Piezoresistive pressure sensor

Abstract

An apparatus including a piezoresistive pressure sensor is provided. The pressure sensor may include at least one diaphragm having a first thickness, the at least one diaphragm having the first thickness being surrounded by at least one second diaphragm having a second thickness, the second thickness being greater than the first thickness. The at least one diaphragm may be comprised of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners. The irregular corner may include a protruding tip that includes a piezoresistor. Opposite pairs of piezoresistors may define a Wheatstone bridge.

Description

Technical Field

[0001] The embodiments disclosed herein relate to devices including piezoresistive pressure sensors. Background Technology

[0002] Many different devices exist for detecting the pressure of various media. In some examples, some of these devices are used in the medical field. The applicant has recognized the numerous technical challenges and difficulties associated with such devices for detecting air bubbles and / or blockages in fluids. Through effort, ingenuity, and innovation, many of these identified problems have been solved by the developed solutions, including those described in the embodiments of this disclosure, and many examples of these solutions are described in detail herein. Summary of the Invention

[0003] The various example implementations described herein relate to devices including piezoresistive pressure sensors.

[0004] According to various embodiments of this disclosure, an apparatus is provided. In some embodiments, the apparatus includes a pressure sensor. In some embodiments, the pressure sensor includes: at least one first diaphragm having a first thickness, the at least one first diaphragm having the first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: the at least one first diaphragm is composed of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions, the protruding sharp regions including piezoelectric resistors defining a Wheatstone bridge.

[0005] In some embodiments, the device also includes four first diaphragms having a first thickness.

[0006] In some implementations, the device also includes four irregular shapes.

[0007] In some embodiments, the device also includes a substrate that defines a substantially circular aperture.

[0008] In some implementations, the substrate is made of glass.

[0009] In some implementations, adjacent piezoelectric resistor pairs are configured to shift in a first or second direction based on applied pressure, the first direction being opposite to the second direction.

[0010] In some implementations, the displacement defines the Wheatstone bridge, which is configured to output a voltage proportional to the displacement of the piezoelectric resistor.

[0011] According to various embodiments of this disclosure, a pressure sensor is provided. In some embodiments, the pressure sensor includes: at least one first diaphragm having a first thickness, the at least one first diaphragm having a first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve a substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: the at least one first diaphragm is composed of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions, the protruding sharp regions including piezoelectric resistors defining a Wheatstone bridge.

[0012] In some embodiments, the device also includes four first diaphragms having a first thickness.

[0013] In some implementations, the device also includes four irregular shapes.

[0014] In some embodiments, the device also includes a substrate that defines a substantially circular aperture.

[0015] In some implementations, the substrate is made of glass.

[0016] In some implementations, adjacent piezoelectric resistor pairs are configured to shift in a first or second direction based on applied pressure, the first direction being opposite to the second direction.

[0017] In some implementations, the displacement defines the Wheatstone bridge, which is configured to output a voltage proportional to the displacement of the piezoelectric resistor.

[0018] According to various embodiments of this disclosure, a system is provided. In some embodiments, the system includes a pressure sensor comprising: at least one first diaphragm having a first thickness, the at least one first diaphragm having the first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve a substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: the at least one first diaphragm is composed of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions, the protruding sharp regions including piezoelectric resistors defining a Wheatstone bridge. In some embodiments, the system includes a means configured to receive information indicating at least one pressure measured by the pressure sensor.

[0019] In some implementations, the pressure sensor also includes four first diaphragms having a first thickness.

[0020] In some implementations, the pressure sensor also includes four irregular squares.

[0021] In some embodiments, the pressure sensor further includes a substrate defining a substantially circular aperture, wherein the substrate is disposed opposite to the at least one first diaphragm.

[0022] In some implementations, adjacent piezoelectric resistor pairs are configured to shift in a first or second direction based on applied pressure, the first direction being opposite to the second direction.

