Helical impedance structure

Abstract

Helical impedance structure An impedance sensing structure is provided, comprising a dielectric layer, a helical electrode pair having a double helix channel formed on the dielectric layer and having an inlet portion in the central region of the double helix channel and an outlet portion at the end of the double helix channel, inlet and outlet elements, and a sensing circuit. The inlet and outlet elements are coupled to the inlet and outlet portions, respectively, to guide a fluid or gas to flow through the double helix channel. The sensing circuit is electrically connected to the helical electrode pair and is configured to sense particles in the fluid or gas in accordance with the impedance of the fluid or gas flowing through the helical electrode pair and the double helix channel.

Description

[Background technology]

[0001] This invention relates, in general, to impedance systems. More specifically, it relates to helical impedance system structures for microelectronic sensing.

[0002] Capacitively coupled contactless conductivity detection (C4D) is a detection technique primarily used in capillary electrophoresis and microchip electrophoresis. The characteristics of C4D detectors are generally simple in structure, easy to miniaturize and integrate, and free from electrode contamination, all of which are common challenges in electrochemical detection. [Overview of the project]

[0003] Embodiments of the present invention relate to impedance sensing structures. Non-limiting examples of impedance sensing structures include a dielectric layer, a pair of helical electrodes forming a double helix channel on the dielectric layer, having an inlet portion in the central region of the double helix channel and an outlet portion at the ends of the double helix channel, an inlet element and an outlet element, and a sensing circuit. The inlet element and the outlet element are coupled to the inlet and outlet portions, respectively, to guide a fluid or gas to flow through the double helix channel. The sensing circuit is electrically connected to the pair of helical electrodes and is configured to sense particles in the fluid or gas in accordance with the impedance of the fluid or gas flowing through the pair of helical electrodes and the double helix channel.

[0004] Embodiments of the present invention relate to impedance sensing structures for sensing particles in a fluid or gas. Non-limiting examples of impedance sensing structures include a dielectric layer, a pair of helical electrodes forming a double helix channel on the dielectric layer and having an inlet portion in the central region of the double helix channel and an outlet portion at the end of the double helix channel, inlet and outlet elements coupled to the inlet and outlet portions, respectively, to guide the fluid or gas through the double helix channel, and a sensing circuit electrically connected to the pair of helical electrodes and configured to sense particles in the fluid or gas in accordance with the impedance of the fluid or gas flowing through the pair of helical electrodes and the double helix channel.

[0005] Embodiments of the present invention relate to methods for fabricating impedance sensing structures. Non-limiting examples of the method include forming a double helix channel opening in a substrate, and constructing a pair of helical electrodes in the double helix channel opening such that each electrode of the helical electrode pair extends upward from the substrate, forming a double helix channel having an inlet portion in the central region of the double helix channel and an outlet portion at the ends of the double helix channel. The method further includes coupling inlet and outlet elements to the inlet and outlet portions, respectively, to guide a fluid or gas through the double helix channel, electrically connecting a sensing circuit to the pair of helical electrodes, and configuring the circuit to sense particles in the fluid or gas in accordance with the impedance of the double helix channel and the fluid or gas.

[0006] Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the present invention are described in detail herein and are considered to be part of the subject matter claimed. For a better understanding, please refer to the detailed description and drawings. [Brief explanation of the drawing]

[0007] Details of the exclusive rights described herein are specifically indicated and are explicitly asserted in the claims in the conclusion of the specification. The aforementioned and other features and advantages of embodiments of the present invention are evident from the following detailed description in conjunction with the accompanying drawings.

[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] This is a top view of the helical channel of the impedance sensing structure shown in Figure 1, according to one or more embodiments of the present invention.

[0010] [Figure 3] This is a top view of a helical channel equipped with an electrode portion of the impedance sensing structure shown in Figure 1, according to one or more embodiments of the present invention.

[0011] [Figure 4] This is a top view of two double helix channels of the impedance sensing structure shown in Figure 1, according to one or more embodiments of the present invention.

[0012] [Figure 5] This is a top view of a set of multiple helical electrodes and a pair of common helical electrodes, each having a set of multiple helical electrodes arranged end-to-end and insulated from one another, according to one or more embodiments of the present invention.

[0013] [Figure 6] This is a top view of a plurality of double helix channels having a plurality of inlet portions and a plurality of outlet portions of the impedance sensing structure shown in Figure 1, according to one or more embodiments of the present invention.

[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.

