Microfluidic chip, temperature measuring method thereof and analysis device

Abstract

The application provides a microfluidic chip and a temperature measurement method and an analysis device thereof, and relates to the technical field of microfluidics.The microfluidic chip comprises a substrate and at least one microfluidic module on the substrate, the microfluidic module comprising a droplet control unit and at least one temperature detection unit; wherein the temperature detection unit comprises a temperature sensor, a first lead group and a second lead group, the temperature sensor being fixed on the substrate, and the first lead group and the second lead group being electrically connected to the temperature sensor; the first lead group is configured to transmit a constant current to the temperature sensor, and the second lead group is configured to electrically connect the temperature sensor and an external voltmeter together. In this way, since no constant current flows through the second lead group, the interference of the lead with the voltage measurement of the temperature sensor is avoided, the accuracy of the measured temperature sensor resistance is improved, and thus the detection accuracy and detection accuracy of the temperature sensor are improved.

Description

Technical Field

[0001] This application relates to the field of microfluidics, and in particular to a microfluidic chip and its temperature measurement method and analysis device. Background Technology

[0002] Microfluidics integrates basic operational units such as sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes onto a single micrometer-scale chip, automating the entire analytical process. Due to its enormous potential in biology, chemistry, and medicine, it has developed into an emerging interdisciplinary field involving chemistry, fluid physics, microelectronics, new materials, biology, and biomedical engineering, attracting widespread attention from industry professionals. Summary of the Invention

[0003] The embodiments of this application adopt the following technical solutions:

[0004] In a first aspect, embodiments of this application provide a microfluidic chip, comprising: a substrate and at least one microfluidic module located on the substrate, the microfluidic module including a droplet control unit and at least one temperature detection unit;

[0005] The temperature detection unit includes a temperature sensor, a first lead group, and a second lead group. The temperature sensor is fixed on the substrate. The first lead group and the second lead group are electrically connected to the temperature sensor. The first lead group is configured to transmit a constant current to the temperature sensor, and the second lead group is configured to electrically connect the temperature sensor and an external voltmeter together.

[0006] In some embodiments of this application, the first lead group includes a first lead and a second lead, and the second lead group includes a third lead and a fourth lead; the temperature detection unit further includes a first conductive pad and a second conductive pad;

[0007] The first lead group and the temperature sensor are electrically connected via two first conductive pads and an external current source; the second lead group and the temperature sensor are electrically connected via two second conductive pads and an external voltmeter.

[0008] In some embodiments of this application, the temperature sensor includes a first thermistor and a second thermistor electrically connected; the first thermistor is a linear thermistor, and the second thermistor is a block thermistor.

[0009] In some embodiments of this application, when the temperature is determined, the first temperature-sensitive resistor is a fixed resistor and the second temperature-sensitive resistor is an adjustable resistor; the resistance ratio of the first temperature-sensitive resistor and the second temperature-sensitive resistor is less than or equal to 20:1.

[0010] In some embodiments of this application, the block-shaped thermistor has at least one hollow area, and the orthographic projection shape of the hollow area on the substrate includes polygons, arcs, and shapes formed by a combination of polygons and arcs.

[0011] In some embodiments of this application, the block-shaped temperature-sensitive resistor has a hollow area, the hollow area including a first hollow sub-area disposed along a first direction and a second hollow sub-area disposed along a second direction, the orthographic projection shape of the first hollow sub-area and the second hollow sub-area on the substrate is rectangular; the first direction is the direction of droplet flow, and the second direction is perpendicular to the first direction;

[0012] The ratio of the maximum dimension of the first hollow sub-region along the first direction to the maximum dimension of the second hollow sub-region along the second direction is in the range of 1:9 to 3:7.

[0013] In some embodiments of this application, the block-shaped temperature-sensitive resistor has a plurality of hollow areas arranged along a first direction, each hollow area having a rectangular orthographic projection shape on the substrate, and each hollow area being unconnected to the others; the first direction is the direction of droplet flow.

[0014] In some embodiments of this application, the orthographic projection shape of the area of ​​the block-shaped thermistor on the substrate, excluding the hollowed-out area, is serpentine.

[0015] In some embodiments of this application, the temperature sensor includes a temperature-sensitive layer and a light-shielding layer located on the substrate, the light-shielding layer being located on the side of the temperature-sensitive layer away from the substrate, and the orthogonal projection of the temperature-sensitive layer on the substrate being within the orthogonal projection of the light-shielding layer on the substrate.

[0016] The temperature-sensitive layer is in direct contact with the first lead group and the second lead group, respectively.

[0017] In some embodiments of this application, the temperature-sensitive layer, the first lead group, and the second lead group are located on the same layer, and the orthographic projection of the temperature-sensitive layer on the substrate and the orthographic projection of the first lead group on the substrate do not overlap.

[0018] In some embodiments of this application, a portion of the temperature-sensitive layer is located on the same layer as the leads in the first lead group and the second lead group, and a portion of the temperature-sensitive layer extends to a portion of the surface of at least one lead in the first lead group and the second lead group that is away from the substrate.

[0019] In some embodiments of this application, the temperature sensor further includes an insulating layer located between the temperature-sensitive layer and the light-shielding layer, wherein the orthographic projection of the insulating layer on the substrate covers the orthographic projection of the temperature-sensitive layer on the substrate, and the orthographic projection of the insulating layer on the substrate covers the orthographic projection of the light-shielding layer on the substrate.

[0020] In some embodiments of this application, the temperature sensor further includes a first electrode and a second electrode that are not connected to each other, wherein the first electrode, the second electrode, each lead in the first lead group and each lead in the second lead group are located in the same layer;

[0021] The first electrode is electrically connected to the first lead and the third lead, respectively, and the second electrode is electrically connected to the second lead and the fourth lead, respectively; the orthographic projection of the first electrode on the substrate and the orthographic projection of the second electrode on the substrate are both located within the orthographic projection of the temperature-sensitive layer on the substrate; wherein, the first electrode and the second electrode are both toothed electrodes.

[0022] In some embodiments of this application, the toothed electrode includes at least three toothed electrodes extending along a first direction, and a connecting electrode extending along a direction perpendicular to the first direction; the connecting electrode electrically connects one end of each of the toothed electrodes together; the toothed electrodes of the first electrode and the toothed electrodes of the second electrode are spaced apart;

[0023] The distance between the toothed electrode of the first electrode and the toothed electrode of the second electrode along a direction perpendicular to the first direction is less than or equal to 50 μm, where the first direction is the direction of droplet flow.