[0023] In some implementations, the displacement defines the Wheatstone bridge, which is configured to output a voltage proportional to the displacement of the piezoelectric resistor. Attached Figure Description

[0024] The description of the exemplary embodiments can be read in conjunction with the accompanying drawings. It will be understood that, for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale unless otherwise described. For example, unless otherwise described, the dimensions of some elements may be exaggerated relative to others. Embodiments incorporating the teachings of this disclosure are shown and described with reference to the accompanying drawings, in which:

[0025] Figure 1A This is a perspective view of the "top surface" of a piezoresistive pressure sensor;

[0026] Figure 1B This is a perspective view of the "bottom surface" of a piezoresistive pressure sensor;

[0027] Figure 2 It is a perspective view and a close-up view of at least a portion of a piezoresistive pressure sensor; and

[0028] Figure 3 These are top and close-up views of a piezoelectric resistor of a piezoresistive pressure sensor according to some embodiments of this disclosure. Detailed Implementation

[0029] Some embodiments of this disclosure will be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments of this disclosure. In fact, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable this disclosure to meet applicable legal requirements. The same reference numerals consistently refer to the same elements.

[0030] As used herein, terms such as “front,” “rear,” “top,” “bottom,” “left,” “right,” etc., in the examples provided below, are used for illustrative purposes to describe the relative positions of certain parts or portions of parts. Additionally, as will be apparent to those skilled in the art based on this disclosure, the terms “substantially” and “approximately” indicate that the referenced element or associated description is accurate within applicable engineering tolerances.

[0031] As used herein, the term “comprising” means including but not limited to, and should be interpreted in the manner typically used in the patent context. The use of broader terms such as “comprising,” “including,” and “having” should be understood to provide support for narrower terms such as “consisting of,” “substantially composed of,” and “substantially constituted by.”

[0032] The phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally mean that the specific feature, structure, or characteristic following the phrase may be included in at least one embodiment of this disclosure, and may be included in more than one embodiment of this disclosure (importantly, such phrases do not necessarily refer to the same embodiment).

[0033] The phrases “in one example,” “according to one example,” “in some examples,” etc., generally refer to a particular feature, structure, or characteristic that follows the phrase and may include at least one example of this disclosure, and may include more than one example of this disclosure (importantly, such phrases do not necessarily refer to the same example).

[0034] If the specification states that a component or feature “may,” “can,” “should,” “will,” “preferably,” “possibly,” “usually,” “optionally,” “for example,” “as an example,” “in some examples,” “often,” or “may” (or other such language) be included or have that characteristic, then the specific component or feature is not necessarily required to include or have that characteristic. Such components or features may be optionally included in some examples or excluded.

[0035] The terms “example” or “exemplary” as used herein mean “serving as an example, instance, or illustration.” Any specific implementation described herein as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other specific implementations.

[0036] The terms “electrically coupled,” “electrically coupled,” “electrically connected,” “electrically linked,” “communicating with,” or “electronically communicating with” in this disclosure refer to two or more elements or components connected by wired and / or wireless means such that signals, voltages / currents, data, and / or information can be transmitted to and / or received from these elements or components.

[0037] The term “fluidly connected to” in this disclosure means that two or more elements or components are connected by one or more paths or pathways, such that fluid or other flowing media can be input to and / or output from these elements or components.

[0038] The term "component" may refer to an article of writing, apparatus, or device that may include one or more surfaces, portions, layers, and / or elements. For example, an example component may include one or more substrates that may provide one or more underlying layers for the component, and may include one or more elements that form a portion on top of the substrate and / or one or more elements that may be disposed on top of the substrate. In this disclosure, the term "element" may refer to an article of writing, apparatus, or device that may provide one or more functions.

[0039] The term "sensor" refers to a component that can detect, measure, and / or identify any one or more properties or characteristics (including, but not limited to, pressure) of an environment or medium.

[0040] In some examples, conventional pressure sensors and their fabrication are limited by various characteristics. For instance, it is difficult to fabricate pressure sensors with very thin diaphragms (e.g., on the order of a few micrometers thick) when using conventional methods. In some examples, conventional pressure sensors exhibit large initial voltage offsets even when no pressure is applied.

[0041] In some examples, embodiments of this disclosure provide an apparatus including a piezoresistive pressure sensor, and in some examples, a piezoresistive ultrasensitive pressure sensor is provided.

