INION II: Totally integrated microengineered ion sensors for large-scale applications

• Research unit: EU RFP
• Project number: 97.0638-1

Key words (English)

microsystems; water monitoring

Alternative project number (English)

EU project number: 31958

Research programs (English)

EU-programme: 4. Frame Research Programme - 1.3 Telematic systems

Short description (English)

See abstract

Partners and International Organizations (English)

ICB, University of Münster (D); BNFL (UK); Farside (UK); RIZA (NL); IFREMER (F); Fluka (CH)

Abstract (English)

The overall objective of the INION project was to develop a novel family of autonomous analytical instruments to be used for in-situ water monitoring. The measurement of ammonia/ammonium content has been chosen as a practically important task with a wide potential market. The project has resulted in a prototype of a new instrument consisting of two sub-systems : 1) the ANIMAL which is an exchangeable analytical cartridge containing a sensor layer (the sensors are Ion-Selective Conductimetric Microsensors -ISCOM-) and fluidic processing layers 2) the AUTENT which is an autonomous unit containing additional fluidic components, the control electronics and embedded software needed to process raw data coming from the ANIMAL.
IMT part of the project (Work package 4) concerned the development of the Sensor-Layer which is the basic element of the ANIMAL. It consists of three main parts: the transducer chip, ion-selective membrane and the flow manifold.
Summary of major achievements:
Optimisation of the fabrication process for the ISCOMs: deposition and patterning of Pt-interdigitated electrodes on pyrex substrates, deposition of the PECVD Si3N4 passivation layer and patterning by plasma
Deposition and patterning of pools (SU-8) for the subsequent deposition of the sensitive membranes
Integration in a miniaturised flow-through cell formed either by SU-8 deposition and patterning or by lamination. Due to the cost reasons, the lamination has been finally chosen. .
The optimised design contains 16 ISCOMs for the detection of ammonium, arranged in four flow-through measurement cells. Although the sensor-layer elements have a limited operational lifetime (ISCOM about one week), through the implementation of redundancy at different levels the requirements of the end users of one month operational lifetime could be achieved.
The field tests have been performed at several test sites - in fresh river water, seawater, industrial effluents and sewage plant. The AUTENT embedded software allows different measurement sequences (calibration, measurement, flushing) and timings to be defined by the end user.
The project has been focused on an ammonia sensor, however the technology is of a generic nature and can be therefore adapted to the monitoring of other analytes.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 97.0638-1