Micro-fluidic chip, manufacturing method and micro-fluidic system

Abstract

The invention belongs to the technical field of microfluidics, and particularly relates to a micro-fluidic chip, a manufacturing method and a micro-fluidic system.The micro-fluidic chip comprises a first substrate and a second substrate, and the first substrate comprises a first substrate and a first electrode; the second substrate and the first substrate are oppositely arranged, and the second substrate and the first substrate form an accommodating cavity for accommodating liquid drops; the second substrate comprises a second substrate, a second electrode layer and a dielectric layer, the second electrode layer and the dielectric layer are both arranged on the second substrate, the second electrode layer comprises a plurality of second electrodes arranged in an array, the adjacent second electrodes are arranged at intervals, and the first electrodes and the second electrodes can drive liquid drops to move; and the dielectric layer covers the second electrode and comprises at least two layers of dielectric films, the at least two layers of dielectric films are sequentially laminated in the direction from the second substrate to the first substrate, and the roughness of the dielectric layer is smaller than that of any dielectric film. According to the scheme, polarization electrification of the liquid drops can be avoided, the service life of the microfluidic chip is guaranteed, and the user experience is improved.

Description

Technical Field

[0001] The present application belongs to the field of microfluidics technology, and specifically relates to a microfluidics chip, a manufacturing method and a microfluidics system. Background Art

[0002] Microfluidic technology is a technology that is mainly characterized by the manipulation of fluids in micrometer-scale space. It can concentrate multiple steps in biological, chemical, and medical analysis processes on a micrometer-level chip and automatically complete the entire analysis process. Due to the strong integration of microfluidic chips, the advantages of fast analysis speed, low loss, low material consumption, and low pollution when processing samples, it has shown great prospects in many fields such as biomedical research, drug synthesis screening, environmental monitoring and protection, health quarantine, forensic identification, and detection of biological reagents.

[0003] Microfluidic chips can automatically prepare and manipulate samples in the form of droplets. They mainly use the dielectric wetting effect to drive the movement of droplets. In the application of the dielectric wetting effect, the dielectric layer is crucial.

[0004] However, the dielectric layer of the microfluidic chip in the prior art will cause the droplets to penetrate into the interior of the substrate, causing the droplets to be polarized and charged, thereby affecting the driving voltage and driving speed of the droplets, resulting in a decrease in the service life of the microfluidic chip and user experience. Summary of the invention

[0005] The purpose of this application is to prevent droplets from penetrating into the interior of the substrate through the dielectric layer, causing the droplets to become polarized and charged, affecting the driving voltage and driving speed of the droplets, and causing the service life of the microfluidic chip and user experience to deteriorate.

[0006] In a first aspect, the present application provides a microfluidic chip for detecting the position of a droplet, the microfluidic chip comprising:

[0007] A first substrate, comprising a first substrate and a first electrode disposed on the first substrate;

[0008] A second substrate is arranged opposite to the first substrate and forms a receiving cavity for receiving the droplets together with the first substrate; the second substrate comprises a second substrate, a second electrode layer and a dielectric layer, the second electrode layer and the dielectric layer are both arranged on the second substrate, the second electrode layer comprises a plurality of second electrodes arranged in an array, adjacent second electrodes are arranged at intervals, and the first electrode and the second electrode can drive the droplets to move; the dielectric layer covers the second electrode, and the dielectric layer comprises at least two dielectric films, the at least two dielectric films are stacked in sequence in the direction from the second substrate to the first substrate, and the roughness of the dielectric layer is less than the roughness of any of the dielectric films.

[0009] In an exemplary embodiment of the present application, the at least two dielectric films are both inorganic films.

[0010] In an exemplary embodiment of the present application, the dielectric layer includes a first dielectric film and a second dielectric film, the first dielectric film is disposed on a side of the second dielectric film close to the second substrate, and the roughness of the first dielectric film is greater than the roughness of the second dielectric film.

[0011] In an exemplary embodiment of the present application, the first dielectric film is silicon oxide; and the second dielectric film is silicon nitride.

[0012] In an exemplary embodiment of the present application, both the first dielectric film and the second dielectric film are silicon nitride.

[0013] In an exemplary embodiment of the present application, the thickness of the first dielectric film is greater than or equal to 20 nm.

[0014] A second aspect of the present application provides a method for manufacturing a microfluidic chip, which is used to manufacture a microfluidic chip as described in any one of the above items, and the method for manufacturing the microfluidic chip comprises:

[0015] preparing a first substrate;

[0016] Prepare a second substrate, the second substrate comprising a second substrate and a second electrode and a dielectric layer disposed on the second substrate, the dielectric layer comprising at least two dielectric films, the at least two dielectric films being sequentially stacked in a thickness direction of the second substrate, and the roughness of the dielectric layer being less than the roughness of any of the dielectric films;

[0017] The first substrate and the second substrate are placed opposite to each other to form a box.

[0018] In another exemplary embodiment of the present application, the dielectric layer includes a first dielectric film and a second dielectric film, the first dielectric film is silicon oxide, the second dielectric film is silicon nitride, and the roughness of the first dielectric film is greater than the roughness of the second dielectric film; the method for preparing the dielectric layer on the second substrate includes:

[0019] preparing a first dielectric film;

[0020] A second dielectric film is prepared, wherein crystals of the second dielectric film are filled into the crystal gaps of the first dielectric film.

