Driving method of microfluidic device and microfluidic device

Abstract

This invention discloses a driving method and a microfluidic device, relating to the field of microfluidics. The driving method includes: introducing a droplet into a first channel; in a first stage, forming a first driving voltage between a driving electrode and a common electrode to fix the droplet directly above the Nth driving electrode, where 1 ≤ N ≤ M; in a second stage, canceling the first signal supplied to the Nth driving electrode and forming a second driving voltage between the Nth driving electrode and the common electrode, the absolute value of the second driving voltage being greater than 0 and less than the absolute value of the first driving voltage; in a third stage, providing a first signal to the (N+1)th driving electrode and forming a first driving voltage between the (N+1)th driving electrode and the common electrode; wherein the second and third stages overlap. This ensures smooth droplet driving while reducing driving power consumption.

Description

[0001] This application is a divisional application of the application with the application date of September 29, 2022, the application number of 202211197175.7, and the title of "Driving method of microfluidic device and microfluidic device". TECHNICAL FIELD

[0002] The present application relates to the technical field of microfluidics, and more particularly to a driving method of a microfluidic device and a microfluidic device. BACKGROUND

[0003] Microfluidics technology is a new cross-disciplinary subject involving chemistry, fluid physics, microelectronics, new materials, biology and biomedical engineering, which can accurately control the movement of droplets, realize the fusion and separation of droplets, and complete various biochemical reactions. It is a technology that mainly features manipulating fluid in micron-scale space. In recent years, microfluidic chips have been widely used in biological, chemical, medical and other fields due to their small size, low power consumption, low cost, small amount of required samples and reagents, ability to realize individual and accurate control of droplets, short detection time, high sensitivity, and easy integration with other devices.

[0004] In the prior art, the flow position of the liquid in the microfluidic device is usually controlled by setting at least one substrate voltage based on the principle of electrowetting. Currently, a commonly used method is to drive the droplet flow by using direct current. During the droplet driving process, the use of continuous direct current greatly increases the driving power consumption. At present, how to effectively reduce the power consumption of droplet driving has become one of the technical problems to be solved. SUMMARY

[0005] Therefore, the present application provides a driving method of a microfluidic device and a microfluidic device, which aims to ensure smooth driving of droplets while reducing driving power consumption.

[0006] In a first aspect, the present application provides a driving method of a microfluidic device, characterized in that the microfluidic device comprises a first substrate, a driving layer and a microfluidic structure layer, the driving layer is located between the first substrate and the microfluidic structure layer, the driving layer comprises a plurality of driving electrodes and a common electrode arranged opposite to the driving electrodes, and the microfluidic structure layer comprises at least one first channel, the first channel comprises M driving electrodes arranged in sequence.

[0007] The driving method comprises:

[0008] The first channel is filled with droplets.

[0009] In a first stage, a first signal is provided to an Nth driving electrode overlapping with the droplet, a constant signal is provided to the common electrode, a first driving voltage is formed between the driving electrode and the common electrode, the droplet is fixed directly above the Nth driving electrode, 1≤N≤M;

[0010] In a second stage, the first signal provided to the Nth driving electrode is cancelled, a second driving voltage is formed between the Nth driving electrode and the common electrode, the absolute value of the second driving voltage is greater than 0 and less than the absolute value of the first driving voltage;

[0011] In a third stage, the first signal is provided to an N+1th driving electrode, the first driving voltage is formed between the N+1th driving electrode and the common electrode;

[0012] Wherein, the second stage and the third stage overlap.

[0013] In a second aspect, based on the same inventive concept, the present application also provides a microfluidic device, comprising: a first substrate, a driving layer and a microfluidic structure layer, the driving layer is located between the first substrate and the microfluidic structure layer, the driving layer comprises a plurality of driving electrodes and a common electrode arranged opposite to the driving electrodes, and the microfluidic structure layer comprises at least one first channel, the first channel comprises M driving electrodes arranged in sequence.

