A 2D scanning micromirror with piezoelectric thin film aluminum nitride (AlN), separately used as actuator and sensor material, is presented. For endoscopic applications, such as fluorescence microscopy, the devices have a mirror plate diameter of 0.7 mm with a 4 mm² chip footprint. After an initial design optimization procedure, two micromirror designs were realized. Different spring parameters for x- and y-tilt were chosen to generate spiral (Design 1) or Lissajous (Design 2) scan patterns. An additional layout, with integrated tilt angle sensors, was introduced (Design 1-S) to enable a closed-loop control. The micromirror devices were monolithically fabricated in 150 mm silicon-on-insulator (SOI) technology. Si (111) was used as the device silicon layer to support a high C-axis oriented growth of AlN. The fabricated micromirror devices were characterized in terms of their scanning and sensor characteristics in air. A scan angle of 91.2° was reached for Design 1 at 13 834 Hz and 50 V. For Design 2 a scan angle of 92.4° at 12 060 Hz, and 123.9° at 13 145 Hz, was reached at 50 V for the x- and y-axis, respectively. The desired 2D scan patterns were successfully generated. A sensor angle sensitivity of 1.9 pC/° was achieved.

North-finders based on angular rate sensors have an advantage over magnetic compasses or GPS (global positioning system) as they are insensitive against local Earth magnetic field variations and independent of electromagnetic transmission. In exchange, very precise and stable gyroscopes are needed to resolve the Earth’s angular rate for north-finding with sufficient accuracy. Therefore, a north-finder is a very good example to demonstrate the advancement in MEMS gyroscope development taking place over the last decade up to a point, where it is possible to reliably determine north-direction with a single fully integrated high precision sensor in a simple system. The north-finder presented in this paper uses the Maytagging algorithm, which enables the use of standard consumer grade mechanical and electrical components. The sensor used, is an in-house developed tuning fork MEMS gyroscope with integrated signal conversion. The paper introduces the basic technology for fabricating the MEMS element, as well as improvements which are planned in the future to enhance the sensitivity even more. The noise and drift of the sensor is low enough to determine the north heading in Chemnitz (at a latitude of $50.8^{\mathrm{o}}$) down to $5^{\mathrm{o}}$ of standard deviation in less than 1.5 minutes. This can be even improved down to 1° by quadrature compensation as will be discussed in this publication as well.

A polymer-based sensor for low frequency acceleration detection is fabricated by using microinjection molding technologies. Finite Element simulations and characterization of the sensing functionality are done. Due to an out-of-plane acceleration a force is applied to a seismic mass (length and width each 3.2 mm, thickness 1 mm), which leads to a deformation of a connected plate with dimensions of 1 mm × 1 mm × 50 μm. Thus, charge separation at the electrodes of integrated piezoelectric polyvinylidene fluoride (PVDF) copolymer sheets occur and can be measured as sensor signal. A charge sensitivity of 0.57 pC/g is determined which is in good agreement with the simulation results. A resonance frequency of 660 Hz was measured. Furthermore, the sensor concept as well as preparation technologies to assemble a compound structure containing piezoelectric layers and the system integration by micro injection molding are discussed. In addition, different bonding techniques for the assembly of the functional components are investigated and described.

In this paper micromirrors based on piezoelectric thin film aluminum nitride (AlN) are presented. The microsystems with a 6 mm² footprint are fabricated successfully in 150 mm SOI technology. A large tilt angle is achieved by FEM-based optimization of the lever arm parameters. Three micromirror types with varied spring widths are characterized, achieving tilt angles up to 51.3° at 1.9 kHz, 31.6° at 4.6 kHz, and 16.5° at 12.5 kHz for an actuation voltage of less than 5 V. For higher actuation voltages up to 20 V, a maximum scan angle of 104.9° is reached, limited by the measurement setup.

North-finders based on gyroscopes are commonly used because of their robustness against local Earth magnetic field distortion and independence of electromagnetic transmission. In this paper, we present an easy to use, compact, transportable, standalone, north-finder based on one MEMS gyroscope. The Maytagging algorithm allows the use of an inexpensive stepper motor. The integrated in-house developed tuning fork MEMS gyroscopes offer low enough noise and drift to determine north heading down to 1 degree of deviation in less than 10 minutes at a latitude of 50.8 degrees without additional signal conversion electronics.