MEMS component

Abstract

The invention relates to a MEMS component comprising: a carrier, a drive element movable along a direction of movement, which is spring-mounted on the carrier and has at least one individually electrically controllable drive electrode, a displacement plate connected to the drive element, a fixed actuator arrangement which has a plurality of electrically insulated and individually electrically controllable actuator electrodes which are arranged one after the other along the direction of movement of the movable drive element, wherein the actuator electrodes are configured to generate an electric stray field upon electrical activation, so that upon electrical activation of the at least one drive electrode, the latter experiences a directed electrostatic force along the direction of movement. The invention relates to a method for operating a MEMS component, a computer program and a machine-readable storage medium.

Description

The invention relates to a MEMS component, a method for operating the MEMS component, a computer program and a machine-readable storage medium.Prior ArtThe basic aim or challenge of MEMS-based loudspeakers is to achieve the highest possible SPL (sound pressure level). A high SPL is associated with a high displaced air volume. At the same time, for cost reasons, the chip area should be kept as small as possible, so that the parameter SPL / chip area is to be optimized or increased. Known concepts for MEMS-based loudspeakers are briefly listed below.Current MEMS loudspeakers are usually designed as planar structures, wherein a vibratory diaphragm or a bending beam is excited in such a way that the displacement and / or compression of the fluid takes place vertically to the diaphragm plane and to the main extension plane of the component. The excitation of such membranes is typically effected by means of a piezoelectric or (quasi)electrostatic drive. Such an embodiment is disclosed, for example, in US2021297787. Due to the clamping of the diaphragm or the bending beam / beams, a maximum deflection is limited. These systems therefore have the disadvantage that they require a large membrane area for displacement of a high fluid volume, which results in a large chip area of the MEMS component. A further limitation of the displaceable air volume is caused by the membrane connected or clamped circumferentially to the substrate material. Due to this circumferential clamping, the local deflection amplitude of the membrane is different over the surface of the membrane (in the clamped edge region, the deflection is virtually zero, while it is typically maximum in the center of the membrane). Such uneven deflection of the diaphragm surface additionally reduces the displaced air volume and also increases total harmonic distortion (THD). In contrast, a planar, cylindrical deflection ("piston mode") of the sound-generating surface would be ideal. US2021297787 proposes structures of the diaphragm which reduce the uneven deflection to a certain extent or increase the area with maximum deflection by providing a torsionally rigid "diaphragm plate" in the diaphragm center, which is embedded circumferentially in the actual diaphragm functioning as an actuator.In general, it applies that corresponding MEMS loudspeakers with such a planar structure or membrane have a fluidically effective surface area which is in principle smaller than the chip surface area. That is, an increase in the volume of air to be displaced inevitably entails an increase in the chip area.In the prior art, concepts are therefore proposed which do not have a single diaphragm with oscillation in the vertical direction, but rather have a plurality of laterally or horizontally movable elements which extend in the vertical direction. It is advantageous here that the displaced volume of the fluid is not scaled solely with the chip area, but can additionally be influenced with the vertical dimension. Due to the vertical raising and alignment of a plurality of membranes or bending beams, the fluidically effective surface is duplicated and can be substantially larger than the actual chip area. MEMS loudspeakers based on this basic concept are disclosed, for example, in WO 2021 / 144400, WO002021223886 or also DE 10 2019 203 914, and in Kaiser et al. Microsystems & Nanoengineering (2019) 5:43.WO002021223886 describes a concept in which a separation of an active drive structure and a passive displacement structure is proposed, wherein the two structures are arranged one above the other (for example as a wafer stack). In other words: in the document, both structures (drive and displacer) lie overlapping in the same surface region. In this case, these two structures can be mechanically connected to one another via a coupling element, with the result that a deflection of the active structure results in a movement of the passive displacement structure.WO22117197 discloses a microfluidic component with vertical displacement elements which is driven by means of leakage electric fields. The displacement elements are laterally clamped there on both sides. The leakage electric fields are formed via electrodes which are arranged both on the underside of the cover substrate and on the upper side of the base substrate. The electrodes are thus oriented toward the displacement structure located therebetween and have the smallest possible distances from the displacement elements. The displacement elements are thus located on the end face (upper side and lower side of the displacement elements) in the stray field of the electrodes (the stray field or the electric field between the electrodes has a directional component vertical to the surface of the electrodes and therefore parallel to the main plane of extension of the displacement elements and a directional component along the deflection of the displacement elements, i.e. perpendicular to their main plane of