title: Electrode contact impedance sensitivity to variations in geometry.
abstract: Electrode contact impedance is a crucial factor in physiological measurements and can be an accuracy-limiting factor when performing electroencephalography and electrical impedance tomography. In this work, standard flat electrodes and micromachined multipoint spiked electrodes are characterized with a finite-element method electromagnetic solver and the dependence of the contact impedance on geometrical factors is explored. It is found that flat electrodes are sensitive to changes in the outer skin layer properties related to hydration and thickness, while spike electrodes are not. The impedance as a function of the effective contact area, number of spikes and penetration depth has also been studied and characterized.
authors.affiliation: ARCES, University of Bologna, Italy. rcardu@arces.unibo.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Cardu
authors.forename: Philip H W
authors.initials: PH
authors.lastname: Leong
authors.forename: Craig T
authors.initials: CT
authors.lastname: Jin
authors.forename: Alistair
authors.initials: A
authors.lastname: McEwan
mesh_terms: D017097:Electric Impedance; D004566:Electrodes; D055590:Electromagnetic Phenomena; D020342:Finite Element Analysis