TY - GEN A1 - Jongmanns, Marcel T1 - Implementation of a hand gesture recognition using ultrasound measurements on a NVIDIA Jetson platform with AI-based evaluation Y1 - 2023 SN - 978-3-8007-6204-0 SN - 978-3-8007-6203-3 N1 - Poster, Tagungsband MikroSystemTechnik Kongress 2023, Dresden, 23. - 25. Oktober 2023 PB - Berlin CY - VDE Verlag ER - TY - GEN A1 - Suawa Fogou, Priscile A1 - Halbinger, Anja A1 - Jongmanns, Marcel A1 - Reichenbach, Marc T1 - Noise-Robust Machine Learning Models for Predictive Maintenance Applications T2 - IEEE Sensors Journal N2 - Predictive maintenance of equipment requires a set of data collected through sensors, from which models will learn behaviors that will allow the automatic detection or prediction of these behaviors. The objective is to anticipate unexpected situations such as sudden equipment stoppages. Industries are noisy environments due to production lines that involve a series of components. As a result, the data will always be obstructed by noise. Noise-robust predictive maintenance models, which include ensemble and deep learning models with and without data fusion, are proposed to enhance the monitoring of industrial equipment. The work reported in this article is based on two components, a milling tool, and a motor, with sound, vibration, and ultrasound data collected in real experiments. Four main tasks were performed, namely the construction of the datasets, the training of the monitoring models without adding artificial noise to the data, the evaluation of the robustness of the previously trained models by injecting several levels of noise into the test data, and the optimization of the models by a proposed noisy training approach. The results show that the models maintain their performances at over 95% accuracy despite adding noise in the test phase. These performances decrease by only 2% at a considerable noise level of 15-dB signal-to-noise ratio (SNR). The noisy training method proved to be an optimal solution for improving the noise robustness and accuracy of convolutional deep learning models, whose performance regression of 2% went from a noise level of 28 to 15 dB like the other models. KW - Accelerometer Y1 - 2023 UR - https://ieeexplore.ieee.org/document/10122864 U6 - https://doi.org/10.1109/JSEN.2023.3273458 SN - 1558-1748 SN - 1530-437X VL - 23 IS - 13 SP - 15081 EP - 15092 ER - TY - GEN A1 - Assafo, Maryam A1 - Lautsch, Martin A1 - Suawa, Priscile Fogou A1 - Jongmanns, Marcel A1 - Hübner, Michael A1 - Reichenbach, Marc A1 - Brockmann, Carsten A1 - Reinhardt, Denis A1 - Langendörfer, Peter T1 - The ForTune Toolbox: Building Solutions for Condition-Based and Predictive Maintenance Focusing on Retrofitting Y1 - 2023 SN - 978-3-8007-6204-0 SN - 978-3-8007-6203-3 N1 - Poster, Tagungsband MikroSystemTechnik Kongress 2023, Dresden, 23. - 25. Oktober 2023 SP - S. 541 PB - VDE Verlag CY - Berlin ER - TY - GEN A1 - Ruffert, Christine A1 - Jongmanns, Marcel A1 - Kaiser, Bert A1 - Langa, Sergiu T1 - Design and characterization of a silicon MEMS microvalve for proportional flow control based on electrostatic bending actuators T2 - Microsystem Technologies N2 - We designed a MEMS microvalve based on the nanoscopic electrostatic drive (NED) technology (Nat Commun 6:10078, 2015). NED actuators, electrostatically controlled bending beams, are implemented in a clamped-clamped configuration. A normally open plunger valve was designed and characterized. The device is manufactured from silicon. Gas flow rates of up to 37 SCCM can be proportionally controlled between 10% and 100%. A 10% leakage is always present at low backpressures (< 10 kPa) and increases to roughly 20% at 75 kPa backpressure. The structure has been tested up to backpressures of 300 kPa without damage to the structures, but the leakage increases to over 95%. Our unprecedented microvalve concept shows that it is possible to manufacture all-silicon MEMS microvalves with proportional control of the flow rate. The presented work is a proof of concept to test the capabilities of the NED technology for the use in microvalves. There are plans to decrease the leakage in future designs by introducing an additional sealing layer as well as manufacturing a shutter instead of a plunger design. Y1 - 2024 U6 - https://doi.org/10.1007/s00542-024-05684-1 SN - 1432-1858 SN - 0946-7076 VL - 2024 ER - TY - GEN A1 - Ruffert, Christine A1 - Monsalve Guaracao, Jorge Mario A1 - Völz, Uwe A1 - Jongmanns, Marcel A1 - Betz, Björn A1 - Langa, Sergiu A1 - Amelung, Jörg A1 - Wiersig, Marcus T1 - Rapid characterisation of mixtures of hydrogen and natural gas by means of ultrasonic time-delay estimation T2 - Journal of Sensors and Sensor Systems N2 - The implementation of the “power-to-gas” concept, where hydrogen and natural gas are blended and transported in the existing network, requires a quick, on-site method to monitor the