Electronic noses, a different approach to the sensitivity and selectivity issues

• Autor(a) principal: Faia, P. M.
• Data de Publicação: 1999
• Outros Autores: Pereira, M. A., Nunes, A. M., Furtado, C. S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/4088; https://doi.org/10.1016/s0955-2219(98)00337-9
• topic: porosity; electrical conductivity; sensors

Many approaches have been made during the past years to the gas sensing task. It may be addressed using one sensor or a set of arranged sensors. Solid state chemical sensing has been systematically used for the development of gas sensor devices, based on semi conducting metal oxides. There are three major issues related to chemical sensing: sensitivity, selectivity and stability. Selectivity may be improved by the use of sensor arrays (also referred as electronic noses), while the use of additives may improve sensitivity (pure doped materials or porosity control). In this paper we describe our current work about the sensitivity and selectivity issues. A tentative explanation of the observed resistance and impedance changes by porosity control is given.