Droplet actuator and method for manipulating droplet thereof

Abstract

A droplet actuator and a method for manipulating the droplet are provided. A droplet actuator according to one embodiment of the present invention comprises a first substrate including a plurality of electrodes for handling a droplet, and a second substrate including a plurality of other electrodes distinguished from the plurality of electrodes, wherein the first substrate and the second substrate are spaced apart from each other so that a space for the droplet to move is defined between the first substrate and the second substrate, wherein the plurality of electrodes include a first electrode and a third electrode, wherein the first electrode and the third electrode are spaced apart from each other with a first gap between them, wherein the plurality of other electrodes include a second electrode, wherein the second electrode is positioned facing the first gap, and the droplet can sequentially move to a first position on the first electrode, a second position on the second electrode, and a third position on the third electrode in response to an operating signal being applied to the plurality of electrodes or the plurality of other electrodes.

Description

Technology Field

[0001] The present invention relates to a droplet actuator using electrowetting and a method for manipulating droplets therefrom. More specifically, the invention relates to a droplet actuator capable of moving, splitting, or merging droplets by applying an electrowetting signal to an electrode provided in the droplet actuator and a method for manipulating droplets therefrom. Background Technology

[0002] Electrowetting refers to the phenomenon in which the surface tension of a fluid changes due to an electric field applied to the fluid. For example, in a fluid whose surface tension has changed due to electrowetting, the solid-liquid contact angle may change due to the potential difference depending on the applied electric signal. As another example, in a fluid whose surface tension has changed due to electrowetting, it may move along the electrode depending on the applied electric signal.

[0003] Attempts to utilize such electrowetting are continuing in various technology fields. For example, efforts are ongoing to use electrowetting to control the thickness of camera lenses or for the commercialization of electronic paper. Prior art literature

[0004] U.S. Patent No. 9,638,662 (Published Nov. 26, 2015) The problem to be solved

[0005] The technical problem to be solved through some embodiments of the present invention is to provide a droplet actuator having a vertical electrode structure in which an electrowetting electrode is provided on an upper substrate and a lower substrate, respectively, and a method for manipulating the droplet thereof.

[0006] Another technical problem to be solved through some embodiments of the present invention is to provide a droplet actuator and a method for manipulating the droplet, in which the movement of the droplet between electrodes is performed smoothly even if the substrate surface is not processed very smoothly or the gap between adjacent electrodes is not close.

[0007] Another technical problem to be solved through some embodiments of the present invention is to provide a droplet actuator and a method for manipulating the droplets thereof, which can reduce production costs by simplifying the production process for substrate processing.

[0008] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0009] A droplet actuator according to an embodiment of the present invention for solving the above technical problem comprises a first substrate including a plurality of electrodes for handling a droplet, and a second substrate including a plurality of other electrodes distinguished from the plurality of electrodes, wherein the first substrate and the second substrate are spaced apart from each other so that a space for the droplet to move is defined between the first substrate and the second substrate, wherein the plurality of electrodes include a first electrode and a third electrode, wherein the first electrode and the third electrode are spaced apart from each other with a first gap between them, wherein the plurality of other electrodes include a second electrode, wherein the second electrode is positioned facing the first gap, and the droplet can sequentially move to a first position on the first electrode, a second position on the second electrode, and a third position on the third electrode in response to an operating signal being applied to the plurality of electrodes or the plurality of other electrodes.

[0010] In one embodiment, the first electrode and the third electrode may be adjacent electrodes among the plurality of electrodes.

[0011] In one embodiment, when viewed from above the second substrate, the second electrode may overlap with at least a portion of the first gap.

[0012] In one embodiment, when viewed from above the second substrate, the second electrode may overlap with at least a portion of the first electrode and at least a portion of the third electrode, respectively.

[0013] In one embodiment, the device may further include a switch circuit for selectively connecting the first electrode, the second electrode, or the third electrode to a signal line to which the operating signal is provided.

[0014] In one embodiment, the first electrode, the second electrode, and the third electrode are sequentially connected to the signal line by the operation of the switch circuit, and a reference potential may be applied to the remaining electrodes while any one of the first electrode, the second electrode, and the third electrode is connected to the signal line.

[0015] In one embodiment, the plurality of other electrodes further include a fourth electrode, the second electrode and the fourth electrode are spaced apart from each other with a second gap in between, the third electrode is positioned facing the second gap, and when viewed from above the second substrate, at least a portion of the second gap, at least a portion of the second electrode, and at least a portion of the fourth electrode may each overlap on the third electrode.

[0016] In one embodiment, the plurality of electrodes further include a fifth electrode and a sixth electrode, and the third electrode, the fifth electrode, and the sixth electrode are each spaced apart from each other with a gap between them, and when viewed from above the second substrate, the fourth electrode may overlap at least partially with the third electrode, the fifth electrode, and the sixth electrode, respectively.

[0017] In one embodiment, the droplet may move from a third position on the third electrode to a fourth position on the fourth electrode in response to an operating signal applied to the plurality of electrodes or the plurality of other electrodes, and then (i) move to a fifth position on the fifth electrode, (ii) move to a sixth position on the sixth electrode, or (iii) split or spread between the fifth position and the sixth position.

[0018] In one embodiment, the first electrode is a reservoir electrode, and the third electrode may be an electrode for dispensing the droplet from the reservoir to a fluid channel. Brief explanation of the drawing

[0019] FIG. 1 is an exemplary drawing of a droplet actuator according to one embodiment of the present invention. Figure 2 is an exemplary drawing of the upper part of the electrode plate described with reference to Figure 1. Figure 3 is an exemplary drawing of the lower part of the electrode plate described with reference to Figure 1. FIG. 4 is an exemplary cross-sectional view of an electrode plate described with reference to FIG. 1. FIG. 5 is an exemplary drawing for more specifically explaining the housing and electrode plate described with reference to FIG. 1. FIG. 6 is an exemplary drawing for more specifically explaining the structure of the electrode described with reference to FIG. 2 to 4. FIG. 7 is an exemplary drawing for more specifically explaining the structure of the base plate described with reference to FIG. 2 to 4. FIG. 8 is another exemplary drawing of the upper part of the electrode plate described with reference to FIG. 1. FIG. 9 is a drawing exemplarily showing a reservoir structure according to one embodiment of the present invention. FIGS. 10 to 12 are drawings for further elaborating on the reservoir structure illustrated in FIG. 9. FIG. 13 is a diagram showing an electrode structure that facilitates optical observation of a droplet according to one embodiment of the present invention. FIGS. 14 to 18 are drawings for further explaining the electrode structure illustrated in FIG. 13 in more detail. FIG. 19 is an exploded perspective view showing an exemplary form of a droplet actuator having a parallel electrode structure according to one embodiment of the present invention. FIG. 20 is a cross-sectional view illustrating the detailed structure of the droplet actuator shown in FIG. 19 and the electrowetting operation by it. FIG. 21 is an exploded perspective view showing an exemplary form of a droplet actuator equipped with a temperature control unit according to one embodiment of the present invention. FIG. 22 is a cross-sectional view illustrating the detailed structure of the droplet actuator shown in FIG. 21 and the method of temperature control by it. FIGS. 23 to 25 are drawings for explaining a droplet actuator equipped with a cleaning function using magnetic force and a cleaning method using the same. FIG. 26 is a diagram illustrating an exemplary configuration of a signal reader that reads the results of testing a sample of a droplet actuator. FIG. 27 is a drawing showing an exemplary configuration of the optical unit of FIG. 26. FIGS. 28 to 31 are drawings for further explaining the configuration and function of the main board of FIG. 26. FIG. 32 is a drawing showing a new stacked structure of a droplet actuator as another embodiment of the present invention. FIG. 33 is a drawing showing a droplet actuator having a vertical electrode structure according to one embodiment of the present invention. FIG. 34 is a drawing showing the side and top views of the droplet actuator described in FIG. 33. FIG. 35 is a diagram showing the switch circuit of the droplet actuator described in FIG. 33. FIGS. 36 and 37 are drawings for explaining the driving of the electrowetting electrode according to the operation of the switch circuit of FIG. 35 and the movement of the droplet by it. FIGS. 38 and 39 are drawings showing exemplary electrowetting electrode arrangements of the droplet actuator described in FIG. 33. FIG. 40 is a drawing showing an exemplary stacked structure of the droplet actuator described in FIG. 33. Specific details for implementing the invention

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the attached drawings. However, the technical concept of the present invention is not limited to the following embodiments but can be implemented in various different forms. The following embodiments are provided merely to complete the technical concept of the present invention and to fully inform those skilled in the art of the scope of the present invention, and the technical concept of the present invention is defined only by the scope of the claims.

[0021] It should be noted that when assigning reference numerals to the components of each drawing, the same components are assigned the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions could obscure the essence of the invention, such detailed description is omitted.

[0022] Unless otherwise defined, all terms used herein (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terms used herein are for describing embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text.

[0023] Additionally, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the present invention. These terms are intended merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by these terms. Where it is stated that a component is "connected," "combined," or "joined" to another component, it should be understood that the component may be directly connected or joined to the other component, but that another component may also be "connected," "combined," or "joined" between each component.

[0024] As used in the specification, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0025] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

[0026] FIG. 1 is an exemplary drawing of a droplet actuator according to one embodiment of the present invention. FIG. 1 illustrates a droplet actuator including an electrode plate (10), a housing (20), and a substrate (30), however, FIG. 1 illustrates only a preferred embodiment for achieving the purpose of the present invention and some components may be added or removed as needed.

[0027] For example, a reader (not shown) implemented as a computing device may be further provided, wherein the reader can generate and control an electrowetting signal (i.e., an electrical signal) to guide the fluid contained in the housing to the target electrode. Additionally, it should be noted that the components of the exemplary droplet actuator illustrated in FIG. 1 represent functionally distinct functional elements, and that multiple components may be implemented in an integrated form in an actual physical environment. Below, the components of the exemplary droplet actuator illustrated in FIG. 1 will be described in more detail.

[0028] The housing (20) can accommodate a fluid. In this case, the housing (20) may include a fluid receiving portion for accommodating the fluid. For example, a sample containing DNA may be accommodated in the fluid receiving portion of the housing (20) to perform PCR (Polymerase Chain Reaction), but the scope of the invention is not limited to this example.

