MEMS device with electrodes and a dielectric

Abstract

Microelectromechanical systems (MEMS) device (100), comprising: a first electrode (110) which is aligned longitudinally along and parallel to an axis (160), wherein the first electrode has a first end (111) and a second end (112); a second electrode (120) which is aligned longitudinally and parallel to the axis, wherein the second electrode has a first end (121) and a second end (122); a third electrode (130) oriented longitudinally along and parallel to the axis, the third electrode having a first end (131) and a second end (132); and a solid dielectric (150) comprising a plurality of passages (156), wherein the first, second and third electrodes are each at least partially arranged within one pass of the plurality of passes, wherein the dielectric surrounds the second end of the second electrode and the first end of the third electrode, wherein the first end of the second electrode and the second end of the third electrode are arranged outside the solid dielectric, wherein the dielectric is mobile relative to the first, second and third electrodes, wherein a first capacitance exists between the first and second electrodes, which changes with a movement of the dielectric relative to the electrodes, and where a second capacitance exists between the first and third electrodes, which changes with a movement of the dielectric relative to the electrodes.

Description

BACKGROUND 1. Area

[0001] The present disclosure relates to a MEMS (microelectromechanical systems) device comprising electrodes and a dielectric. 2. Introduction

[0002] Today, consumer electronic devices such as mobile phones, PCs, smart speakers, hearing aids, and true wireless stereo (TWS) earbuds typically contain one or more small microphones, sensors, and / or actuators, among other host devices. Advances in micro- and nanofabrication technology have led to the development of MEMS devices, such as microphones, sensors, and actuators, that exhibit increasingly smaller dimensions and diverse form factors. Increasing the bias of capacitive microphones, sensors, actuators, and other capacitive elements in MEMS devices results in higher performance and different operational capabilities, but also increases the tendency to collapse and the mechanical stiffness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] To describe how the advantages and features of the disclosure can be achieved, the disclosure is described with reference to specific embodiments illustrated in the accompanying drawings. These drawings show only exemplary embodiments of the disclosure and are therefore not to be considered as limiting its scope. The drawings may have been simplified for clarity and are not necessarily drawn to scale. Fig. Figure 1 is an exemplary cross-sectional view of a MEMS device according to one possible embodiment; Fig. Figure 2 is an exemplary isometric view of a MEMS device according to one possible embodiment; Fig. Figure 3 is an exemplary cross-sectional view of a MEMS device according to one possible embodiment; Fig. Figures 4-7 are isometric example views of MEMS devices according to possible embodiments; Fig. Figures 8-11 are exemplary cross-sectional views of MEMS devices according to possible embodiments; Fig. Figure 12 is an example cross-sectional view of a sensor package according to one possible embodiment; and Fig. Figure 13 is an exemplary representation of an application of a MEMS device according to one possible embodiment. Detailed description

[0004] Embodiments can provide a MEMS device with electrodes and a dielectric. According to one possible embodiment, a MEMS device can include a first electrode oriented longitudinally and parallel to an axis. The first electrode can have a first end and a second end. The MEMS device can include a second electrode oriented longitudinally and parallel to the axis. The second electrode can have a first end and a second end. The MEMS device can include a third electrode oriented longitudinally and parallel to the axis. The third electrode can have a first end and a second end. The MEMS device can include a solid dielectric having a plurality of passages. The first, second, and third electrodes can each be located at least partially within one passage of the plurality of passages.The dielectric can surround the second end of the second electrode and the first end of the third electrode. The first end of the second electrode and the second end of the third electrode can be located outside the solid dielectric.

[0005] At least some embodiments can be based on a dielectric actuator, in which a dielectric is positioned between electrodes with different potentials. The resulting electrostatic force attracts the dielectric and the electrodes so that the dielectric covers as much of the electrodes as possible, thereby maximizing the capacitance between them. The force is proportional to the change in capacitance with displacement and to the square of the voltage.

[0006] When a voltage is applied between adjacent electrodes, an electrostatic force is generated that attracts the dielectric and the electrodes in a way that strengthens the bond between them. The energy in a capacitor is E = ½ CV 2 If the dielectric is moved into a gap between the electrodes, the capacitance increases. The electrostatic force F = δE / δz = ½ δC / δz V 2 , where z is the direction of interaction between the dielectric and the electrodes. The capacitance between the electrodes varies linearly depending on the displacement of the dielectric, as long as the ends of the dielectric do not get too close to the ends of the conductive electrode and as long as the electrodes are ideally shaped. Thus, the generated electrostatic force is constant, regardless of the position of the dielectric between the electrodes.

