Fraunhofer Institute for Physical Measurement Techniques IPMColorimetric gas sensors for fuel cell filter monitoring
Printed, color-change-based gas sensors for monitoring filter breakthroughs in fuel cells
In the DRUIDE project, Fraunhofer IPM, together with industrial partners, worked on developing a printed gas sensor system for condition monitoring of gas-absorbing filters in fuel cells. The focus was on sensors that respond selectively to the target gas, can be manufactured cost-effectively, and operate with low power consumption.
The objective was to develop innovative sensors based on colorimetric detection methods that use specially tailored color-change materials. The dyes respond selectively to a specific target gas. As a result of a chemical reaction, a color change occurs that correlates directly with the concentration of the target gas. As part of the project, selective dyes for the target gases carbon monoxide (CO), nitrogen oxides (NOx), ammonia (NH3), and hydrogen sulfide (H2S) were synthesized and tested.
The sensor systems were manufactured using an inkjet printing process. This method enables the fabrication of complete sensor arrays based on different gas‑sensitive layers and substrates. As a result, an optical sensor for detecting filter breakthroughs can be produced cost‑effectively in the future with minimal material usage.
In the project, Fraunhofer IPM was in charge of synthesizing and characterizing the gas-sensitive dyes. These were subsequently converted into printable inks together with DataPhysics Instruments GmbH, and on this basis a robust inkjet printing process was developed. In parallel with the materials development, smartGAS Mikrosensorik GmbH designed and developed a multichannel demonstrator, which was thoroughly characterized in the laboratory. The insights gained were continuously fed back into further material and process optimization.