Electrochemical behaviour of nanocomposite Ag-x:TiN thin films for dry biopotential electrodes

• Type: Article in International Scientific Journal
• Date: 2014

Authors

P. Pedrosa (Author) FEUP; E. Alves (Author) Other; N.P.. Barradas (Author) Other; N. Martin (Author) Other; P. Fiedler (Author) Other; J. Haueisen (Author) Other; F. Vaz (Author) Other; José Carlos Fonseca (Author) FEUP

Journal

Title: Electrochimica Acta

Vol. 125

Pages: 48-57

ISSN: 0013-4686

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 20 Citations

ISI Web of Science

Scopus - 21 Citations

Scientific classification

FOS: Engineering and technology

CORDIS: Health sciences ; Technological sciences

Associated Projects

WICKEEG - Um novo eletrodo para EEG baseado num polímero poroso para registo de EEG: do desenvolvimento dos materiais até aos testes in-vivo

Other information

Authenticus ID: P-009-5E1

DOI: 10.1016/j.electacta.2014.01.082

Abstract (EN): Ag-x:TiN nanocomposite thin films with Ag contents ranging from similar to 0.1 up to similar to 47.5 at% obtained by DC reactive sputtering on glass substrates were characterized regarding their electrochemical performance in a synthetic sweat solution, aiming at studying their potential application as bioelectrodes. Correlations between the electrochemical behaviour and their exhibited morphology (porosity) and structure (grain size) were established and discussed in detail. The coatings' open circuit potential (OCP) is ruled by the Ag/TiN galvanic coupling and it decreased with the increase of the Ag content. For Ag contents up to 12.1 at% the OCP was found to be close to that of bulk Ag, but for higher Ag contents the OCP of the Ag-x:TiN samples displayed a steep drop, which was ascribed to the effect of Ag grain size reduction (from similar to 28 to similar to 10 nm). Both SEM and voltammetric experiments confirmed a gradual porosity decrease (densification) of the coatings with increasing Ag content, leading to a reduction of the electroactive area. All samples, besides displaying good chemical stability in chloride media, exhibited low impedance moduli and electrochemical noise similar to that of commercial Ag/AgCl electrodes, thus making them suitable to be used as bioelectrodes, from the electrochemical point of view.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10