[0021] In another exemplary embodiment of the present application, the dielectric layer includes a first dielectric film and a second dielectric film, and the first dielectric film and the second dielectric film are made of the same material; and a method for preparing the dielectric layer on the second substrate includes:

[0022] preparing the first dielectric film according to predetermined parameters, wherein the thickness of the first dielectric film is greater than or equal to 20 nm;

[0023] The predetermined parameters are adjusted to prepare the second dielectric film, wherein the roughness of the second dielectric film is smaller than the roughness of the first dielectric film.

[0024] A third aspect of the present application provides a microfluidic system, which includes any of the microfluidic chips described above.

[0025] The microfluidic chip, manufacturing method and microfluidic system of the present application have the following beneficial effects:

[0026] The microfluidic chip of the present application includes a first substrate and a second substrate, and the dielectric layer on the second substrate includes at least two layers of dielectric film, and the at least two layers of dielectric film are stacked in sequence in the direction from the second substrate to the first substrate. By using at least two layers of dielectric film in the dielectric layer, the distance between the droplet and the second electrode can be increased; in addition, since the roughness of the dielectric layer is less than the roughness of any dielectric film, the use of at least two layers of dielectric film structure can improve the roughness of the dielectric layer, and can increase the density of the dielectric layer, avoid the appearance of holes and cracks in the dielectric layer, avoid droplet infiltration, and thus avoid droplet polarization charging, ensure the driving voltage and driving speed of the droplet, ensure the service life of the microfluidic chip and improve the user experience, thereby improving the detection accuracy of the microfluidic system.

[0027] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0028] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 The cross-sectional structure schematic diagram of the microfluidic chip provided in Embodiments 1 to 4 of the present application is shown.

[0031] Figure 2 A schematic cross-sectional structure diagram of the first substrate provided in Embodiments 1 to 4 of the present application is shown.

[0032] Figure 3A schematic cross-sectional structure diagram of the second substrate provided in Embodiments 1 to 4 of the present application is shown.

[0033] Figure 4 A schematic flow chart of the method for preparing the microfluidic chip provided in Examples 1 to 4 of the present application is shown.

[0034] Figure 5 A schematic flow chart of a method for preparing a second substrate provided in Embodiments 1 to 4 of the present application is shown.

[0035] Figure 6 A schematic flow chart of a method for preparing the first dielectric film and the second dielectric film using different materials provided in Embodiment 1, Embodiment 3 and Embodiment 4 of the present application is shown.

[0036] Figure 7 A schematic flow chart of a method for preparing a first dielectric film and a second dielectric film using the same material provided in Embodiment 2, Embodiment 3 and Embodiment 4 of the present application is shown.

[0037] Figure 8 A schematic diagram of the structure of forming a gate on a second substrate provided in Embodiments 1 to 4 of the present application is shown.

[0038] Fig. 9 The structural intent of forming a gate insulating layer on the second substrate provided in Embodiments 1 to 4 of the present application is shown.

[0039] Fig.10 A schematic diagram of the structure in which an active layer, a source electrode and a drain electrode are formed on a gate insulating layer provided in Embodiments 1 to 4 of the present application is shown.

[0040] Fig.11 A schematic diagram of the structure of forming a passivation layer on the gate insulating layer provided in Embodiments 1 to 4 of the present application is shown.

[0041] Fig.12 A schematic diagram of the structure of forming a second electrode layer on the passivation layer provided in Embodiments 1 to 4 of the present application is shown.

[0042] Fig.13 A schematic diagram of the structure of forming a dielectric layer on the passivation layer provided in Embodiments 1 to 4 of the present application is shown.

[0043] Description of reference numerals:

[0044] 100. Microfluidic chip;

[0045] 110, first substrate; 111, first underlayer; 112, first electrode layer; 1120, first electrode; 113, first hydrophobic layer;

[0046] 120, second substrate; 121, second substrate; 122, second electrode layer; 1220, second electrode; 123, driving circuit layer; 1230, gate insulating layer; 1231, passivation layer; 1232, gate; 1233, active layer; 1234, source electrode; 1235, drain electrode; 124, dielectric layer; 1240, first dielectric film; 1241, second dielectric film; 125, second hydrophobic layer;

[0047] 130. Receiving chamber; 200. Droplet. DETAILED DESCRIPTION

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0049] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] In this application, unless otherwise clearly specified and limited, the terms "assembly", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0052] Embodiment 1

[0053] See also Figure 1As shown, the first embodiment of the present application provides a microfluidic chip 100, which can be used as a carrier for droplet 200 operations. The droplet 200 can perform a series of operations in the microfluidic chip 100, such as moving, separating or mixing. The microfluidic chip 100 can also be used to detect the position of the droplet 200 in real time, so as to accurately and quickly obtain the position of the droplet 200 in the microfluidic chip 100.

[0054] It is understandable that, in the exemplary embodiment, the droplet 200 may be a cell, protein, chromosome, etc. in a solution in a biological tissue, or may be other liquid substances, which are not listed here one by one.

[0055] In some embodiments of this application, please continue to refer to Figure 1 As shown, the microfluidic chip 100 includes a first substrate 110 and a second substrate 120 that are arranged oppositely and in parallel. The first substrate 110 and the second substrate 120 are spaced apart by a preset distance to form a receiving cavity 130. A droplet 200 can be received in the receiving cavity 130, and the droplet 200 contacts the surfaces of the first substrate 110 and the second substrate 120, respectively.