[0024] In some embodiments of this application, the temperature-sensitive layer further includes a hollow area that extends along a first direction, and the maximum size of the hollow area along the first direction is less than or equal to half the maximum size of the temperature-sensitive layer along the first direction, where the first direction is the direction of droplet flow.

[0025] In some embodiments of this application, the temperature sensor includes a thermistor, a first conductive layer, and a second conductive layer; the thermistor is electrically connected to the first lead and the third lead respectively through the first conductive layer, and the thermistor is electrically connected to the second lead and the fourth lead respectively through the second conductive layer.

[0026] In some embodiments of this application, the orthographic projections of the first conductive layer and the second conductive layer on the substrate overlap with the orthographic projection of the thermistor on the substrate.

[0027] In some embodiments of this application, the droplet control unit includes a plurality of driving electrode groups, each of the driving electrode groups being arranged along a first direction, the first direction being the direction of droplet flow;

[0028] The driving electrode group includes a plurality of driving electrodes, and a temperature measuring area is provided between each driving electrode in at least one of the driving electrode groups. In the driving electrode group with the temperature measuring area, the outer contour of the orthographic projection of each driving electrode on the substrate and the outer contour of the temperature measuring area partially overlap.

[0029] The temperature sensor is located within the temperature measurement area, and the outer contour of the orthographic projection of the temperature sensor on the substrate is within the outer contour of the temperature measurement area.

[0030] In some embodiments of this application, the orthographic projection shape of the driving electrode on the substrate includes a rectangle and a chamfered rectangle; in the driving electrode group with the temperature measuring area, one corner of each driving electrode has a recess, and the temperature measuring area includes the area where each recess is located;

[0031] The length of the recess along the second direction is less than or equal to one-third of the length of the side of the driving electrode on which the recess is located along the second direction; the second direction is perpendicular to the first direction.

[0032] In some embodiments of this application, the droplet control unit includes an external pump valve, the orthographic projection of which is located within the outer contour of the substrate.

[0033] Secondly, embodiments of this application provide an analysis device, including the microfluidic chip described above.

[0034] Thirdly, embodiments of this application provide a temperature measurement method for a microfluidic chip as described above, the method comprising:

[0035] A constant current is supplied to the temperature sensor of the microfluidic chip through the first lead group, and the current value flowing through the temperature sensor is determined.

[0036] The voltage across the temperature sensor is measured using an external voltmeter electrically connected to the second lead group, and the voltage value is obtained.

[0037] The resistance value of the temperature sensor is determined based on the current value and the voltage value;

[0038] The temperature value detected by the temperature sensor is determined based on the resistance value.

[0039] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of the temperature measurement circuit structure of a microfluidic chip provided for an embodiment of this application;

[0042] Figure 3 A schematic diagram illustrating the temperature measurement principle of the microfluidic chip provided in the embodiments of this application;

[0043] Figure 4 A schematic diagram of the temperature measurement circuit structure of a microfluidic chip in the related art provided for the embodiments of this application;

[0044] Figure 2 , Figures 5-21 The embodiments of this application provide schematic diagrams of the structures of eighteen microfluidic chips;

[0045] Figure 22 A schematic flowchart of a temperature measurement method for a microfluidic chip provided in an embodiment of this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] For clarity, the thickness of regions and layers may be exaggerated in the figures. The same reference numerals in the figures denote the same or similar structures, and therefore their detailed descriptions are omitted. Furthermore, the figures are merely illustrative of this application and are not necessarily drawn to scale.

[0048] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0049] In the embodiments of this application, the use of terms such as "first" and "second" to describe the same or similar items with essentially the same function and effect is only for the purpose of clearly describing the technical solution of the embodiments of this application, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0050] Microfluidics is an emerging interdisciplinary field involving chemistry, fluid physics, microelectronics, new materials, biology, and biomedical engineering, enabling precise control and manipulation of tiny droplets. Chips employing microfluidic technology are commonly referred to as microfluidic chips and are an important component of laboratory-on-a-chip systems. Various samples, such as cells, can be cultured, moved, detected, and analyzed within microfluidic chips, finding wide application not only in chemistry and medicine but also attracting increasing attention in other fields.

[0051] Microfluidic chips are digital microfluidic chips based on dielectric wetting (EWOD) technology. The principle is as follows: a droplet is placed on a surface with a hydrophobic layer. By applying voltage to the droplet through the electrowetting effect, the wettability between the droplet and the hydrophobic layer is changed, causing a pressure difference and asymmetric deformation inside the droplet, thereby realizing the directional movement of the droplet.

[0052] For most biochemical reactions, reaction temperature is crucial to the outcome, necessitating the detection and control of temperature within the microfluidic chip. Currently, temperature detection methods in microfluidic systems can be broadly categorized into contact and non-contact types based on whether the sensor is in contact with the microfluidic chip. Non-contact temperature measurement methods, including fluorescence, fiber optic interferometry, and microwave methods, offer advantages such as non-contact operation and flexibility. However, these methods cannot directly contact the sample and are susceptible to external environmental interference, resulting in lower accuracy. Contact temperature measurement methods, based on whether the sensor is integrated within the microfluidic chip, can be further divided into external and integrated types. External methods attach thermocouples or thermistors to the outside of the microfluidic chip. The effectiveness of these methods is easily affected by external temperatures, and a certain degree of temperature gradient error exists within the substrate layer of the microfluidic chip. Integrated methods use sputtered or evaporated metal or semiconductor materials as thermistors within the microfluidic chip. Sensors prepared using this method are in direct contact with the droplets; however, their detection accuracy is not high.

[0053] Based on this, embodiments of this application provide a microfluidic chip, combined with Figure 1 , Figure 2 and Figure 3 As shown, it includes: a substrate and at least one microfluidic module 100 located on the substrate, the microfluidic module 100 including a droplet control unit and at least one such as Figure 1 The temperature detection unit 101 shown;

[0054] The temperature detection unit 101 includes a temperature sensor 1, a first lead group (e.g., including W1 and W2) and a second lead group (e.g., including W3 and W4). The temperature sensor 1 is fixed on the substrate. The first lead group and the second lead group are electrically connected to the temperature sensor 1, respectively. The first lead group is configured to transmit a constant current to the temperature sensor, and the second lead group is configured to electrically connect the temperature sensor 1 and an external voltmeter together.

[0055] The specific structure of the substrate is not limited here; it can be determined based on the actual application requirements of the microfluidic chip.