[0015] [Figure 8] This is a graphical flowchart illustrating the method shown in Figure 7 according to one or more embodiments of the present invention.

[0016] The drawings shown in this specification are illustrative. Without departing from the scope of the present invention, many modifications are possible to the figures or the operations described therein. For example, actions can be executed in a different order, or actions can be added, deleted, or modified. Also, the term "coupled" and its variations describe having a communication path between two elements and do not imply a direct connection between them without intervening elements / connections between the elements. All of these modifications are considered to be part of this specification.

[0017] In the accompanying drawings and the following detailed description of the embodiments, two - or three - digit reference numbers are assigned to the various elements shown in the figures. With few exceptions, the left - most digit of each reference code corresponds to the figure in which the element is first shown.

Mode for Carrying Out the Invention

[0018] For the sake of brevity, conventional techniques related to the fabrication of semiconductor devices and integrated circuits (ICs) may or may not be described in detail herein. Further, the various tasks and process steps described herein can be incorporated into more comprehensive procedures or processes having additional steps or functionality not described in detail herein. Specifically, since the various steps in the manufacture of semiconductor devices and semiconductor - based ICs are well - known, for the sake of brevity, many conventional steps are only briefly described herein or are omitted entirely, and well - known process details are not provided.

[0019] Referring here to an overview of the technology particularly relevant to aspects of the present invention, C4D has been introduced as a method for quantifying capillary electrophoresis because it tends to be an effective method for conductivity detection for fluid analysis and the measurement of small inorganic ions, as well as organic and biochemical species. Compared to conventional contact-type conductivity detection methods, the electrodes of a C4D sensor can be encapsulated or placed outside the channel so as not to come into direct contact with the fluid being measured. Therefore, some undesirable effects of contact-type conductivity detection methods (such as electrode polarization and electrochemical corrosion) can be avoided. Furthermore, C4D can provide a versatile and non-destructive detection tool and scanning capability. In addition, C4D is useful for field portable devices, especially battery-powered ones, because it typically consumes relatively little power.

[0020] In microchip capillary electrophoresis, two different approaches to C4D are often employed: either an external electrode is used, or the electrode is integrated into the device but separated from the electrolyte solution. The former arrangement is simpler because it requires fewer manufacturing steps to construct a chip without an embedded electrode, while the latter allows for a closer distance between the channel and the electrode. The sensitivity of C4D is directly proportional to the distance of the electrode from the isolation channel.

[0021] The current challenge for sensors is to achieve greater sensitivity in assays at even lower concentrations to enable earlier detection. One such application is identifying the earliest point of onset or the beginning of virus / bacterial formation at the lowest concentration levels in the food supply chain, or detecting infection / transmission to humans. Another useful application is measuring cell membrane properties (capacitance and conductivity) and monitoring changes caused by the action of pharmaceuticals or toxins.

[0022] Referring here to an overview of the aspects of the present invention, one or more embodiments of the present invention address the shortcomings of the prior art described above by providing helical impedance sensing structures and methods, thereby eliminating non-uniform or spatially varying cell sidewall interactions by helical fluidics and enabling unrestricted particle flow. The helical impedance sensing structure enables laminar particle flow over the entire range from static to dynamic flow rates, is scalable to the detection of nanoparticles in terms of size and single particles in terms of quantity, and provides flexible resolution obtained by selecting parameters (these parameters are [decrease in flow rate] × [increase in electrode area] × [number of parallel and / or series electrodes] × [increase in residence time]) to adjust the optimal cost to the signal-to-noise (S / N) ratio, and is compatible with methods for fabricating guarded electrodes that eliminate electromagnetic interference (EMI) problems, crosstalk between adjacent electrodes, and the resulting errors. Furthermore, the helical impedance sensing structure enables electrode encapsulation or deencapsulation and enables differential sensing methods.

[0023] The embodiments of the present invention described above address the shortcomings of the prior art by providing an impedance sensing structure comprising a dielectric layer, a helical electrode pair having an inlet portion in the central region of the helical channel and an outlet portion at the ends of the helical channel, an inlet element and an outlet element, and a sensing circuit. The inlet element and the outlet element are coupled to the inlet and outlet portions, respectively, to guide a fluid or gas to flow through the helical channel. The sensing circuit is electrically connected to the helical electrode pair and is configured to sense particles in the fluid or gas in accordance with the impedance of the fluid or gas flowing through the helical electrode pair and the helical channel.