[0029] In some embodiments, the structure of the housing (20) may include additional configurations other than the fluid receiving portion depending on the application in which the droplet actuator is used. That is, the housing (20) may be configured to provide additional functions in addition to receiving fluid and forming the exterior of the droplet actuator, and it should be noted that all known technologies of droplet actuators may be referenced.

[0030] Next, the electrode plate (10) can induce polarization in a droplet through an electrowetting signal to move a droplet distributed from a fluid contained in the housing (20) to the location of a target electrode. At this time, the electrode plate (10) may include at least one electrode for conducting the electrowetting signal.

[0031] In some embodiments, the electrode plate (10) may include a base plate and at least one electrode formed through the base plate. Here, the base plate may be made of an insulator. According to the present embodiment, the surface tension between the electrode and the droplet can be changed along the electrode formed through the electrically insulated base plate by using electrowetting. The droplet can move between adjacent electrodes by utilizing the change in the contact angle formed between the electrode and the droplet due to this change in surface tension. The structure of the electrode formed on the electrode plate (10) will be specified later through the description in the specification.

[0032] Next, the substrate (30) can transmit an electrowetting signal to the electrode plate (10). For example, the substrate (30) may be any one of a glass substrate, a silicon substrate, a PCB (Printed Circuit Board), and a TFT (Thin Film Transistor). However, the scope of the present invention is not limited to these examples, and any known technology having a structure capable of transmitting an electrowetting signal transmitted by a reader (not shown) to the electrode plate (10) may be applied to the present invention.

[0033] In some embodiments, a reader (not shown) implemented as a computing device may be included in the droplet actuator, but if the droplet actuator is manufactured as a single-use device and multiple droplet actuators are connected to a reader via a connector and used once, not including a reader as in FIG. 1 can reduce the manufacturing cost of the droplet actuator.

[0034] According to an exemplary droplet actuator according to one embodiment of the present invention described so far with reference to FIG. 1, a droplet can be distributed from a fluid contained in a housing (20) and the droplet can be moved to the position of a target electrode.

[0035] The droplet actuator described above can be utilized as a diagnostic device. For example, the droplet actuator can be used to automatically extract and purify cells, vesicles, proteins, and nucleic acids from sample specimens such as animal blood, urine, feces, saliva, nasopharyngeal swabs, nasal swabs, oropharyngeal swabs, cerebrospinal fluid, skin tissue, hair, other somatic cells, body tissues, and semen; it can also perform gene amplification, decoding, synthesis, and diagnosis; perform immunodiagnosis using antigen-antibody reactions; and synthesize and manufacture compounds. Furthermore, it can be used to test for heavy metals, substances harmful to the human body, and narcotics. It should be noted that the technical fields in which the droplet actuator described above may be utilized are merely exemplary, and that the droplet actuator described above may be utilized in various other technical fields as well.

[0036] Hereinafter, the structure of the electrode plate (10) will be described in more detail with reference to FIGS. 2 to 4. FIG. 2 is an exemplary drawing of the upper part of the electrode plate (10) described with reference to FIG. 1, FIG. 3 is an exemplary drawing of the lower part of the electrode plate (10) described with reference to FIG. 1, and FIG. 4 is an exemplary cross-sectional view of the electrode plate (10) described with reference to FIG. 1.

[0037] FIG. 2 illustrates an exemplary upper electrode (11) structure formed on the upper part of an electrode plate (10). Although the upper electrode (11) shown in FIG. 2 is formed in a rectangular shape, it should be noted that this is merely an example and the upper electrode (11) structure can be varied in many ways.

[0038] FIG. 3 illustrates an exemplary lower electrode (12) structure formed on the lower part of an electrode plate (10). Although the lower electrode (12) shown in FIG. 3 is formed in a circle, it should be noted that this is merely an example and the structure of the lower electrode (12) can be varied.

[0039] FIG. 4 illustrates the side structure of an exemplary electrode. Referring to FIG. 4, it can be understood that the electrode (13) may be formed by penetrating the base plate. With respect to the electrode, in some embodiments, the electrode may be formed by injection molding, 3D printing, screen printing, laser patterning, or dispensing of a conductive polymer. The conductive polymer may include a conductive plastic. According to the present embodiment, the electrode of the droplet actuator can be manufactured with a simplified process without complex processes similar to semiconductor processes, such as photolithography and metal deposition processes.

[0040] In relation to the electrode, in some other embodiments, the conductive polymer constituting the electrode may include a compound of a polymer and a metal. In this case, the polymer may include Siloxane, Epoxy, Resin, ABS, PLA, TPU, HIPS, etc. Additionally, the metal may include gold (Au), silver (Ag), copper (Cu), or other conductive metal materials. In this case, the conductive polymer may be composed of at least one of a conductive material such as carbon nanotubes (CNT), carbon fiber, graphite, or graphene together with the metal.

[0041] With respect to the electrode, in some other embodiments, the conductive plastic constituting the electrode may comprise a mixture of PC (Polycarbonate), PMMA (Poly Methyl Methacrylate), COP (Cyclic Olefin Polymer), COC (Cyclic Olefin Copolymer), PET (Polyethylene Terephthalate), PI (Polyimide), PE (Polyethylene), Acrylic, ABS (Acrylonitrile butadiene styrene), PVDF (Polyvinylidene fluoride), PTFE (Polytetrafluoroethylene), PS (Polystyrene), PP (Polypropylene), and PVC (Polyvinyl Chloride). In this case, the mixture may comprise at least one of carbon nanotubes, graphene, carbon fibers, gold, silver, and copper, which are conductive materials, together with the polymers. It should be noted that any other known mixture for conducting an electrical signal may be applied to the present invention to manufacture the electrode.

[0042] With respect to the base plate, in some embodiments, the insulator constituting the base plate may comprise at least one of PC (Polycarbonate), PMMA (Poly Methyl Methacrylate), COP (Cyclic Olefin Polymer), COC (Cyclic Olefin Copolymer), PET (Polyethylene Terephthalate), PI (Polyimide), PE (Polyethylene), Acrylic, ABS (Acrylonitrile butadiene styrene), PVDF (Polyvinylidene fluoride), PTFE (Polytetrafluoroethylene), PS (Polystyrene), PP (Polypropylene), and PVC (Polyvinyl Chloride). In addition, it should be noted that all known compositions, including thermoplastic resins for insulating electrical signals, may be applied to the present invention to manufacture the insulator.

[0043] With respect to the electrode and base plate, in some embodiments, the base plate may be formed first, and then a conductive polymer may be injected into the space of the base plate through an injection gate (or nozzle) in a second step.

[0044] In this case, as one embodiment, the base plate may be formed by injecting an insulator into the space of the mold through another injection gate distinct from the injection gate.

[0045] Alternatively, as another embodiment, the base plate may be formed by press injection molding of an insulator or flat plate drilling.

[0046] Alternatively, as another embodiment, the base plate may be formed by 3D printing using Siloxane, Resin, ABS, PLA, TPU, Nylon, PETG, ASA, PEI, HIPS, etc.

[0047] With respect to the electrode and base plate, in some embodiments, the electrode and base plate may be formed by double shot injection molding. More specifically, the base plate may be formed by injecting an insulator into a first space of a first mold using a first injection gate (or nozzle), and the electrode may be formed by injecting a conductive polymer into a second space of a second mold or a first mold using a second injection gate (or nozzle) distinct from the first injection gate. Here, the first injection gate and the second injection gate may be components included in an injector having two or more injection gates, but the scope of the present invention is not limited thereto and may be components included in different injectors having a single injection gate. According to the present embodiment, electrodes and base plates made of different materials can be manufactured using a simplified process without complex processes similar to semiconductor processes, such as photolithography and metal deposition processes. All known methods of performing double shot injection molding to manufacture electrodes and base plates made of different materials can be applied to the present invention.

[0048] With respect to the electrode and base plate, in some other embodiments, the electrode and base plate may be formed by insert injection molding or overmolding. More specifically, a base plate may be formed by injecting an insulator into a first mold, and then an electrode may be formed by inserting the formed base plate into a second mold and then injecting a conductive polymer into the second mold. Conversely, an electrode may be formed by first injecting a conductive polymer into a third mold, and then a base plate may be formed by inserting the formed electrode into a fourth mold and then injecting an insulator into the fourth mold. According to the present embodiment, electrodes and base plates with different configurations can be manufactured through a simplified process without complex processes similar to semiconductor processes, such as photolithography and metal deposition processes.

[0049] It should be noted that, in addition to the double shot injection molding, insert injection molding, and overmolding described above, various techniques for injection molding different materials to create products composed of two or more different materials may be included within the scope of this disclosure.

[0050] A housing (20) may be coupled to the upper portion of an electrode plate (10) formed according to the various methods described above, as shown in FIG. 5. Here, the fluid contained in the fluid receiving portion (not shown) of the housing (20) may be distributed as droplets based on an electrowetting signal and move along the electrode (13) formed on the electrode plate (10). In some embodiments, the droplets may be moved to a position and / or direction guided by the electrowetting signal through the space between the upper surface of the electrode (13) formed on the electrode plate (10) and the lower surface of the housing facing the upper surface of the electrode. FIG. 5 illustrates an exemplary view of a droplet (70) moving along the electrode (13) based on an electrowetting signal, and the movement of the droplets distributed from the fluid contained in the fluid receiving portion (not shown) of the housing (20) will be explained in more detail later with reference to FIG. 8. Hereinafter, with reference to FIGS. 6 and FIGS. 7, the structure of the electrode and base plate included in the electrode plate (10) will be described in more detail. FIGS. 6 is an exemplary drawing for more specifically describing the structure of the electrode described with reference to FIGS. 2 to 4, and FIGS. 7 is an exemplary drawing for more specifically describing the structure of the base plate described with reference to FIGS. 2 to 4. Since the electrode shown in FIGS. 6 and the base plate shown in FIGS. 7 are each exemplary drawings for explaining some embodiments of the present invention, it should be noted that the scope of the present disclosure is not limited to the structure shown in FIGS. 6 and FIGS. 7.

[0051] Referring to FIG. 6, it can be seen that the upper width (14) of the electrode formed on the electrode plate (10) is a width greater than the middle width (15) of the electrode by a first reference size, and the lower width (16) of the electrode is a width greater than the middle width (15) of the electrode by a second reference size. Here, the middle of the electrode may refer to any position between the upper and lower parts of the electrode. In some embodiments, the position of the middle of the electrode may vary depending on the application of the droplet actuator, and any electrode structure in which the middle width (15) of the electrode is formed smaller than the upper width (14) and the lower width (16) of the electrode should be interpreted as being included within the scope of the present invention. Additionally, it should be noted that the first reference size and the second reference size may vary depending on the application of the droplet actuator.

