Screen-printed Silver/PEDOT:PSS electrodes for bioimpedance measurement: morphological and electrochemical characterization

Abstract In this work, we report the fabrication of an electrode design intended for wearable bioimpedance devices, focusing on characterizing its morphology and in-vitro measurement performance. Finger-track electrode design was fabricated using a screen-printing technique, employing a stretchable Ag paste and PEDOT:PSS on a stretchable TPU substrate. Electrical impedance measurements were conducted across various NaCl concentrations (i.e., 2.4, 4.8, 9.6, and 154 mmol/L) to assess distinct stages of impedance: polarization impedance and bulk resistance. Morphological characterization, including contact angle measurements, revealed that the Ag-electrode surface, compared to the Ag/PEDOT:PSS material, is more prone to wettability. The results suggest that the combination of PEDOT:PSS and Ag has potential for improved electrochemical performance compared to Ag only and different hydrophilicity, motivating further studies on skin contact impedance in the context of wearable bio-impedance measurement.