Patent Application
20240409399
The present disclosure generally relates to systems and methods for generating fluid flow. In some examples the fluid flow is modulated to generate an audio signal. System and methods of generating a modulated fluid flow are applied in a mobile, wearable, or portable device. In other examples the system and methods of generating a modulated fluid flow are applied in earphones, headsets, hearables, or hearing aids.
US 8861752 describes a micropump configured as a picospeaker which is a novel sound generating device and a method for sound generation. The micropump creates an audio signal by generating an ultrasound acoustic beam which is then actively modulated. The resulting modulated ultrasound signal has a lower acoustic frequency sideband which corresponds to the frequency difference between the frequency of the ultrasound acoustic beam and the modulation frequency. US 20160360320 and US20160360321 describe MEMS architectures for realizing the micropump. US20160277838 describes one method of implementation of the micropump using MEMS processing. US 2016277845 describes an alternative method of implementation of the micropump using MEMS processing. MEMS membranes for generating acoustic signals as well as generating sound using the principles of US 8861752 have been described in US 2016277845. In this disclosure we described a non-limiting implementation of the micropump using a one or more piezo actuators. Hence it is desirable to provide an architecture and method of implementation which reduces the complexity and number of processing steps.
Some embodiments of the present disclosure may generally relate to a fluid flow device that includes at least two membranes and a spacer element. A first membrane is positioned is configured to oscillate along a first directional path and at a first frequency. A second membrane is spatially separated from the first membrane and is configured to oscillate along a second directional path. A spacer element is positioned between a first and second membrane defining at least one closed cavity where the dimensions of the cavity are defined by at least a first and a second membrane and at least one dimension of a fluid channels configured to provide fluid flow to the cavity is defined by either a first or second membrane. Other embodiments of the present disclosure may generally relate to a fluid flow device comprising an array of a first and second membrane and spacers wherein the array of membranes operate either independently or driven by a common source. Examples of drive signals include but are not limited to; pulse width modulation and modulated sinusoidal signals. The driving unit is a semiconductor integrated circuit which includes; a communication unit; a charge pump configured to generate a high voltage signal; a switching unit configured to modulate the high voltage signal. The driving unit receives a digital sound data stream and an operating voltage and outputs driving signals for the membrane, and shutter. In some embodiments the membranes operate asynchronously and or independently of each other at one or more frequencies. In other embodiments the membrane operates synchronously at the same frequency. In the synchronous mode of operation, the fluid flow is controlled by any of but not limited to; the relative phase of the membrane operation; the amplitude of the membrane operation; any combination of these.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are therefore not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other examples may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. This disclosure is drawn, inter alia, to methods, apparatus, computer programs, and systems of generating an audio signal.
Some embodiments of the present disclosure may generally relate to a fluid flow device that includes at least two membranes and a spacer element. A first membrane is positioned is configured to oscillate along a first directional path and at a first frequency. A second membrane is spatially separated from the first membrane and is configured to oscillate along a second directional path. A spacer element is positioned between a first and second membrane defining at least one closed cavity where the dimensions of the cavity are defined by at least a first and a second membrane and at least one dimension of a fluid channels configured to provide fluid flow to the cavity is defined by either a first or second membrane. Other embodiments of the present disclosure may generally relate to a fluid flow device comprising an array of a first and second membrane and spacers wherein the array of membranes operate either independently or driven by a common source. Examples of drive signals include but are not limited to; pulse width modulation and modulated sinusoidal signals. The driving unit is a semiconductor integrated circuit which includes; a communication unit; a charge pump configured to generate a high voltage signal; a switching unit configured to modulate the high voltage signal. The driving unit receives a digital sound data stream and an operating voltage and outputs driving signals for the membrane, and shutter. In some embodiments the membranes operate asynchronously and or independently of each other at one or more frequencies. In other embodiments the membrane operates synchronously at the same frequency. In the synchronous mode of operation, the fluid flow is controlled by any of but not limited to; the relative phase of the membrane operation; the amplitude of the membrane operation; any combination of these.