[0007] In conventional sensors with parallel plates, the electrostatic force varies inversely with the square of the gap between the plates. In a MEMS device, such as a microphone, the electrostatic force causes the diaphragm to deflect, thus increasing its stiffness depending on the deflection. If a dielectric motor is used as the sensor in a MEMS device, such as a microphone, the electrostatic force generated by the motor can cause the diaphragm to deflect, thereby contributing to its stiffness. This additional stiffness is proportional to the square of the applied voltage. The sensor's sensitivity is also proportional to the applied voltage, so there is a trade-off between increasing the applied voltage to increase sensitivity and the decreasing mechanical compliance (i.e., the increasing stiffness) of the diaphragm.At least some embodiments can provide a motor with a double dielectric that can make the overall compliance independent of the applied voltage, at least to the first order of magnitude.

[0008] A problem with conventional parallel-plate MEMS microphones is the tendency of the diaphragm to collapse onto the backplate under high shock or acoustic loads. A microphone with two diaphragms and a backplate can become very unstable if the gap between the diaphragm and backplate becomes uneven. Using a dual dielectric for sampling can prevent both electrostatic collapse and electrostatic stiffening of the diaphragm(s). In some embodiments, two opposing dielectric motors can be used to balance the electrostatic force between them. In some embodiments, this can enable large bias voltages with little or no net electrostatic force, or a gradient of electrostatic force with the position between the electrodes and the dielectric of a MEMS device.

[0009] Fig. Figure 1 is an exemplary cross-sectional view of a MEMS device 100 according to one possible embodiment. Fig. Figure 2 is an exemplary isometric view of a MEMS device 200 according to one possible embodiment. Fig. Figure 3 is an exemplary cross-sectional view of a MEMS device 300 according to one possible embodiment. Fig. Figures 4-7 are isometric example views of MEMS devices 400, 500, 600 and 700 according to possible embodiments. Fig. Figures 8-11 are exemplary cross-sectional views of MEMS devices 800, 900, 1000 and 1100 according to possible embodiments. Fig. Figure 12 is an example cross-sectional view of a sensor package 1200 according to one possible embodiment. Fig. 13 is an example representation 1300 of an application of the MEMS device 400 or of another disclosed MEMS device according to a possible embodiment.

[0010] In general, a MEMS device can be described with reference to the Fig. 1-3 comprise a first electrode 110 oriented longitudinally and parallel to an axis 160. The first electrode 110 may have a first end 111 and a second end 112. The MEMS device may comprise a second electrode 120 oriented longitudinally and parallel to the axis 160. The second electrode 120 may have a first end 121 and a second end 122. The MEMS device may comprise a third electrode 130 oriented longitudinally along and parallel to the axis 160. The third electrode 130 may have a first end 131 and a second end 132. The electrodes 110, 120, and 130 may be cylinders, plates, cuboids, prisms, polyhedra, or other electrode shapes. The length of the first electrode 110 can be longer than the length of the second electrode 120 and longer than the length of the third electrode 130.The MEMS device includes a dielectric 150 located between the electrodes. The dielectric 150 has a plurality of passages 156 (in . Fig. (1 not shown) that penetrate the dielectric 150 in a direction parallel to an axis 160. The first, second, and third electrodes can each be arranged at least partially within a passage of the plurality of openings 156. That they are arranged at least partially within a passage can mean that part of an electrode is arranged within a passage and / or the electrode is arranged within a portion of the passage. According to one possible embodiment, at least the second and third electrodes can be arranged only partially within the passages 156 so that their ends are located outside the solid dielectric 150. The electrodes can be substantially fixed relative to each other. For example, the electrodes can be substantially fixed while allowing some relative movement due to bending and other forces.The dielectric 150 and the electrodes are freely movable relative to each other.

[0011] A voltage from a first voltage source V1 is applied between the first electrode 110 and the second electrode 120 to generate a relatively constant force F1. A voltage from a second voltage source V2 is applied between the first electrode 110 and the third electrode 130 to generate a relatively constant force F2. The forces F1 and F2 are opposite. If the structure is relatively symmetrical and the voltage sources V1 and V2 are equal, the forces F1 and F2 are equal, resulting in a net force of zero between the dielectric and the electrodes. The magnitudes of the voltages from voltage sources V1 and V2 can be unequal to compensate for asymmetries in the structure or to intentionally generate a non-zero net force between the dielectric and the electrodes.

[0012] The MEMS device can be a MEMS transducer. For example, the MEMS device can be a sensor or an actuator. The MEMS device can be mechanically driven, for example, for use as a differential sensor, microphone, vibration sensor, or other sensor. The MEMS device can also be electrically driven, for example, to generate mechanical movement as an actuator or loudspeaker.