[0056] It should be noted that the liquid can be injected into the receiving cavity 130 through the liquid droplet 200 inlet of the microfluidic chip 100 .

[0057] In some embodiments of the present application, the first substrate 110 and the second substrate 120 may be relatively fixed by a frame. The frame may be rectangular, circular or other shapes, and may be formed by connecting a plurality of frame strips end to end and arranged at the outer edge of the microfluidic chip 100. The frame strips may be connected by bonding or clamping, or may be an integrated structure.

[0058] It is understandable that in other exemplary embodiments, the first substrate 110 and the second substrate 120 may also be relatively fixed by a frame sealing adhesive.

[0059] In addition, the microfluidic chip 100 may further include a plurality of support columns (not shown) disposed between the first substrate 110 and the second substrate 120 . The support columns are located in the accommodating cavity 130 and are used to support the first substrate 110 and the second substrate 120 .

[0060] In some embodiments of the present application, the height between the first substrate 110 and the second substrate 120 may be greater than the height of the droplet 200 in the thickness direction of the first substrate 110 or the second substrate 120 to ensure that the droplet 200 can move in the receiving cavity 130 to avoid the jamming phenomenon. The thickness direction of the first substrate 110 or the second substrate 120 refers to the direction from the first substrate 110 to the second substrate 120.

[0061] In some embodiments of this application, see Figure 2 and Figure 3 As shown, the first substrate 110 includes a transparent first substrate 111, which is used to provide a platform for forming various functional layers of the first substrate 110. The second substrate 120 includes a transparent second substrate 121, which is used to provide a platform for forming various functional layers of the second substrate 120.

[0062] In some embodiments of the present application, the first substrate 111 and the second substrate 121 may be rigid substrates made of glass or quartz, or may be flexible substrates made of materials such as polyimide (PI), which are not listed here one by one.

[0063] In some embodiments of this application, see Figure 2 As shown, the first substrate 110 also includes a transparent first electrode layer 112 arranged on the side of the first substrate 111 facing the second substrate 121. The first electrode layer 112 includes a first electrode 1120. The first electrode 1120 can adopt a full-surface design to reduce the cost of preparing the first electrode 1120, thereby reducing the cost of the overall microfluidic chip 100.

[0064] In some embodiments of this application, see Figure 2 As shown, the second substrate 120 further includes a second electrode layer 122 disposed on the side of the second substrate 121 facing the first substrate 111. The second electrode layer 122 includes a plurality of second electrodes 1220, and adjacent second electrodes 1220 are spaced apart and insulated from each other.

[0065] It should be noted that the second electrode 1220 may be a transparent electrode or an opaque electrode, which may be specifically designed according to different embodiments.

[0066] In some embodiments of the present application, the first electrode 1120 and the second electrode 1220 can be made of transparent conductive materials such as indium tin oxide (ITO), zinc tin oxide (ZTO), zinc oxide (ZnO), indium zinc oxide (IZO), gallium indium tin oxide (GIZO), etc., which are not listed here one by one.

[0067] The droplet 200 may be driven to move in the receiving chamber 130 by changing the voltage difference between adjacent second electrodes 1220 .

[0068] It should be noted that the principle that the droplet 200 can move in the receiving cavity 130 according to the voltage difference formed between the adjacent second electrodes 1220 is the electrowetting technology on the medium. The electrowetting technology on the medium refers to the technology of changing the contact angle of the droplet 200 on the surface of the medium by applying a voltage signal, causing the droplet 200 to deform asymmetrically, thereby generating internal force to achieve the control of the droplet 200.

[0069] In some embodiments of this application, see Figure 1 As shown, the second substrate 120 further includes a driving circuit layer 123. The driving circuit layer 123 is disposed on a side of the second electrode layer 122 close to the second substrate 121, and the second electrode 1220 is electrically connected to the driving circuit layer 123. The second electrode 1220 can change its voltage according to the action of the driving circuit layer 123, thereby changing the contact angle above the second electrode 1220, and controlling the droplet 200 to move in the receiving cavity 130.

[0070] In some embodiments of the present application, the driving circuit layer 123 includes a plurality of control units arranged in an array. The control units correspond to the positions of the second electrodes 1220 one by one, and the control units are electrically connected to the second electrodes 1220, and can be used to provide a driving voltage to the second electrodes 1220 to change the contact angle above the second electrodes 1220, thereby driving the droplets 200 to move in the receiving chamber 130.

[0071] In some embodiments of this application, see Figure 1 As shown, the second substrate 120 further includes a gate insulating layer 1230 and a passivation layer 1231. The control unit may be a transistor, and each control unit includes a gate 1232, an active layer 1233, a source 1234, and a drain 1235.

[0072] The plurality of gate electrodes 1232 are disposed on a side of the second substrate 121 facing the first substrate 110 , and the plurality of gate electrodes 1232 are spaced apart from each other.

[0073] Please continue to see Figure 1 As shown, the gate insulating layer 1230 covers multiple gates 1232, and the active layer 1233, the source 1234 and the drain 1235 are all arranged on the side of the gate insulating layer 1230 away from the second substrate 121. The gate insulating layer 1230 is used to isolate the gate 1232 and the active layer 1233 to avoid crosstalk between the gate 1232 and the active layer 1233.