extension. In the case of an electrical actuation of the displacement elements, the individual displacement element experiences an electrostatic force (acting on the upper side and the lower side of the displacement structure), which causes a lateral deflection of the displacement element (on account of the leakage field component in the deflection direction of the displacement elements). In contrast to the concept from WO002021223886, the displacement elements do not form a passive displacement structure in this case, but are activated actively with an AC voltage.A disadvantage of this drive concept of the displacer is, in addition to the high technological hurdle for industrial implementation, in particular the small maximum deflection of the displacer elements-this deflection is in the range of a few micrometers (due to the principle, this deflection can have at most only half the distance of the stationary electrodes). Due to this small deflection, in order to achieve a high SPL, both many vertically arranged displacement elements with a small distance from one another (high periodicity) and displacement elements with a high vertical extent are required. The two requirements together lead to a high requirement for the design (specification and tolerances) of the displacement elements, which makes the technological feasibility very cost-intensive.Disclosure of the InventionThe object on which the invention is based is to provide a MEMS component which, for example, enables high SPL (sound pressure level) on a small component area.The object on which the invention is based is to provide a method for operating the MEMS component, with which, for example, high SPLs can be achieved.The object on which the invention is based is to provide a computer program.The object on which the invention is based is to provide a machine-readable storage medium.These objects are achieved by means of the corresponding subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of dependent claims.According to a first aspect, a MEMS device is provided, comprising:a carrier,a drive element which is movable along a direction of movement and is suspended resiliently on the carrier and has at least one individually electrically controllable drive electrode,a displacement plate connected to the drive element,a fixed actuator arrangement which has a plurality of actuator electrodes which are electrically insulated from one another and can be electrically controlled individually and are arranged one after the other along the direction of movement of the movable drive element,wherein the actuator electrodes are configured to generate a stray electric field when electrically controlled, so that when electrically controlled the at least one drive electrode it experiences a directed electrostatic force along the direction of movement.According to a second aspect, a method for operating the MEMS component according to the first aspect is provided, comprising the following steps:electrically driving the driving electrodes to generate a leakage electric field,electrically driving the at least one driving electrode to generate a directional electrostatic force along the moving direction, so that the at least one driving electrode receives the directional electrostatic force along the moving direction.According to a third aspect, a computer program is provided, comprising instructions which, when the computer program is executed by a computer, for example by the MEMS component according to the first aspect and / or by a control device, cause the latter to execute a method according to the second aspect.According to a fourth aspect, a machine-readable storage medium is provided on which the computer program according to the third aspect is stored.The abbreviation "MEMS" stands for micro-electromechanical system (micro-electromechanical system).The invention is based on the finding and includes it that the above object is achieved by providing an actuator arrangement having a plurality of actuator electrodes which are arranged or lined up along a direction of movement of the drive element. By individually electrically driving the actuator electrodes and the drive electrode, a directional electrostatic force along the direction of movement can be generated which acts on the drive electrode, so that the latter can perform or performs a movement along the direction of movement on account of the electrostatic force acting on it. As a result, the drive element and thus also the displacement plate, which is connected to the drive element, moves.By the individual actuation, a continuing movement or deflection of the drive element can be made possible. The drive principle is based on fixed electrodes, the actuator electrodes, which generate a stray electric field, and at least one movable electrode, the drive electrode, which is electrically controlled in such a way that it experiences a directed electrostatic force in the stray electric field along the direction of movement of the electrode. This drive principle is repeated and continued along the direction of movement of the movable electrode, so that a deflection amplitude of the drive electrode and thus also of the displacement plate is increased. The fixed electrodes are repeatedly arranged along the moving direction of the movable electrode. It has been recognized that a perpetuating deflection of the movable electrode becomes possible by a time-varying switching or control of the repeatedly arranged fixed electrodes. In addition, for example, as an alternative or in addition to a time-varying wiring of the stationary electrodes, an exemplary configuration of the movable electrode is provided, which for example allows polyphase actuation and thus also allows a continuing movement in combination with the stationary electrodes configured perpetuating.The following efficiency formula is defined here: The expression "efficiency" for