Stoppel, F.F.StoppelEisermann, C.C.EisermannGu-Stoppel, S.S.Gu-StoppelKaden, D.D.KadenGiese, T.T.GieseWagner, B.B.Wagner2022-03-132022-03-132017https://publica.fraunhofer.de/handle/publica/39862910.1109/TRANSDUCERS.2017.79944752-s2.0-85029386965In 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.enconference paper