Spiral impedance structure

Abstract

An impedance sensing structure is provided and includes a dielectric layer, a spiral electrode pair, an inlet element and an outlet element, and a sensing circuit, the spiral electrode pair forms a double-spiral channel on the dielectric layer and has an inlet portion at a central region of the double-spiral channel and an outlet portion at an end of the double-spiral channel. An inlet element and an outlet element are coupled with the inlet portion and the outlet portion, respectively, for directing fluid or gas through the double helix channel. The sensing circuit is electrically connected with the spiral electrode pair and is configured to sense particles in the fluid or the gas according to the impedance of the spiral electrode pair and the fluid or the gas flowing through the double-spiral channel.

Description

Background Technology

[0001] This invention generally relates to impedance systems. More specifically, this invention relates to a spiral impedance system structure for microelectronic sensing.

[0002] Capacitively coupled non-contact conductivity detection (C4D) is a detection technique primarily used in capillary electrophoresis and microchip electrophoresis. C4D detectors are typically characterized by their simple structure, ease of miniaturization and integration, and the absence of electrode contamination—all common challenges in electrochemical detection. Summary of the Invention

[0003] Embodiments of the present invention relate to an impedance sensing structure. A non-limiting example of the impedance sensing structure includes: a dielectric layer, a pair of helical electrodes, an inlet element and an outlet element, and a sensing circuit. The helical electrode pair forms a double-helical channel on the dielectric layer and has an inlet portion at a central region of the double-helical channel and an outlet portion at an end of the double-helical channel. The inlet element and the outlet element are respectively connected to the inlet portion and the outlet portion for guiding fluid or gas flow through the double-helical channel. The sensing circuit is electrically connected to the helical electrode pair and configured to sense particles in the fluid or gas based on the impedance of the helical electrode pair and the fluid or gas flowing through the double-helical channel.

[0004] Embodiments of the present invention relate to an impedance sensing structure for sensing particles in a fluid or gas. A non-limiting example of the impedance sensing structure includes: a dielectric layer; a pair of helical electrodes forming a double-helical channel on the dielectric layer, the helical electrode pair having an inlet portion located in the central region of the double-helical channel and an outlet portion located at the end of the double-helical channel; an inlet element and an outlet element respectively connected to the inlet portion and the outlet portion for guiding fluid or gas through the double-helical channel; and a sensing circuit electrically connected to the helical electrode pair, the sensing circuit being configured to sense particles in the fluid or gas based on the impedance of the helical electrode pair and the fluid or gas flowing through the double-helical channel.

[0005] Embodiments of the present invention relate to a method for manufacturing an impedance sensing structure. A non-limiting example of the method includes forming a double-helix channel opening in a substrate and constructing a pair of helical electrodes within the double-helix channel opening, such that each electrode of the helical electrode pair extends upward from the substrate to form a double-helix channel having an inlet portion located in a central region of the double-helix channel and an outlet portion located at an end of the double-helix channel. The method further includes coupling an inlet element and an outlet element to the inlet portion and the outlet portion, respectively, to guide fluid or gas flow through the double-helix channel, electrically connecting sensing circuitry to the helical electrode pair, and configuring the circuitry according to the impedance of the double-helix channel and the fluid or gas to sense particles in the fluid or gas.

[0006] Additional technical features and benefits are achieved through the technology of this invention. Embodiments and aspects of the invention are described in detail herein and are considered part of the claimed subject matter. For a better understanding, refer to the specific embodiments and accompanying drawings. Attached Figure Description

[0007] The details of the proprietary rights described herein are specifically pointed out and explicitly claimed in the claims at the end of the specification. The foregoing and other features and advantages of the embodiments of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0008] Figure 1 This is a side view of an impedance sensing structure according to one or more embodiments of the present invention;

[0009] Figure 2 It is according to one or more embodiments of the present invention Figure 1 A top view of the spiral channel of the impedance sensing structure;

[0010] Figure 3 It is a product of one or more embodiments of the present invention. Figure 1 A top view of the spiral channel of the electrode section of the impedance sensing structure;

[0011] Figure 4 It is according to one or more embodiments of the present invention Figure 1 A top view of the double-helix channel of the impedance sensing structure;

[0012] Figure 5 It is according to one or more embodiments of the present invention Figure 1 A top view of the impedance sensing structure having multiple helical channels and a pair of common helical electrodes, the multiple helical channels having a group of multiple helical electrodes arranged end-to-end and insulated from each other;

[0013] Figure 6 It is a product of one or more embodiments of the present invention. Figure 1 A top view of the multiple double-helix channels of the impedance sensing structure with multiple inlet and multiple outlet sections;

[0014] Figure 7 This is a flowchart illustrating a method for manufacturing an impedance sensing structure according to one or more embodiments of the present invention; and

[0015] Figure 8 This illustrates one or more embodiments according to the present invention. Figure 7 A graphical flowchart of the method.