[0056] The specific number of microfluidic modules 100 on the substrate is not limited here. For example, multiple microfluidic modules 100 are disposed on the substrate, and the multiple microfluidic modules 100 are arranged in an array.

[0057] In an exemplary embodiment, the droplet control unit is configured to drive the droplet to move within the microfluidic module 100, assisting the microfluidic chip in completing the analysis of the droplet sample.

[0058] For example, the droplet control unit may include, Figure 2 The multiple driving electrodes 3 shown; or, the droplet control unit may include at least one external pump valve.

[0059] The specific type and structure of the temperature sensor mentioned above are not limited here; they can be determined based on the actual situation.

[0060] For example, the temperature sensor described above may include an NTC type temperature sensor (Negative Temperature Coefficient); or, the temperature sensor described above may include an RTD type temperature sensor (Resistance Temperature Detector).

[0061] In an exemplary embodiment, the meaning of temperature sensor 1 being fixed on the substrate is that temperature sensor 1 is directly integrated on the substrate; or, temperature sensor 1 is mounted on the substrate by a fixing part, wherein the fixing part may include a fixing member and / or an adhesive layer.

[0062] The specific structure and materials of the aforementioned fasteners and adhesive layers are not limited here and can be determined according to the actual situation.

[0063] In practical applications, for temperature sensor 1 directly integrated on the substrate, it can directly contact the test droplet in the microfluidic chip; for temperature sensor mounted on the substrate by a fixing part, at least a portion of its area can directly contact the test droplet in the microfluidic chip.

[0064] In the embodiments of this application, the temperature sensor is fixed on the substrate, so that when the temperature is tested, the droplet can directly contact at least part of the temperature sensor, avoiding interference from the external environment and improving the accuracy of temperature measurement.

[0065] In an exemplary embodiment, the first lead group includes at least two leads, and the number of leads in the first lead group is even.

[0066] For example, the first lead group may include a first lead W1 and a second lead W2 to electrically connect the two ends of the temperature sensor 1 and the two ends of the constant current source.

[0067] For example, the first lead group may include a first lead W1 and a second lead W2, as well as a fifth lead and a sixth lead. The first lead W1 and the second lead W2 can electrically connect the two ends of the temperature sensor 1 and the two ends of the constant current source, and the fifth lead and the sixth lead can also electrically connect the two ends of the temperature sensor 1 and the two ends of the constant current source. In this way, if any one of the first lead W1 and the second lead W2 is damaged, an open circuit between the temperature sensor 1 and the constant current source can be avoided, thereby improving the service life of the microfluidic chip.

[0068] In an exemplary embodiment, the second lead group includes at least two leads, and the number of leads in the second lead group is even.

[0069] For example, the second lead group may include a third lead W3 and a fourth lead W4 to electrically connect the temperature sensor 1 and the external voltmeter together.

[0070] For example, the second lead group may include a third lead W3 and a fourth lead W4, as well as a seventh lead and an eighth lead. The third lead W3 and the fourth lead W4 electrically connect the temperature sensor 1 and the external voltmeter, and the seventh lead and the eighth lead also electrically connect the temperature sensor 1 and the external voltmeter. Thus, if any one of the third lead W3 or the fourth lead W4 is damaged, an open circuit between the temperature sensor 1 and the external voltmeter can be avoided, thereby improving the lifespan of the microfluidic chip.

[0071] In some embodiments of this application, reference is made to Figure 1 or Figure 2 As shown, the first lead group includes a first lead W1 and a second lead W2, and the second lead group includes a third lead W3 and a fourth lead W4; the temperature detection unit 101 also includes a first conductive pad 2 and a second conductive pad 4.

[0072] The first lead group and temperature sensor 1 are electrically connected to an external current source through two first conductive pads 2; the second lead group and temperature sensor 1 are electrically connected to an external voltmeter through two second conductive pads 4.

[0073] There is no limitation on whether the materials of the leads in the first lead group, the leads in the second lead group, and each conductive pad are the same.

[0074] For example, the leads in the first lead group, the leads in the second lead group, and each conductive pad can be made of the same material, and all include at least one or more combinations of molybdenum (Mo), aluminum (Al), copper (Cu), and indium tin oxide (ITO).

[0075] In related technologies, refer to Figure 4As shown, the two ends of temperature sensor 1 are electrically connected to a constant current source via two leads (W10 and W20), and the two ends of temperature sensor 1 are also electrically connected to an external voltmeter via these two leads. When measuring the voltage of temperature sensor 1, due to the resistance of the leads (W10 and W20) themselves, the voltage value actually measured by the external voltmeter is the voltage value after the temperature sensor 1 and the two leads (W10 and W20) are connected in parallel, which seriously reduces the accuracy of measuring the voltage across the temperature sensor.

[0076] In the embodiments of this application, by setting a first lead group, a constant current source from the outside is transmitted to the temperature sensor 1 through the first lead group, so that there is a specific voltage difference between the two ends of the temperature sensor 1. By setting a second lead group, the temperature sensor 1 is electrically connected to an external voltmeter through the second lead group. In this way, since no constant current flows through the second lead group, the interference of the leads on the voltage measurement of the temperature sensor 1 is avoided, so that the voltage value measured by the external voltmeter is infinitely close to the actual voltage value across the two ends of the temperature sensor 1. Then, the resistance value of the temperature sensor 1 is determined based on the voltage value and the constant current value, and the temperature to be measured is determined based on the relationship between the resistance value and the temperature, thereby improving the detection accuracy and precision of the temperature sensor 1.

[0077] It should be noted that, in Figure 3 In the diagram, Rs represents the resistance of temperature sensor 1, Rw1 represents the resistance of the first lead W1, Rw2 represents the resistance of the second lead W2, Rw3 represents the resistance of the third lead W3, and Rw4 represents the resistance of the fourth lead W4. Represents an ammeter. This represents a voltmeter.

[0078] In some embodiments of this application, reference is made to Figure 5 As shown, the temperature sensor 1 includes a first thermistor R1 and a second thermistor R2 that are electrically connected; the first thermistor R1 is a linear thermistor and the second thermistor R2 is a block thermistor.

[0079] In some embodiments of this application, when the temperature is determined, the first thermistor R1 is a fixed resistor and the second thermistor R2 is an adjustable resistor; the resistance ratio of the first thermistor R1 and the second thermistor R2 is less than or equal to 20:1.

[0080] In an exemplary embodiment, a laser trimming process can be used to remove a portion of the block-shaped thermistor, thereby changing the aspect ratio of the block-shaped thermistor and adjusting its resistance.