[0052] Regarding the reference size, in some embodiments, the first reference size may be larger than the second reference size. Since the upper part of the electrode plate (10) is the part that contacts the droplet and the lower part of the electrode plate (10) is the part where the electrical signal is conducted, it may be preferable for the upper width (14) of the electrode to be larger than the lower width (16) of the electrode.

[0053] In relation to the electrode, in some embodiments, the width of the electrode may be tapered from the top toward the middle of the electrode and tapered from the bottom toward the middle of the electrode. According to the present embodiment, by increasing the adhesion between the electrode and the base plate made of different configurations, the yield of the manufactured electrode plate (10) can be increased and the defect rate can be lowered.

[0054] With respect to the electrode, in some other embodiments, the upper width of the electrode may be formed to be greater than or equal to the middle width of the electrode, and the middle width of the electrode may be formed to be greater than or equal to the lower width of the electrode. In some embodiments, the electrode may be formed in a tapered shape from the top toward the bottom.

[0055] Up to this point, the structure of an electrode according to some embodiments of the present invention has been described with reference to FIG. 6. However, it should be noted that, unlike what is shown in FIG. 6, the upper width (14), middle width (15), and lower width (16) of the electrode may each vary as much as desired.

[0056] FIG. 7 illustrates an exemplary electrode gap formed from two or more electrodes formed on an electrode plate (10). Here, the electrode gap may be a base plate portion made of an insulator.

[0057] Regarding the electrode spacing, in some embodiments, the upper width (17) of the electrode spacing may be smaller than the lower width (18) of the electrode spacing. Here, the base plate of the electrode spacing may be formed by positioning an injection gate at the lower part (40) of the electrode spacing and injecting an insulator. By forming the lower width (18) of the electrode spacing larger than the upper width (17) of the electrode spacing, the pressure generated during the injection of the insulator constituting the base plate can be reduced. By reducing the pressure generated during the injection of the insulator, the yield of the manufactured electrode plate (10) may be increased and the defect rate may be lowered.

[0058] Regarding the electrode spacing, in some other embodiments, the width of the electrode spacing may be tapered from the middle of the electrode spacing toward the top and tapered from the middle of the electrode spacing toward the bottom. According to the present embodiment, the adhesion between the electrode and the base plate, which are made of different configurations, is increased, thereby increasing the yield of the manufactured electrode plate (10) and lowering the defect rate.

[0059] Hereinafter, with reference to FIG. 8, a reservoir (19) and electrodes (50a, 50b) that may be included in the electrode plate (10) will be described in more detail. FIG. 8 is another exemplary drawing of the upper part of the electrode plate described with reference to FIG. 1.

[0060] As illustrated in FIG. 8, the electrode plate (10) may further include a reservoir (19) that dispenses fluid contained in the housing (20). According to the present embodiment, the fluid contained in the housing (20) may primarily flow into the reservoir (19). Additionally, the reservoir (19) of the present disclosure may be formed in various structures that dispense fluid to adjacent electrodes, and it should be noted that, for example, a structure in which fluid flows directly into the reservoir (19) from the outside without passing through the housing (20) is also not excluded from the scope of the present disclosure.

[0061] Additionally, as illustrated in FIG. 8, the upper width of the adjacent electrode (50a) formed adjacent to the reservoir (19) may be larger than the upper width of the other electrode (50b). Since the adjacent electrode (50a) is located adjacent to the reservoir (19) compared to the other electrode (50b), it may be located on the path through which droplets distributed from the fluid based on the electrowetting signal essentially travel. Therefore, in order for the adjacent electrode (50a) to accommodate a large amount of droplets compared to the other electrode (50b) or to induce electrowetting by applying voltage to a large amount of droplets, the size of the adjacent electrode (50a) may be formed to be relatively larger than the size of the other electrode (50b).

[0062] With respect to adjacent electrodes, in some embodiments, the number of adjacent electrodes (50a) may be determined based on the size of the reservoir (19). For example, the number of adjacent electrodes (50a) may be increased as the size of the reservoir (19) increases, and the number of adjacent electrodes (50a) may be decreased as the size of the reservoir (19) decreases. It should be noted that the number of adjacent electrodes (50a) shown in FIG. 8 is 5, but this is merely illustrative and does not limit the scope of the invention.

[0063] Up to this point, a droplet actuator according to an embodiment of the present invention has been described with reference to FIGS. 1 to 8. According to this embodiment, unlike conventional droplet actuators in which metal electrodes are deposited, a droplet actuator can be manufactured using only a simple process. As the manufacturing process of the droplet actuator is simplified according to this embodiment, the manufacturing cost of the droplet actuator can be reduced, and the manufacturing cost of the droplet actuator can be reduced to a cost suitable for use as a disposable cartridge (or disposable kit).

[0064] In addition, according to the present embodiment, a droplet actuator having a structure that can increase yield and lower defect rate can be provided through a very simple injection molding process compared to conventional droplet actuator manufacturing processes including photolithography, metal deposition, and etching processes.

[0065] Furthermore, according to the present embodiment, a droplet actuator having a structure that allows a liquid contained in a housing to move more smoothly along a reservoir and an electrode based on an electrowetting signal can be provided.

[0066] Hereinafter, a reservoir structure for increasing the injection productivity and further lowering the defect rate of a droplet actuator according to the present invention is described.

[0067] FIG. 9 is a diagram illustrating an exemplary reservoir structure according to an embodiment of the present invention. Referring to FIG. 9, the reservoir (100) according to the present embodiment includes a plurality of regions (111, 112, 113, 114, 115) in which electrodes are formed, and a plurality of walls (121, 122, 123, 124) located between the plurality of regions (111, 112, 113, 114, 115) to separate each region.

[0068] Unlike the reservoir (19) shown in FIG. 8, the reservoir (100) according to the present embodiment has at least one extension (131, 132, 133) formed on each wall (121, 122, 123, 124).

[0069] This will be explained in more detail with reference to FIGS. 10 to 12.

[0070] FIG. 10 is a drawing showing a portion of the reservoir (100) illustrated in FIG. 9.

[0071] In FIG. 10, the reservoir (100) includes a first region (111), a second region (112) adjacent to the first region (111), and a first wall (121) between the first region (111) and the second region (112).

[0072] In one embodiment, a conductive polymer may be injected into the first region (111) and the second region (112) by injection molding to form an electrode.

[0073] And, the first wall (121) has at least one extension (131, 132, 133) formed along the longitudinal direction (A) of the first wall (121) and having a width greater than that of the periphery (141, 142, 143, 144).

[0074] Here, the peripheral portion (141, 142, 143, 144) refers to a part of the first wall (121) formed at a location adjacent to the extension portion (131, 132, 133).

[0075] In this way, by forming an extension (131, 132, 133) on the first wall (121) having a width (w1) that is increased compared to the width (w2) of the periphery (141, 142, 143, 144), the first wall (121) can better withstand the injection pressure from injection molding when forming an electrode in the first region (111) or the second region (112).

[0076] For example, in the reservoir (19) structure shown in FIG. 8, when a conductive polymer is injected to form an electrode, the walls between each region frequently bend because they cannot withstand the injection pressure.

[0077] In contrast, the reservoir (100) of the present embodiment has an expanded portion (131, 132, 133) formed along the first wall (121) with an increased width (w1) and resists the injection pressure more strongly when injecting a conductive polymer, thereby minimizing the bending phenomenon of the first wall (121).

[0078] Meanwhile, according to the reservoir (100) structure of the present embodiment, in addition to preventing bending of the first wall (121) to lower the defect rate of the product, it can also contribute to increasing the productivity of the product.

[0079] For example, in the reservoir (19) structure of FIG. 8, in order to prevent wall bending, the reservoir portion had to be injected more precisely from the injection stage of the base plate, which resulted in a problem of lower overall product productivity. However, in the reservoir (100) structure of the present embodiment, the wall bending phenomenon is mitigated by the extension portions (131, 132, 133), so the burden of having to inject the reservoir portion more precisely during the injection stage of the base plate as in the conventional method is eliminated. Accordingly, overall product productivity can also be improved.

[0080] Meanwhile, in this embodiment, the extension portions (131, 132, 133) may have the shape of a cylinder with a circular cross-section, but the scope of the present invention is not limited thereto. For example, the extension portions (131, 132, 133) may have the shape of a column with an elliptical or polygonal cross-section, or a closed figure composed of straight lines and curves. Here, the cross-section refers to a cross-section obtained by cutting the extension portions (131, 132, 133) along the longitudinal direction (A) of the first wall (121).

[0081] In one embodiment, at least one extension (131, 132, 133) may be formed apart from each other by a predetermined distance along the first wall (121). Refer to FIG. 11 for further explanation.

[0082] In FIG. 11, at least one extension (131, 132, 133) is formed at a location separated from each other by a predetermined distance (d). That is, among the at least one extension (131, 132, 133), a second extension (132) may be formed at a location d away from the location where the first extension (131) is formed, and a third extension (133) may be formed at a location d away from the location where the second extension (132) is formed.

[0083] This is to ensure that when injecting a conductive polymer into each region (111, 112), each extension (131, 132, 133) evenly shares the injection pressure with one another and effectively supports the first wall (121).

[0084] For example, let us assume that at least one extension (131, 132, 133) is formed on the left side of the first wall (121). In this case, when a conductive polymer is injected, a relatively large injection pressure is applied to the third extension (133) located on the far right, and the third extension (133) may bend or break because it cannot withstand the excessive injection pressure. In addition, in this case, the right side of the first wall (121) is relatively far from the extension (131, 132, 133) and is not supported by the extension (131, 132, 133), and may easily bend due to the injection pressure.

[0085] Accordingly, it is preferable that at least one extension (131, 132, 133) be spaced at equal intervals by a predetermined distance (d), as shown in FIG. 11.

[0086] Meanwhile, as an example, the extensions formed on each wall of the reservoir (100) may be formed at positions symmetrical to each other. This is further explained with reference to FIG. 12.

[0087] Referring to FIG. 12, a portion of a reservoir (100) including a first region (111), a second region (112), and a third region (113) is shown. Between each region (111, 112, 113), a first wall (121) and a second wall (122) are formed, each having at least one extension.

