MESA+ University of Twente
The BIOS Lab-on-a-chip group

The comprehensive integration of microdialysis membranes with silicon sensors

( Ad Sprenkels, Dorota Pijanowska, Heiko van der Linden, Wouter Olthuis, Piet Bergveld )

This project is financially supported by the Dutch foundation for Fundamental Research on Matter (FOM).

Microdialysis is now a major standard sampling technique in clinical applications. In this technique a probe is indwelled in the relevant organ tissue. Extra cellular substances as for example glucose diffuse through the semi-permeable probe-tip into the perfusion liquid which is then pumped to appropriate sensors to measure its composition.

This project deals with the comprehensive integration of all parts of a microdialysis-based measurement system on one chip. Such chips are called "lab-on-a-chip" or micro Total Analysis Systems (µTAS).

The lay out of the complete µTAS is shown in Fig. 1. It comprises a dual electrochemically actuated pump for sensor calibration, an amperometric sensor (2) for e.g. glucose or lactate measurement, a potentiometric sensor (1) for e.g. Na+, K+ or Li+ measurements, a reference electrode (RE) and a needle shaped microdialysis probe. The complete system is realized in a stack of a glass part and a silicon part with total dimensions of about 2.7cm x 1.5cm x 0.1cm.

Fig. 1. Lay out of the complete µTAS chip, including a microdialysis probe, two sensors, a reference electrode and a dual electrochemically actuated dosing pump for sensor calibration.