[0024] Referring here to a more detailed description of aspects of the present invention, Figures 1 and 2 show an impedance sensing structure 101 for sensing particles in a fluid or gas. The impedance sensing structure 101 eliminates artifacts such as sidewalls and resulting eddy currents and non-uniform flow rates between electrodes. The impedance sensing structure 101 also eliminates the need for complex 2D / 3D capacitance measurements and subsequent complex volume tomography modeling. The impedance sensing structure 101 can be widely applied to micro and nanoscale sensing applications (i.e., for bacteria, viruses, DNA, proteins, etc.) and also to large-scale applications (such as detecting the proportion of water in a water-like liquid in an oil pipeline).

[0025] The impedance sensing structure 101 includes a dielectric layer 110 and a pair of helical electrodes 120, including a first helical electrode 121 and a second helical electrode 122, which together form a double helical channel 125 helically on the dielectric layer 110. The double helical channel 125 has an inlet portion 126 in the central region of the helical channel 125 and an outlet portion 127 at the end of the helical channel 125. The inlet portion and outlet portion are interchangeable, such as the inlet portion being 127 and the outlet portion being 126, and it is understood that this flexibility in the assignment of the inlet portion and outlet portion generally applies to all embodiments referred to herein. The impedance sensing structure 101 further includes an inlet element 130 coupled to the inlet portion 126 and an outlet element 131 coupled to the outlet portion 127 for guiding a fluid or gas to flow through the double helical channel 125, and a sensing circuit 140. The sensing circuit 140 can be located adjacent to or part of the dielectric layer 110 within a printed circuit board (PCB) and is electrically connected to the first helical electrode 121 and the second helical electrode 122 of the helical electrode pair 120. The sensing circuit 140 is configured to sense particles in a fluid or gas in accordance with the impedance of the fluid or gas flowing through the helical electrode pair 120 and the double helix channel 125 between the first helical electrode 121 and the second helical electrode 122. The first and second helical electrodes 121 and 122 of the helical electrode pair 120 can be spaced apart in proportion to at least one of the fluid flow rate in the double helix channel 125 and the rate of change of the particle population.

[0026] Therefore, for example, 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 and monitoring internal changes such as formation, growth, and death, as well as changes resulting from external factors such as pharmaceuticals or toxins. The material of the impedance sensing structure 101 may generally be biocompatible or otherwise compatible. This includes a dielectric layer 110 which can be formed from glass, plastic, silicon, etc., first and second helical electrodes 121, 122 which can be formed from gold, platinum, indium tin oxide, iridium, etc., electrode insulators which can be formed from photoresist, polyimide, PMMA, silicon dioxide, silicon nitride, etc., and chamber housing components which can be formed from adhesives, sealants, tubes, valves, pumps, and specific electrical stimuli and / or measuring components. The impedance sensing structure 101 can be adapted to an impedance spectrum in the range of, for example, about 20 Hz to about 2 MHz, and the impedance spectrum can be determined by an LCR meter with a set forced amplitude, for example, 50 mV.

[0027] Impedance measurement can be performed by the impedance sensing structure 101 as follows: When the first and second helical electrodes 121 and 122 are in contact with the ionic solution, the impedance is the capacitance C of the electrochemical double layer. DL and ionic resistance R ion It is composed of, while scaled by the electrical conductivity of the bulk liquid. In these cases, the impedance is frequency f c = 1 / (π*R ion *C DL ) can be measured, and here, C DL It can be short-circuited, 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 helix channel 125.

[0028] As a general matter, impedance resolution is proportional to the sensing length, especially when the concentrations of particles, viruses, and bacteria are very low. Therefore, according to the spiral pattern of the double helix channel 125, a laminar fluid flow through the double helix channel is provided, and a particularly long first spiral electrode 121 and second spiral electrode 122 are provided for a given available surface area without generating eddy currents like a meandering configuration.

[0029] Continuing to refer to FIGS. 1 and 2 and further referring to FIGS. 3-6, according to one or more further embodiments of the present invention, additional or alternative configurations can be provided for the impedance sensing structure 101.

[0030] As shown in FIG. 3, the first spiral electrode 121 of the spiral electrode pair 120 can include a plurality of spiral electrode sections from 1211 denoted as 121 1-N to 121 N These sections are arranged in an end-to-end pattern and are insulated from each other. On the other hand, the second spiral electrode 122 of the spiral electrode pair can be provided as a common spiral electrode 1221 extending along each of the plurality of spiral electrode sections 121 1-N

[0031] As shown in FIG. 4, two pairs of the first spiral electrode 121 and the second spiral electrode 122 of the spiral electrode pair 120 respectively form two double helix channels 401 having double inlet portions 402, 403 and double outlet portions 404, 405. Although FIG. 4 shows two double helix channels 401, it should be understood that other embodiments such as three double helix channels, four double helix channels, etc. are also possible.

[0032] As shown in FIG. 5, the first spiral electrode 121 of the spiral electrode pair 120 is arranged in an end-to-end pattern and is insulated from each other by a first set of a plurality of spiral electrode sections 501 1-N and a second set of a plurality of spiral electrode sections 502 arranged in an end-to-end pattern and insulated from each other. 1-NThe second set may include the second helical electrode 122 of the helical electrode pair 120, which can be provided as a pair of common helical electrodes 503 and 504, where the common helical electrode 503 is a multiple helical electrode section 501 of the first set. 1-N Extending along each of the common helical electrodes 504, the second set of multiple helical electrode sections 502 1-N It extends along each of them.

[0033] As shown in Figure 6, multiple pairs of first helical electrodes 121 and second helical electrodes 122 of the helical electrode pair 120 each form multiple double helical channels 601 having multiple inlet portions 602 and multiple outlet portions 603. Although not required, the multiple first helical electrodes 121 in Figure 6 are arranged in an end-to-end pattern and insulated from one another to form multiple helical electrode sections 610. 1-N ,611 1-N , and 612 1-N It may include multiple sets of multiple helical electrodes 122, and multiple sets of multiple helical electrode sections 610 1-N ,611 1-N , and 612 1-N They may be provided as common helical electrodes 620, 621, and 621 extending along each of them.

[0034] Referring to Figure 7, a method 700 is provided for fabricating an impedance sensing structure such as the impedance sensing structure 101 described above. As shown in Figure 7, the method includes the steps of forming a helical channel opening in a substrate (block 701), constructing a pair of helical electrodes in the helical channel opening so as to form a double helix channel in which each electrode of the helical electrode pair extends upward from the substrate and has an inlet portion in the central region of the helical channel and an outlet portion at the end of the helical channel (block 702), coupling inlet and outlet elements to the inlet and outlet portions, respectively, to guide a fluid or gas to flow through the helical channel (block 703), electrically connecting a sensing circuit to the pair of helical electrodes (block 704), and configuring the circuit to sense particles in the fluid or gas depending on the impedance of the double helix channel and the fluid or gas (block 705). In consideration of the above and below descriptions, it should be understood that, without excessive experimentation, the method 700 can be modified for various embodiments of at least Figures 1 and 2, and Figures 3 to 6.

[0035] Referring to Figure 8, the steps of the implementation of method 700 of Figure 7 are shown. As shown in Figure 8, in the initial implementation, a substrate 801 (i.e., a glass substrate) is formed, an insulating layer 802 is deposited thereon, and through vias 803 are formed that penetrate the substrate 801 and the insulating layer 802. The through vias 803 may be formed as a pair of helical channel openings. In the next implementation, photolithography of the back substrate and the formation of a seed layer are performed to form a sacrificial layer 804 that defines the space for the pads of the first and second electrodes along the through vias 803, and an adhesive seed layer 805 (i.e., made of titanium, tantalum, etc.). In the next implementation, the first and second helical electrodes 806, 807 (i.e., made of copper) are formed in the through vias 803 together with the pads 808, followed by front-side chemical mechanical polishing (CMP) and selective etching of the insulating layer 802. In the final stage of implementation, an upper layer is provided to form inlet and outlet elements, and the double helix channel 810 is formed by covering the first and second helical electrodes 806 and 807. Subsequently, the pad 808 can be joined to the sensing circuit.

[0036] Various embodiments of the present invention are described herein with reference to the relevant drawings. Alternative embodiments can be devised without departing from the scope of the present invention. The following description and drawings describe various connections and positional relationships between elements (e.g., above, below, adjacent, etc.), but those skilled in the art will notice that many of the positional relationships described herein are orientation-independent, provided that the described functionality is maintained even if the orientation changes. These connections and / or positional relationships may be direct or indirect unless otherwise specified, and the present invention is not intended to be limiting in this respect. Thus, the connection between entities may refer to either a direct or indirect connection, and the positional relationship between entities may be a direct or indirect positional relationship. As an example of an indirect positional relationship, when it is referred in this description to form layer "A" on layer "B", it includes a situation in which one or more intermediate layers (e.g., layer "C") exist between layers "A" and "B", provided that the relevant properties and functionality of layers "A" and "B" are not substantially altered by the intermediate layer.

