Papers by Keyword: Multilayer Ceramic

Abstract: In order to prepare lead free multi-layer ceramic (MLC) actuators with Ni inner electrodes, inkjet ink containing NiO was prepared and its rheological properties were examined. The viscosity of the ink followed the Andrade's equation. By using this ink, Ba(Ti,Zr)O3 based MLCs were prepared. The printed NiO layers were reduced to metal Ni and they functioned as the inner electrodes. The remanent polarization of the MLCs increased with the grain growth caused by the increase of firing temperature. The remanent polarization Pr and coercive field Ec of the MLCs fired at 1400°C were 6.4 μC/cm2 and 3.5 kV/cm, respectively. The displacement of the MLCs with 7 active layers was approximately 320nm at 30 kV/cm. The effective d33 shows approximately 160 pm/V when the electric field was 10 kV/cm.

Abstract: A thick film anemometer for in situ control of the flow rate in fluidic systems was designed, manufactured and characterized. The sensor is integrated in a retention modulus consisting of Low Temperature Cofired Ceramics (LTCC). These materials allow the cost-effective realisation of fluidic microsystems with integrated electronics. The challenge of the work is to design an anemometer under the exclusive use of thick film technologies. The necessity to trim resistors causes the external use of relevant pastes. Therefore, the use inside of a closed fluidic system requires the leak of process gases and, at the same time, a maximal heat-insulating of the sensor element from the substrate. Free-standing elements necessitate the control of stress due to shrinking mismatch, TCE mismatch, density gradients and deformation during the lamination. In the presented solution, embossed flue channels prevent blow forming on a free-standing bridge. The anemometer has a linear sensor characteristic for flow rates up to 0.1 ml/min. The layout guarantees that the fluid gets only in contact with the basic ceramic material, which is compatible with a wide range of biological substances. Therefore the sensor is applicable in contact with cell fluids or PCRreagents.