[0014] The driving layer further comprises a plurality of switch control lines, a plurality of data lines and a plurality of driving circuits corresponding to the driving electrodes; at least part of the driving circuits comprises a first transistor, a first capacitor and a second capacitor; in the same first channel, in the driving circuits corresponding to the Nth driving electrode and the N+1th driving electrode, the gates of the first transistors are connected to different switch control lines respectively, the first poles of the first transistors are connected to the same data line, and the second poles of different first transistors are connected to different driving electrodes respectively; the driving electrodes are connected to the first poles of the first capacitors, and the second poles of the first capacitors receive a fixed voltage signal; the Nth driving electrode is electrically connected to the switch control lines corresponding to the N+1th driving electrode through the second capacitor, 1≤N<M.

[0015] Compared with the related art, the microfluidic device driving method and the microfluidic device provided by the present application at least achieve the following beneficial effects:

[0016] The microfluidic device provided by the embodiment of the present application is provided with a driving layer and a microfluidic structure layer, wherein the microfluidic structure layer comprises at least one first channel for accommodating a liquid drop. The driving layer comprises oppositely arranged driving electrodes and a common electrode. When an electric signal is provided to the driving electrodes and the common electrode, a driving voltage for driving the liquid drop to move is formed between the driving electrodes and the common electrode. In the control method of the microfluidic device provided by the embodiment of the present application, after the liquid drop is introduced into the first channel, the liquid drop is driven through three stages. In the first stage, a first signal is first provided to an Nth driving electrode overlapping with the liquid drop, and a constant signal is provided to the common electrode, so as to form a first driving voltage, and the liquid drop is fixed directly above the Nth driving electrode. In the second stage, the signal provided to the Nth driving electrode is cancelled, and the voltage between the Nth driving electrode and the common electrode does not suddenly disappear, but gradually decreases to form a second driving voltage. In the third stage, a first signal is provided to an N+1th driving electrode, and a first driving voltage is formed between the N+1th driving electrode and the common electrode. The third stage overlaps with the second stage, that is, the second driving voltage provided by the Nth driving electrode to the liquid drop and the first driving voltage provided by the N+1th driving electrode to the liquid drop exist at the same time. At this time, the front part (the part adjacent to the N+1th driving electrode) of the liquid drop starts to move, and the tail part does not start to move. At this time, the moving speed of the gravity center of the liquid drop is relatively fast. With the movement of the liquid drop to the N+1th driving electrode by a distance, the tail part of the liquid drop starts to move, and a drag force is formed on the front part of the liquid drop. The overall speed of the liquid drop is reduced. When the tail part of the liquid drop catches up with the front part of the liquid drop, that is, the speeds of the two parts are consistent, the speed of the liquid drop is accelerated under the driving voltage, and the liquid drop moves to the N+1th electrode. The contact area between the liquid drop and the N+1th driving electrode becomes larger and larger. When the gravity center of the liquid drop coincides with the center of the N+1th driving electrode, the first driving voltage fixes the liquid drop above the N+1th driving electrode. In the second stage, even if the electric signal provided to the Nth driving electrode is removed, the second driving voltage between the Nth driving electrode and the common electrode can still be maintained for a period of time, so as to maintain the shape of the liquid drop. When the first signal is applied to the N+1th driving electrode in the third stage, part of the liquid drop is still located on the Nth driving electrode. The small second driving voltage at the corresponding position of the Nth driving electrode can still drive the liquid drop to move to the N+1th driving electrode, so that the first signal with a large voltage value does not need to be continuously provided to the Nth driving electrode in the driving process of the liquid drop. Therefore, while the normal movement of the liquid drop is ensured, the driving power consumption is also reduced.

[0017] Of course, any product implementing the present application does not necessarily need to achieve all the technical effects described above at the same time.

[0018] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0020] Figure 1 The diagram shown is a flowchart of a driving method for a microfluidic device provided in an embodiment of the present invention.

[0021] Figure 2 The diagram shown is a driving timing diagram of a driving method for a microfluidic device provided in an embodiment of the present invention.

[0022] Figure 3 The figure shown is a schematic diagram of a microfluidic device provided in an embodiment of the present invention;

[0023] Figure 4 The diagram shows a relative positional relationship between the droplet and the driving electrode in the first stage.

[0024] Figure 5 The diagram shows a relative positional relationship between the droplet and the driving electrode in the second stage.

[0025] Figure 6 The diagram shows a relative positional relationship between the droplet and the driving electrode in the third stage.

[0026] Figure 7 The diagram shows a relative positional relationship between the droplet and the driving electrode in the third stage.