[0016] The figures depicted herein are illustrative. Many variations may be made to the figures or operations described herein without departing from the scope of the invention. For example, actions may be performed in a different order, or actions may be added, deleted, or modified. Furthermore, the term "link" and its variations describe a communication path between two elements and do not imply a direct connection between the elements without any intermediate elements / connections between them. All such variations are considered part of the specification.

[0017] In the accompanying drawings of the described embodiments and in the following detailed description, the various elements shown in the figures are labeled with two or three numbers. With a few exceptions, the leftmost number of each reference numeral corresponds to the figure in which the element is first shown. Detailed Implementation

[0018] For the sake of brevity, conventional techniques related to the manufacture of semiconductor devices and integrated circuits (ICs) may or may not be described in detail herein. Furthermore, the various tasks and process steps described herein can be incorporated into a more comprehensive procedure or process with additional steps or functions not described in detail herein. In particular, the various steps in the manufacture of semiconductor devices and semiconductor-based ICs are well-known; therefore, for the sake of brevity, many conventional steps will only be briefly mentioned herein or will be omitted entirely without providing well-known process details.

[0019] Turning now to an overview of the technology more specifically related to aspects of the present invention, C4D is introduced as a quantitative method for capillary electrophoresis because it tends to be an efficient method for conductivity detection in the fluid analysis and measurement of small inorganic ions as well as organic and biochemical substances. Compared to conventional contact conductivity detection methods, the electrodes of C4D sensors can be encapsulated or placed outside the channel, so that they do not come into direct contact with the analyte. Therefore, some of the adverse effects of contact conductivity detection methods (such as electrode polarization and electrochemical corrosion) can be avoided. Furthermore, C4D provides a versatile and non-destructive detection tool and scanning capability. In addition, C4D typically consumes relatively little power, making it suitable for use in portable field instruments, especially those powered by batteries.

[0020] For C4D in microchip capillary electrophoresis, two different methods are typically employed. Either external electrodes are used, or the electrodes are embedded within the device but isolated from the electrolyte solution. The former arrangement is simpler because the construction of a chip without embedded electrodes requires fewer fabrication steps, but the latter method allows for a closer distance between the channels and the electrodes. C4D sensitivity is directly proportional to the distance between the electrodes and the separation channels.

[0021] The current challenge for sensors is to achieve higher sensitivity for early detection at increasingly lower concentrations. One such application is to identify the lowest concentration levels or viral / bacterial formation in the food supply chain, or to detect human infection / transmission. Another useful application is to measure cell membrane properties (capacitance and conductivity) and monitor changes caused by the effects of drugs or toxins.

[0022] Turning now to an overview of various aspects of the invention, one or more embodiments of the invention address the aforementioned drawbacks of the prior art by providing a helical impedance sensing structure and method, wherein the helical fluid eliminates non-uniform or spatially varied unit sidewall interactions and allows unrestricted particle flow. The helical impedance sensing structure enables laminar particle flow across a full range of velocities from static to dynamic, scalable to the detection of nanoparticles in terms of size and individual particles in terms of quantity, achieving flexible resolution through parameter selection, adjusting optimal cost based on the signal-to-noise (S / N) ratio (these parameters are [reduced flow rate] x [increased electrode area] x [number of parallel and / or series electrodes] x [increased residence time]), and is compatible with protective electrode manufacturing methods, eliminating electromagnetic interference (EMI) problems and crosstalk between adjacent electrodes and the resulting errors. Furthermore, the helical impedance sensing structure allows for encapsulated or unencapsulated electrodes and differential sensing methods.

[0023] The above aspects of the present invention address the shortcomings of the prior art by providing an impedance sensing structure comprising a dielectric layer, a helical electrode pair, an inlet element, an outlet element, and a sensing circuit. The helical electrode pair forms a double helical channel on the dielectric layer and has an inlet portion at the central region of the helical channel and an outlet portion at the end of the helical channel. The inlet element and the outlet element are respectively connected to the inlet and outlet portions for guiding fluid or gas through the helical channel. The sensing circuit is electrically connected to the helical electrode pair and configured to sense particles in the fluid or gas based on the impedance of the helical electrode pair and the fluid or gas flowing through the helical channel.

