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![](/en/departments/electronics_microsystems_biomedicine/hybrid_micro_systems/Microsystems_LTCCHTCC/Application_Sensors/thermocouples/jcr:content/contentPar/sectioncomponent/sectionParsys/textwithinlinedimage/imageComponent2/image.img.jpg/1565602275375/printed-thermocouple-2.jpg)
![](/en/departments/electronics_microsystems_biomedicine/hybrid_micro_systems/Microsystems_LTCCHTCC/Application_Sensors/thermocouples/jcr:content/contentPar/sectioncomponent/sectionParsys/textwithinlinedimage/imageComponent3/image.img.jpg/1565602275375/printed-thermocouple.jpg)
Thermocouples measure in a wide temperature range. They have a high linearity of the measurement signal and a high robustness. In the point of connection between two conductors, containing metals or alloys, is a thermoelectric voltage generated which is the measuring signal for temperature. Conductors in commercial thermocouples are normally cables, connected at the measurement point, which are non-elastic and hard to miniaturize.
Using the Aerosol-Jet printing technology, thermocouples can be applied directly on the surface or components to be measured. The Fraunhofer IKTS developed printable inks (Ag, Ni, CuNi), which are activated below 300 °C. The direct-printing method applies structures contactless and miniaturized on planar or 3D-objects. Multiple wired printed thermocouples realize high thermoelectric voltages above 35 µV/K close to the standardized thermocouples. The embedding of the thermocouples in polyimide shields against environmental influence. A longtime temperature treatment of 1000 h at 150 °C showed a slightly drift of the thermoelectric voltage under 5 %. This will be a future point of investigation.