[0074] The source electrode 1234 and the drain electrode 1235 are respectively disposed at two ends of the active layer 1233 and are electrically connected to the active layer 1233 to transmit electrical signals.

[0075] In some embodiments of this application, please continue to refer to Figure 1 As shown, the passivation layer 1231 is disposed on the side of the gate insulating layer 1230 away from the second substrate 121 and covers the active layer 1233 , the source 1234 and the drain 1235 . The passivation layer 1231 is used to protect the active layer 1233 , the source 1234 and the drain 1235 .

[0076] In some embodiments of this application, see Figure 1 As shown, the second electrode 1220 is arranged on the side of the passivation layer 1231 away from the second substrate 121, and a via is opened on the passivation layer 1231 for exposing the drain 1235. Part of the second electrode 1220 is accommodated in the via and contacts the drain 1235 exposed by the via, so that the second electrode 1220 is electrically connected to the drain 1235, so that the drain 1235 provides a driving voltage to the second electrode 1220.

[0077] In some embodiments of this application, please continue to refer to Figure 1 and Figure 3 As shown, the second substrate 120 further includes a dielectric layer 124. The dielectric layer 124 is disposed on a side of the passivation layer 1231 away from the second substrate 121, and the dielectric layer 124 is disposed on the peripheral side of the second electrode 1220 and on a side of the plurality of second electrodes 1220 facing away from the passivation layer 1231, that is, the dielectric layer 124 is disposed on the second electrode 1220 facing away from the passivation layer 1231, and the plurality of second electrodes 1220 are covered on the passivation layer 1231.

[0078] It should be noted that the passivation layer 1231 on the second substrate 120 can be used to increase the dielectric constant, thereby improving the driving ability of the second substrate 120 and the first substrate 110 for the droplets 200 , making it easier for the droplets 200 to move in the receiving cavity 130 .

[0079] In some embodiments of this application, see Figure 3 As shown, the dielectric layer 124 includes at least two dielectric films. At least two dielectric films are stacked in sequence in the direction from the second substrate 121 to the first substrate 111, that is, at least two dielectric films are stacked in sequence, which can increase the distance between the droplet 200 and the second electrode 1220, and extend the contact distance between the droplet 200 and the second electrode 1220.

[0080] It should be noted that the roughness of the dielectric layer 124 is less than the roughness of any dielectric film; that is, the overall roughness of the dielectric layer 124 is less than the roughness of any single dielectric film. After at least two layers of dielectric films are combined, the roughness of the dielectric layer 124 can be reduced, and the density of the dielectric layer 124 can be increased, thereby reducing the problem of holes or cracks in the dielectric film, thereby preventing the droplets 200 from penetrating into the second electrode 1220, preventing the droplets 200 from being polarized and charged, ensuring the smoothness of the movement of the droplets 200, and improving the service life of the microfluidic chip 100 and the user experience.

[0081] That is to say, the dielectric layer 124 in the present application scheme can not only increase the thickness of the droplet 200 to the second electrode 1220, but also reduce the problem of holes and cracks formed in the dielectric layer 124, thereby preventing the droplet 200 from penetrating into the second electrode 1220, preventing the droplet 200 from being polarized and charged, and ensuring the correctness and stability of the movement process of the droplet 200.

[0082] In some embodiments of the present application, at least two dielectric films are inorganic films. The dielectric layer 124 made of inorganic films will not be too thick, will not affect the driving voltage of the droplet 200, and the inorganic films can reduce production costs and ensure the uniformity of the dielectric layer 124.

[0083] It should be noted that, in other embodiments, at least two dielectric films may also be made of organic films, as long as they do not affect the movement of the droplets 200 and can prevent the droplets 200 from penetrating and polarizing and charging.

[0084] In some embodiments of this application, please continue to refer to Figure 3 As shown, the dielectric layer 124 includes a first dielectric film 1240 and a second dielectric film 1241. The first dielectric film 1240 is disposed on a side of the second dielectric film 1241 close to the second substrate 121, that is, the first dielectric film 1240 is located at the bottom of the second dielectric film 1241.

[0085] In some embodiments of the present application, the roughness of the first dielectric film 1240 is greater than that of the second dielectric film 1241, so that the film formation gap of the first dielectric film 1240 is greater than the film formation gap of the second dielectric film 1241, the crystal growth is more disordered, and the film formation of the first dielectric film 1240 is relatively loose.

[0086] When forming the second dielectric film 1241 , the second dielectric film 1241 may be filled into the crystal gaps of the first dielectric film 1240 , and the crystals of the second dielectric film 1241 may be arranged in an orderly manner using the crystals of the first dielectric film 1240 , so that the crystal growth of the second dielectric film 1241 is more orderly.

[0087] Ultimately, the crystal gap and roughness of the dielectric layer 124 are the superposition of the first dielectric film 1240 and the second dielectric film 1241, so that the crystal gap and roughness of the dielectric layer 124 are smaller than the crystal gap and roughness of each dielectric film, so that it is not easy for holes and cracks to grow in the dielectric layer 124, and the droplets 200 are prevented from penetrating from the dielectric layer 124 to the second electrode 1220, ensuring that the droplets 200 are not charged, and then ensuring that the droplets 200 move normally, thereby increasing the service life of the microfluidic chip 100 and improving the user experience.

