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This paper presents the structure, operation principle, and fabrication process of a novel type of flow-velocity sensor. Like the well known classical Pitot (Prandtl) tube, it realizes flow velocity detection by measurement of the pressure difference between stagnant fluid pressure in front of the sensor and static pressure in the flow around the sensor. This difference results in a deflection of a diaphragm suspended boss, that serves as the counter electrode of an integrated capacitor which is directly exposed to the fluid to be measured. Experimental results in the wind tunnel and in the gasoline direct injection experimental set-up confirm the sensor's operation principle and show good time response.

Due to the present demand for further improved emissions and performance of diesel engines, there is a growing need to improve the control of fuel injection quantity and timing, as well as spray properties. We have developed a Micro Turbine Sensor that can measure transient injection rate and timing using micro machining technology. This sensor realizes volumetric flow measurement using a tangential turbine as the sensing element which has an outside diameter of 1mm, and which is located next to the inlet connector of the injection nozzle. The measured results are compared with a Bosch type injection rate meter. Since the tendency of measured injection rate shows fair agreement with results of the reference system, this sensor has potential as a fuel flow meter which is able to measure the injection rate and timing directly and continuously during engine operation.

Monitoring motion parameters are increasingly important in automotive and robotics applications, where cheap sensors are highly desirable. A silicon micromachined structure 0.5X2cm in size was designed and fabricated, which can detect not only translational acceleration, but angular acceleration or rate simultaneously and independently, which has a particular merit since it theoretically allows single point detection of all 6 axis of freedom using only three sensors. This is accomplished by capacitive detection of the displacement and the tilt of the seismic mass, symmetrically suspended by two torsion bars. The expected linear dependencies of the output signal on translational and angular accelerations, as well as quadratic dependency on angular rate could be verified. It is shown, that the dynamic response is improved by vacuum packaging.