MEMS-based loudspeakers will be introduced below, which allows the various conceptual approaches with respect to their advantages and disadvantages to be compared with one another. Efficiency is understood to mean: displaceable air volume per chip area-E volume.The relationship for efficiency is: with:E_volume: "efficiency"; displaceable air volume per chip areaA_ acoustic: acoustically active surfaceH_efficiency: effective amplitude or stroke (amplitude=bending of the diaphragm)H_max: maximum deflection or amplitude or strokek: Coefficient of Average Deflection to Maximum DeflectionA_activeChip: ActiveChip AreaPlanar diaphragm concepts, as described, for example, in US2021 / 297787, have an acoustically effective surface area which corresponds approximately to the active chip area. That is to say that the factor [A_ acoustic / A_activeChip] is approximately equal to 1. such concepts therefore require a high effective amplitude and / or a large chip area for a high SPL (sound pressure level).Concepts with a vertical alignment and multiplication of the membranes increase the factor [A_ acoustic / A_activeChip], but apart from the aforementioned technological challenge for producing such concepts, it is to be called H_efficiently the limitation of the displaced volume on account of a lower effective deflection. The effective deflection H_efficiently in relation to the periodicity of the vertical membranes is called a fill factor. However, for a variety of reasons, including production, this fill factor is significantly limited.The concept described here makes it possible, in particular taking account of the technological mikroability or a reduced process complexity, to provide a MEMS-based loudspeaker concept which has a high efficiency E_volume, i.e. which makes possible a high displaceable air volume per chip area. As in the "efficiency formula" listed above, it is important--regardless of the loudspeaker concept used--to increase the maximum deflection for an increased SPL.The approach for high efficiency is to maximize the maximum deflection H_max of a displacer structure: the displacer plate. For this purpose, an actuator arrangement with perpetuating elements, the actuator electrodes, is proposed, whereby the deflection is increased by the fact that the actuator principle or drive principle can be repeatedly utilized in the deflection movement, i.e. the direction of movement.In this case, both the maximum amplitude or deflection H_max is increased and, in one embodiment, a displacement structure having a coefficient k close to or equal to 1 is achieved.Furthermore, the process-technology feasibility or simplicity of the production process is ensured by providing a planar configuration, the direction of movement extending laterally, in one embodiment. Such a planar configuration can be realized by means of a technology based on layer deposition, which is advantageous with respect to a horizontal direction of movement, since a depth-structuring technology should necessarily be used for this purpose for producing the actuator electrodes arranged vertically one above the other.The concept described here can be transferred in particular to all MEMS-based loudspeaker concepts discussed hitherto (but not necessarily restrictively to loudspeaker applications). Due to the planar configuration advantageous from a technological point of view, MEMS components with a planar, vertically deflectable displacement plate are described below and in the figures in particular. This displacement plate is designed to be torsionally rigid over the entire surface, for example, so that the deflection of the displacement plate displaces the maximum possible fluid volume; or in other words, k=1, or H_max=H_efficiency.The surface of the displacement plate is here, for example, equal (or close to equal) to the active chip surface.With the aid of the efficiency formula introduced above and its individual factors, it can also be noted that, based on this concept or on the basis of a substantially increased deflection H_max, for example for the loudspeaker concepts with vertically set-up displacement structures, the requirements imposed on the factor [A_ acoustic / A_activeChip] are reduced. In other words, with the aid of the invention described here, for such concepts, for example structure heights or the periodicity of the displacement elements can be reduced and thus can be contributed positively to the industrial feasibility.According to one embodiment, the MEMS component comprises a control device which is configured to individually electrically drive the at least one drive electrode and the actuator electrodes in such a way that the at least one drive electrode moves along the direction of movement.This brings about the technical advantage, for example, that the drive electrode and the actuator electrodes can be electrically controlled efficiently individually.In one embodiment of the MEMS component, it is provided that the control device is configured to ascertain a position of the at least one drive electrode, wherein the control device is configured to electrically actuate the at least one drive electrode and / or the actuator electrodes on the basis of the ascertained position. The position determination can be effected, for example, by a high-frequency, modulated AC voltage signal (>>20 kHz), which makes it possible to determine the capacitance between the drive electrode and adjacent actuator electrodes and thus their relative position. Alternatively or additionally, position detection can be effected via separate detection electrodes which are arranged laterally next to the actuator electrodes in regions.This brings about the technical advantage, for example, that the drive electrode and the actuator electrodes can be individually electrically controlled depending on the position.In one embodiment of the MEMS component, it is provided that the control