[0013] The MEMS device comprises at least one dielectric 150. With reference to Fig. 2. According to one possible embodiment, the dielectric 150 can be a solid dielectric comprising a plurality of passages 156. The passages 156 are shown as cylindrical for simplicity, but can assume any useful shape. The dielectric 150 can surround the second end 122 of the second electrode 120 and the first end 131 of the third electrode 130. The first end 121 of the second electrode 120 and the second end 132 of the third electrode 130 can be located outside the solid dielectric 150. According to one possible embodiment, the dielectric 150 can fill at least 50% of the distance between the first and second electrodes 120. The distance can be perpendicular to the first length of the first electrode 110. For example, the dielectric 150 can fill at least 75% of the distance, at least 80% of the distance, or at least 80-90% of the distance.The dielectric 150 can fill any amount from 1% to 99% of the gap. The more the dielectric fills the gap between the electrodes, the greater the change in capacitance per unit displacement and the higher the force generated at a given bias between the electrodes. Subject to manufacturing limitations, a minimal gap should remain between the dielectric and the electrodes to allow them to move relative to each other. In some embodiments, the solid dielectric 150 has openings 156, for example, in the form of channels or passages, but the solid dielectric 150 can also take other forms, such as one or more segments or elements, as shown in other embodiments.

[0014] The dielectric 150 can be mobile relative to the first, second, and third electrodes. For example, the dielectric 150 can be substantially and intentionally mobile beyond minor movement due to accidental flexing, bending, lifting, and other minor movements of the dielectric 150. If the dielectric 150 is mobile parallel to the axis 160 relative to the first, second, and third electrodes, then the first, second, and third electrodes can also be mobile relative to the dielectric 150. Because the electrodes and the dielectric 150 are mobile relative to each other, the electrodes and / or the dielectric 150 can be fixed, non-fixed, or mobile with respect to other elements of the MEMS device, with respect to ground, and / or with respect to any other reference point.

[0015] A first capacitance exists between the first electrode 110 and the second electrode 120. A second capacitance exists between the first electrode 110 and the third electrode 130. The capacitance between the electrodes can be a function of the dielectric 150. For example, the values ​​of the first and second capacitances can change in opposite directions if the dielectric 150 is moved in a direction parallel to the axis 160 relative to the electrodes. For example, if the dielectric 150 moves and the first capacitance increases, the second capacitance can decrease. An electrostatic force on the dielectric 150 relative to the electrodes 110, 120, and 130 can be essentially unchanged relative to the displacement.

[0016] The first electrode 110 can be arranged at least partially within a first passage of the plurality of passages 156. The second end 122 of the second electrode 120 can be arranged within a second passage of the plurality of passages 156. The first end 131 of the third electrode 130 can be arranged within a third aperture of the plurality of openings 156. The first, second, and third apertures can be different passages.

[0017] The dielectric 150 can comprise a first surface 151 and a second surface 152. The first surface 151 and the second surface 152 can be parallel to a plane perpendicular to the axis 160. The first end 111 and the second end 112 of the first electrode 110 can be located outside the dielectric 150. The second end 112 of the first electrode 110 and the second end 132 of the third electrode 130 can extend beyond the second surface 152 of the dielectric 150. The first end of the second electrode 120 can extend beyond the first surface 151 of the dielectric 150. The first end 111 of the first electrode 110 can also extend beyond the first surface 151 of the dielectric 150.

[0018] In one embodiment, the first electrode 110 can be an electrically conductive pin from a plurality of first electrically conductive pins that are electrically connected to one another. The second electrode 120 can be an electrically conductive pin from a plurality of second electrically conductive pins that are electrically connected to one another. The third electrode 130 can be an electrically conductive pin from a plurality of third electrically conductive pins that are electrically connected to one another.

[0019] According to one possible embodiment of Fig. The first electrode can be a plurality of first electrodes 110-x, the second electrode can be a plurality of second electrodes 120-x, and the third electrode can be a plurality of third electrodes 130-x. The plurality of second and third electrodes 120-x and 130-x can be arranged offset on either side of the plurality of first electrodes 110-x. This can allow for a larger capacitance and an increase in the capacitance change upon displacement. Other configurations of conductive and dielectric elements, such as rods or rings, can also be used. The plurality of first electrodes 110-x can be collectively referred to as the first plurality of electrodes. Similarly, the plurality of second electrodes 120-x can be collectively referred to as the second plurality of electrodes, and the plurality of third electrodes 130-x can be collectively referred to as the third plurality of electrodes.