[0081] It should be noted that, according to the definition of resistance, R = ρL / S = ρL / (a*b), where ρ is resistivity, a is the thickness of the block temperature resistor, L is the length of the block temperature resistor, and b is the width of the block temperature resistor. After the block temperature resistor is manufactured, its thickness a is a fixed value. Later, its resistance value can be adjusted by using laser trimming technology to adjust the ratio of the length L to the width b of the block temperature resistor.

[0082] In an exemplary embodiment, the first thermistor R1 is the main resistor in temperature sensor 1, and the second thermistor R2 is the auxiliary resistor in temperature sensor 2. The resistance value of the first thermistor R1 is relatively larger than that of the second thermistor R2.

[0083] In practical applications, in order to ensure that the second temperature-sensitive resistor R2 has appropriate adjustment space, the resistance ratio of the first temperature-sensitive resistor R1 and the second temperature-sensitive resistor R2 can be set to be less than or equal to 20:1.

[0084] For example, the resistance ratio of the first thermistor R1 and the second thermistor R2 is equal to 20:1; or, the resistance ratio of the first thermistor R1 and the second thermistor R2 is equal to 20:2.

[0085] In an exemplary embodiment, the sum of the resistance values ​​of the first and second thermistors can be set to a range of 10Ω-1000Ω.

[0086] In the embodiments of this application, the resistance values ​​of different temperature sensors in the same microfluidic chip can be the same or different. When necessary, laser trimming can be used to ensure that the resistance values ​​of different temperature sensors in the same microfluidic chip are the same, thus improving the consistency of sensor resistance values.

[0087] In an exemplary embodiment, the shape of the orthographic projection of the block resistor onto the substrate can include any one of an arc, a polygon, or a combination of arcs and polygons. For example, its shape can be circular, elliptical, triangular, or quadrilateral.

[0088] In some embodiments of this application, reference is made to Figure 6 As shown, the block-shaped thermistor has at least one hollow area L, and the orthographic projection shape of the hollow area on the substrate includes polygons, arcs, and shapes formed by a combination of polygons and arcs.

[0089] For example, polygons may include triangles, squares, rectangles, or rhombuses, and arcs may include circles, sectors, or ellipses.

[0090] The specific dimensions of the cutout area L are not limited here; they can be set according to the actual situation.

[0091] In some embodiments of this application, reference is made to Figure 7 As shown, the block-shaped temperature-sensitive resistor has a hollow area L, which includes a first hollow sub-area L1 disposed along the first direction OA and a second hollow sub-area L2 disposed along the second direction BO. The orthographic projection shape of the first hollow sub-area L1 and the second hollow sub-area L2 on the substrate is rectangular. The first direction OA is the direction of droplet flow, and the second direction BO is perpendicular to the first direction OA.

[0092] The ratio of the maximum dimension D1 of the first hollow sub-region L1 along the first direction OA to the maximum dimension D2 of the second hollow sub-region L2 along the second direction BO ranges from 1:9 to 3:7.

[0093] exist Figure 7 In the diagram, the orthographic projection of the hollow area L onto the substrate is L-shaped.

[0094] In an exemplary embodiment, the maximum dimension D1 of the first cutout sub-region L1 along the first direction OA can account for 10%-30% of the total cutting length, and the maximum dimension D2 of the second cutout sub-region L2 along the second direction BO can account for 70%-90% of the total cutting length.

[0095] In embodiments of this application, the following settings are provided: Figure 7 The hollowed-out area L shown provides a better range of resistance adjustment for the block-shaped thermistor, and the adjustment efficiency is high, saving costs.

[0096] In some embodiments of this application, reference is made to Figure 8 As shown, the block-shaped temperature-sensitive resistor R2 has multiple hollow areas L arranged along the first direction OA. The orthographic projection shape of each hollow area L on the substrate is rectangular, and each hollow area L is not connected to the others. The first direction OA is the direction of droplet flow.

[0097] In an exemplary embodiment, along the first direction OA, each cutout area L has the same size, and the interval D3 between any two adjacent cutout areas L is equal.

[0098] In some embodiments of this application, reference is made to Figure 8 As shown, the orthographic projection shape of the area in the block thermocouple, excluding the hollow area L, on the substrate is serpentine.

[0099] In embodiments of this application, by setting such as Figure 8 The multiple cutout areas L shown make the orthographic projection shape of the area other than the cutout areas L on the substrate of the block temperature resistor serpentine, which can adjust the aspect ratio to the maximum extent, thereby adjusting the resistance value of the block temperature resistor to the maximum extent.

[0100] In some embodiments of this application, reference is made to Figures 9-13As shown in any one of them, the temperature sensor includes a temperature-sensitive layer 204 and a light-shielding layer 203 located on a substrate 201. The light-shielding layer 203 is located on the side of the temperature-sensitive layer 204 away from the substrate 201, and the orthogonal projection of the temperature-sensitive layer 204 on the substrate 201 is within the orthogonal projection of the light-shielding layer 203 on the substrate. The temperature-sensitive layer 204 is in direct contact with the first lead group (including W1 and W2) and the second lead group (including W3 and W4), respectively.

[0101] It should be noted that, Figure 10 yes Figure 9 Cross-sectional view along the A1A2 direction.

[0102] In an exemplary embodiment, the meaning of the orthogonal projection of the temperature-sensitive layer 204 on the substrate 201 being within the orthogonal projection of the light-shielding layer 203 on the substrate is: (Refer to...) Figure 11 As shown, the outer contour of the orthographic projection of the temperature-sensitive layer 204 onto the substrate 201 is located within the outer contour of the orthographic projection of the light-shielding layer 203 onto the substrate; or, referring to... Figure 13 As shown, the outer contour of the orthographic projection of the temperature-sensitive layer 204 on the substrate 201 overlaps with the outer contour of the orthographic projection of the light-shielding layer 203 on the substrate.

[0103] The thermosensitive layer 204 has a thickness in the micrometer range along the direction perpendicular to the substrate. This avoids the thermosensitive layer being too thick and affecting the driving electrode's control of the droplet.

[0104] The specific material of the temperature-sensitive layer 204 described above is not limited here. For example, the material of the temperature-sensitive layer 204 may include at least one of phosphorus-doped amorphous silicon, boron-doped amorphous silicon, vanadium oxide, manganese, iron, cobalt, nickel or copper oxide.

[0105] When the material of the temperature-sensitive layer 204 includes at least one of phosphorus-doped amorphous silicon, boron-doped amorphous silicon, vanadium oxide, manganese, iron, cobalt, nickel or copper oxide, the resistivity of such materials is relatively high. In order to facilitate the use of the temperature-sensitive sensor, the temperature-sensitive layer 204 can be cut using a laser trimming process to adjust the effective aspect ratio of the temperature-sensitive layer.

[0106] In practical applications, during the laser trimming process, the temperature-sensitive layer is usually ablated while the resistance is measured until the target resistance value is obtained.

[0107] In an exemplary embodiment, the ratio of the length L to the width b of the temperature-sensitive layer 204 can be 1:50.

[0108] For example, taking phosphorus-doped amorphous silicon as an example, its sheet resistance is approximately 200 MΩ / □. If the aspect ratio is adjusted to 50:1, the resistance value is approximately 4 MΩ. It can be seen that increasing the aspect ratio helps to reduce the difficulty of resistance measurement and improve detection accuracy. Sheet resistance refers to the resistance between edges of a square thin-film conductive material (such as a temperature-sensitive layer).

[0109] The specific material of the light-shielding layer 203 is not limited here. For example, the material of the light-shielding layer 203 can be black insulating resin; or, the material of the light-shielding layer 203 can be metal. When the material of the light-shielding layer 203 is black insulating resin, an insulating layer may not be required (e.g., Figure 12 (As shown); when the material of the light-shielding layer 203 is a metal material, an insulating layer 202 shall be provided between the light-shielding layer 203 and the temperature-sensitive layer 204.

[0110] For example, the metal may include at least one of molybdenum, chromium, titanium, and aluminum.

[0111] In the embodiments of this application, by providing a light-shielding layer 203 on the temperature-sensitive layer 204, the generation of photogenerated carriers in the temperature-sensitive layer 204 is avoided, and the interference of light on the electrical characteristics of the temperature-sensitive layer 204 is avoided, thereby improving the detection accuracy of the temperature sensor.

[0112] In some embodiments of this application, reference is made to Figure 11 As shown, the temperature-sensitive layer 204, the first lead group (including W1 and W2), and the second lead group (including W3 and W4) are located on the same layer, and the orthographic projection of the temperature-sensitive layer 204 on the substrate 201 and the orthographic projection of the first lead group on the substrate 201 do not overlap. The orthographic projection of the temperature-sensitive layer 204 on the substrate 201 and the orthographic projection of the second lead group on the substrate 201 do not overlap.

[0113] In some embodiments of this application, reference is made to Figure 10 As shown, a portion of the temperature-sensitive layer 204 is located on the same layer as the leads in the first lead group (including W1 and W2) and the second lead group (including W3 and W4). The portion of the temperature-sensitive layer 204 extends to a portion of the surface of at least one lead in the first lead group (including W1 and W2) and the second lead group (including W3 and W4) that is away from the substrate 201.

[0114] In an exemplary embodiment, the orthographic projection of the temperature-sensitive layer 204 on the substrate 201 may overlap with the orthographic projection of at least one lead on the substrate 201. Figure 10The diagram is illustrated using the example of the orthographic projection of the temperature-sensitive layer 204 on the substrate 201 overlapping with the orthographic projection of the first lead W1 on the substrate 201, and the orthographic projection of the temperature-sensitive layer 204 on the substrate 201 overlapping with the orthographic projection of the second lead W2 on the substrate 201.

[0115] In some embodiments of this application, reference is made to Figure 10 , Figure 11 and Figure 13 As shown, the temperature sensor 1 also includes an insulating layer 202, which is located between the temperature-sensitive layer 204 and the light-shielding layer 203. The orthographic projection of the insulating layer 202 on the substrate 201 covers the orthographic projection of the temperature-sensitive layer 204 on the substrate 201, and the orthographic projection of the insulating layer 202 on the substrate 201 covers the orthographic projection of the light-shielding layer 203 on the substrate.

[0116] In an exemplary embodiment, the orthographic projection of the insulating layer 202 on the substrate 201 covers the orthographic projection of the temperature-sensitive layer 204 on the substrate 201, and the orthographic projection of the insulating layer 202 on the substrate 201 covers the orthographic projection of the light-shielding layer 203 on the substrate 201 means: (Referring to...) Figure 11 As shown, the outer contour of the orthogonal projection of the temperature-sensitive layer 204 on the substrate 201 is located within the outer contour of the orthogonal projection of the insulating layer 202 on the substrate 201, and the outer contour of the orthogonal projection of the light-shielding layer 203 on the substrate 201 is located within the outer contour of the orthogonal projection of the insulating layer 202 on the substrate 201; or, the outer contour of the orthogonal projection of the temperature-sensitive layer 204 on the substrate 201 is located within the outer contour of the orthogonal projection of the insulating layer 202 on the substrate 201, and the outer contour of the orthogonal projection of the light-shielding layer 203 on the substrate 201 overlaps with the outer contour of the orthogonal projection of the insulating layer 202 on the substrate 201.

[0117] In an exemplary embodiment, the material of the insulating layer 202 may include at least one of nitride, oxynitride, or oxide, such as silicon nitride, silicon oxide, and silicon oxynitride.

[0118] In some embodiments of this application, reference is made to Figure 14 As shown, the temperature sensor 1 also includes a first electrode 205 and a second electrode 206 that are not connected to each other. The first electrode 205, the second electrode 206, each lead (W1 and W2) in the first lead group and each lead (W3 and W4) in the second lead group are located in the same layer.

[0119] The first electrode 205 is electrically connected to the first lead W1 and the third lead W3, respectively, and the second electrode 206 is electrically connected to the second lead W2 and the fourth lead W4, respectively. The orthographic projection of the first electrode 205 on the substrate 201 and the orthographic projection of the second electrode 206 on the substrate 201 are both located within the orthographic projection of the temperature-sensitive layer 204 on the substrate 201. The first electrode 205 and the second electrode 206 are both toothed electrodes.

[0120] In some embodiments of this application, reference is made to Figure 14 As shown, the toothed electrode includes at least three toothed electrodes 7 extending along the first direction OA, and a connecting electrode 8 extending along a direction perpendicular to the first direction OA; the connecting electrode 8 electrically connects one end of each toothed electrode 7 together; the toothed electrodes 7 of the first electrode 205 and the toothed electrodes 7 of the second electrode 206 are spaced apart.

[0121] In an exemplary embodiment, the spacing between every two adjacent toothed electrodes 7 in the first electrode 205 is the same.

[0122] In an exemplary embodiment, the spacing between every two adjacent toothed electrodes 7 in the second electrode 206 is the same.