[0088] As described in the preceding embodiments, the first wall (121) is located between the first region (111) and the second region (112) to separate the regions (111, 112) from each other. In addition, at least one extension (131, 132, 133) is formed in the first wall (121) at a certain distance along the length direction of the first wall (121).

[0089] Similarly, the second wall (122) is located between the second region (112) and the third region (113) to separate the regions (112, 113) from each other. Also, at least one other extension (141, 142, 143) is formed in the second wall (122) at a certain distance along the longitudinal direction (A) of the second wall (122).

[0090] At this time, the at least one other extension (141, 142, 143) may be formed in a symmetric position with respect to the at least one extension (131, 132, 133). Here, the meaning of symmetric is that at least one extension (131, 132, 133) and at least one other extension (141, 142, 143) are each formed in positions facing each other with respect to the centerline (B) of the second region (112).

[0091] This can serve to increase the structural stability of each wall (121, 122) when a conductive polymer is simultaneously injected into each region (111, 112, 113) of the reservoir (100). For example, if at least one extension (131, 132, 133) and at least one other extension (141, 142, 143) are formed at positions that are not symmetrical to each other, hydrodynamic turbulence may occur more easily within the second region (112), thereby applying stronger local pressure to the first wall (121) or the second wall (122).

[0092] Accordingly, in order to distribute the pressure applied to each part of the wall (121, 122) as evenly as possible, it is desirable to form at least one extension (131, 132, 133) and at least one other extension (141, 142, 143) at symmetrical positions to each other.

[0093] According to the reservoir structure of the present invention described through the above embodiments, by minimizing the bending phenomenon of each wall during the injection molding of a conductive polymer, injection productivity can be improved and the product defect rate reduced. Accordingly, the production process can be simplified and the production cost can be significantly lowered.

[0094] Hereinafter, an electrode structure that facilitates optical observation of a droplet in a droplet actuator according to the present invention is described.

[0095] FIG. 13 is a diagram showing an electrode structure that facilitates optical observation of a droplet according to one embodiment of the present invention. FIG. 13 (a) shows a conventional electrode structure, and FIG. 13 (b) shows an electrode structure according to the present embodiment.

[0096] Referring to FIG. 13 (a), a conventional electrode structure has the entire electrode (11) filled with an opaque conductor, for example, a conductive polymer. Therefore, a droplet located on the electrode (11) is obscured by the opaque conductor, making optical observation of the droplet difficult.

[0097] Meanwhile, referring to FIG. 13(b), the electrode structure according to the present embodiment has a hole (211) formed inside the electrode (210) that is not filled with an opaque conductor. Therefore, a droplet located on the electrode (210) can be directly observed through the hole (211), making optical observation of the droplet and the light emitted from the droplet easier.

[0098] FIGS. 14 to 18 are drawings for further explaining the electrode structure illustrated in FIG. 13 in more detail.

[0099] FIG. 14 is a more detailed enlarged view of the electrode (210) structure of FIG. 13. Referring to FIG. 14, the electrode (210) includes a hole (211) located at the center of the electrode (210) and a peripheral portion (212).

[0100] As previously explained, the hole (211) is a configuration formed inside the electrode (210) that is not filled with an opaque conductor.

[0101] In one embodiment, the interior of the hole (211) may be empty or filled with a transparent conductor or insulating material.

[0102] In one embodiment, the hole (211) may be located at the center of the electrode (210) as shown in FIG. 13.

[0103] The periphery (212) is a portion surrounding the hole (211) of the electrode (210) and is filled with an opaque conductor. In one embodiment, the opaque conductor may be a conductive polymer.

[0104] According to the structure of the electrode (210) illustrated in FIG. 14, a droplet located on the electrode (210) can be induced in a specific direction by an electric potential or electric signal applied to the periphery (212), and the droplet and the light emitted by the droplet can be optically observed through the hole (211) of the electrode (210). Thus, an electrode structure is made possible that allows for optical observation of the droplet while performing the induction of the droplet by electrowetting without problems.

[0105] Meanwhile, although the hole (211) is exemplified as being circular in this embodiment, the scope of the invention is not limited thereto. For example, the hole (211) may be elliptical or polygonal in shape in addition to being circular.

[0106] In one embodiment, the size of the hole (211) may increase as the size of the electrode (210) increases. Refer to FIG. 15 for further explanation regarding this.

[0107] FIG. 15 illustrates a plurality of electrodes (220, 230) of different sizes. A droplet actuator according to the present invention may simultaneously include electrodes of different sizes. For example, referring to the example in FIG. 8, an electrode (50a) located near the reservoir (19) may have a larger size than another electrode (50b).

[0108] Thus, when there are electrodes of different sizes in a single droplet actuator, the hole (P) formed in the larger electrode (220) can have a larger size than the hole (Q) formed in the smaller electrode (230).

[0109] The larger the size of the hole, the larger the area for observing the droplet, making optical observation easier; however, the peripheral area filled with conductor is reduced accordingly, so the force inducing the droplet may be reduced. Therefore, in order to secure the minimum force required to induce the droplet, the size of the hole (Q) in the small electrode (230) must be limited to less than a certain amount. On the other hand, in the large electrode (220), even if the size of the hole (P) is increased, the peripheral area can be secured to a certain amount or more, so it is possible to have a hole of a larger size compared to the small electrode (230).

[0110] In one embodiment, the ratio of the hole size to the electrode size may be limited to within a predetermined range. Refer to FIG. 16 for further explanation regarding this.

[0111] As described in FIG. 16 above, increasing the size of the hole (241) makes optical observation of the droplet easier, but the area of ​​the periphery (242) is reduced accordingly, so the force inducing the droplet may be reduced. Therefore, by adjusting the ratio of the hole (241) to the size of the electrode (240) to an appropriate range, both optical observation of the droplet and induction of the droplet by electrowetting can be achieved.

[0112] In one embodiment, the ratio of the size of the hole to the size of the electrode may be the ratio of the widths. In the example of FIG. 12, the electrode (240) is a square with a width wd1, and the hole (241) is a circle with a width wd2. In this case, the ratio R of the size of the hole to the size of the electrode may be wd2 / wd1.

[0113] In another embodiment, the ratio of the size of the hole to the size of the electrode may be the ratio of the areas. Referring again to the example in FIG. 16, the area of ​​the electrode (240) is wd1^2 and the area of ​​the hole (241) is π*(wd2 / 2)^2. In this case, the ratio R of the size of the hole to the size of the electrode may be π*(wd2 / 2)^2 / wd1^2.

[0114] In one embodiment, the ratio R of the hole size to the electrode size may be limited to a value of less than 1 / 2. This is because if the hole size exceeds 1 / 2 of the electrode size, the droplet induction function by electrowetting may be excessively weakened.

[0115] Meanwhile, even if the electrode sizes are the same, the hole size may be larger in the electrode of interest where optical observation of the droplet is important. Refer to Fig. 17 for further explanation regarding this.

[0116] Referring to FIG. 17, a plurality of electrodes (251, 252, 253, 254, 255, 256) of equal size are shown. Among them, let us assume that the first electrode (251) and the sixth electrode (256) are electrodes of interest for which optical observation of the droplet is important. For example, let us assume that a droplet in which a first reaction has occurred is guided to the first electrode (251), and that the droplet passes through the second to fifth electrodes (252, 253, 254, 255) to undergo a second reaction and emits the reaction result as light on the sixth electrode (256).

[0117] In this case, it may be desirable to make the hole size relatively large in the first electrode (251) where the first reaction result of the droplet can be observed and the sixth electrode (256) where the second reaction result can be observed, in order to facilitate optical observation. On the other hand, in the second to fifth electrodes (252, 253, 254, 255) where optical observation of the droplet is not very important, it may be desirable to reduce the hole size and increase the peripheral area to make it easier to induce the droplet by electrowetting.

[0118] Therefore, even if the electrode sizes are the same, the hole size can be formed relatively larger in the electrode of interest where optical observation of the droplet is important.

[0119] Meanwhile, if the hole of the electrode is made of a transparent insulator, the hole can be formed in a form integrated with the base plate. For further explanation regarding this, refer to FIG. 18.

[0120] Referring to FIG. 18, an exemplary form (260) of a base plate and a hole according to one embodiment of the present invention is shown.

[0121] The hole (261) is composed of a transparent insulator, and the lower part (261b) of the hole (261) is connected to the base plate (262) through the connecting part (263). The upper part (261a) of the hole (261) is separated from the base plate (262) at a certain distance. A conductive polymer is filled between the hole (261) and the base plate (262) to form the periphery of the electrode.

[0122] In one embodiment, the hole (261) can be formed together with the base plate (262) by an injection molding method. For instance, the hole (261) and the base plate (262) can be formed at once by injecting a transparent insulator through an injection gate into a mold in which a space corresponding to the hole (261) and the base plate (262) is formed. Accordingly, since the hole and the base plate are formed in a single process, the entire process is simplified and the manufacturing cost of the device is reduced.

[0123] According to the electrode structure of the present invention described through the above embodiments, a droplet and light emitted from the droplet can be optically observed through a hole formed inside the electrode.

[0124] Hereinafter, an embodiment is described in which the electrowetting driving force is improved by providing a plurality of electrodes parallel to each other in a droplet actuator according to the present invention.

[0125] FIG. 19 is an exploded perspective view showing an exemplary form of a droplet actuator having a parallel electrode structure according to one embodiment of the present invention.

[0126] The embodiment of FIG. 19 also includes an electrode plate (10), a housing (20), and a substrate (30) similar to the embodiment of FIG. 1. However, the embodiment of FIG. 9 includes another electrode layer (310) and another substrate (320) between the electrode plate (10) and the housing (20).

[0127] The housing (20) can accommodate fluid. At this time, the housing (20) may include a fluid receiving portion for accommodating fluid. Since the configuration and function of the housing (20) according to the present embodiment are substantially the same as the configuration and function of the housing (20) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0128] The electrode plate (10) can induce polarization in a droplet through an electrowetting signal to move a droplet distributed from a fluid contained in a housing (20) to the position of a target electrode. At this time, the electrode plate (10) may include at least one electrode for conducting the electrowetting signal. Since the configuration and function of the electrode plate (10) according to the present embodiment are substantially the same as the configuration and function of the electrode plate (10) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0129] The substrate (30) can transmit an electrowetting signal to the electrode plate (10). For example, the substrate (30) may be any one of a glass substrate, a silicon substrate, a PCB (Printed Circuit Board), and a TFT (Thin Film Transistor). Since the configuration and function of the substrate (30) according to the present embodiment are substantially the same as the configuration and function of the substrate (30) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0130] Another electrode layer (310) is spaced apart from the electrode plate (10) and positioned facing the electrode plate (10). A droplet is positioned between the other electrode layer (310) and the electrode plate (10). When the electrode plate (10) applies an electrowetting signal to the droplet through an electrode array formed inside, the other electrode layer (310) applies a predetermined reference potential to the droplet.