[0020] With reference to the Fig. To accommodate the multitude of interconnected conductive pins, the first, second, and third passages 156 can each be a first, second, and third plurality of passages 156, respectively. The first plurality of electrically conductive pins can be arranged in a two-dimensional configuration in a plane perpendicular to the axis 160. The second and third plurality of electrically conductive pins can be arranged in corresponding two-dimensional configurations in a plane perpendicular to the axis 160 and between the first plurality of electrically conductive pins. According to one possible embodiment, the dielectric 150 can be considered a non-conductive element for modulating the electric field, depending on the embodiment.

[0021] With reference to Fig. 4. The MEMS device can comprise a membrane 170 coupled to at least the first electrodes 110-x. The membrane 170 can have a substantially flat surface 172 perpendicular to the axis 160. The surface 172 can be substantially flat, although it may have irregularities, or it can be slightly curved or uneven, while still functioning in a manner useful for a membrane. The membrane 170 can also have layered sections.

[0022] According to one possible embodiment, the membrane 170 can be a first membrane connected to the first electrodes 110-x and the third electrodes 130-x. The MEMS device can include a second membrane 174 connected to the first electrodes 110-x and the second electrodes 120-x. The second membrane 174 can be located on the side of the dielectric 150 opposite the first membrane 170. The second membrane 174 can have a substantially flat surface 176 perpendicular to the axis 160. The first membrane 170 and the second membrane 174 are spaced apart from the dielectric 150 to allow relative movement between the electrodes connected to the first and second membranes and the dielectric 150. A low-pressure area can be established and sealed between the membranes 170 and 174 to reduce noise and attenuation of the structure.The first electrodes 110-x are connected to both the first membrane 170 and the second membrane 174, preventing the membranes from collapsing onto the dielectric 150. This low-pressure region can essentially be a vacuum, such as a pressure of less than 1 Torr, less than 300 m Torr, or less than 100 m Torr.

[0023] Membranes 170 and 174 can be made of a dielectric material such as silicon nitride. Dielectric 150 can also be silicon nitride. Electrodes 110-x, 120-x, and 130-x can be made of polysilicon. However, other materials can also be used. For example, one or more of membranes 170 and 174 and dielectric 150 can be made of polyimide. As another example, the electrode conductors can be made of coated metals.

[0024] According to Fig. In 4, the dielectric 150 is fixed in its position, with its periphery attached to a substrate 180 by means of spacer layers 182, 184, and 186. The peripheries of the membranes are also attached to the substrate 180 by means of spacer layers 182, 184, and 186. The dielectric 150 is relatively thick and rigid compared to the membranes 172 and 174 and remains relatively immobile when the membranes 172 and 174 are deflected. The deflection of the membranes 172 and 174 moves the electrodes 110-x, 120-x, and 130-x relative to the dielectric 150.

[0025] Fig. Figure 5 shows a perspective view of the MEMS device of Fig. Figure 4, which is partially assembled and shows only a second membrane 174, first electrodes 110-x and second electrodes 120-x. An example connection 114 is shown that electrically connects the electrodes 110-x (for example, the pins of a first electrode), while an example connection 124 is shown that electrically connects the electrodes 120-x (for example, the pins of a second electrode).

[0026] Fig. 6 continues the construction of the MEMS device of Fig. 4 continued, wherein a dielectric 150 with passages 156 is added, in which the first and second electrodes are accommodated.

[0027] Fig. 7 continues the construction of the MEMS device of Fig. 4 continues with the placement of the third electrodes 130-x and an exemplary intermediate connection 134 that electrically connects the third electrodes 130-x (for example, the pins of the third electrode 130-x). The construction continues with the addition of the first membrane 170 and the removal of the central area of ​​the spacer layers 182, 184, and 186 by sacrificial etching to create the MEMS device of Fig. to form 4.

[0028] With reference to Fig. 8 and Fig. 9. The MEMS device can include a fourth electrode 140. The fourth electrode 140 can have a first end 141 and a second end 142. The dielectric 150 can surround the first end 111 of the first electrode 110 and the second end 142 of the fourth electrode 140. The second end 112 of the first electrode 110 and the first end 141 of the fourth electrode can be located outside the dielectric 150. The fourth electrode 140 may or may not be electrically coupled to the first electrode 110. With reference to Fig. 9 the fourth electrode 140 can be coaxial with the first electrode 110, for example by being arranged in the same passage.

