MEMS-based micro speakers are attractive candidates as sound transducers for smart devices,particularly wearables and hearables.For such devices,high sound pressure levels,low harmonic distortion and low power consump...MEMS-based micro speakers are attractive candidates as sound transducers for smart devices,particularly wearables and hearables.For such devices,high sound pressure levels,low harmonic distortion and low power consumption are required for industrial,consumer and medical applications.The ability to integrate with microelectronic circuitry,as well as scalable batch production to enable low unit costs,are the key factors benchmarking a technology.The Nanoscopic Electrostatic Drive based,novel micro speaker concept presented in this work essentially comprises inplane,electrostatic bending actuators,and uses the chip volume rather than the its surface for sound generation.We describe the principle,design,fabrication,and first characterization results.Various design options and governing equations are given and discussed.In a standard acoustical test setup(ear simulator),a MEMS micro speaker generated a sound pressure level of 69 dB at 500 Hz with a total harmonic distortion of 4.4%,thus proving the concept.Further potential on sound pressure as well as linearity improvement is outlined.We expect that the described methods can be used to enhance and design other MEMS devices and foster modeling and simulation approaches.展开更多
Electrostatic actuators are of particular interest for microsystems(MEMS),and in particular for MEMS audio transducers for use in advanced true wireless applications.They are attractive because of their typically low ...Electrostatic actuators are of particular interest for microsystems(MEMS),and in particular for MEMS audio transducers for use in advanced true wireless applications.They are attractive because of their typically low electrical capacitance and because they can be fabricated from materials that are compatible with standard complementary metal-oxide semiconductor(CMOS)technology.For high audio performance and in particular low harmonic distortion(THD)the implementation of the push-pull principle provides strong benefits.With an arrangement of three electrodes in a conjunct moving configuration on a beam,we demonstrate here for the first time a balanced bending actuator incarnating the push-pull principle operating at low voltages.Our first design already exhibits a harmonic distortion as low as 1.2%at 79 dB using a signal voltage of only 6 V_(p) and a constant voltage of only±10 V_(dc) in a standard acoustic measurement setup.Thus,exceeding our previously reported approach in all three key performance indications at the same time.We expect that our novel electrode configurations will stimulate innovative electrostatic actuator developments for a broad range of applications.In this paper we report the basic theory,the fabrication and the performance of our novel actuator design acting as an audio transducer.展开更多
基金This work was funded by the German Federal Ministry of Education and Research(BMBF)as part of the MEMSound project in the funding measure“Validation of the technological and social innovation potential of scientific research-VIP+”under the grant number 03VP01800。
文摘MEMS-based micro speakers are attractive candidates as sound transducers for smart devices,particularly wearables and hearables.For such devices,high sound pressure levels,low harmonic distortion and low power consumption are required for industrial,consumer and medical applications.The ability to integrate with microelectronic circuitry,as well as scalable batch production to enable low unit costs,are the key factors benchmarking a technology.The Nanoscopic Electrostatic Drive based,novel micro speaker concept presented in this work essentially comprises inplane,electrostatic bending actuators,and uses the chip volume rather than the its surface for sound generation.We describe the principle,design,fabrication,and first characterization results.Various design options and governing equations are given and discussed.In a standard acoustical test setup(ear simulator),a MEMS micro speaker generated a sound pressure level of 69 dB at 500 Hz with a total harmonic distortion of 4.4%,thus proving the concept.Further potential on sound pressure as well as linearity improvement is outlined.We expect that the described methods can be used to enhance and design other MEMS devices and foster modeling and simulation approaches.
基金supported by Fraunhofer Zukunftsstiftung and by the State of Brandenburg and the European Union under contract PROFIT/EFRE No.80256335.
文摘Electrostatic actuators are of particular interest for microsystems(MEMS),and in particular for MEMS audio transducers for use in advanced true wireless applications.They are attractive because of their typically low electrical capacitance and because they can be fabricated from materials that are compatible with standard complementary metal-oxide semiconductor(CMOS)technology.For high audio performance and in particular low harmonic distortion(THD)the implementation of the push-pull principle provides strong benefits.With an arrangement of three electrodes in a conjunct moving configuration on a beam,we demonstrate here for the first time a balanced bending actuator incarnating the push-pull principle operating at low voltages.Our first design already exhibits a harmonic distortion as low as 1.2%at 79 dB using a signal voltage of only 6 V_(p) and a constant voltage of only±10 V_(dc) in a standard acoustic measurement setup.Thus,exceeding our previously reported approach in all three key performance indications at the same time.We expect that our novel electrode configurations will stimulate innovative electrostatic actuator developments for a broad range of applications.In this paper we report the basic theory,the fabrication and the performance of our novel actuator design acting as an audio transducer.