device is configured to actuate the drive electrodes in the same phase and / or actuate the actuator electrodes in multiple phases in the case of at least two drive electrodes.This has the technical advantage, for example, that the electrostatic drive is implemented in a manner matching the deflection position of the drive electrodes and thus particularly efficiently.In one embodiment of the MEMS component, it is provided that the drive element has at least one opening for a fluid exchange.This brings about the technical advantage, for example, that no fluid damping counteracts the desired vertical drive movement in the drive element and thus reduces the SPL that can be achieved, since a fluid, in particular air, in the volume between the drive element and the displacement plate would otherwise be compressed or diluted, which would lead to an additional damping restoring force. With the at least one opening, the fluid, in particular the air, can flow back and forth in contrast.In one embodiment of the MEMS component, it is provided that the drive element is connected to the displacement plate by means of at least one piston.This brings about, for example, the technical advantage that the drive element is efficiently connected to the displacement plate.In one embodiment of the MEMS component, it is provided that the drive element is suspended resiliently on the carrier by means of a spring suspension comprising at least one spring.This brings about the technical advantage, for example, that a force acting against the movement is generated, so that the drive element can move back into its initial position when the electrodes are switched off.In one embodiment of the MEMS component, it is provided that the carrier for the at least one spring comprises in each case a movement channel, within which the at least one spring is arranged movably.This brings about, for example, the technical advantage that a movement of the at least one spring can be guided efficiently.In one embodiment of the MEMS component, it is provided that actuator electrodes are arranged vertically spaced apart from one another, in particular substantially symmetrically, on both sides of the drive electrode in a rest position.This has the technical advantage, for example, that the drive element can be actively driven from its rest position in both directions with a symmetrical electrostatic force curve.In one embodiment of the MEMS component, it is provided that the carrier has a block shape in which a cutout is formed in which the drive element and the fixed actuator arrangement are arranged.This brings about, for example, the technical advantage that the drive element and the fixed actuator arrangement are arranged in a space-saving manner.In one embodiment of the MEMS component, provision is made for an acoustic inlet to be formed on the rear side of the carrier, from which at least one acoustic channel runs as far as the cutout.This brings about the technical advantage, for example, that the movement of the drive element is not restricted by fluidic damping, because a fluid, in particular air, in the volume between the drive element and the displacement plate would otherwise be compressed or diluted, which would lead to an additional damping restoring force. Via the acoustic inlet, the acoustic channel and the recess, the fluid, in particular the air, can flow back and forth in contrast.In one embodiment of the MEMS component, it is provided that the displacement plate is arranged within a cutout in the carrier and the movement of which is limited to the region of the cutout. In other words, the displacement plate is at all times overlapped at its periphery by the circumferential carrier edge. The gap between the displacement plate and the carrier edge should be as small as possible, for example <10 μm, in particular <5 μm.This brings about the technical advantage, for example, that acoustic sound pressure losses due to air leaks around the edge of the displacement plate are substantially minimized.In one embodiment of the MEMS component, it is provided that the carrier is arranged within a housing which has a housing opening on the rear side at the acoustic inlet.This brings about, for example, the technical advantage that the acoustic input can efficiently fulfil its function.In one embodiment of the MEMS component, it is provided that the housing has an acoustic output on the front side.This brings about the technical advantage, for example, that sound waves generated, for example, by the movement of the displacement plate can efficiently leave the housing and the sound is not unnecessarily shielded by the housing.In one embodiment of the MEMS component, it is provided that the displacement plate is designed to be torsionally rigid.This brings about, for example, the technical advantage that the displacement plate can efficiently generate sound waves with a low distortion factor during movement.In one embodiment of the MEMS component, provision is made for a respective dielectric for electrically insulating the drive electrodes from one another to be arranged between the drive electrodes.This brings about, for example, the technical advantage that the drive electrodes can be electrically insulated from one another efficiently.In one embodiment of the MEMS component, it is provided that the direction of movement is a vertical direction of movement, wherein the actuator electrodes are arranged one above the other, or that the direction of movement is a lateral direction of movement, wherein the actuator electrodes are arranged next to one another.This brings about the technical advantage, for example, that suitable directions of movement are provided.The method is, for example, a computer-implemented method.Technical features and functionalities of the MEMS component are obtained analogously from corresponding technical functionalities and technical features of