[0029] Referring to Fig. 4. The second electrodes 120-x can be coaxial with the respective third electrodes 130-x. With reference to Fig. 9-11 The second electrodes 120-x can be coaxial with the respective third electrodes 130-x. For example, the second and third electrodes can be arranged in the same passage. As in Fig. 10 and Fig. As shown in Figure 11, an optional dielectric support layer D can be located between the second and third electrodes 120 and 130. The dielectric support layer D may or may not have the same cross-sectional area as the second and third electrodes 120 and 130. The dielectric D can be used for structural purposes, taking into account additional parasitic capacitances. For example, the dielectric D can serve to prevent a collapse or contact between the second electrode 120 and the third electrode 130 when the cavity between the membranes is under vacuum.

[0030] Referring to Fig. The MEMS device, which functions as a sensor as used in a microphone, can include a first charge amplifier 194 coupled to the second electrode 120. The first charge amplifier 194 can bias the second electrode 120 to a first potential relative to the first electrode 110. The MEMS device can also include a second charge amplifier 196 coupled to the third electrode 130. The second charge amplifier 196 can bias the third electrode 130 to a second potential relative to the first electrode 110. The first potential can be essentially the same as the second potential. The first potential can also differ from the second potential. The first and second charge amplifiers 194 and 196 can generate complementary outputs when the dielectric 150 is moved relative to the electrodes. For example, Q = C * V, and when using a charge amplifier, V is held constant.If C increases, Q can increase, and vice versa. This can lead to complementary outputs.

[0031] According to one possible embodiment, for example, one electrode, such as electrode 110, can be continuous and another electrode can be divided into segments, for example, electrodes 120 and 130. The first electrode 110 can be biased. With the aid of the charge amplifiers 194 and 196, the driven electrodes 120 and 130 can be biased to a fixed potential, i.e., to ground, through a very high resistance via the feedback capacitor. The charge amplifiers 194 and 196 can generate complementary outputs when the dielectric 150 is moved along an axis that is essentially parallel to the lengths of the first, second, and third electrodes.

[0032] Referring to Fig. 11. The MEMS device, which functions as a sensor, as used, for example, in a microphone, can include a high-impedance voltage amplifier 1000 with a first input 1010 and a second input 1020. The first input 1010 can be connected to the second electrode 120, and the second input 1020 to the third electrode 130. The inputs 1010 and 1020 are biased to a fixed potential, i.e., ground, by very high resistors. As mentioned earlier, Q = C*V. When using a high-impedance amplifier, Q can be kept constant because no current flows. If C increases, V decreases, and vice versa. This can lead to a complementary output.

[0033] With reference to Fig. 12. The MEMS device 100, or any other disclosed MEMS device, can be part of a sensor package 1200. The sensor package 1200 can comprise a housing 1111, which may include a base 1110 and a cover 1105, such as a can or other cover, connected to the base 1110. The first, second, and third electrodes 110-x, 120-x, and 130-x, as well as the solid dielectric 150, can be arranged within the housing 1111. For example, the housing 1111 can enclose a MEMS device between the cover 1105 and the base 1110. The sensor package 1100 can include an interface for external devices 1520, which is arranged on the base 1110. The 1520 external device interface can be implemented as a surface mount interface or include conduits configured for through-hole mounting on a host device.

[0034] The sensor package 1200 can include an integrated circuit 1530, such as an application-specific integrated circuit (ASIC), which is electrically connected to the first, second, and third electrodes 110, 120, and 130, respectively. The integrated circuit 1530 can also be coupled to contacts of the external device interface 1520, for example, via an electrical line 1534 and / or lines passing through the base 1110. The integrated circuit 1530 can receive an electrical signal from the MEMS device 100, for example, via an electrical line 1532, and can communicate with a host device, for example, via the electrical line 1534 and / or lines in the base 1110, using the contacts of the external device interface 1520. According to one possible implementation, the integrated circuit 1530 can be covered by a protective layer 1526.

[0035] According to one possible embodiment, the base 1110 can include a sound port 1150. The MEMS device 100 can be acoustically coupled to the sound port 1150. For example, the sound port 1150 can be a pass-through in the base 1110, allowing sound to pass through the base to the MEMS device 100. The illustrative embodiments can be considered a bottom-port configuration, but the sound port 1150 can also be located at other points in the transducer assembly. For example, the sound port 1150 can also be located on the cover 1105 for a top-port configuration. Furthermore, the sound port 1150 may be located on one side of the sensor package 1100, the sound port 1150 may be located at another location on the sensor package 1100, or there may be no sound port 1150, as is the case with a MEMS die vibration sensor or another sensor.According to one possible embodiment, if the MEMS device 100 comprises at least one diaphragm 170 and / or 174, the diaphragm 170 and / or 174 can be acoustically coupled to the sound port 1150. According to other embodiments, the MEMS device 100 cannot be used in a sensor package, for example, if the MEMS device 100 is an actuator, as described above.

