Advanced electronic tongue concept

This effort, directed at developing a sensor for evaluating water quality, is based on electrochemical techniques that detect and identify ions in solution. This paper discusses the use of Cyclic Voltammetry (CV), corrosion measurements, and Anodic Stripping Voltammetry (ASV) to measure three marker ions Cu, Fe, and Zn using the electronic tongue concept. The use of genetic algorithms is suggested as an approach to facilitate the search for optimum measurement conditions. In addition, the possibility of changing the physical conditions of the sample chamber is discussed as a way of increasing the sensor's apparent sensitivity of and confidence in the measurements.

1. Introduction

This paper extends the work reported at last year's IEEE Aerospace conference where the design principles for the fabrication of Etng1 (Electronic Tongue No. 1) [Buehler, 2001] were discussed. In this effort the capabilities of Etng1 are explored using three sets of electrochemical measurements including Cyclic Voltammetry (CV) [Kissinger, 1996], corrosion measurements [Stansbury, 2000], and Anodic Stripping Voltammetry (ASV) [Wang, 2000]. This effort is an outgrowth of the 25-cm³ electrochemical cell developed for the MECA (Mars Environmental Compatibility Assessment) project [West, 1999] which included 20 prefabricated Ion Selective Electrodes, a conductivity sensor, a temperature sensor and an oxidation reduction potential sensor. Traditional electrochemical sensors are fabricated at the end of a pencil-like cylindrical tube. Such sensors cannot be configured easily in a multi-sensor array nor can they be miniaturized.