[0088] That is, when preparing the dielectric layer 124, after preparing the first dielectric film 1240 in advance, the second dielectric film 1241 is prepared on the first dielectric film 1240, so that the second dielectric film 1241 is embedded in the first dielectric film 1240, so that the crystal gap and roughness of the dielectric layer 124 are smaller than the crystal gap and roughness of each dielectric film.

[0089] In some embodiments of the present application, the first dielectric film 1240 and the second dielectric film 1241 may be made of different materials, for example, the first dielectric film 1240 is silicon oxide, and the second dielectric film 1241 is silicon nitride. Due to the different film forming processes of different materials, the roughness of the dielectric films of different materials can be different, so that the crystal gap and roughness of the dielectric layer 124 are smaller than the crystal gap and roughness of each dielectric film, thereby preventing the droplet 200 from penetrating into the second electrode 1220, thereby preventing the droplet 200 from being polarized and charged.

[0090] For example, the first dielectric film 1240 is silicon oxide, and its roughness is about 2.7 nm, the second dielectric film 1241 is silicon nitride, and its roughness is 2.0 nm, and the roughness of the dielectric layer 124 is 1.2 nm.

[0091] In some embodiments of this application, see Figure 1 As shown, the first substrate 110 further includes a first hydrophobic layer 113, and the second substrate 120 further includes a second hydrophobic layer 125. The first hydrophobic layer 113 is disposed on a side of the first electrode layer 112 away from the first substrate 111, and the second hydrophobic layer 125 is disposed on a side of the dielectric layer 124 away from the second substrate 121.

[0092] Please refer to Figure 1 As shown, the first hydrophobic layer 113 and the second hydrophobic layer 125 are arranged opposite to each other and spaced apart, and the droplet 200 is located between the first hydrophobic layer 113 and the second hydrophobic layer 125. The first hydrophobic layer 113 and the second hydrophobic layer 125 are used to prevent the droplet 200 from excessively adhering to the first substrate 110 and the second substrate 120, thereby facilitating the droplet 200 to move in the accommodating cavity 130.

[0093] In an exemplary embodiment, the first hydrophobic layer 113 and the second hydrophobic layer 125 may be made of the same material, such as Teflon.

[0094] In some embodiments of the present application, the microfluidic chip 100 may be a digital microfluidic chip 100 , so that the droplets 200 may be manipulated more accurately.

[0095] Embodiment 2

[0096] The difference between the second embodiment of the present application and the first embodiment is that the first dielectric film 1240 and the second dielectric film 1241 are made of the same material, such as silicon nitride.

[0097] It should be noted that by adjusting the film forming parameters and the film forming process of the first dielectric film 1240 and the second dielectric film 1241 , it is possible to achieve different roughnesses of the first dielectric film 1240 and the second dielectric film 1241 .

[0098] For example, the first dielectric film 1240 and the second dielectric film 1241 can be made of silicon nitride. The first dielectric film 1240 is prepared at a film forming power of 13000 W, a film forming spacing of 900 milli-inches (1 milli-inch = 25.4 microns), a film forming pressure of 1100 millitorr (1 millitorr = 133.322 Pa), a nitrogen gas flow rate of 45000 sccm (standard cubic centimeters per minute), an ammonia gas flow rate of 19000 sccm (standard cubic centimeters per minute), and a monosilane gas flow rate of 4500 sccm (standard cubic centimeters per minute). The roughness of the first dielectric film 1240 is 2.5 nm. The second dielectric film 1241 was prepared at a film forming power of 16000 W, a film forming spacing of 650 mils (1 mil = 25.4 microns), a film forming pressure of 950 mTorr (1 mTorr = 133.322 Pa), a nitrogen gas flow rate of 60000 sccm (standard cubic centimeters per minute), an ammonia gas flow rate of 21000 sccm (standard cubic centimeters per minute), and a silane gas flow rate of 7500 sccm (standard cubic centimeters per minute). The roughness of the second dielectric film 1241 was 1.6 nm.

[0099] By embedding the first dielectric film 1240 and the second dielectric film 1241 into each other, the roughness of the dielectric layer 124 can be made smaller than the roughness of each dielectric film, thereby avoiding holes and cracks in the dielectric layer 124 and preventing the droplets 200 from penetrating into the second electrode 1220 and polarizing and charging, thereby ensuring the movement of the droplets 200.

[0100] In some embodiments of the present application, the thickness of the first dielectric film 1240 is greater than or equal to 20 nm. In this way, it can be ensured that the first dielectric film 1240 has a complete interface state after film formation, thereby providing the necessary conditions for the second dielectric film 1241 to continue to grow and prepare a roughness that meets the expected requirements.

[0101] Embodiment 3

[0102] See also Figures 4 to 7 As shown, the third embodiment of the present application provides a method for manufacturing a microfluidic chip 100, which may include the following steps:

[0103] S100 , preparing a first substrate 110 .

[0104] See also Figure 2 As shown, a transparent first substrate 111 is provided, and a first electrode layer 112 and a first hydrophobic layer 113 are sequentially formed on one side of the first substrate 111 by deposition, thereby forming a first substrate 110. The first substrate 111 can be a rigid substrate made of glass or quartz, or a flexible substrate made of materials such as polyimide (PI); the first electrode 1120 can be made of transparent conductive materials such as indium tin oxide (ITO), zinc tin oxide (ZTO), zinc oxide (ZnO), indium zinc oxide (IZO), gallium indium tin oxide (GIZO), etc., which are not listed here one by one. The first hydrophobic layer 113 can be made of Teflon.

