 bottom radius) plastic cylindrical container. A 500 mV sine wave was applied at a frequency ranging from 50 to 0.01 Hz with 12 measurements per decade. This procedure was performed before implantation of the device as well as post-surgery.