Winfried Kupke

Silicon angular rate sensor for automotive applications with piezoelectric drive and piezoresistive read-out

In this work a silicon angular rate sensor for automotive applications with a new architecture is presented. It is based on the vibrating tuning fork principle with excitation direction of the tines perpendicular to the wafer surface. This arrangement allows the design of tines with significant inertial masses which lead to substantial signal. The oscillation of the tines is excited by a piezoelectric drive using an AlN thin film layer. The angular rate to be measured causes a torsional oscillation of the stem. The torsional amplitude is proportional to the angular rate and is measured by a piezoresistive read-out structure. We use silicon bulk micromachining based on a new twofold SOI-technique.

Simulation and Experimental Results of a Hot-Film Anemometer Array on a Flexible Substrate

Micro-Electro-Mechanical Systems (MEMS) play an important role for studying gaseous or liquid fluid flows experimentally due to device dimensions on the µm-scale. For aerodynamic applications the realization of sensor-actuator networks on airfoils is a challenging task to improve the lift properties of aircrafts by the precise detection and the systematic manipulation of the transition point from laminar to turbulent airflow conditions. Based on the well-established principle of thermal anemometry, an array of hot-film anemometers on a flexible polyimide substrate was developed. In a first step, FEM (Finite Element Method) simulations were performed to estimate the corresponding temperature distribution within the air flow and the organic substrate at different flow conditions. In wind tunnel experiments, the sensor array on a wooden test wing proved its principal mode of operation.