the method and vice versa. This therefore means in particular that method features are produced analogously from features of the MEMS component and vice versa.The MEMS component is configured, for example, to carry out all steps of the method according to the second aspect.For example, the control device of the MEMS component is configured in a program-technical manner to execute the computer program.If the singular is used in the description for the drive electrode, the plural and vice versa shall always be read along. Embodiments made in connection with a drive electrode apply analogously to a plurality of drive electrodes and vice versa. This therefore means, for example, that a plurality of individually electrically controllable drive electrodes can be provided.The phrase "at least one(s) means "one(s) or more.".The phrase "at least one(s) means "one(s) or more.".The invention is explained in more detail below with reference to preferred exemplary embodiments. The following are shown here: FIG. 1 shows a MEMS component in a cross-sectional view, FIG. 2 shows various operating states of the MEMS component of FIG. 1, FIG. 3 is a cross-sectional view of the MEMS device of FIG. 1 , FIG. 4 shows a plan view of the MEMS component of FIG. 3, FIG. 5 is a cross-sectional view of the MEMS device of FIG. 1 , FIG. 6 shows a plane section of the MEMS component, FIG. 7 shows polyphase actuation of the drive electrode, FIG. 8 shows polyphase actuation of the drive electrode, FIG. 9 shows an in-phase control of the drive electrode, FIG. 10 shows an arrangement of drive electrodes and actuator electrodes, wherein the direction of movement is a lateral direction of movement, FIG. 11 shows a method for operating a MEMS component according to the first aspect, and FIG. 12 shows a machine-readable storage medium.The same reference numerals can be used below for the same features.It is noted at this point that exemplary MEMS structures within the meaning of the concept described here are shown in the figures. As already mentioned above, the actuator concept with aligned actuator elements, the actuator electrodes, for an (ultra wide) deflection is to be described below by way of example on the basis of a MEMS-based loudspeaker structure with a planar displacement plate. Consequently, the fixed actuator electrodes are arranged vertically stacked one above the other and the movable drive electrode carries out a movement perpendicular to the main extension plane of the MEMS component or MEMS chip.Nevertheless, the actuator concept is also provided in combination with MEMS loudspeaker concepts with vertically set-up displacement elements (such as WO22117197 or WO002021223886), wherein here the fixed actuator electrodes are arranged in a plane and the movable drive electrode executes a lateral movement direction.FIG. 1 shows a MEMS component 101 comprising a housing 103. A carrier 105 is arranged within the housing 103, wherein the carrier 105 can be a chip, for example.The housing has a housing opening 107 on the rear side. The carrier 105 comprises an acoustic input 109. The housing 103 comprises the housing opening 107 on the rear side at the acoustic inlet 109.The carrier 105 has a recess 111. An acoustic channel 113 runs from the acoustic inlet 109 as far as the recess 111.The MEMS component comprises a drive element 115, which is formed, for example, as a drive plate. This therefore means that the drive element 115 is, for example, a drive plate.The drive element 115 is movable in a direction of movement. For the sake of better illustration, a Cartesian coordinate system 117 is drawn in FIG. 1, wherein the z-axis of the Cartesian coordinate system 117 runs perpendicular to the main extension plane of the MEMS component 101. Along this vertical z-axis of the Cartesian coordinate system 117, the drive element 115 is movable. The direction of movement in the MEMS component 101 is thus a vertical direction of movement.The drive element 115 is suspended resiliently on the carrier 105 via a spring suspension 119. The spring suspension comprises a plurality of springs, which can be seen better in the sectional illustration according to FIG. 6.The drive element 115 comprises a plurality of drive electrodes 121, which can each be electrically actuated individually.The drive element 115 is connected to a displacement plate 123. The displacement plate 123 is formed of, for example, silicon. The displacement plate 123 has a thickness of 5 μm to 10 μm, for example.The displacement plate 123 is designed to be torsionally rigid, for example.The displacement plate 123 is mechanically connected to the drive element 115 via a piston 125. This means that, when the drive element 115 moves along the z-axis of the Cartesian coordinate system 117, the displacement plate 123 will also move along the z-axis.The drive element 117 is arranged within the recess 111 of the carrier 105.Furthermore, the MEMS component 101 comprises a fixed actuator arrangement 127 which has a plurality of actuator electrodes 129 which are electrically insulated from one another and can be individually electrically controlled. The actuator electrodes 129 are arranged one after the other along the vertical direction of movement of the movable drive element 115, in the present case therefore arranged one above the other, for example stacked.The fixed actuator assembly 127 is disposed within the recess 111.The housing 103 comprises an acoustic output 131 on the front side, through which sound waves 133 generated due to a movement of the displacement plate 123 can emerge.The actuator electrodes 129 are configured to generate a stray electric field when electrically controlled, so that when electrically controlled the drive electrodes 121 they experience a directed electrostatic force along the z-axis, i.e. along the direction of movement. Thus, by appropriate actuation of the actuator electrode 129 and the