[0036] With reference to Fig.13 is the MEMS device, such as the MEMS device 400 or any other apparent MEMS device acting as an actuator, as used, for example, in a loudspeaker, connected to an amplifier 1310. The output of the amplifier 1310 is connected to the first electrodes 110-x of the MEMS device. The second and third electrodes 120-x and 130-x are connected to the power supply rails V1 and V2, respectively. The output of the amplifier 1310 oscillates between the power supply rail values ​​of V1 and V2 in response to an input signal. When the amplifier output is at the midpoint of the rail (V1 + V2) / 2, the electrostatic force acting on the electrodes, and thus on the diaphragms 170 and 172, is balanced. As the amplifier output approaches one of the power supply rails, the electrostatic force exerted on the electrodes, and thus on the diaphragms, reaches a maximum in that direction.As the amplifier output approaches the opposite power supply rail, the electrostatic force acting on the electrodes, and thus on the diaphragms, reaches a maximum in the other direction. Since the electrostatic force is proportional to the square of the voltage, this design results in non-linear movement.

[0037] The 1310 amplifier can be a pulse-width modulation (PWM) or pulse-density modulation (PDM) amplifier, with a digital output that oscillates between the two power supply rails. The average output value of a PWM amplifier and the average output value of a PDM amplifier are functions of their inputs. The output of the digital amplifier is applied to the first electrodes 110-x. The electrostatic force acting on the electrodes, and thus on the diaphragms, is proportional to the square of the average value. The digital amplifier can incorporate a square root function, so that the movement of the diaphragm is linear with the input. The diaphragms can couple their movement directly to the air, thus generating sound, or they can couple their movement via an auxiliary diaphragm to move air and thus generate sound.

[0038] According to one possible embodiment, a MEMS device can comprise a solid dielectric, wherein the dielectric can have a first outer surface and a second outer surface opposite the first outer surface. The dielectric can have a plurality of openings, such as through-holes, wherein each of the plurality of openings can have an opening on the first outer surface and an opening on the second outer surface. The MEMS device can be a MEMS transducer. The MEMS device can include an electrode array. The dielectric and the electrode array can be movable relative to each other.

[0039] The electrode set can include a first electrode that is partially located within a first pass of a plurality of passes, such that a first end of the first electrode extends beyond the first outer surface and a second end of the first electrode extends beyond the second outer surface. The first electrode can be one of a plurality of first electrodes that are electrically connected to each other.

[0040] The electrode set can include a second electrode that is partially located within a second passage of the plurality of passages, such that a first end of the second electrode extends beyond the first outer surface and a second end of the second electrode lies within the second passage. The second electrode can be one of a plurality of second electrodes that are electrically connected to each other.

[0041] The electrode array can include a third electrode, which is partially located within a third passage of the plurality of passages, such that a first end of the third electrode is within the third passage and a second end of the third electrode extends beyond the second outer surface. The third electrode can be one of a plurality of third electrodes that are electrically connected to each other. The first, second, and third electrodes can be fixed relative to each other.

[0042] According to another possible embodiment, an apparatus can comprise an electrode assembly and a dielectric element. The electrode assembly can comprise at least a first, a second, and a third electrode. The electrodes of the electrode assembly can each have an individual height with an upper and lower surface at the ends of each height. Capacitance exists at least between the first and second electrodes and between the first and third electrodes of the electrode assembly.

[0043] The dielectric element can have a height with a top and bottom surface at its ends. The dielectric element can have through-holes so that it surrounds the electrode assembly and is spaced apart from each electrode of the assembly. The dielectric element must not be in mechanical contact with any electrode of the assembly.

[0044] The upper surface of the first electrode of the electrode set can be located above the upper surface of the dielectric element, and the lower surface of the first electrode of the electrode set can be located below the lower surface of the dielectric element. The upper surface of the second electrode of the electrode set can be located above the upper surface of the dielectric element, and the lower surface of the second electrode can be located between the upper and lower surfaces of the dielectric element. The upper surface of the third electrode of the electrode set can be located between the upper and lower surfaces of the dielectric element, and the lower surface of the third electrode of the electrode set can be located below the lower surface of the dielectric element.

[0045] The physical positions of the electrodes in the electrode set can be essentially fixed relative to each other. The physical position of the electrode set in relation to the position of the dielectric element can be movable.