[0131] According to this, compared to when the droplet is guided only by the lower electrode plate (10) in the embodiments of FIGS. 1 to 9, polarization within the droplet occurs more effectively, thereby improving the electrowetting driving force, and accordingly, the droplet can be guided more effectively in the intended direction.

[0132] As one embodiment, the predetermined reference potential may be ground, i.e., 0V.

[0133] Another substrate (320) is positioned on top of another electrode layer (310) to provide an electrical path for applying a predetermined reference potential to the other electrode layer (310).

[0134] The other substrate (320) may be, for example, any one of a glass substrate, a silicon substrate, a PCB (Printed Circuit Board), and a TFT (Thin Film Transistor). However, the scope of the present invention is not limited to these examples, and any known technology having a structure capable of transmitting a reference potential to another electrode layer (310) may be applied to the present invention.

[0135] Meanwhile, other electrode layers (310) can be formed in various shapes.

[0136] In one embodiment, another electrode layer (310) may be formed by coating, depositing, attaching, or bonding a conductive polymer, ITO (Indium Tin Oxide), or metal to another substrate (120).

[0137] In another embodiment, another electrode layer (310) may be formed on or inside a separate base plate, in the same manner as the electrode is formed within the electrode plate (10), or may be formed in a form in which the other electrode layer (310) penetrates the interior of the base plate.

[0138] In this case, the separate base plate may be formed by injecting an insulator into a part of the mold using an injection gate, and the other electrode layer (310) may be formed by injecting a conductive polymer into a different space of the mold using another injection gate distinct from the injection gate.

[0139] In one embodiment, the insulator may comprise at least one of PC (Polycarbonate), PMMA (Poly Methyl Methacrylate), COP (Cyclic Olefin Polymer), COC (Cyclic Olefin Copolymer), PET (Polyethylene Terephthalate), PI (Polyimide), PE (Polyethylene), Acrylic, ABS (Acrylonitrile butadiene styrene), PVDF (Polyvinylidene fluoride), PTFE (Polytetrafluoroethylene), PS (Polystyrene), PP (Polypropylene), and PVC (Polyvinyl Chloride). In addition, all known compositions including thermoplastic resins for insulating electrical signals may be applied to the present invention to manufacture the insulator.

[0140] In one embodiment, the conductive polymer may comprise a mixture of a polymer and a conductive material. In this case, the mixture may comprise at least one of carbon nanotubes, graphene, and carbon fibers, which are conductive materials, together with the polymer. In addition, any known mixture for conducting an electrical signal may be applied to the present invention to manufacture an electrode.

[0141] FIG. 20 describes the cross-sectional structure of the droplet actuator illustrated in FIG. 19 and the electrowetting operation by means of the same. In the description of FIG. 20, for convenience of explanation, the electrode array formed within the electrode plate (10) is referred to as the first electrode, the substrate (30) as the lower substrate, and the other electrode layer (310) and the other substrate (320) between the electrode plate (10) and the housing (20) are referred to as the second electrode and the upper substrate, respectively. The following description refers to the drawings.

[0142] FIG. 20 is a cross-sectional view of a droplet actuator having the stacked structure of FIG. 19.

[0143] Referring to FIG. 20, the structure of a droplet actuator is shown, comprising a lower substrate (30), an electrode plate (10) having a first electrode (13) formed inside, a second electrode (310), an upper substrate (320), and a housing (20).

[0144] A spacer (330) is placed between the first electrode (13) and the second electrode (310) to maintain a gap between the first electrode (13) and the second electrode (310), thereby creating a space (A) through which a droplet (70) can move.

[0145] In one embodiment, a dielectric layer (not shown) may be additionally laminated between the droplet (70) and the first electrode (13), or between the droplet (70) and the second electrode (310), and a hydrophobic coating may be applied to the surface of the first electrode (13) or the second electrode (110).

[0146] In the droplet actuator of FIG. 20, to guide the droplet (70) in a specific direction, an electrowetting signal for moving the droplet (70) in the specific direction is applied to the first electrode (13), and a reference potential is applied to the second electrode (310). As a result, polarization by an electric field occurs inside the droplet (70), and accordingly, the surface tension and shape change, allowing the droplet (70) to be moved in the desired direction.

[0147] At this time, the droplet actuator of FIG. 20 is equipped with a second electrode (310) to which a reference potential is applied, so that it forms a stronger electric field than the droplet actuator of FIG. 1 to FIG. 8, and thus the electrowetting driving force for moving the droplet (70) also becomes stronger.

[0148] According to the structure of the diagnostic device described in the above embodiments, the electrowetting driving force is enhanced by the lower electrode to which the electrowetting signal is applied and the upper electrode having a reference potential, so the induction of the droplet can be achieved more easily.

[0149] Hereinafter, an embodiment of a droplet actuator according to the present invention is described, which includes a temperature control function for a local area and a cleaning function within the droplet.

[0150] FIG. 21 is an exploded perspective view showing an exemplary form of a droplet actuator having a temperature control unit according to one embodiment of the present invention.

[0151] The embodiment of FIG. 21 also includes an electrode plate (10), a housing (20), and a substrate (30) similar to the embodiment of FIG. 1. However, the embodiment of FIG. 9 further includes another substrate (1110) between the electrode plate (10) and the housing (20).

[0152] The housing (20) can accommodate a droplet. At this time, the housing (20) may include a fluid receiving portion for accommodating a fluid. Since the configuration and function of the housing (20) according to the present embodiment are substantially the same as the configuration and function of the housing (20) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0153] The electrode plate (10) can induce polarization in a droplet through an electrowetting signal to move a droplet distributed from a fluid contained in a housing (20) to the position of a target electrode. At this time, the electrode plate (10) may include at least one electrode for conducting the electrowetting signal. Since the configuration and function of the electrode plate (10) according to the present embodiment are substantially the same as the configuration and function of the electrode plate (10) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0154] The substrate (30) can transmit an electrowetting signal to the electrode plate (10). For example, the substrate (30) may be any one of a glass substrate, a silicon substrate, a PCB (Printed Circuit Board), and a TFT (Thin Film Transistor). Since the configuration and function of the substrate (30) according to the present embodiment are substantially the same as the configuration and function of the substrate (30) described above in FIGS. 1 to 8, a detailed description thereof is omitted here to avoid duplication of description.

[0155] Another substrate (1110) is positioned on top of the electrode plate (10) and is provided with one or more temperature control units (1111). The temperature control unit (1111) may be a heater for locally heating a portion of the electrode plate (10), but the scope of the invention is not limited thereto. For example, the temperature control unit (1111) may be a cooler for locally cooling a portion of the electrode plate (10).

[0156] In one embodiment, when the temperature control unit (1111) is a heater, the temperature control unit (1111) may include one or more resistors that generate heat when current flows.

[0157] In one embodiment, when the temperature control unit is a heater, the temperature control unit may include a magnetic induction type heating device.

[0158] In one embodiment, the other substrate (1110) may be any one of a glass substrate, a silicon substrate, a PCB (Printed Circuit Board), and a TFT (Thin Film Transistor). However, the scope of the present invention is not limited to these examples, and any known technology having a structure in which a temperature control unit (1111) can be embedded may be applied to the present invention.

[0159] FIG. 22 is a cross-sectional view illustrating the detailed structure of the droplet actuator shown in FIG. 21 and the temperature control method using it.

[0160] FIG. 22 describes the cross-sectional structure of the droplet actuator shown in FIG. 21 and the temperature control operation by means of it. In FIG. 22, for clarity of terminology, the substrate (30) located relatively lower is referred to as the lower substrate, and the other substrate (1110) located relatively higher is referred to as the upper substrate.

[0161] Referring to FIG. 22, the structure of a droplet actuator is shown, comprising a lower substrate (30), an electrode plate (10) having an electrode (13) formed inside, an upper substrate (1110), and a housing (20).

[0162] A spacer (1130) is disposed between the electrode plate (10) and the upper substrate (1110) to maintain a gap between the electrode plate (10) and the upper substrate (1110), thereby creating a space (A) through which a droplet (70) can move.

[0163] One or more temperature control units (1111) are disposed on the upper substrate (1110). The temperature control unit (1111) is configured to control the temperature of a droplet (70) located within a heat region (B), and may be, for example, a heater for selectively localizing the heat region (B) or a cooler for localizing the heat region (B). The heat region (B) includes at least a portion of the electrode plate (10).

[0164] When the temperature control unit (1111) is a heater, the temperature control unit (1111) is heated according to a control signal transmitted through the upper substrate (1110), and heat is transferred from the temperature control unit (1111) to the heat area (B). As a result, the droplet (70) located within the heat area (B) is also heated.

[0165] These temperature control functions are necessary to enable specific processes to be performed under predetermined temperature conditions. For example, temperature control functions may be necessary for DNA denaturation for droplet analysis, etc. Specifically, the temperature control unit (1111) can be controlled to heat the heat region (B) to a temperature suitable for denaturing DNA within the droplet (70), or to heat the heat region (B) to a temperature effective for performing other reaction steps, such as annealing of a primer for a template strand DNA, or extension of a primer by a DNA polymerase.

[0166] According to the embodiment of FIG. 22, the droplet actuator is equipped with a temperature control unit (1111) so that it can satisfy the optimal temperature conditions required for droplet analysis and diagnosis.

[0167] FIGS. 23 to 25 are drawings for explaining a droplet actuator equipped with a cleaning function using magnetic force and a cleaning method using the same.

[0168] Here, washing means separating and removing some substances contained within the droplet (70) to the outside of the droplet (70).

[0169] Referring to FIG. 23, a plurality of magnetic beads (M) are included inside the droplet (70). And, a magnetic force providing unit (400) is provided inside or outside the droplet actuator to guide or fix the magnetic beads (M) to a specific position or direction. The magnetic force providing unit (400) may include a permanent magnet or an electromagnet.

[0170] The magnetic force providing unit (400) may be used to remove some substances from the droplet (70) before droplet analysis. At this time, the substances to be removed may include contaminants contained in the droplet (70), excess reagents, or substances to be separated from the droplet (70) for separate analysis.

[0171] First, a magnetic bead (M) is included within the droplet (70). At this time, the magnetic bead (M) may be included within the droplet (70) from the beginning, injected into the droplet (70) in a specific section within the droplet actuator during the process of guiding the droplet (70) to its current position, or placed in advance at a specific location within the droplet actuator and then naturally mixed with the droplet (70) as the droplet (70) moves to that location.

[0172] In FIG. 23, since the cleaning function has not yet been activated, the magnetic force providing unit (400) is kept in the OFF state, so no magnetic force acts on the droplet (70). At this time, the magnetic bead (M) reacts with a specific substance in the droplet (70) and binds to that substance.

[0173] In one embodiment, the magnetic force providing unit (400) may be a component provided within the droplet actuator, or a component provided in a separate tester outside the droplet actuator.

[0174] Meanwhile, in this embodiment, the magnetic force providing unit (400) is exemplified as being located below the lower substrate (30), but the scope of the present invention is not limited thereto. For example, the magnetic force providing unit (400) may be located between the lower substrate (30) and the electrode plate (10), located above or below the upper substrate (1110), or located above or to the side of the droplet actuator.

[0175] Next, the method of operating the cleaning function will be explained with reference to FIGS. 24 and FIGS. 25.

[0176] In FIG. 24, the magnetic force providing unit (400) is switched to the ON state, and a magnetic force is applied from the magnetic force providing unit (400) to the droplet (70). The magnetic force applied to the droplet (70) pulls the magnetic bead (M) inside the droplet (70) in the direction where the magnetic force providing unit (400) is located. At this time, the material bound to the magnetic bead (M) is also pulled together in the direction where the magnetic force providing unit (400) is located.

[0177] Next, referring to FIG. 25, while the magnetic bead (M) and the material bound thereto are pulled in the direction where the magnetic force providing unit (400) is located, the droplet (70) is moved to a different location according to the electrowetting signal applied to the electrode (13). At this time, the magnetic bead (M) is pulled downward by the magnetic force and does not follow the droplet (70), but remains in its original location separated from the droplet (70). At this time, the material bound to the magnetic bead (M) is also left in its original location together with the magnetic bead (M).

[0178] In this way, a specific substance, namely the substance bound to the magnetic bead (M), can be separated and removed from the droplet (70).

[0179] FIG. 26 is a diagram illustrating an exemplary configuration of a signal reader that reads the results of testing a sample of a droplet actuator.

[0180] Referring to FIG. 26, a signal reader (2100) includes a housing (2110), an optical unit (2120), an upper socket (2130), a lower socket (2140), and a main board (2160). A droplet actuator (2150), previously described in FIG. 1 to 25, may be inserted in the form of a cartridge between the upper socket (2130) and the lower socket (2140). In one embodiment, the signal reader (2100) may further include a screen (not shown).

[0181] The signal reader (2100) generates and controls an electrowetting signal applied to the droplet actuator (2150). A sample within the droplet actuator (2150) can be sensed by an optical method such as colorimetry, fluorometry, imaging, etc. through the signal reader (2100). Alternatively, a sample within the droplet actuator (2150) can be sensed by an electrochemical method or by electromagnetic induction through the signal reader (2100).

[0182] The optical unit (2120) provides an optical means for sensing a sample within a droplet actuator (2150).

[0183] The upper socket (2130) and the lower socket (2140) provide mechanical means for accommodating a droplet actuator (2150).

[0184] The main board (2160) performs electrical or electronic control, such as temperature control, magnetic field control, and droplet position detection, for the droplet actuator (2150).

[0185] FIG. 27 is a drawing showing an exemplary configuration of the optical unit of FIG. 26.

[0186] Referring to FIG. 27, the optical unit may include a blue LED, a photodiode, a dichroic mirror, one or more lenses, and one or more filters.

[0187] FIGS. 28 and 29 are drawings for further explaining the droplet position detection function of the main board of FIG. 26.

[0188] FIG. 28 shows an exemplary configuration of a droplet position detection circuit provided on a main board. The main board may include a droplet position detection circuit as illustrated in FIG. 28 for determining the position of a droplet on an electrowetting electrode within a droplet actuator. The main board may detect the current position of a droplet by using the droplet position detection circuit to sense changes in resistance or capacitance due to the movement of the droplet, or by using an image sensor.

[0189] FIG. 29 illustrates an exemplary form of a droplet position detection result using a droplet position detection circuit.

[0190] FIG. 29 (a) shows a case where droplet movement according to the electrowetting signal fails. Since the droplet movement signal (2220) has increased to High but the droplet sensing signal (2210) remains in a Low state in that section, this means that droplet movement did not actually occur even though the electrowetting signal was applied.

[0191] Figure 29 (b) shows a case where droplet movement according to the electrowetting signal is successful. As the droplet movement signal (2220) increases to High, the droplet sensing signal (2210) also changes to High in that section, which means that droplet movement actually occurred due to the application of the electrowetting signal.

[0192] Figures 30 and 31 are drawings for further explaining the temperature control function of the main board of Figure 26.

[0193] FIG. 30 shows an exemplary configuration of a temperature control circuit provided on a main board. The main board may include a temperature control circuit as shown in FIG. 30 to control the temperature of a temperature control unit (e.g., a heater) of a droplet actuator. The main board controls the temperature through the temperature control circuit by sensing a change in resistance value according to the temperature within the device or the value of other temperature sensors.

[0194] FIG. 31 illustrates an exemplary form for controlling multiple temperature sensing circuit outputs with a single temperature controller.

[0195] As the temperature sensor selection signal (2320) changes, it can be confirmed that the sensor value (2310) input to the temperature controller has changed to the selected sensor output.

[0196] FIG. 32 is a drawing showing a new stacked structure of a droplet actuator as another embodiment of the present invention. Referring to FIG. 32, a droplet actuator (2400) having a stacked structure according to the present embodiment may include a lower plate in which a lower housing (2411), a PCB substrate (2412), a lower substrate (2413), a metal pattern layer (2414), a dielectric layer (2415), and a hydrophobic coating layer (2416) are sequentially stacked, and an upper plate in which a hydrophobic coating layer (2421), a conduction layer (2422), an upper substrate (2423), a heater (2424), and an upper housing (2425) are sequentially stacked. The upper plate and the lower plate may be spaced apart from each other so that a space for accommodating a droplet is formed between them.

[0197] In the above space, there may be a bonding (2431) that joins the upper plate and the lower plate, at least one filler (2432), and / or at least one sample (2433).

[0198] In one embodiment, the PCB substrate (2412) can function as an interconnect layer.

[0199] In one embodiment, a conductive polymer electrode may be formed on the lower substrate (2413).

[0200] In one embodiment, the conduction layer (2422) may include ITO, a metal, or a conductive polymer.

[0201] The dielectric layer (2415) is configured to provide electrical insulation between a conductive polymer electrode or a conduction layer and a droplet, and may include an insulating polymer or a material such as Parylene-C, SiO2, Si3N4.

[0202] The hydrophobic coating layer (2416, 2421) is a layer for hydrophobic coating treatment on the surface of the metal pattern layer (2414) or the conduction layer (2422), and the hydrophobic coating layer (2416, 2421) can be coated by methods such as spin coating, dip coating, spray coating, and plasma coating using HMDS, fluorine solution or gas, etc.

[0203] The filler (2432) is a fluid material that fills between the upper plate and the lower plate to facilitate the movement of droplets and prevent the evaporation of droplets and the generation of bubbles at high temperatures. The filler (2432) may be a non-polar solvent that is insoluble in water, or a mixture thereof with a surfactant or a lubricant.

[0204] In one embodiment, siloxane or silicone oil may be used as the filler (2432).

[0205] Meanwhile, a spacer is placed between the upper plate and the lower plate to maintain a gap between the upper plate and the lower plate, thereby creating a space through which droplets can move. At this time, the upper plate and the lower plate can be bonded using methods such as adhesive material, ultrasonic welding, or laser welding.

[0206] FIG. 33 is a drawing showing a droplet actuator having a vertical electrode structure according to an embodiment of the present invention. Referring to FIG. 33, the droplet actuator (3100) according to the present embodiment includes a lower substrate (3110) including a plurality of electrodes (3111, 3112, 3113) and an upper substrate (3120) including a plurality of other electrodes (3121, 3122). The upper substrate (3120) and the lower substrate (3110) are spaced apart from each other, so that a space is formed or defined between them to accommodate a droplet and for the droplet to move.

[0207] A plurality of electrodes (3111, 3112, 3113) are electrowetting electrodes for handling droplets, and a gap is formed between adjacent electrodes so that they are spaced apart from each other with the gap in between. For example, among the plurality of electrodes (3111, 3112, 3113), the first electrode (3111) and the third electrode (3112) that are adjacent to each other are spaced apart from each other with the first gap (g1) in between.

[0208] A plurality of other electrodes (3121, 3122) also serve as electrowetting electrodes for handling droplets, and a gap is formed between adjacent electrodes. For example, among the plurality of other electrodes (3121, 3122), the adjacent second electrode (3121) and the fourth electrode (3122) are spaced apart from each other with a second gap (g2) in between.

[0209] At this time, a plurality of electrodes (3111, 3112, 3113) formed on the lower substrate (3110) and a plurality of other electrodes (3121, 3122) formed on the upper substrate (3120) are arranged to be staggered from each other. For example, the second electrode (3121) of the upper substrate (3120) is positioned to face the first gap (g1) between the first electrode (3111) and the third electrode (3112) of the lower substrate (3110), so as to be staggered from the first electrode (3111) and the third electrode (3112). Similarly, the third electrode (3112) of the lower substrate (3110) is positioned facing the second gap (g2) between the second electrode (3121) and the fourth electrode (3122) so as to be staggered with the second electrode (3121) and the fourth electrode (3122) of the upper substrate (3120).

[0210] Meanwhile, to more clearly show the electrode arrangement structure of FIG. 33, refer to FIG. 34. FIG. 34 (a) is a side view of a droplet actuator, and FIG. 34 (b) is a top view of the upper substrate (3120) of the droplet actuator.

[0211] FIG. 34 (a) is illustrated for mutual comparison with FIG. 34 (b), and its structure and technical features are the same as those described in FIG. 33.

[0212] Referring to FIG. 34 (b), the arrangement relationship in a plan view between the electrodes (3121, 3122) of the upper substrate (3120) and the electrodes (3111, 3112, 3113) of the lower substrate (3110) is clearly illustrated.

[0213] In FIG. 34 (b), each of the electrodes (3121, 3122) of the upper substrate (3120) is positioned to overlap at least partially with two adjacent electrodes of the lower substrate (3110) and the gap between them when viewed from above.

[0214] For example, when viewed from above the upper substrate (3120), the second electrode (3121) is at least partially overlapped with the adjacent first electrode (3111) and third electrode (3112). Also, when viewed from above the upper substrate (3120), the second electrode (3121) is at least partially overlapped with the first gap (g1) between the first electrode (3111) and the third electrode (3112). A similar arrangement structure is applied to other electrodes (3122) of the upper substrate (3120).

[0215] According to this electrode arrangement structure, when an operating signal (i.e., an electrowetting signal) is applied to move a droplet, the droplet can be moved by alternately adhering to the upper substrate (3120) and the lower substrate (3110), and the movement of the droplet between the electrode of the upper substrate (3120) and the electrode of the lower substrate (3110) can be performed more smoothly. A more detailed explanation of this will be described later with reference to FIGS. 36 and 37.

[0216] FIG. 35 is a diagram showing a switch circuit of a droplet actuator. The switch circuit of FIG. 35 is configured to selectively apply an operating signal to each electrode (3111, 3112, 3113, 3121, 3122) of a droplet actuator (3100). The switch circuit of the present embodiment includes one or more signal lines (3101, 3102) and a plurality of switches (S1, S2, S3, S4, S5).

[0217] Among one or more signal lines (3101, 3102), the first signal line (3101) is a signal line to which an operating signal (Vin, i.e., an electrowetting signal) is provided. Among one or more signal lines (3101, 3102), the second signal line (3102) is a signal line to which a reference potential (Vref, e.g., ground potential) is applied. One or more signal lines (3101, 3102) can be electrically connected to each electrode (3111, 3112, 3113, 3121, 3122) of the droplet actuator (3100) by switches (S1, S2, S3, S4, S5).

[0218] A plurality of switches (S1, S2, S3, S4, S5) are switch elements for selectively connecting each electrode (3111, 3112, 3113, 3121, 3122) of a droplet actuator (3100) to any one of the signal lines (3101, 3102). Each of the plurality of switches (S1, S2, S3, S4, S5) can be controlled independently of each other and can be matched one-to-one with each electrode (3111, 3112, 3113, 3121, 3122).

[0219] In one embodiment, the control of the plurality of switches (S1, S2, S3, S4, S5) can be performed by a control unit (not shown) provided in the droplet actuator (3100).

[0220] Alternatively, as another embodiment, the control of the plurality of switches (S1, S2, S3, S4, S5) may be performed by a control unit (not shown) provided in a test device outside the droplet actuator (3100). In this case, each element (3101, 3102, S1, S2, S3, S4, S5) constituting the switch circuit may be a component included in an external test device rather than the droplet actuator (3100).

[0221] In one embodiment, a plurality of switches (S1, S2, S3, S4, S5) can be controlled so that an operating signal (Vin) is sequentially provided to each electrode (3111, 3112, 3113, 3121, 3122). At this time, the plurality of switches (S1, S2, S3, S4, S5) can be controlled so that a reference potential (Vref) is applied to the electrode to which the operating signal (Vin) is not provided.

[0222] For a clear understanding of this, we will explain it with reference to Figs. 36 and 37.

[0223] FIG. 36 is a diagram showing the driving of the electrowetting electrode and the movement of the droplet caused thereby over time, and FIG. 37 is a timing diagram showing the operation of the switch circuit and the potential state of the electrode for each time interval. The following description refers to the drawings.

[0224] First, at time t1, the first switch (S1) is controlled so that an operating signal (Vin) is applied to the first electrode (3111) (S1=High), and thereby a droplet is positioned on the first electrode (3111). At this time, other switches (S2, S3, S4, S5) are controlled so that a reference potential (Vref) is applied to the remaining electrodes (3112, 3113, 3121, 3122) (S2, S3, S4, S5=Low).

[0225] Then, at time t2, the second switch (S2) is controlled so that an operating signal (Vin) is applied to the second electrode (3121) in order to move the droplet from the first electrode (3111) to the second electrode (3121) (S2=High). At the same time, other switches (S1, S3, S4, S5) are controlled so that a reference potential (Vref) is applied to the remaining electrodes (3111, 3112, 3113, 3122) (S1, S3, S4, S5=Low).

[0226] Then, at time t3, the third switch (S3) is controlled so that an operating signal (Vin) is applied to the third electrode (3112) in order to move the droplet from the second electrode (3121) to the third electrode (3112) (S3=High). At the same time, other switches (S1, S2, S4, S5) are controlled so that a reference potential (Vref) is applied to the remaining electrodes (3111, 3113, 3121, 3122) (S1, S2, S4, S5=Low).

[0227] Then, at time t4, the fourth switch (S4) is controlled so that an operating signal (Vin) is applied to the fourth electrode (3122) in order to move the droplet from the third electrode (3112) to the fourth electrode (3122) (S4=High). At the same time, other switches (S1, S2, S3, S5) are controlled so that a reference potential (Vref) is applied to the remaining electrodes (3111, 3112, 3113, 3121) (S1, S2, S3, S5=Low).

[0228] According to the operation of the droplet actuator (3100) described in FIGS. 36 and 37, an operating signal (Vin) is sequentially applied to the first electrode (3111), the second electrode (3121), the third electrode (3112), and the fourth electrode (3122), and the droplet moves sequentially to the surface of the first electrode (3111), the surface of the second electrode (3121), the surface of the third electrode (3112), and the surface of the fourth electrode (3122) accordingly.

[0229] This has the following advantageous technical effects. Conventional droplet actuators are equipped with electrowetting electrodes only on the lower substrate, so when a droplet moves through the gap between adjacent electrodes during droplet manipulation, if the surface of the lower substrate is processed somewhat roughly, there was a problem in that the droplet could not pass through the gap and stopped in the middle due to friction with the gap surface.

[0230] In contrast, according to the droplet actuator of the present embodiment, when a droplet passes through the gap between adjacent electrodes, it moves to another electrode formed on the facing substrate and passes in close contact with it, thereby reducing the frictional force between the droplet and the gap surface, and thus, even if the substrate surface is processed somewhat roughly, the movement of the droplet between the electrodes can be performed smoothly.

[0231] In addition, as a result, the surface of the substrate does not need to be processed to be very smooth when manufacturing the substrate, so the manufacturing process of the droplet actuator can be simplified and the overall production cost can be lowered.

[0232] In addition, unlike the case where electrodes are formed only on the lower substrate, even if the gap between adjacent electrodes is not very close, they can move to another electrode formed on the opposite substrate, so there is no difference in performance even if the precision of the manufacturing process of the droplet actuator is somewhat lowered, and thus production costs can be reduced.

[0233] FIGS. 38 and 39 are drawings showing an exemplary electrowetting electrode arrangement of the droplet actuator described in FIG. 33.

[0234] FIG. 38 is a top view of the upper substrate of a droplet actuator showing an electrowetting electrode arrangement in the form of an intersection where the droplet path branches.

[0235] Referring to FIG. 38, a first electrode (3111), a second electrode (3121), a third electrode (3112), and a fourth electrode (3122) are arranged sequentially in the direction of travel of the droplet. The first electrode (3111) and the third electrode (3112) are electrodes formed on a lower substrate, and the second electrode (3121) and the fourth electrode (3122) may be electrodes formed on an upper substrate.

[0236] Next to the fourth electrode (3122), the fifth electrode (3113) and the sixth electrode (3114) are disposed. The fifth electrode (3113) and the sixth electrode (3114) are electrodes formed on the lower substrate and may be electrodes spaced apart from the third electrode (3112) with a gap in between. The fifth electrode (3113) and the sixth electrode (3114) may also be spaced apart from each other with a gap in between.

[0237] In one embodiment, the fourth electrode (3122) may overlap at least partially with the third electrode (3112), the fifth electrode (3113), and the sixth electrode (3114) respectively when viewed from above the upper substrate (i.e., in the plan view of FIG. 38).

[0238] In the electrode arrangement of FIG. 38, the droplet (70) may move from the first electrode (3111) through the second electrode (3121) and the third electrode (3112) to the surface of the fourth electrode (3122) in response to sequentially applying an operating signal to each electrode (3111, 3121, 3112, 3122). Then, in response to selectively applying an operating signal to the fifth electrode (3113) and / or the sixth electrode (3114), it may (i) move over the fifth electrode (3113), (ii) move over the sixth electrode (3114), or (iii) be split or spread over the fifth electrode (3113) and the sixth electrode (3114).

[0239] For example, after the droplet (70) is moved to the surface of the fourth electrode (3122), an operating signal is applied to the fifth electrode (3113) and a reference potential is applied to the remaining electrodes (3111, 3121, 3112, 3122, 3114), the droplet (70) is moved onto the fifth electrode (3113). Alternatively, after the droplet (70) is moved to the surface of the fourth electrode (3122), an operating signal is applied to the sixth electrode (3114) and a reference potential is applied to the remaining electrodes (3111, 3121, 3112, 3122, 3113), the droplet (70) is moved onto the sixth electrode (3114). Alternatively, after the droplet (70) is moved to the surface of the fourth electrode (3122), if an operating signal is applied to the fifth electrode (3113) and the sixth electrode (3114) and a reference potential is applied to the remaining electrodes (3111, 3121, 3112, 3122), the droplet (70) is split or spread over the fifth electrode (3113) and the sixth electrode (3114).

[0240] FIG. 39 is a top view of an example of applying the vertical electrode arrangement of the present invention to the reservoir and distribution regions of a droplet actuator, viewed from above on an upper substrate.

[0241] Referring to FIG. 39, a first electrode (3111), a second electrode (3121), a third electrode (3112), a fourth electrode (3122), and a fifth electrode (3113) are arranged sequentially in the direction toward the fluid channel in the reservoir area. The first electrode (3111), the third electrode (3112), and the fifth electrode (3113) are electrodes formed on a lower substrate, and the second electrode (3121) and the fourth electrode (3122) may be electrodes formed on an upper substrate.

[0242] At this time, the first electrode (3111) and the second electrode (3121) are reservoir electrodes that induce the flow of fluid in the reservoir, and the third electrode (3112), the fourth electrode (3122), and the fifth electrode (3113) may be distribution electrodes for distributing droplets from the reservoir and transferring them to the fluid channel.

