Piezoresistive Ceramics for High-Temperature Force and Pressure Sensing

Konferenz: Sensoren und Messsysteme 2014 - Beiträge der 17. ITG/GMA-Fachtagung
03.06.2014 - 04.06.2014 in Nürnberg, Deutschland

Tagungsband: ITG-Fb. 250: Sensoren und Messsysteme 2014

Seiten: 4Sprache: EnglischTyp: PDF

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Roth, F.; Ionescu, E.; Nicoloso, N.; Riedel, R. (TU Darmstadt, Institut für Materialwissenschaft, Jovanka-Bontschits-Str. 2, 64287 Darmstadt, Germany)
Guillon, O.; Schmerbauch, C. (Friedrich-Schiller-Universitaet Jena, Chemie und Geowissenschaften, Fuerstengraben 1, 07743 Jena, Germany)

Here we report on the high-temperature piezoresistivity of carbon-containing silicon oxycarbide nanocomposites. Sam-ples with contents of segregated carbon of 13.5 vol% were prepared from a polysilsesqioxane via thermal cross-linking, pyrolysis and subsequent hot-pressing. Their electrical resistance was assessed as a function of the mechanical load (1 -10 MPa) and temperature (1000 – 1200 °C). The piezoresistive behavior of the C/SiOC nanocomposites relies on the presence of a disordered sp2 - sp3 carbon network, as revealed by Raman spectroscopy. C/SiOC exhibits enhanced k fac-tor values as compared to highly-ordered graphite (HOPG) or graphene, though lower than those reported for similar C/SiOCN nanocomposites. In view of the measured k values of about 40 at the highest temperature reading (T = 1200 °C), C/SiOC is a primary candidate for high-temperature piezoresistive force and pressure sensors.