A Comparative Study of Polypyrrole and Ag/Polypyrrole Hybrid Nanocomposites as Sensitive Material Used for New Dry Polarizable Bioimpedance Sensors

• Main Authors: Gabriela Telipan, Lucian Pîslaru-Dănescu, Eduard-Marius Lungulescu, Ioana Ion, Virgil Marinescu
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Applied Sciences
• Subjects: polypyrrole; hybrid nanocomposite Ag/polypyrrole; dry polarizable bioimpedance sensor; electric bioimpedance
• Online Access: https://www.mdpi.com/2076-3417/11/9/4168

Three types of dry polarizable electric bioimpedance sensor for skin bioimpedance monitoring without skin preparation have been developed. The sensitive materials as a component of these sensors are the conductive polypyrrole and hybrid nanocomposite polypyrrole-Ag, with 10% and 20% Ag incorporated in the polypyrrole matrix. The hybrid nanocomposites Ag nanoparticles (NPs)/polypyrrole were obtained by introducing the colloid solution of Ag NPs in pyrrole solution, followed by polymerisation, and calculated for 10% and 20% of monomer’s mass. The structural characterisation and morphological analysis of these sensitive materials were carried-out by Raman spectrometry, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. In making the electrodes, the technique of pressing powders of polypyrrole and hybrid composites Ag NPs/polypyrrole in a hydraulic press was used in the form of a disk. The electric bioimpedance performance of sensors was investigated using a two-point method in the frequency range of 1–300 kHz, at a voltage of 2 V_peak-peak, on six human subjects, three men and three women. For these three bioimpedance sensors, it was found that the electric bioimpedance of the skin decreases across the frequency range and shows good linearity of the impedance-frequency curve on the range frequency of interest in bioimpedance measurements.