[0024] Now we turn to a more detailed description of aspects of the present invention. Figure 1 and Figure 2 An impedance sensing structure 101 for sensing particles in fluids or gases is depicted. The impedance sensing structure 101 eliminates sidewalls and generated artifacts such as eddy currents and non-uniform flow velocities across electrodes. The impedance sensing structure 101 also eliminates the complexities of 2D / 3D capacitance measurements and subsequent complex volumetric tomography modeling. The impedance sensing structure 101 can be widely applied to micron and nanoscale sensing applications (i.e., for bacteria, viruses, DNA, proteins, etc.) and also to large-scale applications (e.g., detecting water / aqueous fluids in oil pipelines).

[0025] The impedance sensing structure 101 includes a dielectric layer 110 and a helical electrode pair 120. The helical electrode pair 120 includes a first helical electrode 121 and a second helical electrode 122, which together form a double helical channel 125 on the dielectric layer 110. The double helical channel 125 has an inlet portion 126 at a central region of the helical channel 125 and an outlet portion 127 at an end of the helical channel 125. It should be understood that the aforementioned inlet and outlet portions are interchangeable; for example, the inlet portion may be 127 and the outlet portion may be 126, and generally, this flexibility in the allocation of the inlet and outlet portions applies to all embodiments mentioned herein. The impedance sensing structure 101 also includes an inlet element 130 coupled to the inlet portion 126 and an outlet element 131 coupled to the outlet portion 127 for guiding fluid or gas flow through the double helical channel 125 and the sensing circuit 140. Sensing circuitry 140 may be disposed within a printed circuit board (PCB) adjacent to or part of dielectric layer 110, and electrically connected to the first helical electrode 121 and the second helical electrode 122 of helical electrode pair 120. Sensing circuitry 140 is configured to sense particles in a fluid or gas based on the impedance of helical electrode pair 120 and the fluid or gas flowing through the double helical channel 125 between the first helical electrode 121 and the second helical electrode 122. The first and second helical electrodes 121, 122 of helical electrode pair 120 may be spaced apart at least proportionally to the fluid flow rate and particle size distribution rate in the double helical channel 125.

[0026] Therefore, the impedance sensing structure 101 can be provided as a component of an impedance system for measuring the membrane properties (i.e., capacitance and conductivity) of particles / viruses / cells / organisms, for example, for monitoring internal changes such as formation, growth, death, etc., as well as changes caused by externalities, such as changes caused by drugs or toxins. The materials of the impedance sensing structure 101 can typically be biocompatible or other compatible. This includes a dielectric layer 110 that can be formed from glass, plastic, silicon, etc.; a first helical electrode 121 and a second helical electrode 122 that can be formed from gold, platinum, indium tin oxide, iridium, etc.; an electrode insulator that can be formed from photoresist, polyimide, PMMA, silicon dioxide, silicon nitride, etc.; and a chamber housing component that can be formed from adhesives, sealants, pipes, valves, pumps, and certain electrical stimulation and / or measurement components. The impedance sensing structure 101 can be compatible with an impedance spectrum, for example, between about 20 Hz and about 2 MHz, wherein the impedance spectrum can be determined by an LCR meter having a set applied force amplitude (e.g., 50 mV).

[0027] Impedance measurement can be performed by the impedance sensing structure 101 as follows. For the case where the first helical electrode 121 and the second helical electrode 122 are in contact with the ionic solution, the impedance is determined by the capacitance C of the electrochemical double layer. DL and ion resistance R ion The composition is proportional to the bulk liquid conductivity. In these or other cases, it can be expressed at a frequency f. c =1 / (π*R ion *C DL ) Measure impedance, where C DL It can be short-circuited and R ion =ρ·L / A, where ρ is the mass resistivity of the fluid or gas, L is the length of the first helical electrode 121 and the second helical electrode 122, and A is the area of ​​the double helical channel 125.

[0028] Generally, impedance resolution is proportional to sensing length, especially for very low concentrations of particles, viruses, and bacteria. Thus, the helical pattern of the double-helix channel 125 provides laminar fluid flow through the double-helix channel and provides exceptionally long lengths for the first helical electrode 121 and the second helical electrode 122, giving usable surface area without generating eddies as in a serpentine configuration.

