Articles | Volume 13, issue 1
https://doi.org/10.5194/jsss-13-9-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/jsss-13-9-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Laboratory robustness validation of a humidity sensor system for the condition monitoring of grease-lubricated components for railway applications
AC2T research GmbH, 2700 Wiener Neustadt, Austria
Institute of Sensor and Actuator Systems, TU Wien, 1040 Vienna, Austria
Christoph Schneidhofer
AC2T research GmbH, 2700 Wiener Neustadt, Austria
Nicole Dörr
AC2T research GmbH, 2700 Wiener Neustadt, Austria
Ulrich Schmid
Institute of Sensor and Actuator Systems, TU Wien, 1040 Vienna, Austria
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Scanning electron microscopy (SEM) and atomic force microscopy (AFM) enable sub-nanometer surface imaging and complement each other's limitations. Integrating AFM into a SEM vacuum chamber combines their strengths. However, vacuum increases the cantilever's Q factor and reduces scan speed. We develop a feedback circuit and a piezoelectric MEMS cantilever to tune the Q factor, enabling vacuum AFM at air-like speeds.
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We present an automated, contactless method to map thin film thickness and stress across microelectromechanical systems (MEMS) wafers. Using white light interferometry on cantilevers and step profiles, we extract both mean and gradient stress with orientation sensitivity. Applied to six thin films, the approach reveals process-dependent variations, offering a reliable tool for evaluating and comparing MEMS materials and fabrication methods.
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Dominik Huber, Michael Schneider, Paul Fulmek, Georg Pfusterschmied, and Ulrich Schmid
J. Sens. Sens. Syst., 14, 89–98, https://doi.org/10.5194/jsss-14-89-2025, https://doi.org/10.5194/jsss-14-89-2025, 2025
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Photo-thermal actuation and laser Doppler vibrometry enable fast, contactless characterization of MEMS (microelectromechanical system) resonators already before electrical connections are made. This paper details a tailored setup combining a precision stage, vacuum chamber, laser diode, and vibrometer to analyze silicon MEMS devices on a wafer level. Tests reveal how silicon device layer thickness affects resonance frequency and identify dominant loss mechanisms in different vibrational modes.
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Short summary
A new method for water detection in lubricated rail components is presented. It is based on a robust humidity sensor combined with robust data evaluation to determine the water content of greases. Based on a laboratory evaluation in the relevant environment, the presented approach offers an online monitoring tool to predict the water content of grease-lubricated rail parts, thereby enhancing the reliability and safety while reducing the maintenance costs and downtime of railway wagons.
A new method for water detection in lubricated rail components is presented. It is based on a...
Special issue