drive electrode 121, the drive plate 115 can be moved along the z-axis and thus also the displacement plate 123.Thus, the MEMS device 101 may be operated according to the method for operating a MEMS device according to the second aspect.The MEMS device 101 is, for example, a loudspeaker.In the drive plate 115, openings 135 for fluid exchange are provided for damping reduction.Furthermore, bonding pads 137 are provided on the carrier 105 for electrical contacting of the carrier 105. The carrier 105 can thus be electrically contacted via electrical connections 139 in order to thus electrically drive the electrodes.The MEMS component 101 comprises, for example, a control device, not shown, which is configured to individually drive the drive electrodes 121 and the actuator electrodes 129 in such a way that the drive electrode(s) 121 moves along the z-axis, that is to say along the direction of movement.FIG. 2 shows the MEMS component 101 at three different points in time during active operation, wherein the displacement plate 123 is respectively deflected differently.In the left illustration, the displacement plate 123 is maximally deflected in the +z direction. However, the displacement plate 123 is still within the recess 111.In the middle illustration, the displacement plate is in a rest position, that is to say in a zero position.In the right illustration, the displacement plate 123 is located in a maximum deflection in the -z direction.Reference symbol 201 indicates a volume displacement range which is defined by the maximum possible deflection in the +z and -z directions.FIG. 3 shows the MEMS component 101 in a cross-sectional view without the housing 103.FIG. 4 shows a plan view according to the arrow represented in FIG. 3 with the reference symbol 301 of the MEMS component 101.FIG. 5 shows a cross-sectional view of the MEMS device 101 without the housing 103.FIG. 6 is a cross-sectional view taken along line 501 shown in FIG. 5.In the sectional view according to FIG. 6, four springs 601, 603, 605, 607 of the spring suspension 119 can be seen, which are each movably arranged within a separate movement channel 609, 611, 613, 615.Two of the four illustrated actuator electrodes 129 may be used as, for example, detection electrodes to determine a position of the drive electrodes 121.FIG. 7 shows an exemplary polyphase actuation of the drive electrodes.The reference numeral 700 indicates an arrangement of drive electrodes and actuator electrodes in the idle state, i.e. in the zero position according to the middle illustration shown in FIG. 2.The drive electrodes 129 are each electrically insulated from one another by a dielectric 701. The same is also provided for the drive electrodes 121, which are likewise electrically insulated from one another by a further dielectric 702.This means that a dielectric layer, for example, is located between two drive electrodes 121.This therefore means that a dielectric layer is provided between two actuator electrodes 129.Ideally, it applies that a thickness of the further dielectric 702 in the drive element 115, i.e. a layer thickness of the dielectric layer between two drive electrodes 121, corresponds substantially to a total thickness of a full dielectric layer 701, i.e. a layer thickness of the dielectric layer between two actuator electrodes 129, and half an actor electrode layer, i.e. half a thickness of an actuator electrode 129, in the actuator electrode stack. Thus, at least one of the two drive electrodes 121 is always offset in the drive direction with respect to the two closest actuator electrodes 129.In FIG. 7, four phases of a control of the individual electrodes following one another in time are shown by way of example: phase 1, denoted by the reference symbol 703, phase 2, denoted by the reference symbol 705, phase 3, denoted by the reference symbol 707, and phase 4, denoted by the reference symbol 709.The actuator electrodes 129 can be electrically controlled individually in such a way that they are either at a potential U 1 or at a potential U 2.For better differentiation, the upper drive electrode 121 is additionally provided with the reference number 711 and the lower drive electrode 121 is additionally provided with the reference number 713. An electric voltage Ubias,1is applied to the lower driving electrode 713. An electric voltage Ubias,2is applied to the upper driving electrode 711.Furthermore, a graph 715 is drawn in in FIG. 7, which shows a sinusoidal voltage profile at the two drive electrodes 711, 713 in arbitrary units over the deflection in the z direction or drive direction, that is to say over a position of the drive electrodes 711, 713.In this respect, the graph 715 shows a first sine curve 717, which shows the voltage profile Ubias,1over a position of the lower drive electrode 713, and a second sine curve 719, which shows the voltage profile Ubias,2over a position of the upper drive electrode 711.At the beginning, i.e. at t=0, Ubias,1=1 is present at the lower drive electrode 713 and Ubias,2=0 is present at the upper drive electrode 711.Phase 1 (phase 703) shows the state for t=0: the upper drive electrode 711 experiences no vertical force, i.e. a force in the z direction, since one of the actuator electrodes 129 exactly lies symmetrically opposite the upper drive electrode 711. The lower drive electrode 713, on the other hand, experiences a vertical force since it is situated exactly between two actuator electrodes 129, where the static leakage electric field (caused by the static electric voltages U 1, U 2) is at a maximum.In phase 1, the upper driving electrode 711 has no driving potential, and the lower driving electrode 713 has a maximum positive driving potential.Positive means in the +-direction of the z-direction, i.e. in the direction of the upper drive electrode 711. Negative means the opposite direction relative to the + direction, i.e. in the direction