[0029] Continue to refer to Figure 1 and Figure 2 And refer to other Figures 3 to 6 Furthermore, according to one or more other embodiments of the invention, the impedance sensing structure 101 may be provided with additional or alternative configurations.

[0030] like Figure 3 As shown, the first helical electrode 121 of the helical electrode pair 120 may include 1211 to 121 N Multiple helical electrode segments, denoted as 121 1-N They are arranged in an end-to-end pattern and insulated from each other, and the second helical electrode 122 of the helical electrode pair can be configured along multiple helical electrode segments 121. 1-N Each extended common spiral electrode 1221 in the process.

[0031] like Figure 4 As shown, the two pairs of first and second helical electrodes 121 and 122 of the helical electrode pair 120 respectively form a double-double helical channel 401 with dual inlet portions 402 and 403 and dual outlet portions 404 and 405. It should be understood that, although... Figure 4 A double-helix channel 401 is shown, but other embodiments are also possible, such as a triple-helix channel, a quadruple-helix channel, etc.

[0032] like Figure 5As shown, the first helical electrode 121 of the helical electrode pair 120 may include a first group of multiple helical electrode segments 501. 1-N It is arranged in an end-to-end pattern and insulated from each other, and includes a second set of multiple spiral electrode segments 502. 1-N They are arranged in an end-to-end pattern and insulated from each other, and the second spiral electrode 122 of the spiral electrode pair 120 can be provided as a pair of common spiral electrodes 503 and 504, wherein the common spiral electrode 503 is along the first set of multiple spiral electrode segments 501. 1-N Each extension of the common spiral electrode 504 along the second set of multiple spiral electrode segments 502 1-N Each extension in.

[0033] like Figure 6 As shown, the helical electrode pair 120 forms multiple pairs of first and second helical electrodes 121, 122, each forming a multiple double-helical channel 601 with multiple inlet portions 602 and multiple outlet portions 603. Although not strictly necessary, Figure 6 The plurality of first helical electrodes 121 may include multiple groups of multiple helical electrode segments 610 1-N 611 1-N and 612 1-N They are arranged in an end-to-end pattern and insulated from each other, and a plurality of second helical electrodes 122 can be provided along a plurality of sets of plurality of helical electrode segments 610 1-N 611 1-N and 612 1-N Each set of extended common spiral electrodes 620, 621 and 621.

[0034] Reference Figure 7 A method 700 is provided for manufacturing an impedance sensing structure (such as the impedance sensing structure 101 described above). Figure 7 As shown, the method includes forming a helical channel opening in a substrate (box 701), constructing a helical electrode pair in the helical channel opening such that each electrode of the helical electrode pair extends upward from the substrate to form a double helical channel having an inlet portion at a central region of the helical channel and an outlet portion at an end of the helical channel (box 702), connecting an inlet element and an outlet element to the inlet portion and the outlet portion respectively for guiding fluid or gas flow through the helical channel (box 703), electrically connecting a sensing circuit to the helical electrode pair (box 704), and configuring the circuit to sense particles in the fluid or gas based on the impedance of the double helical channel and the fluid or gas (box 705). It should be understood that, given the description provided above and below, this method can be applied to at least... Figure 1 and Figure 2 Various embodiments and Figure 3-6 Each of the 700 modified methods in the code can be modified without much experimentation.

[0035] refer to Figure 8 , showed Figure 7 The 700 operation phase of the method. For example... Figure 8 As shown, in the initial operation phase, an insulating layer 802 is deposited on a substrate 801 (i.e., a glass substrate), and vias 803 are formed through the substrate 801 and the insulating layer 802. The vias 803 can be formed as a pair of helical channel openings. In the next operation phase, back-side substrate photolithography and seed layer formation are performed to form a sacrificial layer 804 that defines spaces for pads for the first and second electrodes along the vias 803, and an adhesion seed layer 805 (i.e., titanium, tantalum, etc.) is formed. In the next operation phase, first and second helical electrodes 806 and 807 (i.e., copper) are formed in the vias 803 with pads 808, followed by front-side chemical mechanical polishing (CMP) and selective etching of the insulating layer 802. In the final operation phase, an upper layer is provided to form inlet and outlet elements and to cover the first helical electrode 806 and the second helical electrode 807, thereby forming a double-helical channel 810. Subsequently, the pads 808 can be bonded to a sensing circuit.