[0042] Example embodiments of the device described herein may include a device comprising a pressure sensor. Example embodiments of the device described herein may include a pressure sensor comprising: at least one first diaphragm having a first thickness, the at least one first diaphragm having a first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve substantially zero effective stress, wherein the second thickness is greater than the first thickness. In some examples, the at least one diaphragm is composed of at least one irregular shape (e.g., an irregular square, an irregular rectangle, and / or other shape), wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions. In some examples, the protruding sharp regions include piezoelectric resistors, and opposing piezoelectric resistor pairs define a Wheatstone bridge.

[0043] In some examples, exemplary embodiments of this disclosure provide a pressure sensor and / or an apparatus including a pressure sensor having one or more first diaphragms having a first thickness and one or more second diaphragms having a second thickness (e.g., a surrounding region, connecting beam, and / or surrounding edge, etc.), wherein the second thickness is greater than the first thickness. In some examples, the one or more second diaphragms consist of two or more layers of material having a thickness selected to achieve substantially zero effective stress. In some examples, these diaphragms are thin (e.g., 5 micrometers, 5 micrometers or less, 3 micrometers or less, etc.). In some examples, the one or more second diaphragms are thinner and / or thicker than the first diaphragm (e.g., 10 micrometers, 10 micrometers or less, 6 micrometers or less, etc.). In some examples, these diaphragms have an irregular shape (e.g., an irregular square, an irregular rectangle, and / or other shapes) with piezoelectric resistors at half or both corners of their corners. Thus, in some examples, exemplary embodiments of this disclosure provide a piezoresistive pressure sensor. In some examples, such a piezoresistive pressure sensor can be used in medical applications. For example, such piezoresistive pressure sensors can detect pressure (e.g., approximately 250 Pa, 250 Pa, 250 Pa or less, 250 Pa or more) supplied by water (such as one inch of water, one inch and / or less).

[0044] As described herein, in some examples, embodiments of this disclosure provide means for determining the pressure of various media. In some examples, embodiments of this disclosure provide ultrasensitive pressure sensors that are more sensitive than conventional pressure sensors. In some examples, embodiments of this disclosure provide pressure sensors with a negligible initial voltage offset (e.g., the pressure sensor outputs a voltage that is almost zero if no pressure is applied and / or detected).

[0045] To address the challenges and limitations associated with devices used to determine the pressure of various media, various examples of this disclosure are provided. For example, various examples of this disclosure may provide example devices, associated sensors, and associated methods for sensing pressure.

[0046] Figures 1A to 1B This is a perspective view of a piezoresistive pressure sensor. Now refer to... Figure 1A This provides a perspective view of the "top surface" of the piezoresistive pressure sensor 100. The piezoresistive pressure sensor 100 can be an ultrasensitive piezoresistive pressure sensor. The piezoresistive pressure sensor 100 includes at least one first diaphragm 102, at least one second diaphragm 104, at least one electrical contact 106, and / or a substrate 108 (relative to...). Figure 1B (Further details are provided). A “top surface” can be defined as a surface having at least one membrane 102, wherein the at least one membrane is exposed. A “bottom surface” can be defined as a surface having a substrate 108.

[0047] A piezoresistive pressure sensor 100 may include at least one first diaphragm 102 having a first thickness, surrounded by at least one second diaphragm 104 having a second thickness (e.g., including a region with a second thickness greater than the first thickness). The at least one second diaphragm 104 may consist of two or more layers of material having a thickness selected to achieve substantially zero effective stress. The at least one first diaphragm 102 may consist of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the irregular corners include protruding sharp regions. The protruding sharp regions of the at least one first diaphragm 102 may include piezoelectric resistors. Opposing piezoelectric resistor pairs may define a Wheatstone bridge such that when pressure is applied, two opposing piezoelectric resistors may shift in a first direction and another two opposing piezoelectric resistors may shift in a second direction (opposite to the first direction), generating an output voltage.

