TY - CONF A1 - Mieller, Björn A1 - Gemeinert, Marion A1 - Koppert, R. A1 - Bolte, J. A1 - Rabe, Torsten T1 - LTCC substrates for high performance strain gauges N2 - Recent advances in the development of high gauge factor thin-films for strain gauges prompt the research on advanced substrate materials. A glass ceramic composite has been developed in consideration of a high coefficient of thermal expansion and a low modulus of elasticity for the application as support material for thin-film sensors. Constantan foil strain gauges were fabricated from this material by tape casting, pressure-assisted sintering and subsequent lamination of the metal foil on the planar ceramic substrates. The sensors were mounted on a strain gauge beam arrangement and load curves and creep behavior were evaluated. The accuracy of the assembled load cells correspond to accuracy class C6. That qualifies the load cells for the use in automatic packaging units and confirms the applicability of the LTCC substrates for fabrication of accurate strain gauges. To facilitate the deposition of thin film sensor structures onto the LTCC substrates, the pressure-assisted sintering technology has been refined. By the use of smooth setters instead of release tapes substrates with minimal surface roughness were fabricated. Metallic thin films deposited on these substrates exhibit low surface resistances comparable to thin films on commercial alumina thin-film substrates. The presented advances in material design and manufacturing technology are important to promote the development of high performance thin-film strain gauges. T2 - CICMT 2012 - 8th International conference on ceramic interconnect & ceramic microsystems technologies CY - Erfurt, Germany DA - 16.04.2012 KW - LTCC KW - Thin-film substrate KW - Pressure-assisted sintering KW - Strain gauge PY - 2012 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. SP - 000175 EP - 000180 (Session TP 4 / TP 43) AN - OPUS4-27567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gemeinert, Marion A1 - Steinborn, Gabriele T1 - Stabilized dielectric barium titanate dispersions for sensor filling N2 - Resolution of special capacitive sensors can be improved enormously by replacement of the gaseous material between the capacitor plates by a ceramic dispersion with high permittivity. High dielectric liquid dispersions of ceramic submicron and nano barium titanate powders should be qualified as dielectric fluid with long-term shelf life for this use. Investigations for the production of stabilized barium titanate dispersions in aqueous and organic liquids by use of different dispersant aids were performed. Characterization of dispersed particles and agglomerates was done by use of zeta potential measurements for aqueous dispersions as well as particle sizing by laser diffraction, ultrasound spectroscopy and dynamic light scattering for aqueous and organic dispersions. Optimization of stability was evaluated by accelerated sedimentation measurements with an optical centrifuge. Best results were achieved for barium titanate dispersions in silicone oil. T2 - 91. Jahrestagung der deutschen keramischen Gesellschaft CY - Freiberg, Germany DA - 07.03.2016 KW - Stabilized dispersions KW - Barium titanate nanopowder KW - Particle size analysis PY - 2016 AN - OPUS4-35635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steinborn, Gabriele A1 - Gemeinert, Marion A1 - Schmidt, Wolfram T1 - Vergleich verschiedener Messverfahren zur Partikelgrößenanalyse am Beispiel von nanodispersem ZrO2-Pulver N2 - Fünf verschiedene Messverfahren wurden zur Partikelgrößenanalyse von nanodispersen ZrO₂-Pulver verglichen. Mit der Laserstreulichtanalyse, der dynamischen Lichtstreuung (heterodyne DLS und homodyne DLS-PCS), der Sedimentationsanalyse im Zentrifugalfeld und der Ultraschallspektrometrie wurden wässrige ZrO₂-Suspensionen mit verschiedenen Feststoffkonzentrationen hinsichtlich ihrer Partikelgrößenverteilung analysiert. Als Referenz diente die REM-Analyse zur Ermittlung der Primärpartikelgröße (ca. 40 nm). Mit den hier vorgestellten Messverfahren konnten in den entsprechenden Suspensionen nur Sekundärpartikel im Bereich von 105 nm bis 224 nm detektiert werden, die somit auf das Vorhandensein von Aggregaten bzw. harten Agglomeraten hinweisen. T2 - Tagung, Produktgestaltung in der Partikeltechnologie CY - Berlin, Germany DA - 23.04.2015 KW - Agglomeration KW - Nanopulver KW - Partikelgröße KW - Suspension PY - 2016 DO - https://doi.org/10.1002/cite.201500164 SN - 0009-286 X VL - 88 IS - 7 SP - 984 EP - 994 PB - WILEY-VCH CY - Weinheim AN - OPUS4-36960 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wohlleben, W. A1 - Mielke, Johannes A1 - Bianchin, A. A1 - Ghanem, A. A1 - Freiberger, H. A1 - Rauscher, H. A1 - Gemeinert, Marion A1 - Hodoroaba, Vasile-Dan T1 - Reliable nanomaterial classification of powders using the volume-specific surface area method N2 - The volume-specific surface area (VSSA) of a particulate material is one of two apparently very different metrics recommended by the European Commission for a definition of "nanomaterial" for regulatory purposes: specifically, the VSSA metric may classify nanomaterials and non-nanomaterials differently than the median size in number metrics, depending on the chemical composition, size, polydispersity, shape, porosity, and aggregation of the