[0123] In an exemplary embodiment, the toothed electrode 7 of the first electrode 205 and the toothed electrode 7 of the second electrode 206 are spaced apart, and the distance D4 between the toothed electrode 7 of the first electrode 205 and the toothed electrode 7 of the second electrode 206 along a direction perpendicular to the first direction OA is less than or equal to 50 μm, where the first direction OA is the direction of droplet flow.

[0124] In embodiments of this application, when the material of the temperature-sensitive layer 204 includes at least one of phosphorus-doped amorphous silicon, boron-doped amorphous silicon, vanadium oxide, manganese, iron, cobalt, nickel, or copper oxide, due to the high resistivity of such materials, toothed electrodes are provided to facilitate the use of the temperature-sensitive sensor. Figure 5 The structure of the temperature sensor shown achieves a small resistance to better match practical application requirements and facilitate measurement.

[0125] It should be noted that, for Figure 5 The toothed temperature sensor shown has an effective length L of 206, defined as the minimum distance between the first electrode 205 and the second electrode 206 along the first direction OA. The effective width b is the path length of the region between the first electrode 205 and the second electrode 206. According to the definition of resistance, R = ρL / S = ρL / (a*b), where ρ is resistivity, a is the thickness of the block temperature resistor, L is the length of the block temperature resistor, and b is the width of the block temperature resistor. After the block temperature resistor is manufactured, its thickness a is a fixed value. By reducing the effective length L and increasing the effective width b, the effective resistance value of the temperature sensor can be adjusted.

[0126] In some embodiments of this application, reference is made to Figure 15 As shown, the temperature-sensitive layer 204 also includes a hollow area L, which extends along the first direction OA, and the maximum size of the hollow area L along the first direction OA is less than or equal to half of the maximum size of the temperature-sensitive layer 204 along the first direction OA, where the first direction OA is the direction of droplet flow.

[0127] For example, in Figure 15 In the temperature sensor shown, the hollow area L can also extend to the insulating layer, the light-shielding layer, and the substrate.

[0128] Here for Figure 15 The shape of the orthographic projection of the cutout area L shown on the substrate is not limited. Its projection shape can be rectangular, or it can be arc or other polygons, which can be determined according to actual needs.

[0129] In some embodiments of this application, reference is made to Figure 16 As shown, the temperature sensor includes a thermistor 10, a first conductive layer 9, and a second conductive layer 11. The thermistor 10 is electrically connected to the first lead W1 and the third lead W3 through the first conductive layer 9, and the thermistor 10 is electrically connected to the second lead W2 and the fourth lead W4 through the second conductive layer 11.

[0130] In some embodiments of this application, reference is made to Figures 17-19 As shown, the orthographic projection of the first conductive layer 9 on the substrate 201 and the orthographic projection of the second conductive layer 11 on the substrate 201 overlap with the orthographic projection of the thermistor 10 on the substrate 201.

[0131] In an exemplary embodiment, the conductive layer (including the first conductive layer 9 and the second conductive layer 11) is made of a solderable metal, such as copper or tin.

[0132] In an exemplary embodiment, reference is made to Figure 18 As shown, the conductive layer (including the first conductive layer 9 and the second conductive layer 11) is located on the side of the leads (including the first lead W1, the second lead W2, the third lead W3 and the fourth lead W4) away from the substrate 201, and the conductive layer and the leads partially overlap.

[0133] In an exemplary embodiment, reference is made to Figure 17 As shown, a portion of the conductive layer (including the first conductive layer 9 and the second conductive layer 11) is located on the side of the leads (including the first lead W1, the second lead W2, the third lead W3 and the fourth lead W4) away from the substrate 201 and overlaps with the lead portion. Another portion of the conductive layer extends to the surface of the substrate 201 and covers a portion of the substrate 201 and a portion of the side of the leads.

[0134] In an exemplary embodiment, reference is made to Figure 19 As shown, when a portion of the conductive layer (including the first conductive layer 9 and the second conductive layer 11) extends to the surface of the substrate 201 and covers a portion of the substrate 201, in order to avoid short circuits between the first conductive layer 9 and the second conductive layer 11 due to instability in the fabrication process, an insulating wall 12 is provided in the temperature sensor. The insulating wall 12 is located between the first conductive layer 9 and the second conductive layer 11, and between the substrate 201 and the thermistor 10. The outer contour of the orthogonal projection of the insulating wall 12 on the substrate 201 is within the outer contour of the orthogonal projection of the thermistor 10 on the substrate 201.

[0135] In some embodiments of this application, reference is made to Figure 20 As shown, the droplet control unit 100 includes multiple driving electrode groups Z, each driving electrode group Z is arranged along a first direction OA, the first direction OA is the direction of flow of the droplet 12; the driving electrode group Z includes multiple driving electrodes 3, and a temperature measuring area T is provided between each driving electrode in at least one driving electrode group Z, and in the driving electrode group Z with the temperature measuring area T provided, the outer contour of the orthographic projection of each driving electrode 3 on the substrate 201 overlaps with the outer contour of the temperature measuring area T.

[0136] Temperature sensor 1 is located within temperature measurement zone T, and the outer contour of the orthographic projection of temperature sensor 1 on substrate 201 is within the outer contour of temperature measurement zone T.

[0137] In some embodiments of this application, reference is made to Figure 20 As shown, the orthographic projection shape of the driving electrode 3 on the substrate 201 includes a rectangle and a chamfered rectangle; in the driving electrode group Z with the temperature measuring area T, each driving electrode 3 has a recessed portion at one corner, and the temperature measuring area T includes the area where each recessed portion is located; the length D6 of the recessed portion along the second direction BO is less than or equal to one-third of the length D5 of the side of the driving electrode 3 with the recessed portion along the second direction BO; the second direction BO is perpendicular to the first direction OA.

[0138] In an exemplary embodiment, for the driving electrode group Z without a temperature measuring area T, the orthographic projection shape of each driving electrode 3 on the substrate 201 is rectangular; for the driving electrode group Z with a temperature measuring area T, the orthographic projection shape of each driving electrode 3 on the substrate 201 is a chamfered rectangle.

[0139] In an exemplary embodiment, the outer contour shape of the projection of the recessed portion may include a triangle, a quadrilateral, or a sector. The embodiment in this application uses a quadrilateral shape as an example to illustrate the drawing of the outer contour shape of the projection of the recessed portion.

[0140] In an exemplary embodiment, in the driving electrode group Z with the temperature measuring zone T, the shape and size of the recessed portion of each driving electrode 3 are the same.

