The Materials Solutions for Chemical Sensing program line develops active materials systems for use in chemical sensors. Such systems can measure the presence of chemical species within gases or liquids. These innovative materials follow the demand for better requirements in fields such as health monitoring (both for structural and occupational hazard) and also application areas like deep well exploration, erosion detection and tracking (natural) gas composition in distribution grids.
Want to know more, interested in using new sensing systems within your application or perhaps willing to explore how your application can integrate and make use of sensing? Get in touch with Arjen Boersma.
Chemical sensors are devices that can measure the presence of chemical species in gases or liquids. The ideal chemical sensor is a low-cost, wearable, easy-to-use device that instantaneously responds with perfect selectivity to the target chemical substance (analyte) that is present at any concentration in a gas or liquid medium and results in a measurable and indisputable signal output. Unfortunately, such ideal chemical sensors are far from reality although enormous technical advances have been made over the past decades. Real-life chemical sensors are complex electronic or optical devices, generally optimized for a particular application, and showing cross-sensitivity for many interfering chemicals. The variety of chemical sensors available on the market is large: ranging from small, low cost sensors that are sensitive to many chemicals, to large wearable devices that have a high sensitivity and selectivity, but also high costs.
In this wide field of technologies, TNO works actively on two approaches, both based on the interactions of the chemicals to be measured with a responsive material applied to the sensor:
1. Low cost miniaturized multi-parameter sensors, that can detect multiple chemical species in a gas or liquid.
2. Remote fiber-optic sensors that are able to detect the presence of chemical species at remote locations and/or at extreme conditions
TNO has identified and developed various technologies to solve the challenges for the two application areas that are mentioned above:
The application areas and markets for which the chemical sensor developments are pursued are very diverse, but have in common their need for small and low cost or remote sensing:
The facilities of TNO include equipment for the manufacturing of chemical sensors as well as custom made setups to characterization, testing and calibration.
Most sensors developed by TNO use responsive coating technologies. Therefore we count with the ability to synthesize the required chemicals in our laboratories. Applying such coatings is important. For that we use inkjet printing, spray coating, drop casting and other methods. Functionalization of fiber sensors can be done using plasma workstation for cleaning and fiber recoaters to apply thin functional layers on the fibers. In addition growing of ceramic coatings on various substrate is among the present capabilities.
Several exposure systems are available. In particular our Gas Exposure System (GES) is a gas mixture station that can apply mixtures of up to 8 gases simultaneously to the sensor, which is inserted in a high pressure vessel. This vessel can be heated up to 50 °C and is suitable for pressures up to 8 bar.
Analysis and testing of newly developed systems is a must. Accordingly sensors can be interrogated in multiple ways such as with the Frequency Response Analyser (FRA) for capacitance monitoring and both optical interrogators and FTIR analysers in the case of fibers.