[0105] S200 , preparing a second substrate 120 .

[0106] S210, see Figure 5 and Figure 8 As shown, a second substrate 121 is provided, a first metal layer is coated on the second substrate 121 , and the first metal layer is patterned to obtain a plurality of gates 1232 .

[0107] It should be noted that the second substrate 121 may be a transparent substrate, a rigid substrate made of glass or quartz, or a flexible substrate made of polyimide (PI) or other materials. The first metal layer may be coated on the second substrate 121 by physical vapor deposition or other methods. Patterning includes photolithography, etching, and other methods.

[0108] The gate 1232 may be made of metals such as aluminum (Al), magnesium (Mg), and silver (Ag), which are not listed here one by one. The gate 1232 may also be formed by stacking multiple layers of metals.

[0109] S220, see Fig. 9 As shown, a gate insulating layer 1230 is formed on the surfaces of the plurality of gates 1232 , and the gate insulating layer 1230 covers the plurality of gates 1232 to the second substrate 121 .

[0110] A gate insulating layer 1230 is formed on the surface of the plurality of gates 1232 facing away from the second substrate 121 by chemical vapor deposition and etching, and the gate insulating layer 1230 covers the plurality of gates 1232 to the second substrate 121 .

[0111] The gate insulating layer 1230 may be made of other transparent insulating materials such as silicon oxide, silicon nitride, aluminum oxide, etc., which are not listed here one by one.

[0112] S230, see Fig.10As shown, a plurality of active layers 1233 are formed on a side of the gate insulating layer 1230 facing away from the plurality of gates 1232 , wherein positions of the plurality of active layers 1233 correspond one-to-one to positions of the plurality of gates 1232 .

[0113] The active layer 1233 is formed on the side of the gate insulating layer 1230 facing away from the gate 1232 by chemical vapor deposition, photolithography, and etching, and the positions of the multiple active layers 1233 are arranged opposite to the positions of the multiple gates 1232. The active layer 1233 can be made of semiconductor material.

[0114] S240, see Fig.10 As shown, a plurality of source electrodes 1234 and a plurality of drain electrodes 1235 are formed on a side of the gate insulating layer 1230 facing away from the plurality of gate electrodes 1232 .

[0115] A plurality of source electrodes 1234 and a plurality of drain electrodes 1235 are formed on a side of the gate insulating layer 1230 facing away from the gate electrode 1232 by means of physical vapor deposition, photolithography, and etching.

[0116] The source electrode 1234 and the drain electrode 1235 are spaced apart from each other and are respectively connected to two ends of the active layer 1233 . The gate electrode 1232 , the active layer 1233 , the source electrode 1234 and the drain electrode 1235 together form a thin film transistor (TFT).

[0117] S250, see Fig.11 As shown, a passivation layer 1231 is formed on the side of the active layer 1233 , the source electrode 1234 , and the drain electrode 1235 facing away from the gate insulating layer 1230 .

[0118] A passivation layer 1231 is formed on the side of the active layer 1233 , the source electrode 1234 , and the drain electrode 1235 facing away from the gate insulating layer 1230 by chemical vapor deposition. The passivation layer 1231 covers the active layer 1233 , the source electrode 1234 , and the drain electrode 1235 to the gate insulating layer 1230 .

[0119] When preparing the passivation layer 1231, a via hole exposing the drain electrode 1235 is opened on the passivation layer 1231. The passivation layer 1231 can be made of other transparent insulating materials such as silicon oxide, silicon nitride, aluminum oxide, etc., which are not listed here one by one.

[0120] S260, see Fig.12 As shown, a plurality of second electrodes 1220 are formed on a side of the passivation layer 1231 facing away from the gate insulating layer 1230 .

[0121] A plurality of second electrodes 1220 are formed on the side of the passivation layer 1231 facing away from the active layer 1233, the source electrode 1234, and the drain electrode 1235 by physical vapor deposition, photolithography, and etching in sequence, and part of the second electrodes 1220 are accommodated in the via holes and electrically connected to the drain electrode 1235. The second electrodes 1220 can be made of transparent conductive materials such as indium tin oxide (ITO), zinc tin oxide (ZTO), zinc oxide (ZnO), indium zinc oxide (IZO), and gallium indium tin oxide (GIZO), which are not listed here one by one.

[0122] S270, see Fig.13 As shown, a dielectric layer 124 is formed on a side of the second electrode 1220 facing away from the passivation layer 1231 .

[0123] A dielectric layer 124 is formed on a side of the second electrode 1220 facing away from the passivation layer 1231 by deposition, and the dielectric layer 124 covers the second electrode 1220 .

[0124] Among them, the dielectric layer 124 includes at least two layers of dielectric films, and the at least two layers of dielectric films are stacked in sequence in the thickness direction of the second substrate 121, so that the roughness and crystal gap of the dielectric layer 124 are smaller than the roughness and crystal gap of each dielectric film, thereby increasing the distance from the droplet 200 to the second electrode 1220 and extending the penetration path of the droplet 200; in addition, the roughness of the dielectric layer 124 is greater than the roughness of each dielectric film, which can avoid the appearance of holes and cracks in the dielectric layer 124, further avoid the droplet 200 from penetrating into the second electrode 1220, avoid the polarization and charging of the droplet 200, ensure the normal movement of the droplet 200, and thereby ensure the service life of the microfluidic chip 100 and improve the user experience.