particles in the powder. Here we evaluate the extent of agreement between classification by electron microscopy (EM) and classification by VSSA on a large set of diverse particulate substances that represent all the anticipated challenges except mixtures of different substances. EM and VSSA are determined in multiple labs to assess also the level of reproducibility. Based on the results obtained on highly characterized benchmark materials from the NanoDefine EU FP7 project, we derive a tiered screening strategy for the purpose of implementing the definition of nanomaterials. We finally apply the Screening strategy to further industrial materials, which were classified correctly and left only borderline cases for EM. On platelet-shaped nanomaterials, VSSA is essential to prevent false-negative classification by EM. On porous materials, approaches involving extended Adsorption isotherms prevent false positive classification by VSSA. We find no false negatives by VSSA, neither in Tier 1 nor in Tier 2, despite real-world industrial polydispersity and diverse composition, shape, and coatings. The VSSA screening strategy is recommended for inclusion in a technical guidance for the implementation of the definition. KW - Nanomaterial KW - Nanomaterial classification KW - Regulation KW - VSSA KW - Size measurement KW - Particle size PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-391450 DO - https://doi.org/10.1007/s11051-017-3741-x SN - 1388-0764 SN - 1572-896X VL - 19 IS - 2 SP - Article 61, 1 EP - 16 PB - Springer Nature AN - OPUS4-39145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mieller, Björn A1 - Gemeinert, Marion A1 - Rabe, Torsten A1 - Bolte, J. T1 - Low-temperature co-fired ceramic substrates for high-performance strain gauges N2 - Recent advances in the development of high gauge factor thin films for strain gauges prompt the research on advanced substrate materials. A glass ceramic composite has been developed in consideration of a high coefficient of thermal expansion (9.4 ppm/K) and a low modulus of elasticity (82 GPa) for the application as support material for thin-film sensors. In the first part, constantan foil strain gauges were fabricated from this material by tape casting, pressure-assisted sintering, and subsequent lamination of the metal foil on the planar ceramic substrates. The accuracy of the assembled load cells corresponds to accuracy class C6. That qualifies the load cells for the use in automatic packaging units and confirms the applicability of the low-temperature co-fired ceramic (LTCC) substrates for fabrication of accurate strain gauges. In the second part, to facilitate the deposition of thin-film sensor structures to the LTCC substrates, pressure-assisted sintering step is modified using smooth setters instead of release tapes, which resulted in fabrication of substrates with low average surface roughness of 50 nm. Titanium thin films deposited on these substrates as test coatings exhibited low surface resistances of 850 Ω comparable to thin films on commercial alumina thin-film substrates with 920 Ω. The presented material design and advances in manufacturing technology are important to promote the development of high-performance thin-film strain gauges. KW - LTCC KW - Thin-film substrate KW - Strain gauge PY - 2013 DO - https://doi.org/10.1111/ijac.12052 SN - 1546-542X SN - 1744-7402 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. VL - 10 IS - 3 SP - 413 EP - 420 PB - American Ceramic Soc. CY - Westerville, Ohio AN - OPUS4-28301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuchenbecker, Petra A1 - Gemeinert, Marion A1 - Rabe, Torsten T1 - Inter-laboratory study of particle size distribution measurements by laser diffraction N2 - Presented are results of an inter-laboratory study (ILS) for measurements of the particle size distribution of fine powders in wet dispersion by laser diffraction. In this proficiency test 32 participants from four countries took part. They utilized 13 different devices from 7 manufacturers. Three commercial powders (glass spheres and two silicon carbide powders) showing a median diameter of about 30, 10 and 1 µm (volume distribution), respectively, were chosen for the procedure. A homogeneity study was carried out after the units had been separated and bottled. All participants received their test samples including a description of the standard operating procedures based on ISO 13320:2009 – to ensure that experiments were performed in a consistent manner. Results were calculated using the Mie Theory. The general means and the precision of the results were estimated in accordance with ISO 5725-2:2002. The evaluation showed excellent values of repeatability standard deviation. Values of 4 to 21?% of the reproducibility standard deviation of the results were found in the particle size range above 1 µm. Much larger deviation between the labs was detected in the case of smaller particles. Differences in the design of the analyzers were unambiguously identified as the main reason for the large deviations. KW - Accuracy experiment KW - Inter-laboratory study KW - Laser diffraction KW - Micron and submicron powder KW - Particle size distribution PY - 2012 DO - https://doi.org/10.1002/ppsc.201000026 SN - 0934-0866 SN - 1521-4117 VL - 29 IS - 4 SP - 304 EP - 310 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -