Linear fluid cell trap device for single cell detection

Abstract

A sensing structure is provided, which includes a tubular element through which a fluid can flow along a single path; an array of sensors arranged along the length of the tubular element, thereby allowing the fluid to flow through each of the sensors; and a sensing circuit configuration electrically connected to each of the sensors, configured to measure the reactance of each of the sensors and to determine that any reactance indicates the presence of living cells in the fluid flowing through the corresponding sensor.

Description

[Technical Field]

[0001] The present invention generally relates to detection systems. More specifically, the present invention relates to a linear fluid cell trapping device for the detection of a single cell. [Background technology]

[0002] A single cell represents a fundamental biological unit. Unfortunately, biological knowledge is generally derived from studying large cell populations due to the availability of simple, easy-to-use, and inexpensive instruments, and / or the ease of sample preparation. However, fundamental and applied problems still exist that can only be addressed at the single-cell level, such as the transcriptional regulation of stem cell differentiation, endogenous noise in gene expression, and the origin of disease.

[0003] Furthermore, identifying a single bacterial cell or viral particle is crucial for identifying food or agricultural product contamination and for individual health monitoring, respectively. Identifying a single bacterial cell can help identify pathogenic contamination in food or agricultural products. Identifying viral particles can help determine whether an unwell individual is infected with Covid or the common influenza virus, preferably at home, without the need to visit a diagnostic laboratory or hospital. [Overview of the project]

[0004] Embodiments of the present invention relate to sensing structures. Non-limiting examples of sensing structures are provided, such sensing structures include a tubular element through which a fluid can flow along a single path; an array of sensors arranged along the length of the tubular element, thereby allowing the fluid to flow through each of the sensors; and a sensing circuit configuration electrically connected to each of the sensors, configured to measure the reactance of each of the sensors and to determine that the reactance indicates the presence of living cells in the fluid flowing through the corresponding sensor.

[0005] Embodiments of the present invention relate to sensing structures. Non-limiting examples of sensing structures include a bottom wafer, a top wafer, an insulating layer interposed between the bottom wafer and the top wafer and formed to define a channel through which a fluid can flow along a single path, sensors arranged along the length of the channel so that the fluid can flow through each of the sensors, and a sensing circuit configuration electrically connected to each of the sensors and configured to measure at least one of the capacitance and inductance of each of the sensors, and to determine that either the capacitance and the at least one of the inductance indicates the presence of living cells in the fluid flowing through the corresponding sensor.

[0006] Embodiments of the present invention relate to a method for operating a sensing structure for sensing living cells in a fluid. Non-limiting examples of such a method include the steps of: arranging sensors in an array along a single path; obtaining a baseline reactance for each of the sensors; flowing the fluid through the sensors in the array and along the single path; obtaining a test reactance for each of the sensors during the step of flowing the fluid; and determining that a difference exists between the baseline reactance and the test reactance for each of the sensors, indicating the presence of living cells.

[0007] Additional technical features and benefits are realized through the technology 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]

[0008] Details of the exclusive rights described herein are specifically indicated and expressly asserted in the claims in the conclusions herein. The aforementioned and other features and advantages of embodiments of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.

[0009] [Figure 1A] A side view of a sensing structure and the sensing structure showing the operation of the sensing structure according to one or more embodiments of the present invention.

[0010] [Figure 1B] A graph of measurement values from the sensing circuit configuration of the sensing structure of FIG. 1A according to one or more embodiments of the present invention.

[0011] [Figure 2] A schematic top view showing a sensing structure according to one or more embodiments of the present invention.

[0012] [Figure 3] A side view of the sensing structure of FIG. 2 when cut along line A-A' of FIG. 2 according to one or more embodiments of the present invention.

[0013] [Figure 4] A side view of the sensing structure of FIG. 2 when cut along line C-C' of FIG. 2 according to one or more embodiments of the present invention.

[0014] [Figure 5] A flowchart illustrating a method of operating a sensing structure for sensing living cells in a fluid according to one or more embodiments of the present invention.

[0015] [Figure 6] A flowchart illustrating a method of constructing a sensing structure according to one or more embodiments of the present invention.

[0016] [Figure 7A] A graphic flowchart showing a method of manufacturing the sensing structure of FIGS. 2 to 4 according to one or more embodiments of the present invention. [Figure 7B] A graphic flowchart showing a method of manufacturing the sensing structure of FIGS. 2 to 4 according to one or more embodiments of the present invention.

[0017] The drawings shown herein are illustrative. Many variations may exist to the drawings or the actions described herein without departing from the spirit of the invention. For example, actions may be performed in a different order, or actions may be added, deleted, or modified. Furthermore, the term “coupled” and its variations describe the existence of a communication path between two elements, and do not imply a direct connection between them without an intervening element / connection. All of these variations are considered part of this specification.

[0018] In the attached drawings and the following detailed description of the embodiments described, various elements illustrated in the drawings are given two- or three-digit reference numerals. With a few exceptions, the leftmost digit of each reference numeral corresponds to the drawing in which the element is first shown. [Modes for carrying out the invention]

[0019] For the sake of brevity, prior art related to the manufacture of semiconductor devices and integrated circuits (ICs) may or may not be described in detail herein. Furthermore, various tasks and process steps described herein may be incorporated into more comprehensive procedures or processes that have additional steps or functionalities 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 may be only briefly mentioned herein or omitted entirely without providing well known process details.

[0020] Moving on to a more specific overview of the technology related to aspects of the present invention, existing methods for measuring transcription product levels in single cells include quantitative reverse transcription polymerase chain reaction (RT-qPCR), single-molecule counting using digital PCR, hybridization probes, and next-generation sequencing. Of these, single-cell RT-qPCR offers advantages such as sensitivity, specificity, and dynamic range, but its main drawbacks are low throughput, high reagent costs, and the difficulty in accurately measuring low-abundance transcription products.

[0021] Moving on to an overview of the embodiments of the present invention, one or more embodiments of the present invention address the shortcomings of the prior art described above by providing multiple (N) linearly connected single-cell traps that enable higher throughput, as determined by assay flow rate and detector sampling rate. Measurement accuracy is improved by having individual current or voltage stimulation electrodes for each cell and individually insulated embedded detection / measurement probes within the main pathway of the stimulation electrodes. Furthermore, wafer-to-wafer parallel manufacturing methods result in substantially lower costs.

[0022] The embodiments of the present invention described above address the shortcomings of the prior art by providing a sensing structure comprising a tubular element through which a fluid can flow along a single path, an array of sensors arranged along the length of the tubular element so as to allow the fluid to flow through each sensor, and a sensing circuit configuration electrically connected to each of the sensors, configured to measure the reactance of each of the sensors and to determine that the measured reactance indicates the presence of living cells in the fluid flowing through the corresponding sensor.

[0023] Turning now to a more detailed description of aspects of the present invention, FIG. 1A depicts a sensing structure 101, which includes a tubular element 110 through which fluid can flow along a single path 111, and sensors 1201-5 arranged along the length L of the tubular element 110 such that when fluid flows through the tubular element 110, it flows through sensors 120 1~5 ,

[0025] , as shown. The sensing structure 101 also includes a sensing circuit configuration 130. The sensing circuit configuration 130 is electrically connected to each of the sensors 120 1~5 and is configured to measure the reactance of each of the sensors 120 1~5 and determine if any reactance indicates the presence of biological cells in the fluid flowing through the corresponding sensor 120 1~5 .

[0024] Each of the sensors 120 1~5 includes opposing electrodes 121, 122 placed on opposite sides of the tubular element 110 at uniform and regular intervals along the length L. Five groups of sensors 120 1~5 are shown in FIG. 1A, but the sensing structure 101 includes at least three or more of the sensors within a group of sensors 120 1~5 to ensure that a statistically significant number of detection and determination events occur in a given implementation. It should be understood that additional sensors may be arranged along the length L in addition to the sensors 120 1~5 .

[0025] [[ID=​​1~5 Measure at least one of capacitance and inductance across the entire array, and / or sensor 120 1~5 It is configured to measure at least one of the capacitance and inductance of each of the components.

[0026] When the fluid does not contain living cells, and when the fluid contains living cells, the sensing circuit configuration can be controlled to acquire the dielectric constant of the fluid over a range of operating frequencies. Furthermore, when the fluid contains only one type of living cells, by acquiring the dielectric constant of the fluid over a range of operating frequencies, the sensor 120 1~5 The array and sensing circuit configuration 130 can be calibrated.

[0027] In other words, in the operation of the sensing structure 101, the sensor 120 1~5 The baseline reactance is obtained by measuring the reactance when no fluid is present in the tubular member 110. Subsequently, the dielectric constant of the fluid can be obtained by measuring the reactance while the fluid is flowing through the tubular member 110, under the condition that the fluid is known not to contain any biological cells. In this case, the sensing circuit configuration 130 obtains the dielectric constant from the difference between the reactance when there is no fluid and the reactance of the fluid that does not contain biological cells. At this point, once the dielectric constant of the fluid is known, the fluid, which may contain biological cells, is flowed through the tubular member 110. The sensing circuit configuration 130 obtains the dielectric constant from the change in reactance, as shown in the graphic elements of Figure 1A, from the sensor 120 1~5 The presence of living cells can be determined in any one of these cases.

[0028] Referring to Figure 1B, the sensing circuit configuration may be used to generate measurements that identify the type of biological cell detected by the sensing structure 101, as described below. The tubular element 110 is filled with a fluid / buffer medium that does not contain biological cells (i.e., bacteria or viruses) for background measurements. Next, capacitive or reactance is measured over a frequency range (preferably 0.1 to 100 MHz) to extract the dielectric constant of the background medium. Then, a fluid containing biological cells (i.e., bacteria or viruses or other biological material) is passed through the tubular member 110, and the same type of frequency scan is repeated to obtain a new dielectric constant over the above frequency range. The different peaks and peak FWHMs in the dielectric dispersion curve in Figure 1B will, in this case, indicate the peaks and peak FWHMs corresponding to different types of biological cells. To achieve this by calibrating the sensing structure 101, dielectric dispersion measurements are performed using only one type of biological cell at a time. This process is repeated with a different type of biological cell in each iteration. A neural network model can be trained using this data to identify various types of biological cells.

[0029] Referring to Figures 2 to 4, a top view of the sensing structure 201 is provided, showing the bottom wafer 210, top wafer 220, insulating layer 230, and sensor 240. 1~5 The group includes, as shown herein, an IC integrated sensing circuit configuration 250. The insulating layer 230 is interposed between the bottom wafer 210 and the top wafer 220 and is formed to define a channel 235 through which a fluid can flow along a single path 236. Sensor 240 1~5 It is positioned along the length L of channel 235, so that when the fluid flows through channel 235, sensor 240 1~5 It is possible to flow through each of them. Sensing circuit configuration 250 is configured similarly to sensing circuit configuration 130 in Figure 1, and sensor 240 1~5Each of them is electrically connected. The sensing circuit configuration 250 can be provided as an integrated IC as shown in Figure 2, or as an external feature as shown in Figure 1, and the sensor 240 1~5 Measure at least one of the capacitance and inductance of each of the sensors 240, and if at least one of the capacitance and inductance is equal to the corresponding sensor 240 1~5 It is configured to determine the presence of living cells in a fluid flowing through it.

[0030] As shown in the enlarged view of Figure 2, sensor 240 1~5 This is a reference sensor (C) that is interleaved alternately along length L. R ) and sample sensor (C S ) may include. In any case, sensor 240 1~5 Each of these may include a ground-signal-ground (GSG) electrode pair 241 on the opposite side of channel 235.

[0031] The sensing circuit configuration 250 may include a plurality (e.g., four) of probes 251. Each probe 251 has a pad 252 exposed to the outside of the sensing structure 201, a reference sensor C R and sample sensor C S The probe tip 253 is positioned in electrical contact with a corresponding one of the reference sensors C, and the metallization 254 extends through the insulating layer 230 between each of the corresponding pads 252 and the corresponding probe tip 253. According to the embodiment, the probe tip 253 of each probe 251 is positioned with respect to the reference sensor C R and sample sensor C S The probes are arranged to be in electrical contact with adjacent ones, and a pair of probes 251 may have overlapping probe tips 253.

[0032] As shown in Figure 3, two probe tips 253 of the probe 251 may be mounted along the same sidewall of the channel 235, while the probe tips of the other two probes 251 may be mounted opposite each other on the top and bottom walls of the channel 235. For example, certain probe tips 253 (i.e., stimulating probes) may be positioned on the top and bottom walls of the channel 235, while other probe tips 253 (i.e., measuring sensing probes) may be mounted along the same sidewall of the channel 235, or as labeled "probe 251" on the right and left sides of the enlarged view in Figure 2, respectively. In each case, as shown in the enlarged view in Figure 2, the probe tips 253 may be arranged in an alternating ground-probe-ground configuration along length L, which can prevent noise generation or influence on capacitance / inductance measurements. In addition, positioning the measuring sensing probes and contacts on the opposite side of the channel 235 from the stimulating probes also contributes to noise immunity.

[0033] Figure 4 shows the cross-section labeled C-C' in the unenlarged view of Figure 2, where channel 235 has at least two inlets 237, 238, thereby directing fluid into channel 235. This not only allows the sensing structure 201 to be initialized and calibrated (as described above), but also provides an escape port for trapped air or gas that would block the desired microfluidic flow. Specifically, inlet 237 is employed to direct fluid known not to contain living cells into channel 235, and inlet 238 may be used to direct fluid that may contain living cells into channel 235.

[0034] Referring to Figure 5, a method 500 is provided for operating a sensing structure for sensing living cells in a fluid, such as the sensing structure 101 in Figure 1 and the sensing structure 201 in Figure 2. The method 500 includes the steps of: arranging sensors in an array along a single path (block 501); calibrating the sensors over a range of operating frequencies (block 502); obtaining the baseline reactance of each sensor (block 503); flowing fluid through the sensors in the array along a single path (block 504); obtaining the test reactance of each sensor during the fluid flow step (block 505); and determining that a difference exists between the baseline reactance and test reactance of each sensor, indicating the presence of living cells (block 506). The steps described above for obtaining the baseline reactance and test reactance of blocks 503 and 505 each include a step for obtaining the capacitance of each sensor, or alternatively, the steps described above for obtaining the baseline reactance and test reactance of blocks 503 and 505 each include a step for obtaining the inductance of each sensor. The step for obtaining the baseline reactance of block 503 may include a step for obtaining a first reactance of each sensor in an empty state (block 5031), and a step for obtaining a second reactance of each sensor while a fluid completely free of living cells is flowing through it (block 5032). As described below with reference to Figure 6, the step for obtaining the test reactance of each sensor in block 505 may include a step for continuing the acquisition of block 505 if one or more of the following is determined: a statistically significant number of living cells are not detected, data analytics do not detect a sufficient number of detections and specific events, or neural network training is not complete. According to one or more embodiments of the present invention, method 500 may further include a step (block 507) of training a neural network model to identify various types of living cells.

[0035] Continuing with reference to Figure 5, and further with reference to Figure 6, the method 500 of Figure 5 will be described in more detail. As shown in Figure 6, the microfluidic flow parameters are set in block 601. Next, the empty capacitance or reactance (Z) between the opposing electrode pairs in the array of both the reference and sample sensing pairs is set. air / C air The capacitance or reactance (Z) between the same electrode pair is measured over a short period (10 to several thousand ms) and a frequency range (preferably 0.1 to 100 MHz) to obtain a first dielectric constant (block 602), and the microfluidic chamber is filled with a buffer fluid that does not contain bacteria, viruses, or animal cells, and the capacitance or reactance (Z) between the same electrode pair is measured over the same frequency range. liq / C liq The measurement of (Z) is repeated to obtain a second dielectric constant (block 603), which reflects the dielectric constant of the buffer liquid. Next, the buffer liquid is filled with a buffer containing bacteria / viruses / animal cells, and the capacitance or reactance (Z) between the same electrode pair of both the reference and sample sensing pairs is measured. liq / C liq The measurement of the dielectric constant of bacteria / viruses / animal cells is repeated to obtain the dielectric constant of the cells (block 604).

[0036] At this point, it is determined that a sufficient number of sensing pairs have detected the passage or presence of living cells (block 605). If no detections have been made, control returns to block 601, where the sampling frequency is reduced accordingly and / or the residence time is increased. If detections have been made, control proceeds to continue the measurement using the same sampling frequency (block 606) and determines that a statistically significant number of living cells have been detected (block 607). If a determination cannot be made, control returns to block 606. If a determination can be made, control proceeds to perform offline data analytics to count the detected living cells or to train a model for counting (block 608).

[0037] Next, data analytics determine whether sufficient cell detection and specific events have occurred (block 609). If this determination cannot be made, control returns to block 606. If it is determined that sufficient cell detection and specific events have occurred, control proceeds to determine whether the training and / or refinement of the neural network model for online cell counting and type identification is complete (block 610). If completion cannot be determined, control returns to block 606. If completion is determined, control proceeds to terminate the cell detection and recognition cycle (block 611).

[0038] Referring to Figures 7A and 7B, a method is provided for manufacturing at least the sensing structure 201 shown in Figures 2 to 4. As shown in Figure 7A, the method includes operations 1 to 4 of depositing and etching layers of dielectric material onto a wafer, operations 5 to 23 of forming metallizations of pads, probe tips, and multiple probes within the layers of dielectric material, and operation 24 of forming channels so that each probe tip can communicate. As shown in Figure 7B, the method may further include forming a top wafer having additional probes positioned above the channels.

[0039] 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 recognize that many of the positional relationships described herein are orientation-independent if the described functionality is maintained even when 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 herein that layer "A" is formed 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.

[0040] The following definitions and abbreviations are used in the claims and interpretation of this specification. Where used herein, the words “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains,” or “containing,” or any other variation thereof, are intended to describe 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, but may include other elements not expressly listed or that are inherent to such composition, mixture, process, method, article, or apparatus.

[0041] In addition, the term “exemplary” is used herein to mean “serving as an example, case, or illustration.” Any embodiment or design described herein as “exemplary” 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 “multiple” 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.”

[0042] 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 phrases do not necessarily refer to the same embodiments. Moreover, when certain features, structures, or characteristics are described in relation to one embodiment, it is considered within the knowledge of those skilled in the art that such features, structures, or characteristics may be affected in relation to other embodiments, whether or not they are explicitly described.

[0043] For the purposes of the following explanation, terms such as “top,” “bottom,” “right,” “left,” “vertical,” “horizontal,” “top,” and “bottom,” and their derivatives, refer to the structures and methods described in the orientation of the drawings. Terms such as “on top,” “on the top of,” “at the top of,” “positioned on,” or “positioned on the top of” mean that a first element, such as a first structure, is located on a second element, such as a second structure, where intervening elements, such as an interface structure, may be present 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 without any intermediate conductive, insulating, or semiconductor layers at the interface between these two elements.