[0048] In some examples, at least one first membrane 102 comprises four membranes (e.g., as shown in the image). Figure 1A(As shown). In some examples, the four diaphragms consist of irregular shapes (e.g., irregular squares, irregular rectangles, and / or other shapes). The irregular shapes may have two opposing, substantially circular corners and two opposing, irregular corners. In some examples, each of the four diaphragms includes a pair of opposing, irregular corners with protruding sharp regions. The protruding sharp regions may include high-stress piezoelectric resistors. For example, if a pressure difference is sensed by a pressure sensor (e.g., different pressures are sensed on the "top surface" and "bottom surface" of the pressure sensor), each pair of adjacent irregular corners will be displaced in a first or second direction (e.g., where opposing pairs of irregular corners are displaced in the same direction as each other). This displacement defines a Wheatstone bridge that will output a voltage proportional to the displacement of the piezoelectric resistors.

[0049] At least one film 102 may be composed of bare silicon. At least one first film 102 may substantially remove an oxide film (e.g., which may be deposited during a manufacturing process). At least one film 102 may have a first thickness. At least one second film 104 may have a second thickness. The second thickness may be greater than the first thickness. For example, the first thickness may be approximately 3 micrometers to 5 micrometers (e.g., 5 micrometers, 5 micrometers or less, 3 micrometers, etc.), and / or the second thickness may be approximately 6 micrometers to 10 micrometers (e.g., 10 micrometers, 10 micrometers or less, 6 micrometers, etc.).

[0050] In some examples, at least one second diaphragm 104 comprises one or more layers. In some examples, at least one second diaphragm 104 comprises two or more layers. In some examples, at least one second diaphragm 104 comprises a first silicon layer including a piezoresistive region, an oxide layer, and / or a second silicon layer, wherein the second silicon layer is thicker than the first silicon layer. In some examples, at least one second diaphragm 104 comprises a silicon oxide / silicon nitride stack, wherein the silicon oxide layer has compressive stress and the silicon nitride layer has tensile stress; based on the selection of a predetermined thickness of silicon oxide and / or silicon nitride, near-zero "effective stress" can be achieved in the stack. In some examples, at least one second diaphragm 104 comprises a silicon oxide / polysilicon / silicon nitride stack, wherein the polysilicon (e.g., doped polysilicon) acts as an electric field protection plate. The thickness of the silicon oxide, polysilicon, and / or silicon nitride can be selected to generate near-zero "effective stress" on the silicon substrate. In some examples, at least one second diaphragm 104 includes an irregularly shaped region surrounding at least one diaphragm 102.

[0051] In some examples, at least one electrical contact 106 is a metallic contact. For example, at least one electrical contact 106 may consist of a first layer of titanium tungsten (TiW) and / or a layer of gold (Au), forming at least one TiW / Au contact. In some examples, at least one electrical contact 106 is used to transmit pressure data from a pressure sensor to at least one other device.

[0052] In some examples, the device may include a pressure sensor, such as a piezoresistive pressure sensor 100. Devices including piezoresistive pressure sensors can be used in medical applications to sense the pressure of various media, such as fluids.

[0053] Now for reference Figure 1B This image provides a perspective view of the "bottom surface" of a piezoresistive pressure sensor 100. The piezoresistive pressure sensor 100 includes a substrate 108. The substrate 108 may be composed of a substrate (e.g., a plate and / or other object). The substrate may be composed of glass, silicon, a material having a thermal expansion coefficient substantially similar to silicon, and / or other materials. For example, the substrate 108 may define a substantially circular aperture, wherein the substantially circular aperture is located approximately at the center of the substrate 108. The substrate 108 may be disposed opposite to at least one first diaphragm. The substantially circular aperture of the substrate 108 exposes the "bottom surface" of the piezoresistive pressure sensor 100 to a "reference pressure" (e.g., pressure outside the pressure sensor, such as ambient pressure).

[0054] The piezoresistive pressure sensor 100 may be included in a system that also includes another device configured to receive information indicating at least one pressure measured by the piezoresistive pressure sensor 100. This other device may be coupled to the piezoresistive pressure sensor 100 via at least one electrical contact 106 (e.g., via lead engagement to at least one electrical contact 106).