of the lower drive electrode 713.In phase 2 (phase 705) and in phase 4 (phase 709), the lower drive electrode 713 is situated symmetrically opposite one of the actuator electrodes 129, so that no force transmission takes place. On the other hand, the upper drive electrode 711 is located between two actuator electrodes 129, so that a force transmission takes place.In phase 2, the upper driving electrode 711 has a maximum positive driving potential, and the lower driving electrode 713 has no driving potential.In phase 4, the upper driving electrode 711 has a maximum negative driving potential, and the lower driving electrode 713 has no driving potential.In phase 3 (phase 707), the upper drive electrode 711 experiences no vertical force because one of the actuator electrodes 129 is symmetrically exactly opposite the upper drive electrode 711. The lower drive electrode 713, on the other hand, experiences a vertical force since it is situated exactly between two actuator electrodes 129, where the static leakage electric field (caused by the static electric voltages U 1, U 2) is at a maximum.In phase 3, the upper driving electrode 711 has no driving potential, and the lower driving electrode 713 has a maximum negative driving potential.The actuator electrodes 129 have alternately a different polarity, which is represented in FIG. 7 by different hatchings.According to this exemplary polyphase control, provision is made for the drive electrodes 121 to be electrically controlled depending on the position.Thus, polyphase driving of the movable drive electrodes 121 takes place. The stationary actuator electrodes have an alternating polarity.An electrode distance between two drive electrodes 121 is in particular designed such that at least one drive electrode is always located in a stray electric field of two fixed actuator electrodes 129.By a position-dependent electrical actuation of the drive electrodes 121, a recurring electrostatic force in the direction of movement and thus a continuing movement can be achieved.FIG. 8 shows an exemplary polyphase control of the movable electrodes 121 in a similar manner to the illustration shown in FIG. 7, so that reference is made to the corresponding explanations and explanations in order to avoid repetitions.In contrast, according to the control system shown in FIG. 8, it is provided that an electrical charge reversal of the actuator electrodes is provided, which is shown by way of example by arrows with the reference symbol 801.Accordingly, it is provided that the polarity of the actuator electrodes 129 changes.According to the polyphase control according to FIG. 8, a position-dependent, i.e. depending on a position of the movable drive electrodes 121, electric charge reversal is thus provided, for example. For example, a time-variable electrical charge reversal of the actuator electrodes 129 can be provided.In the case of a time-variable electrical charge reversal, provision is made in particular for the electrical charge reversal to be coupled or synchronized with the movement of the movable drive electrodes 121. A specific advantage of a time-variable electrical charge reversal is, in particular, that the charge in the MEMS component only has to be pumped around and does not have to be buffered, for example in an ASIC (application-specific integrated circuit, or in German: application-specific integrated circuit). This reduces electric power consumption.FIG. 9 shows an in-phase control of the drive electrodes 121 and a polyphase control of the fixed actuator electrodes 129.In other words, the electric potential of the driving electrodes 121 does not change during the movement. Thus, for example, the lower drive electrode is placed on Ubias,1and, for example, the upper drive electrode 121 is placed on Ubias,2.The stationary actuator electrodes 129 can thus be placed, for example, at four different potentials U 1, U 2, U 3, U 4 in each case. In this case, the actuator electrodes 129 are thus each located one after the other on U 1, U 2, U 3, U 4 and then again on U 1, U 2, U 3, U 4 and so on depending on the number of actuator electrodes 129.Thus, according to the illustration shown in FIG. 9, an in-phase actuation of the drive electrodes 121 with polyphase actuation of the fixed actuator electrodes 129 is provided.FIG. 10 shows an exemplary embodiment according to which the direction of movement is not a vertical direction, but rather a lateral direction, i.e. according to the Cartesian coordinate system 117 in the x direction.For clarity, not all elements of the MEMS device are shown. A plurality of actuator electrodes 1001 and a plurality of movable drive electrodes 1003 are shown schematically.Depending on a corresponding actuation of the actuator electrodes 1001 and drive electrodes 1003, an electrostatic force can thus be generated, which acts on the movable electrode 1003 in the x direction, so that the latter carries out a movement along the x direction, that is to say in the lateral direction.In FIG. 10, six exemplary representations of the movement of the movable drive electrodes 1003 are shown, numbered 1st, 2nd, 3rd, 4th, 5th and 6.Thus, FIG. 10 shows an exemplary configuration of the fixed actuator electrodes and of the drive electrodes for a direction of movement in the lateral direction. By means of a position-dependent, i.e. dependent on a position of the drive electrodes 1003, electrical actuation of the fixed actuator electrodes 1001, a continuing movement (beyond an electrode pair of the fixed actuator electrodes 1001) can be achieved. Analogously to the vertical deflection or direction of movement, the multi- or in-phase actuation possibilities can also be provided here, which have already been described above.FIG. 11 shows a flow diagram of a method for operating a MEMS component according to one of the preceding claims, comprising the following steps:electrically driving 1101 the driving electrodes to generate a leakage electric field,electrically driving 1103 the at least one driving electrode to generate a directional electrostatic force along the direction of movement, such that the at least one driving electrode experiences a directional electrostatic force along the direction of movement.FIG. 12 shows a machine-readable storage medium 1201 on which a computer program 1203 is stored. The computer program 1203 comprises instructions which, when the computer program 1203 is executed by a computer, cause the computer program to execute a method according to the second aspect.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 2021297787 [0003, 0023]WO 2021 / 144400