[0046] The relative position of each electrode to the others can be essentially fixed. Some electrodes can be fixed, while others can move. For example, the first electrode and the dielectric element can be rigidly connected, while the second and third electrodes are allowed to move relative to the dielectric element. Other configurations are possible.

[0047] The first electrode of the electrode set can be divided into two electrically independent elements. The first element can have an upper surface and a second lower surface. The second element can have a second upper surface and a lower surface. The upper surface of the first element of the first electrode can be located above the upper surface of the dielectric. The second lower surface of the first element of the first electrode can be located between the upper and lower surfaces of the dielectric. The second upper surface of the second element of the first electrode can be located between the upper and lower surfaces of the dielectric, and the lower surface of the second element of the first electrode can be located below the lower surface of the dielectric.

[0048] According to one possible embodiment, a MEMS device can comprise a solid dielectric having a plurality of passages. The MEMS device can comprise a first plurality of electrodes, wherein the first plurality of electrodes extends completely through a first subset of the plurality of passages. The MEMS device can comprise a second plurality of electrodes, wherein the second plurality of electrodes extends partially into a second subset of the plurality of passages. The second subset can differ from the first subset. The MEMS device can comprise a third plurality of electrodes, wherein the third plurality of electrodes extends partially into a third subset of the plurality of passages. The third subset can differ from the first subset.

[0049] According to one possible embodiment of the above embodiment, the solid dielectric can comprise a first side and a second side opposite the first side. The plurality of passages can extend from the first side to the second side. The second plurality of electrodes can extend partially from the first side into the second subset. The third plurality of electrodes can extend partially from the second side into the third subset. The second subset can be identical to or different from the third subset.

[0050] While this disclosure has been described with specific embodiments thereof, it is obvious that many alternatives, modifications, and variations are apparent to those skilled in the art. For example, various components of the embodiments can be exchanged, added, or substituted in other embodiments. Furthermore, not all elements of the individual figures are necessary for the operation of the disclosed embodiments. For instance, a person skilled in the art with normal technical knowledge of the disclosed embodiments would be able to produce and use the teachings of the disclosure simply by using the elements of the independent claims. Accordingly, the embodiments of the disclosure, as set forth here, are illustrative and not limiting. Various modifications can be made without departing from the spirit and scope of the disclosure.