[0036] Various embodiments of the invention are described herein with reference to the accompanying drawings. Alternative embodiments may be devised without departing from the scope of the invention. Although various connections and positional relationships (e.g., above, below, adjacent, etc.) between elements are illustrated in the following description and drawings, those skilled in the art will recognize that many of the positional relationships described herein are orientation-independent, provided that the described functionality is maintained even when the orientation changes. Unless otherwise stated, these connections and / or positional relationships may be direct or indirect, and the invention is not intended to be limited in this respect. Thus, the connection of entities may refer to direct or indirect connection, and the positional relationship between entities may be direct or indirect positional relationship. As an example of an indirect positional relationship, the reference in this specification to forming layer "A" on layer "B" includes the case where one or more intermediate layers (e.g., layer "C") are between layer "A" and layer "B," provided that the relevant characteristics and functions of layer "A" and layer "B" are not substantially altered by the intermediate layers.

[0037] The following definitions and abbreviations are used to interpret the claims and specification. As used herein, the terms “comprising,” “including,” “containing,” “comprising,” “having,” “having,” “containing,” or “comprising” or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such compositions, mixtures, processes, methods, articles, or apparatus.

[0038] Additionally, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "at least one" and "one or more" should be understood to include any integer greater than or equal to one, i.e., one, two, three, four, etc. The term "multiple" is understood to include any integer greater than or equal to two, i.e., two, three, four, five, etc. The term "connection" can include both indirect "connection" and direct "connection."

[0039] References to "an embodiment," "embodiment," "example embodiment," etc., in the specification indicate that the described embodiment may include a particular feature, structure, or characteristic; however, each embodiment may or may not include a particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed that implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge of those skilled in the art.

[0040] For the purposes described below, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” and their derivatives shall apply to the described structures and methods, as oriented as shown in the accompanying drawings. The terms “cover,” “top,” “on top,” “positioned on,” or “positioned on top” mean that a first element (such as a first structure) is present on a second element (such as a second structure), wherein an intermediate element, such as an interface structure, may be present between the first and second elements. The term “direct contact” means that the first element (such as a first structure) and the second element (such as a second structure) are connected at the interface of the two elements without any intermediate conductive, insulating, or semiconductor layer.

[0041] For ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” “upper,” etc., are used herein to describe the relationship between one element or feature and another, as shown in the figures. It should be understood that, in addition to the orientation shown in the figures, spatial relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features would be oriented “above” other elements or features. Thus, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein shall be interpreted accordingly.

[0042] The phrase “selective to”, such as “the first element is selective to the second element”, means that the first element can be etched and the second element can act as an etch stop layer.

[0043] The terms “approximately,” “substantially,” “approximately,” and their variations are intended to include the degree of error associated with a measurement based on a specific quantity of equipment available at the time of application submission. For example, “approximately” could include a range of ±8%, 5%, or 2% of a given value.

[0044] As previously mentioned, for the sake of brevity, conventional manufacturing techniques may or may not be described in detail herein. However, as background, a more general description of semiconductor device manufacturing processes that can be used to implement one or more embodiments of the present invention will now be provided. Although specific manufacturing operations for implementing one or more embodiments of the present invention may be individually known, the combinations of operations and / or resulting structures described in the present invention are unique. Thus, the unique combinations of operations associated with manufacturing according to the present invention utilize a variety of individually known physical and chemical processes performed on a substrate, some of which are described in the following paragraphs.

[0045] Generally, the various processes used to form certain devices fall into four main categories: film deposition, removal / etching, semiconductor doping, and patterning / photolithography. Deposition is any process that grows, coats, or otherwise transfers material onto a wafer. Available techniques include physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), molecular beam epitaxy (MBE), and more recently, atomic layer deposition (ALD). Removal / etching is any process that removes material from a wafer. Examples include etching processes (wet or dry) and chemical mechanical planarization (CMP). Semiconductor doping alters electrical properties by doping, for example, transistor sources and drains (typically by diffusion and / or by ion implantation). These doping processes are followed by furnace annealing or rapid thermal annealing (RTA). Annealing is used to activate the implanted dopant. Films of conductors (e.g., polysilicon, aluminum, copper, etc.) and insulators (e.g., various forms of silicon dioxide, silicon nitride, etc.) are used for connection and isolation. Selective doping allows the conductivity of a substrate to change with the application of voltage. Photolithography is the process of creating a three-dimensional relief image or pattern, which is then transferred onto a substrate. In semiconductor photolithography, the pattern is formed from a photosensitive polymer called a photoresist. The photolithography and etching pattern transfer steps can be repeated multiple times. Each printed pattern is aligned with a previously formed pattern.