[0005] WO002021223886 [0005, 0006, 0007, 0074]DE 10 2019 203 914

[0005] WO 22117197 [0007, 0074]Cited Non-Patent LiteratureKaiser et al. Microsystems & Nanoengineering (2019) 5:43

[0005]

Claims

A MEMS component (101) comprising: a carrier (105), a drive element (115) which is movable along a direction of movement and is suspended resiliently on the carrier (105) and has at least one individually electrically controllable drive electrode (121), a displacement plate (123) connected to the drive element (115), a fixed actuator arrangement (127) which has a plurality of actuator electrodes (129) which are electrically insulated from one another and individually electrically controllable and are arranged one after the other along the direction of movement of the movable drive element (115), wherein the actuator electrodes (129) are configured to generate a leakage electric field when electrically controlled, so that when electrically controlled the at least one drive electrode (121) it experiences a directed electrostatic force along the direction of movement.The MEMS component (101) according to claim 1, comprising a control device which is configured to individually electrically drive the at least one drive electrode (121) and the actuator electrodes (129) such that the at least one drive electrode (121) moves along the direction of movement.The MEMS component (101) according to claim 2, wherein the control device is configured to determine a position of the at least one drive electrode (121), wherein the control device is configured to electrically drive the at least one drive electrode (121) and / or the actuator electrodes (129) based on the determined position.The MEMS component (101) according to claim 2 or 3, wherein the control device is configured to drive the drive electrodes (121) in the same phase and / or to drive the actuator electrodes (129) in polyphase fashion.The MEMS device (101) according to any of the preceding claims, wherein the drive element (115) comprises at least one opening (135) for a fluid exchange.The MEMS component (101) according to one of the preceding claims, wherein the drive element (115) is connected to the displacement plate (123) by means of a piston (125).The MEMS component (101) according to one of the preceding claims, wherein the drive element (115) is suspended resiliently on the carrier (105) by means of a spring suspension (119) comprising at least one spring (601, 603, 605, 607).The MEMS device (101) according to claim 7, wherein the carrier (105) for the at least one spring (601, 603, 605, 607) comprises in each case a movement channel (609, 611, 613, 615), within which the at least one spring (601, 603, 605, 607) is movably arranged.The MEMS component (101) according to one of the preceding claims, wherein the carrier (105) has a block shape in which a recess (111) is formed, in which the drive element (115) and the fixed actuator arrangement (127) are arranged.The MEMS component (101) according to claim 9, wherein an acoustic inlet (109) is formed on the rear side of the carrier (105), from which an acoustic channel (113) runs as far as the recess (111).The MEMS component (101) according to claim 10, wherein the carrier (105) is arranged within a housing (103), which has a housing opening (107) on the rear side at the acoustic inlet (109).The MEMS device (101) according to claim 11, wherein the housing (103) has an acoustic output (131) on the front side.The MEMS component (101) according to one of the preceding claims, wherein the displacement plate (123) is designed to be torsionally rigid.The MEMS component (101) according to one of the preceding claims, wherein a dielectric (703) for electrically insulating the drive electrodes (121) from one another is arranged in each case between the drive electrodes (121).The MEMS device (101) according to any one of the preceding claims, wherein the direction of movement is a vertical direction of movement, wherein the actuator electrodes (129) are arranged one above the other, or that the direction of movement is a lateral direction of movement, wherein the actuator electrodes (129) are arranged next to each other.The MEMS component (101) according to one of the preceding claims, wherein the displacement plate (123) is arranged within a recess in the carrier (105) and the movement of which is limited to the region of the recess.Method for operating a MEMS component (101) according to one of the preceding claims, comprising the following steps: electrically driving (1101) the drive electrodes (121) in order to generate a leakage electric field, electrically driving (1103) the at least one drive electrode (121) in order to generate a directed electrostatic force along the direction of movement, such that the at least one drive electrode (121) experiences a directed electrostatic force along the direction of movement.A computer program (1203) comprising instructions which, when the computer program (1203) is executed by a computer, cause the computer program to perform a method according to claim 17.A machine readable storage medium (1201) having stored thereon the computer program (1203) of claim 18.

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