At HANNOVER MESSE 2023, Fraunhofer ISIT will present current development results on various key topics of MEMS optics and acoustics within the framework of a Fraunhofer joint booth of more than 1000 m², thus setting trend-setting impulses for the Industrial Metaverse.
Our researchers' goal was to develop a system for providing nautical information for navigation and optimal decision support on a ship's bridge, to bring the real environment into congruence with augmented content, and to meet the harsh environmental conditions and requirements of the maritime industry.
A 2D MEMS scanner-based laser projection system was developed to generate an image generated from projected laser pixels over a large area, which on the one hand has the necessary requirements in terms of contrast, brightness, stability and refresh rate, and on the other hand ensures the safety of bridge personnel. The basis of the laser projection system is the 2D MEMS scanners developed at ISIT, which deflect a laser beam with suitable beam parameters into a solid angle range of approximately Θ = 60° and Φ = 40°. An essential prerequisite for generating images with a scanning laser projection is the provision of control electronics that operate reliably in terms of precise pixel generation, repeatability and high image stability under the given boundary conditions in shipping. This includes the development of a suitable algorithm that processes the image data in such a way that image distortions, intensity distributions and, for example, amplitude fluctuations that impair the visual impression of a projected image are compensated for or rendered ineffective. The interaction of the MEMS scanner control and image generation must be of a high level of quality to reliably provide information to bridge personnel even under the most adverse conditions.
Laser material processing is a key technology in the production of modern quality products. Faster laser beam deflection systems can significantly improve this technology.
Fraunhofer ISIT has transferred the advantages of MEMS scanner technology to macroscopic conditions. Novel scanner mirrors with apertures down to 2 cm now allow highly dynamic biaxial laser beam deflection for CW laser powers up to 500 watts.These compact MEMS scanners thus open up new fields of application and products.
The 3D camera is based on a 2D MEMS scanner that uses the principle of the phase difference of an emitted laser beam to the detected "echo" as a distance measurement. The phase detection algorithm enables 60 million 3D measurements per second. The camera has a resolution of 450 x 450 pixels and delivers six images per second. The depth resolution is specified as a few millimeters and the maximum detectable distance to the object is 2 m.
Fraunhofer ISIT develops highly miniaturized piezoelectric micromechanical ultrasonic transducers (PMUTs) suitable for a variety of technical applications such as distance measurement, gesture recognition, haptic feedback or medical imaging. Depending on the target frequency and application, the concept is based on actuators or membranes made of high-performance piezoelectric materials AlN, AlScN and PZT, which enable very high sound pressure levels as well as sensitivities. In this way, efficient ultrasonic transducers with center frequencies from a few kHz up to several hundred MHz can be realized. Manufacturing with the aid of semiconductor technology enables both high miniaturization and cost-efficient production in high volumes.
Fraunhofer ISIT develops highly miniaturized microelectromechanical (MEMS) loudspeaker technologies for in-ear applications, such as true wireless stereo (TWS) headphones, hearables and hearing aids. The concept is based on piezoelectrically driven flexural transducers fabricated using semiconductor technology, offering high miniaturization and cost-effective high-volume production. The MEMS loudspeakers feature exceptionally high area-normalized sound pressure levels (SPLs) of over 95 dB/mm² across the entire reproduction range. Through design variation and the integration of multiple loudspeakers on a single chip, the SPLs are almost infinitely scalable. In addition to unmatched miniaturization potential, our MEMS loudspeakers offer high fidelity, high bandwidth and low power consumption. Ongoing research is focused on further miniaturization, design improvements and integration of new materials, such as aluminum scandium nitride, to further improve energy efficiency, sound pressure levels, attenuation and linearity, and to enable a fully CMOS-compatible process.
Based on the modulation of surface acoustic waves (SAW), Fraunhofer ISIT is developing a sensor platform for the measurement of different physical phenomena and quantities. The basic principle is the use of one electrode each for transmitting and receiving as well as an interposed functional layer for the modulation of the surface acoustic wave. Depending on the coating, elastic, viscoelastic, magnetic or electrical effects can thus be exploited in addition to mass absorption. This enables a wide range of applications, such as pressure, humidity, electric field, vibration, gas, bio or magnetic field or current sensors. The sensor platform will be demonstrated using a high-performance current sensor with a magnetostrictive coating that has a dynamic range of up to eight orders of magnitude and a bandwidth in the MHz range. This sensor is designed to accurately measure the very fast switching operations (~kA/ns) of modern switching power supplies, enabling highly efficient power conversion.
Fraunhofer Institute for Silicon Technology