[0037] The following definitions and abbreviations are for use in interpreting the claims and specification. Where used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains,” or “containing,” or any other variation thereof, are intended to cover non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus containing a list of elements is not necessarily limited to those elements alone, and may include other elements not expressly listed, or other elements specific to such composition, mixture, process, method, article, or apparatus.

[0038] Furthermore, in this specification, the term “exemplary” is used to mean “serving as an example, case, or illustration.” Any embodiment or design described as “exemplary” in this specification should not necessarily be construed as being preferable or advantageous to other embodiments or designs. The terms “at least one” and “one or more” may be understood to include any integer greater than or equal to 1, i.e., 1, 2, 3, 4, etc. The term “a plurality” is understood to include any integer greater than or equal to 2, i.e., 2, 3, 4, 5, etc. The term “connection” may include indirect and direct “connections.”

[0039] Where the terms "one embodiment," "an embodiment," and "an example embodiment" are used herein, the embodiments described may include certain features, structures, or characteristics, but not all embodiments may include or not include such features, structures, or characteristics. Furthermore, such terms do not necessarily refer to the same embodiments. Moreover, if certain features, structures, or characteristics are described in relation to one embodiment, it is considered that their influence on other embodiments, whether explicitly described or not, is within the knowledge of those skilled in the art.

[0040] For the purposes of the following explanation, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” and “bottom,” and their derivatives, shall be used in relation to the structures and methods described, as oriented within the drawings. The terms “overlying,” “atop,” “on top,” “positioned on,” or “positioned atop” mean that a first element, such as a first structure, is located on a second element, such as a second structure, and an intervening element, such as an interface structure, may be located between the first and second elements. The term “direct contact” means that a first element, such as a first structure, and a second element, such as a second structure, are connected at the interface between the two elements without any intermediate conductive, insulating, or semiconductor layers.

[0041] For example, spatially relative terms such as “beneath,” “below,” “lower,” “above,” “upper,” and similar terms are used herein for the sake of simplicity of explanation and may describe the relationship between one element or feature and another as illustrated in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientations shown in the figures. For example, if the device in the figures is rotated, an element described as “below” or “beneath” of another element or feature will be oriented “above” of the other element or feature. Thus, the term “below” may encompass both upward and downward orientations. The device may be oriented in other ways (90-degree rotation or other orientations), and the spatially relative descriptors used herein will be interpreted accordingly.

[0042] For example, the phrase "selective to" in "a first element selective to a second element" means that the first element can be etched and the second element can act as an etch stop.

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

[0044] As previously stated herein, for the sake of brevity, conventional fabrication techniques may or may not be described in detail herein. However, for background purposes, a more general description of semiconductor device fabrication processes that may be used when implementing one or more embodiments of the present invention is provided here. While specific fabrication operations used when implementing one or more embodiments of the present invention may be individually known, the combination of operations described and / or the resulting structures of the present invention are unique. Thus, the unique combination of operations described in relation to fabrication according to the present invention utilizes 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 specific devices are classified into four common categories: film deposition, removal / etching, semiconductor doping, and patterning / lithography. Deposition is any process of growing, coating, or otherwise transferring material onto a wafer. Available technologies include, among many others, 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 of removing material from a wafer. Examples include etching processes (either wet or dry), chemical mechanical planarization (CMP), and similar processes. Semiconductor doping is the modification of electrical properties by doping the source and drain of a transistor, for example, generally by diffusion and / or ion implantation. These doping processes are followed by furnace annealing or rapid thermal annealing (RTA). Annealing works to activate the implanted dopants. For connection and insulation, films of both conductors (e.g., polysilicon, aluminum, copper, etc.) and insulators (e.g., various forms of silicon dioxide, silicon nitride, etc.) are used. By selectively doping, the conductivity of the substrate can be changed by applying a voltage. Lithography is the process of forming a three-dimensional relief image or pattern and then transferring that pattern to a substrate. In semiconductor lithography, the pattern is formed using a photosensitive polymer called a photoresist. The lithography and etching pattern transfer steps can be repeated multiple times. Each pattern to be printed is aligned with a previously formed pattern.