[0243] The reservoir electrodes (3111, 3121) may have different sizes from the distribution electrodes (3112, 3122, 3113), and typically, the reservoir electrodes (3111, 3121) are formed to be larger than the distribution electrodes (3112, 3122, 3113). FIG. 39 shows that even when electrowetting electrodes of different sizes are mixed in this way, the vertical electrode arrangement according to the present invention can be applied.

[0244] FIG. 40 is a drawing showing an exemplary stacked structure of the droplet actuator described in FIG. 33.

[0245] Referring to FIG. 40, a droplet actuator (3100) having a stacked structure according to the present embodiment may include a lower plate in which a lower housing (3131), a heater (3132), a routing layer (3133), a lower substrate (3110), a dielectric layer (3134), and a hydrophobic coating layer (3135) are sequentially stacked, and an upper plate in which a hydrophobic coating layer (3145), a dielectric layer (3144), an upper substrate (3120), a routing layer (3143), a heater (3142), and an upper housing (3141) are sequentially stacked. At this time, the upper plate and the lower plate may be spaced apart from each other so that a space for accommodating a droplet is formed between them.

[0246] In the above space, there may be a bonding (3151) that joins the upper plate and the lower plate, at least one filler (3152), and / or at least one sample (3153).

[0247] The lower housing (3131) is a component forming the lower exterior of the droplet actuator (3100), protecting the internal components of the droplet actuator (3100) and providing an interface connecting the droplet actuator (3100) to an external device (e.g., a tester). In one embodiment, the lower housing (3131) may be composed of a polymer or plastic.

[0248] The heater (3132) is configured to heat a droplet inside the droplet actuator (3100) and may be a resistive heater, a magnetic induction heater, or a thermoelectric heater.

[0249] The routing layer (3133) may be a layer comprising a contact pad pattern as an interconnection layer for electrically connecting the droplet actuator (3100) and an external device (e.g., a tester). In this case, the contact pad is connected to a conductive element (e.g., a conductive polymer) of the lower substrate (3110) through vias. In one embodiment, the routing layer (3133) may be composed of a metal (e.g., Ag, Au, Cu, Cr) and a conductive polymer. In one embodiment, the routing layer (3133) may be formed by evaporation, sputtering, screen printing, inkjet printing, laser ablation, or an R2R process.

[0250] The lower substrate (3110) is a layer on which an electrowetting electrode (3111) is formed, electrically connecting the routing layer (3133) and the electrowetting electrode (3111). The lower substrate (3110) may include a base and a conductive plastic that penetrates and fills the base. In one embodiment, the base may be composed of a polymer (e.g., PMMA, PC, COP), ceramic, glass, or silicon. In one embodiment, the lower substrate (3110) may be formed by an injection molding, dispensing, screen printing, or 3D printing process.

[0251] Meanwhile, as one embodiment, the electrowetting electrode (3111) is an electrode for inducing electrowetting and may be composed of a metal (e.g., Ag, Au, Cu, Cr) or a conductive polymer and may be formed by deposition, sputtering, screen printing, inkjet printing, laser ablation, or R2R process.

[0252] The dielectric layer (3134) is a layer formed on the lower substrate (3110) or the electrowetting electrode (3111) to provide electrical insulation to the lower substrate (3110) or the electrowetting electrode (3111), and may be a thin film coating structure. The dielectric layer (3134) may be composed of various insulating materials such as SiO2, Si3N4, Parylene, fluoropolymer, SU8, or PDMS, and may be formed by spin, dip, spray, plasma, deposition, sputtering, ALD, CVD, or e-beam processes.

[0253] The hydrophobic coating layer (3135) is a layer for hydrophobizing the surface of the dielectric layer (3134) and may be a thin film coating structure. The hydrophobic coating layer (3135) may be composed of a fluoropolymer and may be formed by a spin, dip, spray, plasma, deposition, sputtering, ALD, CVD, or e-beam process.

[0254] A gap spacer for forming a gap is formed between the hydrophobic coating layers (3135, 3145).

[0255] The gap space is a space that accommodates droplets and filler fluid, and is the space where the upper plate and the lower plate are connected. The gap space is formed by a spacer, and the spacer and the upper plate and / or lower plate can be formed by a method of bonding using laser welding, ultrasonic welding, thermal welding, pressure welding, or an adhesive. The height of the gap space can be adjusted by the spacer.

[0256] Meanwhile, the spacer may be a separate component distinct from the upper plate and the lower plate, or it may be a component included as part of the upper plate or the lower plate. In one embodiment, the spacer may be composed of a polymer.

[0257] In one embodiment, the bonding (3151) can function as a spacer for forming the gap space.

[0258] The hydrophobic coating layer (3145) is a layer for hydrophobizing the surface of the dielectric layer (3144) and may be a thin film coating structure. The hydrophobic coating layer (3145) may be composed of a fluoropolymer and may be formed by a spin, dip, spray, plasma, deposition, sputtering, ALD, CVD, or e-beam process.

[0259] The dielectric layer (3144) is a layer formed on the upper substrate (3120) or the electrowetting electrode (3121) to provide electrical insulation to the upper substrate (3120) or the electrowetting electrode (3121), and may be a thin film coating structure. The dielectric layer (3144) may be composed of various insulating materials such as SiO2, Si3N4, Parylene, fluoropolymer, SU8, or PDMS, and may be formed by spin, dip, spray, plasma, deposition, sputtering, ALD, CVD, or e-beam processes.

[0260] The upper substrate (3120) is a layer on which an electrowetting electrode (3121) is formed, electrically connecting the routing layer (3143) and the electrowetting electrode (3121). The upper substrate (3120) may include a base and a conductive plastic that penetrates and fills the base. In one embodiment, the base may be composed of a polymer (e.g., PMMA, PC, COP), ceramic, glass, or silicon. In one embodiment, the upper substrate (3120) may be formed by an injection molding, dispensing, screen printing, or 3D printing process.

[0261] Meanwhile, as one embodiment, the electrowetting electrode (3121) is an electrode for inducing electrowetting and may be composed of a metal (e.g., Ag, Au, Cu, Cr) or a conductive polymer and may be formed by deposition, sputtering, screen printing, inkjet printing, laser ablation, or R2R process.

[0262] The routing layer (3143) may be a layer comprising a contact pad pattern as an interconnection layer for electrically connecting the droplet actuator (3100) and an external device (e.g., a tester). In this case, the contact pad is connected to a conductive element (e.g., a conductive polymer) of the upper substrate (3120) through vias. In one embodiment, the routing layer (3143) may be composed of a metal (e.g., Ag, Au, Cu, Cr) and a conductive polymer. In one embodiment, the routing layer (3143) may be formed by deposition, sputtering, screen printing, inkjet printing, laser ablation, or R2R processes.

[0263] The heater (3142) is configured to heat a droplet inside the droplet actuator (3100) and may be a resistance heater, a magnetic induction heater, or a thermoelectric heater.

[0264] The upper housing (3141) is a component forming the upper exterior of the droplet actuator (3100), protecting the internal components of the droplet actuator (3100) and providing an interface connecting the droplet actuator (3100) to an external device (e.g., a tester). In one embodiment, the upper housing (3131) may be composed of a polymer or plastic.

[0265] Various embodiments of the present invention and the effects according to those embodiments have been described above with reference to the drawings. The effects according to the technical concept of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description in the specification.

[0266] Although it has been described above that all components constituting the embodiments of the present invention are combined as one or operate in combination, the technical concept of the present invention is not necessarily limited to such embodiments. That is, within the scope of the objectives of the present invention, all components may be selectively combined in one or more ways to operate.

[0267] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within the equivalent scope shall be interpreted as being included within the scope of rights of the technical concept defined by the present invention.

Claims

Claim 1 A first substrate comprising a plurality of electrodes for handling droplets; a second substrate comprising a plurality of other electrodes distinct from the plurality of electrodes; The apparatus includes a switch circuit, wherein the first substrate and the second substrate are spaced apart from each other so that a space for the droplet to move is defined between the first substrate and the second substrate, wherein the plurality of electrodes include a first electrode and a third electrode, wherein the first electrode and the third electrode are spaced apart from each other with a first gap between them, wherein the plurality of other electrodes include a second electrode, wherein the second electrode is positioned facing the first gap, wherein the droplet moves sequentially to a first position on the first electrode, a second position on the second electrode, and a third position on the third electrode in response to the sequential application of an operation signal to the first electrode, the second electrode, and the third electrode, wherein the switch circuit is for selectively connecting the first electrode, the second electrode, or the third electrode to a signal line to which the operation signal is provided, wherein the first electrode, the second electrode, and the third electrode are sequentially connected to the signal line by the operation of the switch circuit, and A droplet actuator in which a reference potential is applied to the remaining electrodes while any one of the first electrode, the second electrode, and the third electrode is connected to the signal line. Claim 2 delete Claim 3 In claim 1, the first electrode and the third electrode are adjacent electrodes among the plurality of electrodes, forming a droplet actuator. Claim 4 In claim 3, the droplet actuator, wherein when viewed from above the second substrate, the second electrode overlaps with at least a portion of the first electrode and at least a portion of the third electrode, respectively. Claim 5 delete Claim 6 delete Claim 7 A droplet actuator according to claim 1, wherein the plurality of other electrodes further include a fourth electrode, the second electrode and the fourth electrode are spaced apart from each other with a second gap between them, the third electrode is positioned facing the second gap, and when viewed from above the second substrate, at least a portion of the second gap, at least a portion of the second electrode, and at least a portion of the fourth electrode each overlap on the third electrode. Claim 8 In claim 7, the plurality of electrodes further comprises a fifth electrode and a sixth electrode, wherein the third electrode, the fifth electrode, and the sixth electrode are each spaced apart from each other with a gap between them, and when viewed from above the second substrate, the fourth electrode overlaps at least partially with the third electrode, the fifth electrode, and the sixth electrode, respectively, droplet actuator. Claim 9 In claim 8, the droplet actuator, in response to an operating signal applied to the plurality of electrodes or the plurality of other electrodes, moves from a third position on the third electrode to a fourth position on the fourth electrode, and then (i) moves to a fifth position on the fifth electrode, (ii) moves to a sixth position on the sixth electrode, or (iii) is split or spread between the fifth position and the sixth position. Claim 10 A droplet actuator according to claim 1, wherein the first electrode is a reservoir electrode and the third electrode is an electrode for dispensing the droplet from the reservoir to a fluid channel.

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