[0046] The flowcharts and block diagrams in the accompanying drawings illustrate possible implementations of methods for manufacturing and / or operating according to various embodiments of the present invention. Various functions / operations of the method are represented by blocks in the flowcharts. In some alternative implementations, the functions mentioned in the blocks may not occur in the order shown in the figures. For example, two blocks shown consecutively may actually be performed substantially simultaneously, or these blocks may sometimes be performed in reverse order, depending on the functions involved.

[0047] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the described embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles of the embodiments, their practical application, or technical improvements to technologies found in the market, or to enable those skilled in the art to understand the embodiments described herein.

Claims

1. An impedance sensing structure, comprising: a dielectric layer; a pair of spiral electrodes forming a double spiral channel on the dielectric layer and having an inlet portion at a central region of the double spiral channel and an outlet portion at an end of the double spiral channel; an inlet element and an outlet element coupled with the inlet portion and the outlet portion, respectively, for directing a flow of fluid or gas through the double spiral channel; and a sensing circuit electrically connected with the pair of spiral electrodes and configured to sense particles in the fluid or gas as a function of the fluid or gas flowing through the double spiral channel and an impedance of the pair of spiral electrodes. the pair of spiral electrodes is spaced apart proportionally to at least one of: a flow rate of the fluid in the double spiral channel, and a rate of change of a population of particles per unit time with flow rate.

2. The impedance sensing structure of claim 1, wherein, the pair of spiral electrodes includes a plurality of spiral electrodes and a common spiral electrode arranged end-to-end and insulated from each other.

3. The impedance sensing structure of claim 1, wherein, the pair of spiral electrodes forms a double-double spiral channel having a double inlet portion and a double outlet portion.

4. The impedance sensing structure of claim 1, wherein, the pair of spiral electrodes includes a first plurality of spiral electrodes and a second plurality of spiral electrodes arranged end-to-end and insulated from each other, and a pair of common spiral electrodes.

5. The impedance sensing structure of claim 4, wherein, the pair of spiral electrodes forms a multiple-double spiral channel having a plurality of inlet portions and a plurality of outlet portions.

6. The impedance sensing structure of claim 1, wherein, the pair of spiral electrodes includes a first plurality of spiral electrodes and a second plurality of spiral electrodes arranged end-to-end and insulated from each other, and a pair of common spiral electrodes.

7. The impedance sensing structure of claim 11, wherein, 8. A method of manufacturing an impedance sensing structure, the method comprising: forming a double spiral channel opening in a substrate; constructing a pair of spiral electrodes in the double spiral channel opening such that each electrode of the pair of spiral electrodes extends upward from the substrate to form a double spiral channel having an inlet portion at a central region of the double spiral channel and an outlet portion at an end of the double spiral channel; coupling an inlet element and an outlet element with the inlet portion and the outlet portion, respectively, for directing a flow of fluid or gas through the double spiral channel; electrically connecting a sensing circuit to the pair of spiral electrodes; and configuring the circuit to sense particles in the fluid or gas as a function of the fluid or gas and an impedance of the double spiral channel. the constructing of the pair of spiral electrodes includes: arranging a plurality of spiral electrodes end-to-end; 9. The method of claim 8, wherein, insulating the plurality of spiral electrodes from each other; and configuring the plurality of spiral electrodes into a spiral pattern having a common spiral electrode. the constructing of the pair of spiral electrodes is performed such that the pair of spiral electrodes forms a double-double spiral channel having a double inlet portion and a double outlet portion. the constructing of the pair of spiral electrodes includes:

10. The method of claim 9, wherein, arranging a first plurality of spiral electrodes and a second plurality of spiral electrodes end-to-end; 11. The method of claim 10, wherein, insulating the first plurality of spiral electrodes and the second plurality of spiral electrodes from each other; and configuring the first plurality of spiral electrodes and the second plurality of spiral electrodes into a pair of spiral patterns having a pair of common spiral electrodes. the constructing of the pair of spiral electrodes is performed such that the pair of spiral electrodes forms a multiple-double spiral channel having a plurality of inlet portions and a plurality of outlet portions. ​ 12. The method of claim 8, wherein, ​ 13. The method of claim 12, wherein, The construction of the pair of spiral electrodes includes: arranging a plurality of groups of multiple spiral electrodes end-to-end; insulating the plurality of groups of multiple spiral electrodes from each other; and configuring the plurality of groups of multiple spiral electrodes into a plurality of spiral patterns having a plurality of common spiral electrodes.

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