[0046] The flowcharts and block diagrams in the figures illustrate possible implementations of methods of fabrication and / or operation according to various embodiments of the present invention. In the flowcharts, various functions / operations of the method are represented by blocks. In some alternative implementations, the functions shown in the blocks may occur in a different order than shown in the figures. For example, depending on the functionality involved, two blocks shown consecutively may actually be executed substantially simultaneously, or the blocks may be executed in reverse order.

[0047] The descriptions of various embodiments of the present invention are presented for illustrative purposes only and are not intended to be exhaustive or to limit oneself to the embodiments described. Many modifications and variations will become apparent to those skilled in the art without departing from the scope of the embodiments described. The terminology used herein has been selected to best describe the principles of the embodiments, the practical applications of the technology found in the market, or the technical improvements to the technology, or to enable other those skilled in the art to understand the embodiments described herein.

Claims

1. Dielectric layer; A pair of helical electrodes having a double helix channel formed on the dielectric layer, with an inlet portion in the central region of the double helix channel and an outlet portion at the end of the double helix channel; Inlet and outlet elements, respectively, that are coupled to the inlet and outlet portions to guide a fluid or gas to flow through the double helix channel; and A sensing circuit is electrically connected to the helical electrode pair and configured to sense the particles in the fluid or gas in accordance with the impedance of the fluid or gas flowing through the helical electrode pair and the double helix channel. An impedance sensing structure equipped with this feature.

2. The impedance sensing structure according to claim 1, wherein the pair of helical electrodes are spaced apart in proportion to at least one of the flow rate of the fluid in the double helix channel and the rate of change of the particle population due to the flow rate per unit time.

3. The impedance sensing structure according to claim 1, wherein the pair of helical electrodes comprises a plurality of helical electrodes arranged with their ends facing each other and insulated from one another, and a common helical electrode.

4. The impedance sensing structure according to claim 1, wherein the pair of helical electrodes forms two double helix channels having a double inlet portion and a double outlet portion.

5. The impedance sensing structure according to claim 4, wherein the pair of helical electrodes comprises a first and second set of multiple helical electrodes arranged end-to-end and insulated from one another, and a pair of common helical electrodes.

6. The impedance sensing structure according to claim 1, wherein the pair of helical electrodes forms a plurality of double helix channels having a plurality of inlet portions and a plurality of outlet portions.

7. The impedance sensing structure according to claim 11, wherein the pair of helical electrodes comprises a first and second set of multiple helical electrodes arranged end-to-end and insulated from one another, and a pair of common helical electrodes.

8. A method for fabricating an impedance sensing structure, wherein the method is The step of forming a double helix channel opening in the substrate; and A step of constructing the helical electrode pair in the opening of the double helix channel such that each electrode of the helical electrode pair extends upward from the substrate and forms a double helix channel; The double helix channel has an inlet portion in the central region and an outlet portion at the end, The above method further, The step of connecting inlet and outlet elements to the inlet and outlet portions, respectively, in order to guide the fluid or gas to flow through the double helix channel; The step of electrically connecting the sensing circuit to the helical electrode pair; and The step of configuring the circuit to sense particles in the fluid or gas in accordance with the impedance of the double helix channel and the fluid or gas. A method for providing this.

9. The step of constructing the aforementioned helical electrode pair is: The stage of arranging multiple helical electrodes with their ends aligned; The step of insulating the plurality of helical electrodes from each other; and The method according to claim 8, further comprising the step of configuring the plurality of helical electrodes into a helical pattern having a common helical electrode.

10. The method according to claim 9, wherein the step of constructing the helical electrode pair is performed such that the helical electrode pair forms two double helix channels having a double inlet portion and a double outlet portion.

11. The step of constructing the aforementioned helical electrode pair is: The step of arranging multiple helical electrodes of the first and second sets with their ends aligned; The step of insulating the multiple helical electrodes of the first and second sets from each other; and The method according to claim 10, further comprising the step of configuring the plurality of helical electrodes of the first and second sets to form a pair of helical patterns having a pair of common helical electrodes.

12. The method according to claim 8, wherein the step of constructing the helical electrode pair is performed such that the helical electrode pair forms a plurality of double helix channels having a plurality of inlet portions and a plurality of outlet portions.

13. The step of constructing the aforementioned helical electrode pair is: The stage of arranging multiple sets of multiple helical electrodes, aligning their ends; The step of insulating the multiple helical electrodes of the multiple sets from each other; and The method according to claim 12, further comprising the step of configuring the plurality of helical electrodes of the plurality of sets to form a plurality of helical patterns having a plurality of common helical electrodes.

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