[0044] In this specification, spatially relative terms such as “beneath,” “below,” “bottom,” “above,” “top,” and similar terms may be used to facilitate descriptions of the relationship between one element or feature and another, as shown in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of a device in use or operation, in addition to the orientation shown in the figures. For example, if the device in the figure is inverted, 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 differently (rotated 90 degrees, or in other orientations), and the spatially relative descriptors used herein will be interpreted accordingly.

[0045] 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 etching stop.

[0046] 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.

[0047] The term "conformal" (e.g., conformal layer) means that the thickness of a layer is substantially the same on all surfaces, or that the variation in thickness is less than 15% of the nominal thickness of the layer.

[0048] The terms "epitaxial growth and / or deposition" and "epitaxially formed and / or grown" refer to the process of growing one semiconductor material (crystalline material) on the deposition surface of another semiconductor material (crystalline material), where the growing semiconductor material (crystalline overlayer) has substantially the same crystalline properties as the semiconductor material on the deposition surface (seed material). In the epitaxial deposition process, the chemical reactants provided by the source gas can be controlled, and system parameters can be set so that the atoms to be deposited arrive at the deposition surface of the semiconductor substrate with sufficient energy to move along the surface, and as a result, the atoms to be deposited orient themselves to match the crystalline arrangement of the atoms on the deposition surface. Epitaxially grown semiconductor material can have substantially the same crystalline properties as the deposition surface on which the epitaxially grown material is formed. For example, an epitaxially grown semiconductor material deposited on a {100}-oriented crystalline surface can have a {100} orientation. In some embodiments of the present invention, the epitaxial growth and / or deposition steps may be selective for formation on a semiconductor surface, and the material cannot be deposited on an exposed surface such as a silicon dioxide or silicon nitride surface.

[0049] As previously stated herein, for the sake of brevity, prior art relating to the manufacture of semiconductor devices and integrated circuits (ICs) may or may not be described in detail. However, for background purposes, a more general description of semiconductor device manufacturing processes that may be used when implementing one or more embodiments of the present invention is provided here. While specific manufacturing 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 the manufacture of semiconductor devices according to the present invention utilizes a variety of individually known physical and chemical processes performed on a semiconductor (e.g., silicon) substrate, some of which are described in the following paragraphs.

[0050] Generally, the various processes used to form microchips that are packaged into ICs 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 activates the implanted dopants. To connect and insulate transistors and their components, films of both conductors (e.g., polysilicon, aluminum, copper, etc.) and insulators (e.g., various forms of silicon dioxide, silicon nitride, etc.) are used. Selective doping of different regions of a semiconductor substrate allows the conductivity of the substrate to be changed by applying a voltage. By fabricating the structures of these various components, millions of transistors can be constructed and wired together to form the complex circuit configurations of modern microelectronic devices. Semiconductor lithography is the process of forming a three-dimensional relief image or pattern on a semiconductor substrate and then transferring the pattern to the substrate. In semiconductor lithography, the pattern is formed using a photosensitive polymer called a photoresist. The lithography and etching pattern transfer steps are repeated multiple times to construct the complex structures that make up the transistors and the many wires that connect the millions of transistors in the circuit.Each pattern printed on the wafer is aligned with a previously formed pattern, and conductors, insulators, and selectively doped regions are slowly constructed to form the final device.

[0051] The flowcharts and block diagrams in the figures illustrate possible implementations of manufacturing and / or operating methods 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 consecutively shown blocks may actually be executed substantially simultaneously, or these blocks may be executed in reverse order.

[0052] The descriptions of various embodiments of the present invention are presented for illustrative purposes only and are not intended to be comprehensive or limitless to the embodiments described. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the embodiments described. The terminology used herein has been selected to best describe the principles of the embodiments, the practical application of the technology found in the market or technical improvements thereto, or to enable other persons skilled in the art to understand the embodiments described herein.

Claims

1. A tubular element through which a fluid can flow along a single path; An array of sensors arranged along the length of the tubular element, thereby allowing the fluid to flow through each of the sensors; and A sensing circuit configuration which is electrically connected to each of the sensors, measures the reactance of each of the sensors, and determines whether the reactance indicates the presence of living cells in the fluid flowing through the corresponding sensor. A sensing structure that includes this.

