Electrical properties of ultrathin films on sensors for an electronic tongue

• Grant number: 05/01578-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2005
• Effective date (End): April 30, 2006
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: José Alberto Giacometti
• Grantee: Marcelo Vitor de Oliveira Forin
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The project aims to improve the knowledge on the transduction mechanism involved in an “electronic tongue” based on nanostructured materials. Polypyrrole Langmuir-Blodgett (LB) and chitosan self-assembled ultra thin films will be deposited on the top of gold interdigitated electrodes to be employed as individual sensing units for the device. The materials choice is interesting due to their different chemical structures and distinct electric characteristics, as observed by our research group in this sort of application. The sensing units will be immersed in several liquids and their electrical response will be investigated by impedance spectroscopy technique. The measuring frequency will be analysed using equivalent electric circuits and the Havrialiak-Negami (HN) phenomenological equation. The HN parameters and the equivalent circuits for several liquids will be determined envisaging their dependence with the physical-chemical characteristics of the liquids investigated.