In a non-limiting example, we describe the micropump as modulated flow device. A first and or second membrane is driven by an electric signal that oscillates at a frequency Ω and hence moves at b cos (2π*Ωt), where b is the amplitude of the membrane movement, and t is time. The electric signal is further modulated by a portion that is derived from an audio signal a (t). The acoustic signal is characterized as:
Applying a Fourier transform to Equation (1) results in a frequency domain representation
Where A(f) is the spectrum of the audio signal. Equation (2) describes a signal with an upper and lower side band around a carrier frequency of Ω. In one example the second membrane can be described as a modulator operating the signal of eq(1). results in
Where I is the loss of the modulator and m is the modulation function and due to energy conservation I+m<1. In the frequency domain
Where b/4*m A(f) is an audio signal. The remaining terms are ultrasound signals where m A(f+2Ω) is at twice the modulation frequency and A(f−Ω)+A(f+Ω) is the original unmodulated signal. Additional acoustic signals may be present due to any but not limited to the following; ultrasound signal from the shutter movement; intermodulation signals due to nonlinearities of the acoustic medium; intermodulation signals due to other sources of nonlinearities including electronic and mechanical. In one example where a(t)=1, i.e. the acoustic signal is constant, the device operates as a constant flow pump. For a more detailed description we need to examine the dynamics of the membranes as defined by the interaction of a driving force; mechanical dynamics of the membrane; and fluid membrane interaction. Examples of driving force include but are not limited to electrostatic; thermoelectric or piezo electric. Examples of mechanical dynamics include but are not limited to; second order mechanical system; second order mechanical system with damping; higher order mechanical system. The mechanical dynamics are configured to include at least one resonance frequency for each membrane. The membrane dynamics are simulated using either a computational fluid dynamics (CFD) model or a simplified coupled differential equation describing mechanical movement and membrane fluid coupling. One example of the coupled equations with only second order dynamics for the membranes is described in equations (1) to (4) includes but is not limited to;
Where the index (1,2,3) refers to first, second or third membrane, bx is the damping coefficient, kx is the spring coefficient, Fx is the actuation force, FPx is the fluid membrane interaction. Equation (4) describes the second order dynamics of the fluid enclosed between the membranes where bp and kp are defined by the membrane displacement and FPp is the aggregate membrane fluid interaction. Equations (5-8) describe the action of membranes to generate fluid flow {dot over (P)}.
To sum in one example, presented is a micropump comprised of: a substrate with at least one back side hole; a first piezoelectric layer stack; a spacer layer; a second piezoelectric stack; wherein a gap layer is in contact with at least two layers or a layer and a substrate and substrate, first piezoelectric stack and second piezoelectric stack are electrically isolated. In a further example the gap layer is comprised of at least two materials; a first material with high etch rate to an etchant and second material with slow etch rate to same etchant. In a further example the gap layer is comprised of any of but not limited to Tungsten, Copper, Nickel, SiRN, SiN, Aluminum, Ag, Au or combinations of these materials. In a further example the first or second piezo electric layer stack includes at least a support layer, bottom electrode, piezoelectric layer, top electrode. In a further example the piezoelectric layer comprising of any but not limited to AlN, AlScN, PZT, KNN, PVDF. In a further example the first or second piezo electric layer stack includes at least a bottom electrode, first piezoelectric layer, middle electrode, second piezoelectric material, top electrode. In a further example the piezoelectric layer comprising of any but not limited to AlN, AlScN, PZT, KNN, PVDF. In an alternative example a method for manufacturing a micropump comprised of depositing a first gap layer comprised of a sacrificial material and etch stop material; depositing and patterning first piezoelectric layer stack; depositing a second gap layer comprised of a sacrificial material and etch stop material; depositing a spacer layer; depositing a third gap layer comprised of a sacrificial material and etch stop material; depositing and patterning a second piezoelectric layer stack; removing sacrificial material using isotropic etch. In a further example the gap layer comprising of at least two materials; a first material with high etch rate to an etchant and second material with slow etch rate to same etchant. In a further example the gap layer is comprised of any of but not limited to Tungsten, Copper, Nickel, SiRN, SIN, Aluminum, Ag, Au or combinations of these materials. In a further example the first or second piezo electric layer stack includes at least a support layer, bottom electrode, piezoelectric layer, top electrode. In a further example the piezoelectric layer comprising of any but not limited to AlN, AlScN, PZT, KNN, PVDF. In a further example the first or second piezo electric layer stack includes at least a bottom electrode, first piezoelectric layer, middle electrode, second piezoelectric material, top electrode. In a further example the piezoelectric layer comprising of any but not limited to AlN, AlScN, PZT, KNN, PVDF. In an alternative example, a micropump is comprised of a substrate with at least two through holes; at least two piezoelectric membranes; wherein an acoustic volume is defined between the at least two membranes; and the at least two membranes are operated independently to generate a fluid flow. In a further example between membrane and substrate is a gap layer. In a further example the gap layer comprising of any of but not limited to Tungsten, Copper, Nickel, SiRN, SIN, Aluminum, Ag, Au or combinations of these materials. In a further example the first or second piezo electric layer stack includes at least a support layer, bottom electrode, piezoelectric layer, top electrode. The micropump of claim 15, wherein the piezoelectric layer comprising of any but not limited to AlN, AlScN, PZT, KNN, PVDF.
There is little distinction left between hardware and software implementations of aspects of systems; the use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software can become significant) a design choice representing cost versus efficiency tradeoffs. There are various vehicles by which processes and/or systems and/or other technologies described herein can be effected (e.g., hardware, software, and/or firmware), and that the preferred vehicle will vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle; if flexibility is paramount, the implementer may opt for a mainly software implementation; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.
The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Versatile Disk (DVD), a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).
Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein can be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system generally includes one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems including feedback loops and control motors (e.g., feedback for sensing position and/or velocity; control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems.
The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to disclosures containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”. Speaker and micropump are interchangeable and can be used in in place of the other.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 63471794 | Jun 2023 | US | |
| 63590793 | Oct 2023 | US |
