PhD Student, Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands

Polymer-based Capacitive Sensor Array

The progress in development of electronic noses and electronic tongues makes it promising to utilize the technique of chemically diverse multi-array sensors combined with multi-component analysis tools and pattern recognition techniques for a wider range of medical and environmental applications. The Ph.D. project on polymer-based multi-array sensors aims to develop such a sensor for the detection of organic compounds in the aqueous phase. The sensor platform is formed by metallic interdigitated electrodes (IDEs), also known as finger electrodes, deposited onto an inert substrate such as glass via standard IC technologies. A polymer coating of controlled thickness serves as a partially selective sensing layer. Interaction of the sensing layer and the target compound is achieved via adsorption, absorption and consequent swelling of the polymeric layer. This interaction influences the electric field established between the finger electrodes and leads to a change of the capacitive response of the sensor that can be measured (Figure 1).

Figure 1. Schematic representation of a polymer-based IDE sensor.
 

The choice of chemical sensing layers must satisfy the requirements for fast diffusion processes, reversibility and sufficient chemical diversity. Chemical diversity within a sensor array can be achieved by using chemically diverse polymer layers on the different sensor elements. An electronic sensing interface connects the individual sensors to an electronic response array. As the partial selectivity and hence cross-sensitivity among the different sensor elements leads to a multi-variant response, a sophisticated algorithm is required that interprets this response in functions of pollutant presence and concentration.

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About the speaker:

Judith Staginus finished a 3-year apprenticeship as a car electrician at Daimler Sprinter Werk, Düsseldorf, Germany in 2001. She received the academic degree of Master in Industrial Chemical Engineering at the Group T Engineering College in Leuven, Belgium in 2007 and the Master in Environmental Science and Technology at the Catholic University of Leuven, Belgium in 2008. She is currently pursuing her Ph.D. in the field of environmental sensors. Her Ph.D. project is on polymer-based chemical capacitive sensors for the detection of organic water pollutants. To her research activities belong the development of the sensor platform and fluidic system, the synthesis of polymeric sensing layers and the sensor surface modification with functional monolayers. She is also involved in several teaching activities. Her research interests are sustainable engineering solutions.