content of hydrogen in the mixture. We evaluate a rapid characterisation of this mixture based on the measurement of the speed of sound, using micromachined ultrasonic transducers (MUTs). Two MUT-based prototypes were implemented to analyse a mixture of natural gas and hydrogen under controlled conditions. Changes in the hydrogen content below 2 mol % (in a mixture that was adjusted between 6 mol % and 16 mol %) were discriminated by both devices, including the uncertainty due to the temperature compensation and the time-delay estimation. The obtained values of the speed of sound were consistent with those calculated from independent, non-acoustic measurements performed with a gas chromatograph and a density sensor. An MUT-based flow meter is thus capable of reporting both gas intake and the molar fraction of hydrogen, provided that the source of natural gas is kept constant. Y1 - 2024 U6 - https://doi.org/10.5194/jsss-13-179-2024 SN - 2194-878X VL - 13 IS - 2 SP - 185 ER - TY - GEN A1 - Uhlig, Sebastian A1 - Gaudet, Matthieu A1 - Langa, Sergiu A1 - Ruffert, Christine A1 - Jongmanns, Marcel A1 - Schenk, Harald T1 - Highly integrable silicon micropumps using lateral electrostatic bending actuators T2 - Microsystem Technologies N2 - We present the design, fabrication, and characterization of an innovative silicon-based micropump with high potential for portable lab-on-chip (LoC) as well as point-of-care (PoC) applications. The actuators of the pump are electrostatic driven in-plane bending devices, which were presented earlier (Borcia et al. in Phys Rev Fluids 3(8): 084202, 2018. 10.1103/PhysRevFluids.3.084202; Uhlig et al. in Micromachines, 9(4), 2018. 10.3390/mi9040190). This paper presents the characterization results achieved with the micropump. The dielectric non-polar liquid Novec7100™ was used as a test liquid due to its adequate physical properties. When applying a periodic voltage of 130 V, a flow rate of up to 80 µL/min was detected. The counter pressure amounts up to 30 kPa and the correspondent fluidic power (volumetric flow rate times the counter pressure) was calculated to 10 µW. The pump contains passive flap valves at the inlet and outlet, which are based on a bending cantilever design. Depending on the application requirements, the micropump can be designed modularly to adjust the specific parameters by an adequate arrangement of pump base units. In this paper, the proof of principle is shown using a single base unit with different number of stacked NED-actuator beams, as well as the serial arrangement of base units. Both modular concepts target the increase of backpressure of the NED-micropump in an inherently different way compared to conventional membrane micropumps. Y1 - 2024 U6 - https://doi.org/10.1007/s00542-024-05635-w SN - 0946-7076 VL - 30 IS - 8 SP - 949 EP - 960 PB - Springer Science and Business Media LLC ER - TY - GEN A1 - Monsalve, Jorge M. A1 - Jongmanns, Marcel A1 - Koch, Sandro G. A1 - Schenk, Harald T1 - Flow measurement by means of wideband acoustic signals in single-mode waveguides T2 - Journal of sensors and sensor systems N2 - A novel concept of an acoustic flowmeter, based on single-mode waveguides, is proposed, implemented, and analysed in this work. Instead of transmitting a pulse diagonally across the duct's cross-section, this device operates with two ducts that operate simultaneously as pipes and as waveguides. Below the frequency threshold for single-mode propagation, acoustic waves are forced to traverse the waveguides with a plane front, precluding the possibility of beam drifting, inner reflections, and spreading losses. This enables the designer to flexibly increase the sound path and perform a highly sensitive measurement of the flow velocity and speed of sound, even if the excitation frequency is required to be kept below a relatively low value. A device based on this principle was constructed and tested for flow measurements in air. It consists of two waveguides of a circular cross-section (5 mmdiameter) coupled to electroacoustic transducers for the transmission of a wideband chirp (9.8–18.2 kHz). Usage of a wideband signal was possible due to the combined frequency response of a special kind of micromachined ultrasound transducer (MUT) and a commercial micro-electromechanical system (MEMS) microphone. The constructed flowmeter was capable of measuring flow velocities up until the transition to turbulent flow at 16 Lmin-1with a resolution of 0.3 Lmin-1, and it also detected changes of less than 0.2 ms-1in the speed of sound. This topology for flow measurement could prove advantageous for applications where gases of variable composition are conducted in ducts of diameters in the millimetre range. Y1 - 2025 U6 - https://doi.org/10.5194/jsss-14-275-2025 SN - 2194-878X VL - 14 IS - 2 SP - 275 EP - 284 PB - Copernicus Publications CY - Göttingen, Germany ER -