In this paper a novel type of piezoelectric MEMS loudspeaker is presented. The device concept is based on concentrically cascaded PZT actuators making it the first two-way MEMS speaker reported. As a further novelty, the device is designed to operate without a closed membrane offering significant improvements with respect to acoustic performance, energy efficiency and manufacturability. Extensive FEA studies have revealed a very high SPL of more than 85 dB at 500 Hz for a device 10 × 10 mm2 in size. At higher frequencies even larger SPL values are achieved enabling a flat frequency response with 95 dB for frequencies above 800 Hz. Based on the concept speaker prototypes have been fabricated using MEMS technology and are currently being characterized

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Small size, low power consumption and the capability to produce sharp images without need of an objective make MEMS scanning laser based pico-projectors an attractive solution for embedded cell-phone projection displays. To fulfil the high image resolution demands the MEMS scanning mirror has to show large scan angles, a large mirror aperture size and a high scan frequency. An additional important requirement in pico-projector applications is to minimize power consumption of the MEMS scanner to enable a long video projection time. Typically high losses in power are caused by gas damping. For that reason Fraunhofer ISIT has established a fabrication process for 2D-MEMS mirrors that includes vacuum encapsulation on 8-inch wafers. Quality factors as high as 145,000 require dedicated closed loop phase control electronics to enable stable image projection even at rapidly changing laser intensities. A capacitive feedback signal is the basis for controlling the 2D MEMS oscilla tion and for synchronising the laser sources. This paper reports on fabrication of two-axis wafer level vacuum packaged scanning micromirrors and its use in a compact laser projection display. The paper presents different approaches of overcoming the well-known reflex problem of packaged MEMS scanning mirrors

MEMS based laser projection is of high interest for automotive head-up displays and dashboard displays, as well as for an increasing number of personal mobile projection applications. These applications require scanning mirrors that offer high scan frequencies and wide scan angles while showing low power consumption. This paper presents a novel low-power high-Q scanning mirror that is vacuum encapsulated on wafer level and thereby exhibits Q-factors exceeding 145,000. A new glass forming process enables fabrication of glass wafers with inclined 3D-shaped windows needed to spatially separate the direct reflex from the projected image

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