Fully textile electrodes for wearable electrophysiological signal monitoring systems

In recent years, there has been a particular interest in wearable electronics due to the continue miniaturization of electronic devices. This led to the use of this technology in various fields as fashion, fitness or medical devices. The ultimate goal is the integration of sensors and electronics in clothes and garments. In this work, textiles electrodes obtained by treating natural cotton fabric with the conductive polymer poly-3,4- ethylenedioxythiophene doped with poly(styrene sulfonate) (PEDOT:PSS) are presented. The intrinsic ionic conductivity of the PEDOT:PSS coated fabrics eliminates the need of electrolytes, pastes or solutions for acquiring bioelectrical potentials directly from the human skin. The electrodes have been tested on human volunteers, in dry and wet conditions, at rest and during physical activity. The achieved results reveal that these electrodes can be effectively used to acquire ECG signals. The performance of fabric electrodes in term of skin-electrode impedance and noise level is comparable to gelled Ag/AgCl electrodes. A printing technique able to achieve good definition and control over the quantity of deposited polymer is also presented as an alternative to the treatment of the whole tissue.