[0055] Now for reference Figure 2 It provides a perspective view and a close-up view of at least a portion of the piezoresistive pressure sensor. Figure 2A perspective view 200 of a piezoresistive pressure sensor is shown. The piezoresistive pressure sensor in view 200 may be a piezoresistive pressure sensor 100. A close-up view of at least a portion of the piezoresistive pressure sensor shows a cross-section of, for example, at least one second diaphragm 104. The cross-sectional view of at least one second diaphragm 104 includes a silicon oxide / silicon nitride stack, wherein the silicon oxide layer is indicated by reference numeral 204 and the silicon nitride layer is indicated by reference numeral 202. The silicon nitride layer 202 (e.g., a silicon nitride film) may have tensile stress. The silicon oxide layer 204 (e.g., a silicon oxide film) may have compressive stress. Combined, the silicon oxide / silicon nitride stack may have an "effective stress" close to zero. The cross-sectional view of at least one second diaphragm 104 may include two or more layers, such as a silicon oxide / polysilicon / silicon nitride stack, wherein the polysilicon (e.g., doped polysilicon) acts as an electric field protection plate. The thickness of silicon oxide, polysilicon, and / or silicon nitride can be selected to generate near-zero "effective stress" on the silicon substrate.

[0056] Now for reference Figure 3 The diagram provides top and close-up views of the piezoelectric resistor of a piezoresistive pressure sensor. Referring now to top view 300, it is assumed that the irregular corner pairs in the image can be described as “top,” “bottom,” “left,” and “right” according to their orientation in the exemplary image. The top and bottom piezoelectric resistors may be substantially parallel to the edge of at least one diaphragm 102. The left and right piezoelectric resistors may be substantially perpendicular to the edge of at least one diaphragm 102. Close-up view 302 shows how the piezoelectric resistors at the top (and / or bottom) may be substantially parallel to the edge of at least one diaphragm 102. Close-up view 304 shows how the right (and / or left) piezoelectric resistors may be substantially perpendicular to the edge of at least one diaphragm 102. The piezoelectric resistor may be a lightly doped p-type piezoelectric resistor. A lightly doped p-type piezoelectric resistor may be substantially... <110> In orientation. At least one silicon diaphragm 102 can be substantially in <110> Direction.

[0057] The operations and procedures described herein support combinations of means for performing a specified function and combinations of operations for performing a specified function. It will be understood that one or more operations, and combinations of operations, can be implemented by a computer system based on dedicated hardware or a combination of dedicated hardware and computer instructions to perform the specified function.

[0058] In some example implementations, some of the operations described herein may be modified or further amplified as described below. Furthermore, in some implementations, additional optional operations may be included. It should be understood that each of the modifications, optional additions, or amplifications described herein may be included in the operations herein, either individually or in combination with any other feature described herein.

[0059] The foregoing description of methods and processes is provided as illustrative examples only and is not intended to require or imply that the steps of the various embodiments must be performed in the presented order. As those skilled in the art will understand, the order of steps in the above embodiments can be performed in any order. Words such as “after,” “then,” “next,” and similar terms are not intended to limit the order of steps; these words are merely used to guide the reader through the description of the method. Furthermore, any reference to singular claim elements, for example, using the articles “a,” “an,” or “the,” should not be construed as limiting the element to the singular and, in some cases, may be interpreted in the plural form.

[0060] Although various embodiments based on the principles disclosed herein have been shown and described above, modifications can be made thereto by those skilled in the art without departing from the teachings of this disclosure. The embodiments described herein are representative only and not intended to be limiting. Many variations, combinations, and modifications are possible and are within the scope of this disclosure. Alternative embodiments resulting from the merging, integration, and / or omission of features of the embodiments are also within the scope of this disclosure. Therefore, the scope of protection is not limited by the description given above, but is defined by the following claims, which include all equivalents of the subject matter of the claims. Each claim is incorporated into the specification as further disclosure, and the claims are embodiments of this disclosure. Furthermore, any of the foregoing advantages and features may relate to a particular embodiment, but the application of such published claims should not be limited to methods and structures that achieve any or all of the above advantages or have any or all of the above features.