2. The sensing structure according to claim 1, wherein the sensor includes counter electrodes on opposite sides of the tubular elements.

3. The sensing structure according to claim 1, wherein three or more of the sensors are arranged along the length of the tubular element.

4. The sensing structure according to claim 1, wherein the sensors are arranged at uniform intervals along the length of the tubular element.

5. The sensing structure according to claim 1, wherein the sensing circuit configuration is configured to measure at least one of capacitance and inductance over the entire array of the sensors.

6. The sensing structure according to claim 1, wherein the sensing circuit configuration is configured to measure at least one of the capacitance and inductance of each of the sensors.

7. The sensing structure according to claim 1, wherein, when the fluid does not contain the living cells, and when the fluid does contain the living cells, the sensing circuit configuration is controllable to acquire the dielectric constant of the fluid over a range of operating frequencies.

8. The sensing structure according to claim 7, wherein the array of sensors and the sensing circuit configuration are calibrated by obtaining the dielectric constant of the fluid over a range of operating frequencies when the fluid contains only one type of the biological cells.

9. Bottom wafer; Top wafer; An insulating layer interposed between the bottom wafer and the top wafer, formed to define a channel through which a fluid can flow along a single path; Sensors arranged along the length of the channel, thereby allowing the fluid to flow through each of the sensors; and A sensing circuit configuration is electrically connected to each of the aforementioned sensors and is configured to measure at least one of the capacitance and inductance of each of the sensors, and to determine whether at least one of the capacitance and inductance indicates the presence of living cells in the fluid flowing through the corresponding sensor. A sensing structure that includes this.

10. The sensing structure according to claim 9, wherein the sensor includes a reference sensor and a sample sensor interleaved along the length of the channel.

11. The sensing structure according to claim 10, wherein each of the sensors includes a ground-signal-ground (GSG) electrode pair on the opposite side of the channel.

12. The sensing circuit configuration has probes, each probe having: Pads that are exposed to the outside; A tip portion that is electrically in contact with the corresponding reference sensor and sample sensor; and Metallization extending through the insulating layer between the pad and the tip portion including, The sensing structure according to claim 10.

13. The sensing structure according to claim 12, wherein the tip of each probe is arranged in electrical contact with an adjacent reference sensor and sample sensor.

14. The sensing structure according to claim 12, wherein the pair of probes includes overlapping tips.

15. A method for operating a sensing structure for sensing living cells in a fluid, wherein the method is: The step of placing sensors within an array along a single path; A step of acquiring the baseline reactance of each of the aforementioned sensors; A step of flowing the fluid through the sensors in the array and along the single path; During the step of flowing the fluid, a step of acquiring the test reactance of each of the sensors; and A step in determining whether a difference exists between the baseline reactance and the test reactance of each of the sensors, indicating the presence of living cells. Methods that include...

16. The steps of acquiring the baseline reactance and acquiring the test reactance each include the step of acquiring the capacitance of each of the sensors, The steps of acquiring the baseline reactance and acquiring the test reactance each include the step of acquiring the inductance of each of the sensors. The method according to claim 15.

17. The method according to claim 15, further comprising the step of calibrating the sensor over a range of operating frequencies.

18. The steps for obtaining the baseline reactance are: A step of acquiring the first reactance of each of the sensors in an empty state; and Steps to acquire the second reactance of each of the sensors during the step of flowing the fluid that does not contain living cells. including, The method according to claim 15.

19. The method according to claim 15, wherein the step of acquiring the test reactance of each of the sensors is continued if one or more of the following is determined: that a statistically significant number of the living cells are not detected, that data analytics does not detect a sufficient number of detections and specific events, or that neural network training is not complete.

20. The method according to claim 15, further comprising the step of training a neural network model to identify various types of the aforementioned living cells.

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