Participation in the development of electrodes for human physiological recordings.

Electrodes are the first crucial elements of a wearable recording device for human biopotentials. Their research and development require reliable testing methods and characterisation processes. The purpose of this master thesis is the development of an in vitro skin model in order to have a relevant impedance and noise characterisation process before the electrodes are tested on human subjects. To reach this goal, biological and non-biological models have been investigated using electrochemical impedance spectroscopy and noise measurements. After obtaining a skin model with an impedance close to the human skin and having checked its repeatability and reproducibility, the model was validated by characterising different electrodes already tested on human subjects. The results obtained on the non-biological model Framis made of a non-conductive textile, a breathable membrane and a saline solution were very close to the one obtained on people. Thus, the relevance of this skin model for the impedance and noise characterisation of electrodes have been successfully proven. Hereafter, this skin model will be integrated to the company test protocols.