Articles | Volume 4, issue 1
J. Sens. Sens. Syst., 4, 133–136, 2015
https://doi.org/10.5194/jsss-4-133-2015

Special issue: 17th ITG/GMA-Conference on Sensors and Measurement Systems...

J. Sens. Sens. Syst., 4, 133–136, 2015
https://doi.org/10.5194/jsss-4-133-2015

Regular research article 31 Mar 2015

Regular research article | 31 Mar 2015

High-temperature piezoresistive C / SiOC sensors

F. Roth1, C. Schmerbauch2, E. Ionescu1, N. Nicoloso1, O. Guillon2, and R. Riedel1 F. Roth et al.
  • 1Technical University Darmstadt, Institute of Material Science, Jovanka-Bontschits-Strasse 2, 64287 Darmstadt, Germany
  • 2Forschungszentrum Jülich, Institute of Energy and Climate Research, Wilhelm-Johnen-Strasse, 52425 Jülich, Germany

Abstract. Here we report on the high-temperature piezoresistivity of carbon-containing silicon oxycarbide nanocomposites (C / SiOC). Samples containing 13.5 vol% segregated carbon have been prepared from a polysilsesquioxane 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 dispersed nanocrystalline graphite with a lateral size ≤ 2 nm and non-crystalline carbon domains, as revealed by Raman spectroscopy. In comparison to highly ordered carbon (graphene, HOPG), C / SiOC exhibits strongly enhanced k factor values, even upon operation at temperatures beyond 1000 °C. The measured k values of about 80 ± 20 at the highest temperature reading (T = 1200 °C) reveal that C / SiOC is a primary candidate for high-temperature piezoresistive sensors with high sensitivity.

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We report on the high-temperature piezoresistivity of carbon-containing silicon oxycarbide nanocomposites (C/SiOC). The piezoresistive behavior of the C/SiOC nanocomposites relies on the presence of dispersed nanocrystalline graphite and non-crystalline carbon domains. In comparison to highly ordered carbon, C/SiOC exhibits strongly enhanced sensitivities, even at high temperatures. Thus, k values of ca. 80 at the highest temperature reading, 1200°C, reveal that C/SiOC is a primary candidate.