[0125] In some embodiments, the dielectric layer 124 includes a first dielectric film 1240 and a second dielectric film 1241. The first dielectric film 1240 and the second dielectric film 1241 are made of different materials. The first dielectric film 1240 is made of silicon oxide, and the second dielectric film 1241 is silicon nitride. The first dielectric film 1240 and the second dielectric film 1241 are made of different materials, and the film forming process of the first dielectric film 1240 is different from the film forming process of the second dielectric film 1241, so that the crystal gap and roughness of the first dielectric film 1240 and the second dielectric film 1241 can be different, so that the crystal gap and roughness of the final dielectric layer 124 are smaller than the crystal gap and roughness of the first dielectric film 1240 and the second dielectric film 1241, so as to avoid polarization charging of the droplet 200 and ensure the normal movement of the droplet 200.

[0126] Among them, see Figure 6 and Fig.13 As shown, when the first dielectric film 1240 and the second dielectric film 1241 are made of different materials, the preparation method of the dielectric layer 124 includes:

[0127] S271 , preparing a first dielectric film 1240 .

[0128] The roughness of the first dielectric film 1240 is 2.7 nm.

[0129] S272 , preparing a second dielectric film 1241 on the first dielectric film 1240 .

[0130] The crystals in the second dielectric film 1241 are filled into the crystal gaps of the first dielectric film 1240, and the growth path of the second dielectric film 1241 is limited by the crystal gaps of the first dielectric film 1240, so that the growth of the second dielectric film 1241 is more orderly, so that the crystal gaps and roughness of the second dielectric film 1241 are smaller than those of the first dielectric film 1240. The roughness of the second dielectric film 1241 is 2.0 nm.

[0131] Ultimately, the roughness of the composite dielectric layer 124 is made to be 1.2 nm, and the crystal gap and roughness of the dielectric layer 124 are smaller than the crystal gap and roughness of the first dielectric film 1240 and the crystal gap and roughness of the second dielectric film 1241, so as to avoid the appearance of holes and cracks in the dielectric layer 124, further avoid the droplets 200 from penetrating into the second electrode 1220, avoid the polarization and charging of the droplets 200, ensure the normal movement of the droplets 200, and further ensure the service life of the microfluidic chip 100 and improve the user experience.

[0132] In some other embodiments, the dielectric layer 124 includes a first dielectric film 1240 and a second dielectric film 1241. The first dielectric film 1240 and the second dielectric film 1241 are made of the same material. The first dielectric film 1240 and the second dielectric film 1241 are both made of silicon nitride, and their respective film forming processes are adjusted so that the first dielectric film 1240 and the second dielectric film 1241 have different crystal gaps and roughness.

[0133] Among them, see Figure 7 and Fig.13 As shown, when the first dielectric film 1240 and the second dielectric film 1241 are made of the same material, the preparation method of the dielectric layer 124 includes:

[0134] S271, preparing a first dielectric film 1240 under predetermined film forming process parameters;

[0135] The predetermined film forming process parameters include film forming power, film forming spacing, film forming pressure, nitrogen gas flow rate, ammonia gas flow rate and monosilane gas flow rate. Among them, the film forming power is 13000W, the film forming spacing is 900 milliinches (1 milliinch = 25.4 micrometers), the film forming pressure is 1100 millitorr (1 millitorr = 133.322 Pa), the nitrogen gas flow rate is 45000 sccm (standard cubic centimeters per minute), the ammonia gas flow rate is 19000 sccm (standard cubic centimeters per minute), and the monosilane gas flow rate is 4500 sccm (standard cubic centimeters per minute). Under this preset film forming process parameter, the roughness of the first dielectric film 1240 is 2.5nm.

[0136] It should be noted that the thickness of the first dielectric film 1240 is greater than or equal to 20 nm, so that the first dielectric film 1240 can be guaranteed to have a complete interface state after film formation, thereby providing the necessary conditions for the second dielectric film 1241 to continue to grow and prepare a roughness that meets the expected requirements.

[0137] S272 , adjusting predetermined film forming parameters, and forming a second dielectric film 1241 on the first dielectric film 1240 .

[0138] Adjusting the predetermined film forming parameters includes film forming power, film forming spacing, film forming pressure, nitrogen gas flow rate, ammonia gas flow rate and monosilane gas flow rate. Among them, the film forming power is 16000W, the film forming spacing is 650 milliinches (1 milliinch = 25.4 micrometers), the film forming pressure is 950 millitorr (1 millitorr = 133.322 Pa), the nitrogen gas flow rate is 60000 sccm (standard cubic centimeters per minute), the ammonia gas flow rate is 21000 sccm (standard cubic centimeters per minute), and the monosilane gas flow rate is 7500 sccm (standard cubic centimeters per minute). Under another preset film forming process parameter, the roughness of the second dielectric film 1241 is 1.6nm.