[0141] In the embodiments of this application, reference is made to Figure 20 As shown, when droplet 12 moves along the first direction OA, just before it reaches the driving electrode group Z with the temperature measuring zone T, the droplet first contacts the side of the driving electrode 3 along the second direction BO. Figure 20 (The side marked with an arrow in the middle) to cause the droplet 12 to continue moving along the first direction OA. When setting the recess, in order not to affect the normal flow of the droplet, the length D6 of the recess along the second direction BO is set to be less than or equal to one-third of the length D5 of the side of the driving electrode 3 with the recess along the second direction BO. While ensuring the normal flow of the droplet, the reasonable distribution of the temperature sensor 1 in the temperature measuring area T is ensured, saving space.

[0142] In some embodiments of this application, the droplet control unit 100 includes an external pump valve, the orthographic projection of which on the substrate 201 is located within the outer contour of the substrate 201.

[0143] The specific structure of the external pump valve is not limited here; it can be determined based on the actual situation.

[0144] It should be noted that microfluidic chips also include other components and structures. This description focuses only on the structures related to the invention. Other components and structures included in microfluidic chips can be found in relevant technologies and will not be elaborated here.

[0145] An embodiment of this application provides an analysis device, including the microfluidic chip described above.

[0146] In the analytical apparatus of the related technology, in order to test the temperature of the target sample, a temperature sensor is set in the microfluidic chip, and the two ends of the temperature sensor 1 are electrically connected to a constant current source through two leads. The two ends of the temperature sensor 1 are also electrically connected to an external voltmeter through these two leads. When measuring the voltage of the temperature sensor 1, due to the resistance of the leads themselves, the voltage value actually measured by the external voltmeter is the voltage value after the temperature sensor 1 and the two leads are connected in parallel, which seriously reduces the accuracy of measuring the voltage across the temperature sensor.

[0147] In the embodiments of this application, by setting a first lead group, a constant current source from the outside is transmitted to the temperature sensor 1 through the first lead group, so that there is a specific voltage difference between the two ends of the temperature sensor 1. By setting a second lead group, the temperature sensor 1 is electrically connected to an external voltmeter through the second lead group. In this way, since no constant current flows through the second lead group, the interference of the lead to the voltage measurement of the temperature sensor 1 is avoided, so that the voltage value measured by the external voltmeter is infinitely close to the actual voltage value across the two ends of the temperature sensor 1. Then, the resistance value of the temperature sensor 1 is determined based on the voltage value and the constant current value, and the temperature to be measured is determined based on the relationship between the resistance value and the temperature, thereby improving the detection accuracy and precision of the temperature sensor.

[0148] The embodiments of this application provide a temperature measurement method for the microfluidic chip as described above, with reference to... Figure 22 As shown, the method includes:

[0149] S1. A constant current is supplied to the temperature sensor of the microfluidic chip through the first lead group, and the current value flowing through the temperature sensor is determined.

[0150] In an exemplary embodiment, the first lead group includes at least two leads, and the number of leads in the first lead group is even.

[0151] For example, the first lead group may include a first lead W1 and a second lead W2 to electrically connect the two ends of the temperature sensor 1 and the two ends of the constant current source.

[0152] S2. Measure the voltage across the temperature sensor using an external voltmeter electrically connected to the second lead group, and obtain the voltage value;

[0153] In an exemplary embodiment, the second lead group includes at least two leads, and the number of leads in the second lead group is even.

[0154] For example, the second lead group may include a third lead W3 and a fourth lead W4 to electrically connect the temperature sensor 1 and the external voltmeter together.

[0155] S3. Determine the resistance value of the temperature sensor based on the current and voltage values;

[0156] S4. Determine the temperature value detected by the temperature sensor based on the resistance value.

[0157] For example, the temperature sensor described above may include an NTC type temperature sensor (Negative Temperature Coefficient); or, the temperature sensor described above may include an RTD type temperature sensor (Resistance Temperature Detector).

[0158] It should be noted that there is a preset relationship between the resistance and temperature value of the temperature sensor, and the relationship between the resistance and temperature value of the temperature sensor is determined by the structure and materials of the temperature sensor. Once the structure and materials of the temperature sensor are determined, the relationship between the resistance and temperature value of the temperature sensor is fixed.

[0159] In related technologies, in order to test the temperature of droplets on a microfluidic chip, two leads are used to electrically connect the two ends of temperature sensor 1 to a constant current source, and these two leads are also used to electrically connect the two ends of temperature sensor 1 to an external voltmeter. When measuring the voltage of temperature sensor 1, due to the resistance of the leads themselves, the voltage value actually measured by the external voltmeter is the voltage value after the temperature sensor 1 and the two leads are connected in parallel, which seriously reduces the accuracy of measuring the voltage across the temperature sensor.

[0160] In the embodiments of this application, by setting a first lead group, a constant current source from the outside is transmitted to the temperature sensor 1 through the first lead group, so that there is a specific voltage difference between the two ends of the temperature sensor 1. By setting a second lead group, the temperature sensor 1 is electrically connected to an external voltmeter through the second lead group. In this way, since no constant current flows through the second lead group, the interference of the lead to the voltage measurement of the temperature sensor 1 is avoided, so that the voltage value measured by the external voltmeter is infinitely close to the actual voltage value across the two ends of the temperature sensor 1. Then, the resistance value of the temperature sensor 1 is determined based on the voltage value and the constant current value, and the temperature to be measured is determined based on the relationship between the resistance value and the temperature, thereby improving the detection accuracy and precision of the temperature sensor.

[0161] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A microfluidic chip, wherein, include: A substrate and at least one microfluidic module located on the substrate, the microfluidic module including a droplet control unit and at least one temperature detection unit; The temperature detection unit includes a temperature sensor, a first lead group, and a second lead group. The temperature sensor is fixed on the substrate. The first lead group and the second lead group are electrically connected to the temperature sensor. The first lead group is configured to transmit a constant current to the temperature sensor, and the second lead group is configured to electrically connect the temperature sensor and an external voltmeter together. The droplet control unit includes multiple driving electrode groups, each of which is arranged along a first direction, which is the direction of droplet flow. The driving electrode group includes a plurality of driving electrodes, and a temperature measuring area is provided between each driving electrode in at least one of the driving electrode groups. In the driving electrode group with the temperature measuring area, the outer contour of the orthographic projection of each driving electrode on the substrate and the outer contour of the temperature measuring area partially overlap. The temperature sensor is located within the temperature measurement area, and the outer contour of the orthographic projection of the temperature sensor on the substrate is within the outer contour of the temperature measurement area.