Claims

[1] Microelectromechanical systems (MEMS) device (100), comprising: a first electrode (110) which is aligned longitudinally along and parallel to an axis (160), wherein the first electrode has a first end (111) and a second end (112); a second electrode (120) which is aligned longitudinally and parallel to the axis, wherein the second electrode has a first end (121) and a second end (122); a third electrode (130) oriented longitudinally along and parallel to the axis, the third electrode having a first end (131) and a second end (132); and a solid dielectric (150) comprising a plurality of passages (156), wherein the first, second and third electrodes are each at least partially arranged within one pass of the plurality of passes, wherein the dielectric surrounds the second end of the second electrode and the first end of the third electrode, wherein the first end of the second electrode and the second end of the third electrode are arranged outside the solid dielectric, wherein the dielectric is mobile relative to the first, second and third electrodes, wherein a first capacitance exists between the first and second electrodes, which changes with a movement of the dielectric relative to the electrodes, and where a second capacitance exists between the first and third electrodes, which changes with a movement of the dielectric relative to the electrodes. [2] MEMS device (100) according to claim 1, wherein the first electrode (110) is arranged at least partially within a first pass of the plurality of passes, wherein the second end (122) of the second electrode (120) is arranged within a second pass of the plurality of passes, wherein the first end (131) of the third electrode is arranged within a third pass of the plurality of passes, and where the first, second and third rounds are different rounds. [3] MEMS device according to claim 1, wherein the first capacitance and the second capacitance change differently in response to the movement of the dielectric relative to the electrodes. [4] MEMS device (100) according to claim 1, further comprising a fourth electrode (140), wherein the fourth electrode has a first end (141) and a second end (142), wherein the dielectric (150) surrounds the first end of the first electrode and the second end of the fourth electrode, and wherein the second end of the first electrode and the first end of the fourth electrode are located outside the dielectric. [5] MEMS device (100) according to claim 1, wherein the dielectric (150) comprises a first surface (151) and a second surface (152), wherein the second end (112) of the first electrode (110) and the second end (131) of the third electrode (130) extend beyond the second surface, and wherein the first end (111) of the second electrode (110) extends beyond the first surface. [6] MEMS device according to claim 1, wherein a first voltage source applies a first voltage between the first electrode and the second electrode to generate a first force, and a second voltage source applies a second voltage between the first electrode and the third electrode to generate a second force that opposes the first force. [7] MEMS device (100) according to claim 1, wherein the first electrode (110) comprises a first plurality of electrically conductive pins which are electrically connected to each other, wherein the second electrode (120) comprises a second plurality of electrically conductive pins which are electrically connected to each other, and wherein the third electrode (130) comprises a third plurality of electrically conductive pins which are electrically interconnected. [8] MEMS device (100) according to claim 7, wherein the first plurality of electrically conductive pins is arranged in a two-dimensional arrangement in a plane perpendicular to the axis (160), and wherein the second and third plurality of electrically conductive pins are arranged in respective two-dimensional arrangements in a plane perpendicular to the axis and are mixed between the first plurality of electrically conductive pins. [9] MEMS device (100) according to claim 1, wherein the electrodes are substantially fixed relative to each other. [10] MEMS device (100) according to claim 1, wherein the second electrode is coaxial with the third electrode. [11] MEMS device (100) according to claim 1, wherein the first and second ends of the first electrode are located outside the dielectric. [12] MEMS device (100) according to claim 1, wherein the MEMS device comprises a MEMS transducer. [13] MEMS device (100) according to claim 1, further comprising: a housing (1111), comprising: a base (1110); and a cover (1105) which is connected to the base, wherein the first (110), second (120) and third electrode (130) and the solid dielectric (150) are arranged inside the housing. [14] MEMS device (100) according to claim 1, further comprising a membrane (170) coupled to at least the first electrode, wherein the membrane has a substantially planar surface perpendicular to the axis. [15] MEMS device (100) according to claim 14, wherein the membrane (170) comprises a first membrane coupled to the first electrode (110) and the third electrode (130), and wherein the MEMS device further comprises a second membrane coupled to the first electrode and the second electrode, wherein the second membrane is arranged on a side of the dielectric opposite the first membrane and wherein the second membrane has a substantially planar surface perpendicular to the axis. [16] MEMS device (100) according to claim 1, wherein the first electrode (110) is longer than the second electrode (120) and the first electrode is longer than the third electrode (130). [17] MEMS device (100) according to claim 1, wherein the solid dielectric fills at least 50% of a distance between the first and the second electrode, measured perpendicular to a length of the first electrode. [18] MEMS device (100) according to claim 1, further comprising a voltage source which applies a voltage between the first electrode and the second electrode, wherein the voltage generates a force which acts in a direction which increases the capacitance between the first and the second electrode. [19] MEMS device (100) according to claim 1, further comprising: a first charge amplifier (194) coupled to the second electrode, wherein the first charge amplifier biases the second electrode to a first potential relative to the first electrode; and a second charge amplifier (196) coupled to the third electrode, wherein the second charge amplifier biases the third electrode to a second potential relative to the first electrode. [20] MEMS device (100) according to claim 1, further comprising a voltage amplifier (1000) with high input impedance, comprising a first input and a second input, wherein the first input is coupled to the second electrode and the second input is coupled to the third electrode. [21] MEMS device (100) according to claim 1, further comprising an amplifier (1310) comprising: an output that is coupled to the first electrode; a first power supply rail that is coupled to the second electrode; and a second power supply rail that is coupled to the third electrode. [22] Microelectromechanical systems (MEMS) device (100), comprising: a solid dielectric (150), wherein the dielectric has a first outer surface (151) and a second outer surface (152) opposite the first outer surface, wherein the dielectric has a plurality of passages (156), each of the plurality of passages having an opening on the first outer surface and an opening on the second outer surface; and a set of electrodes (110, 120, 130), comprising: a first electrode (110) which is partially arranged within a first pass of the plurality of passes, such that a first end (111) of the first electrode extends beyond the first outer surface and a second end (112) of the first electrode extends beyond the second outer surface; a second electrode (120) which is partially arranged within a second pass of the plurality of passes, such that a first end (121) of the second electrode extends beyond the first outer surface and a second end (122) of the second electrode lies within the second pass; and a third electrode (130) which is partially arranged within a third passage of the plurality of passages, such that a first end (131) of the third electrode lies within the third passage and a second end (132) of the third electrode extends beyond the second outer surface, wherein the first, second and third electrodes are fixed relative to each other, and where the dielectric and the electrode set are movable relative to each other. [23] MEMS device (100) according to claim 22, wherein the MEMS device comprises a MEMS transducer. [24] MEMS device (100) according to claim 22, wherein the first electrode (110) comprises a plurality of first electrodes which are electrically connected to each other, wherein the second electrode (120) comprises a plurality of second electrodes which are electrically connected to each other, and wherein the third electrode (130) comprises a plurality of third electrodes which are electrically connected to each other.

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