[0139] Ultimately, the crystal gap and roughness of the composite dielectric layer 124 are smaller than the crystal gap and roughness of the first dielectric film 1240 and the crystal gap and roughness of the second dielectric film 1241, so as to avoid the appearance of holes and cracks in the dielectric layer 124, further avoid the droplets 200 from penetrating into the second electrode 1220, avoid the polarization and charging of the droplets 200, ensure the normal movement of the droplets 200, and further ensure the service life of the microfluidic chip 100 and improve the user experience.

[0140] S280 , preparing a second hydrophobic layer 125 on the dielectric layer 124 .

[0141] The second hydrophobic layer 125 is formed on the side of the dielectric layer 124 facing away from the second electrode 1220 by deposition, thereby forming the second substrate 120. The second hydrophobic layer 125 can be made of Teflon.

[0142] S300 , the first substrate 110 and the second substrate 120 are placed opposite to each other to form a box.

[0143] The first substrate 111 and the second substrate 121 are arranged opposite to each other so that the first electrode 1120, the first hydrophobic layer 113, the gate 1232, the gate insulating layer 1230, the active layer 1233, the source 1234, the drain 1235, the passivation layer 1231, the second electrode 1220, the dielectric layer 124 and the second hydrophobic layer 125 are all located between the first substrate 111 and the second substrate 121, thereby forming a microfluidic chip 100. The first hydrophobic layer 113 and the second hydrophobic layer 125 are spaced apart to form a receiving cavity 130, and the receiving cavity 130 is used to receive the droplet 200.

[0144] Embodiment 4

[0145] Embodiment 4 of the present application provides a microfluidic system, which may be a micro-total analysis system (MTAS), which may realize the control of the movement, separation, polymerization, chemical reaction, biological detection, etc. of a small amount of droplets 200. The microfluidic system includes not only the above-mentioned microfluidic chip 100, but also an optical unit.

[0146] Through the above-mentioned microfluidic chip 100, the droplets 200 in the receiving chamber 130 can be prevented from penetrating into the second electrode 1220 to be polarized and charged, thereby ensuring the normal movement of the droplets 200, increasing the service life of the microfluidic chip 100 and improving the user experience, thereby improving the detection accuracy of the microfluidic system.

[0147] In the description of this specification, the description with reference to the terms "some embodiments", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0148] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent of this application.

Claims

1. A microfluidic chip for detecting the position of a droplet, characterized in that: The microfluidic chip comprises: A first substrate, comprising a first substrate and a first electrode disposed on the first substrate; A second substrate is arranged opposite to the first substrate and forms a receiving cavity for receiving the droplets together with the first substrate; the second substrate comprises a second substrate, a second electrode layer and a dielectric layer, the second electrode layer and the dielectric layer are both arranged on the second substrate, the second electrode layer comprises a plurality of second electrodes arranged in an array, adjacent second electrodes are arranged at intervals, and the first electrode and the second electrode can drive the droplets to move; the dielectric layer covers the second electrode, and the dielectric layer comprises at least two dielectric films, the at least two dielectric films are stacked in sequence in the direction from the second substrate to the first substrate, and the roughness of the dielectric layer is less than the roughness of any of the dielectric films.

2. The microfluidic chip according to claim 1, characterized in that: The at least two dielectric films are both inorganic films.

3. The microfluidic chip according to claim 2, characterized in that: The dielectric layer includes a first dielectric film and a second dielectric film, the first dielectric film is arranged on a side of the second dielectric film close to the second substrate, and the roughness of the first dielectric film is greater than the roughness of the second dielectric film.

4. The microfluidic chip according to claim 3, characterized in that: The first dielectric film is silicon oxide; the second dielectric film is silicon nitride.

5. The microfluidic chip according to claim 3, characterized in that: The first dielectric film and the second dielectric film are both silicon nitride.

6. The microfluidic chip according to claim 5, characterized in that: The thickness of the first dielectric film is greater than or equal to 20 nm.

7. A method for manufacturing a microfluidic chip, characterized in that: Used to manufacture the microfluidic chip according to any one of claims 1 to 6, the method for manufacturing the microfluidic chip comprising: preparing a first substrate; Prepare a second substrate, the second substrate comprising a second substrate and a second electrode and a dielectric layer disposed on the second substrate, the dielectric layer comprising at least two dielectric films, the at least two dielectric films being sequentially stacked in a thickness direction of the second substrate, and the roughness of the dielectric layer being less than the roughness of any of the dielectric films; The first substrate and the second substrate are placed opposite to each other to form a box.

8. The method according to claim 7, characterized in that: The dielectric layer includes a first dielectric film and a second dielectric film, the first dielectric film is silicon oxide, the second dielectric film is silicon nitride, and the roughness of the first dielectric film is greater than the roughness of the second dielectric film; The method for preparing the dielectric layer on the second substrate comprises: preparing a first dielectric film; A second dielectric film is prepared, wherein crystals of the second dielectric film are filled into the crystal gaps of the first dielectric film.

9. The manufacturing method according to claim 7, characterized in that: The dielectric layer includes a first dielectric film and a second dielectric film, and the first dielectric film and the second dielectric film are made of the same material; and the method for preparing the dielectric layer on the second substrate includes: preparing the first dielectric film according to predetermined parameters, wherein the thickness of the first dielectric film is greater than or equal to 20 nm; The predetermined parameters are adjusted to prepare the second dielectric film, wherein the roughness of the second dielectric film is smaller than the roughness of the first dielectric film.

10. A microfluidic system, comprising the microfluidic chip according to any one of claims 1 to 6.

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