2. The microfluidic chip according to claim 1, wherein, The first lead group includes a first lead and a second lead, and the second lead group includes a third lead and a fourth lead; the temperature detection unit also includes a first conductive pad and a second conductive pad; The first lead group and the temperature sensor are electrically connected via two first conductive pads and an external current source; the second lead group and the temperature sensor are electrically connected via two second conductive pads and an external voltmeter.

3. The microfluidic chip according to claim 1, wherein, The temperature sensor includes a first thermistor and a second thermistor that are electrically connected; the first thermistor is a linear thermistor and the second thermistor is a block thermistor.

4. The microfluidic chip according to claim 3, wherein, When the temperature is constant, the first thermistor is a fixed resistor and the second thermistor is an adjustable resistor; the resistance ratio of the first thermistor and the second thermistor is less than or equal to 20:

1.

5. The microfluidic chip according to claim 4, wherein, The block-shaped temperature-sensitive resistor has at least one hollow area, and the orthographic projection shape of the hollow area on the substrate includes polygons, arcs, and shapes formed by a combination of polygons and arcs.

6. The microfluidic chip according to claim 5, wherein, The block-shaped temperature-sensitive resistor has a hollow area, which includes a first hollow sub-area disposed along a first direction and a second hollow sub-area disposed along a second direction. The orthographic projection shape of the first hollow sub-area and the second hollow sub-area on the substrate is rectangular. The first direction is the direction of droplet flow, and the second direction is perpendicular to the first direction. The ratio of the maximum dimension of the first hollow sub-region along the first direction to the maximum dimension of the second hollow sub-region along the second direction is in the range of 1:9 to 3:

7.

7. The microfluidic chip according to claim 5, wherein, The block-shaped temperature-sensitive resistor has a plurality of hollow areas arranged along a first direction. The orthographic projection shape of each hollow area on the substrate is rectangular, and each hollow area is not connected to the others. The first direction is the direction of droplet flow.

8. The microfluidic chip according to claim 7, wherein, The orthographic projection shape of the block-shaped temperature-sensitive resistor, excluding the hollowed-out area, on the substrate is serpentine.

9. The microfluidic chip according to claim 2, wherein, The temperature sensor includes a temperature-sensitive layer and a light-shielding layer located on the substrate. The light-shielding layer is located on the side of the temperature-sensitive layer away from the substrate, and the orthogonal projection of the temperature-sensitive layer on the substrate is within the orthogonal projection of the light-shielding layer on the substrate. The temperature-sensitive layer is in direct contact with the first lead group and the second lead group, respectively.

10. The microfluidic chip according to claim 9, wherein, The temperature-sensitive layer, the first lead group, and the second lead group are located on the same layer, and the orthographic projection of the temperature-sensitive layer on the substrate and the orthographic projection of the first lead group on the substrate do not overlap.

11. The microfluidic chip according to claim 9, wherein, A portion of the temperature-sensitive layer is located on the same layer as the leads in the first lead group and the second lead group, and a portion of the temperature-sensitive layer extends to a portion of the surface of at least one lead in the first lead group and the second lead group that is away from the substrate.

12. The microfluidic chip according to claim 9, wherein, The temperature sensor further includes an insulating layer located between the temperature-sensitive layer and the light-shielding layer. The orthographic projection of the insulating layer on the substrate covers the orthographic projection of the temperature-sensitive layer on the substrate, and the orthographic projection of the insulating layer on the substrate covers the orthographic projection of the light-shielding layer on the substrate.

13. The microfluidic chip according to claim 9, wherein, The temperature sensor also includes a first electrode and a second electrode that are not connected to each other, and the first electrode, the second electrode, each lead in the first lead group and each lead in the second lead group are located in the same layer; The first electrode is electrically connected to the first lead and the third lead, respectively, and the second electrode is electrically connected to the second lead and the fourth lead, respectively; the orthographic projection of the first electrode on the substrate and the orthographic projection of the second electrode on the substrate are both located within the orthographic projection of the temperature-sensitive layer on the substrate; wherein, the first electrode and the second electrode are both toothed electrodes.

14. The microfluidic chip according to claim 13, wherein, The toothed electrode includes at least three toothed electrodes extending along a first direction, and a connecting electrode extending along a direction perpendicular to the first direction; the connecting electrode electrically connects one end of each of the toothed electrodes together; the toothed electrodes of the first electrode and the toothed electrodes of the second electrode are spaced apart. The distance between the toothed electrode of the first electrode and the toothed electrode of the second electrode along a direction perpendicular to the first direction is less than or equal to 50 μm, where the first direction is the direction of droplet flow.

15. The microfluidic chip according to claim 9, wherein, The temperature-sensitive layer further includes a hollow area that extends along a first direction, and the maximum size of the hollow area along the first direction is less than or equal to half the maximum size of the temperature-sensitive layer along the first direction, where the first direction is the direction of droplet flow.

16. The microfluidic chip according to claim 2, wherein, The temperature sensor includes a thermistor, a first conductive layer, and a second conductive layer; the thermistor is electrically connected to the first lead and the third lead through the first conductive layer, and the thermistor is electrically connected to the second lead and the fourth lead through the second conductive layer.

17. The microfluidic chip according to claim 16, wherein, The orthographic projections of the first conductive layer and the second conductive layer on the substrate overlap with the orthographic projections of the thermistor on the substrate.

18. The microfluidic chip according to claim 1, wherein, The orthographic projection shape of the driving electrode on the substrate includes a rectangle and a chamfered rectangle; in the driving electrode group with the temperature measuring area, each driving electrode has a recessed portion at one corner, and the temperature measuring area includes the region where each recessed portion is located. The length of the recess along the second direction is less than or equal to one-third of the length of the side of the driving electrode on which the recess is located along the second direction; the second direction is perpendicular to the first direction.

19. The microfluidic chip according to claim 1, wherein, The droplet control unit includes an external pump valve, the orthographic projection of which is located within the outer contour of the substrate.

20. An analytical apparatus, wherein, Including the microfluidic chip as described in any one of claims 1-19.

21. A temperature measurement method for a microfluidic chip as described in any one of claims 1-19, wherein, The method includes: A constant current is supplied to the temperature sensor of the microfluidic chip through the first lead group, and the current value flowing through the temperature sensor is determined. The voltage across the temperature sensor is measured using an external voltmeter electrically connected to the second lead group, and the voltage value is obtained. The resistance value of the temperature sensor is determined based on the current value and the voltage value; The temperature value detected by the temperature sensor is determined based on the resistance value.

Images