An Electro-Mechanical Contact Formulation for Dry/Wet Electrode-Scalp Interfaces in an EEG Headset

Vangu Kitoko, Tuan N. Nguyen, and Hung T. Nguyen


Bristle electrode, Wearable EEG headset, Skin roughness, scalp


The process of generating an initial prototype for a new dry electrode wearable EEG headset system design can be time and resource intensive. The ability to predict the mechanical and electrical characteristics of this recording device could lead to major cost savings in this process. Since the skin surface roughness has a deep impact on the decrease of brain electric contact conductance (or the increase of the contact impedance) when electrode with bristles contact scalp skin, the estimation of electric conductance across rough dry and wet boundaries is a challenging task in the designing optimization of the wearable EEG headset system. In this contribution, the contact mechanism to predict the electrical conductance of scalp skin pressed against the electrode is considered as the electrical connection by the mechanical contact. For mechanical contact analysis, a new normal force-displacement approach based on the micro-mechanical studies is developed for analyse of the non-linear electrode-skin contact interface problem with “high contact precision”. For the electrical contact conductance modelling, in this paper, we have extended the Pohrt and Popov model by including the effects of conductive gel. An experiment is developed and carried-out to validate the interfacial contact impedance model.

Important Links:

Go Back