[0061] Furthermore, the section headings used herein are intended to align with or provide organizational clues for the recommendations of 37 C. FR § 1.77. These headings should not limit or characterize the disclosure set forth in any of the claims published in this disclosure. For example, the description of the technology in the “Background Art” section should not be construed as an admission that a particular technology is prior art to any disclosure in this disclosure. Nor should “Summary of the Invention” be considered a limiting characterization of the disclosure set forth in the published claims. Furthermore, any reference in this disclosure to the singular forms of “Disclosure” or “Simplification” should not be used to prove that there is only one novel point in this disclosure. Multiple embodiments of this disclosure may be set forth according to the limitations of the multiple claims published in this disclosure, and such claims accordingly define the disclosure protected by them and their equivalents. In all cases, the scope of these claims should be considered in accordance with the advantages of the claims themselves, and should not be limited by the headings set forth herein.

[0062] Furthermore, without departing from the scope of this disclosure, the systems, subsystems, devices, technologies, and methods described and illustrated in various embodiments in a discrete or separate manner can be combined or integrated with other systems, modules, technologies, or methods. Other devices or components shown or discussed as coupled or communicating with each other may be indirectly coupled through some intermediate devices or components, whether such coupling is electrical, mechanical, or otherwise. Other examples of variations, substitutions, and modifications that can be identified by those skilled in the art without departing from the scope of this disclosure are also provided.

[0063] Those skilled in the art to which these embodiments pertain will recognize numerous modifications and other embodiments of the disclosure set forth herein, which benefit from the teachings presented in the foregoing description and associated drawings. Although the drawings show only certain components of the devices and systems described herein, various other components may be used in conjunction with the components and structures disclosed herein. Therefore, it should be understood that this disclosure is not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the appended claims. For example, various elements or components may be combined, rearranged, or integrated into another system, or certain features may be omitted or not implemented. Furthermore, the steps in any of the methods described above may not necessarily occur in the order depicted in the drawings, and in some cases, one or more of the depicted steps may occur substantially simultaneously, or additional steps may be involved. Although specific terms are used herein, they are used only in a general and descriptive sense and not for limiting purposes.

Claims

1. An apparatus, the apparatus comprising: Pressure sensor, the pressure sensor comprising: At least one first diaphragm having a first thickness, the at least one first diaphragm having a first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: The at least one first diaphragm comprises at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions, the protruding sharp regions including piezoelectric resistors defining a Wheatstone bridge.

2. The apparatus according to claim 1, further comprising four first diaphragms having the first thickness.

3. The apparatus according to claim 1, further comprising four irregular squares.

4. The apparatus of claim 1, further comprising a substrate defining a substantially circular aperture, wherein the substrate is disposed opposite to the at least one first diaphragm.

5. The apparatus of claim 4, wherein the substrate is composed of glass.

6. The apparatus of claim 1, wherein opposing adjacent piezoelectric resistor pairs are configured to shift in a first direction or a second direction based on applied pressure, the first direction being opposite to the second direction.

7. The apparatus of claim 6, wherein the displacement defines the Wheatstone bridge, the Wheatstone bridge being configured to output a voltage proportional to the displacement of the piezoelectric resistor.

8. A system comprising: Pressure sensor, the pressure sensor comprising: At least one first diaphragm having a first thickness, the at least one first diaphragm having a first thickness being surrounded by at least one second diaphragm having a second thickness, wherein the at least one second diaphragm is composed of two or more layers of material having a thickness selected to achieve substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: The at least one first diaphragm comprises at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding pointed regions, the protruding pointed regions including piezoelectric resistors defining a Wheatstone bridge; and The device is configured to receive information indicating at least one pressure measured by the pressure sensor.

9. The system of claim 8, wherein the pressure sensor further comprises at least: Four first films having the first thickness; or Four irregular squares.

10. A method, the method comprising: Manufacturing an apparatus including a pressure sensor, the pressure sensor comprising: At least one first membrane having a first thickness, said at least one first membrane having a first thickness is surrounded by at least one second membrane having a second thickness. The at least one second diaphragm comprises two or more layers of material having a thickness selected to achieve substantially zero effective stress, wherein the second thickness is greater than the first thickness, and wherein: The at least one first diaphragm is composed of at least one irregular shape, wherein the at least one irregular shape includes two opposing substantially circular corners and two opposing irregular corners, wherein the two opposing irregular corners include protruding sharp regions, the protruding sharp regions including piezoelectric resistors defining a Wheatstone bridge. The substrate is configured to define a substantially circular aperture; and The substrate is positioned opposite the at least one first membrane.

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