[0027] Figure 8 The diagram shows a relative positional relationship between the droplet and the driving electrode in the third stage.

[0028] Figure 9 The diagram shows a relative positional relationship between the droplet and the driving electrode in the third stage.

[0029] Figure 10 The diagram shown is a driving timing diagram of a driving method for a microfluidic device provided in an embodiment of the present invention.

[0030] Figure 11 The diagram shown is a schematic of the driving electrode and the connected switch control line and data line;

[0031] Figure 12 The diagram shows a variation of the driving signal generated by the Nth driving electrode and the common electrode.

[0032] Figure 13 The diagram shown is a schematic of a driving circuit corresponding to the microfluidic driving device in this invention.

[0033] Figure 14 Fig. 1 shows a schematic diagram of a micro-fluidic driving device according to an embodiment of the present application; Figure 13 Fig. 2 shows a driving timing diagram corresponding to the driving circuit of the micro-fluidic driving device shown in Fig. 1;

[0034] Figure 15 Fig. 3 shows a schematic diagram of a driving circuit corresponding to the micro-fluidic driving device according to an embodiment of the present application;

[0035] Figure 16 Fig. 4 shows a schematic diagram of a micro-fluidic driving device according to an embodiment of the present application; Figure 15 Fig. 5 shows a driving timing diagram corresponding to the driving circuit of the micro-fluidic driving device shown in Fig. 4;

[0036] Figure 17 Fig. 6 shows a schematic diagram of a film layer of a driving layer in a micro-fluidic device according to an embodiment of the present application;

[0037] Figure 18 Fig. 7 shows a schematic diagram of a driving circuit corresponding to M driving electrodes;

[0038] Figure 19 Fig. 8 shows a schematic diagram of a structure of a driving electrode according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps, the numerical expressions, and the numerical values set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting to the scope of the application or its applications or uses.

[0041] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, the techniques, methods, and apparatus should be construed as being a part of the specification, where appropriate.

[0042] In all of the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not limiting. Thus, other examples of the exemplary embodiments can have different values.

[0043] Various modifications and changes can be made to the present application in light of the above teachings, it is therefore intended that the present application not be limited to the embodiment disclosed but to cover all modifications and changes as can come within the true spirit and scope of the present application. It should be noted that the embodiments provided by the present application can be combined with each other, if not in contradiction.

[0044] It should be noted that similar reference numerals and letters refer to like items in the several figures of the drawings described below, and that, as such, a discussion of the same item does not need to be repeated in each figure where such item is present.

[0045] Figure 1 Fig. 1 shows a flow chart of a driving method of a microfluidic device according to an embodiment of the present application, Figure 2 Fig. 2 shows a driving timing chart of a driving method of a microfluidic device according to an embodiment of the present application, wherein PN represents a driving voltage of a droplet at a position of an Nth driving electrode P, PN+1 represents a driving voltage of a droplet at a position of an N+1th driving electrode P, and PN+2 represents a driving voltage of a droplet at a position of an N+2th driving electrode P. Figure 3 Fig. 3 shows a structural schematic diagram of a microfluidic device according to an embodiment of the present application, please refer to Figure 1 and Figure 3 Fig. 4 shows a driving method of a microfluidic device according to an embodiment of the present application, wherein the microfluidic device comprises a first substrate 00, a driving layer 10 and a microfluidic structure layer 20, the driving layer 10 is located between the first substrate 00 and the microfluidic structure layer 20, the driving layer 10 comprises a plurality of driving electrodes P and a common electrode 11 arranged opposite to the driving electrodes P, and the microfluidic structure layer 20 comprises at least one first channel 21, the first channel 21 comprises M driving electrodes P arranged in sequence.

[0046] The driving method comprises:

[0047] S101, a droplet 30 is introduced into the first channel 21;

[0048] S102, in a first stage t1, please refer to Figure 2 and Figure 4 a first signal is provided to an Nth driving electrode P overlapped with the droplet 30, a constant signal is provided to the common electrode 11, a first driving voltage V1 is formed between the driving electrode P and the common electrode 11, and the droplet is fixed directly above the Nth driving electrode P, 1≤N≤M, wherein Figure 4 Fig. 5 shows a relative position relationship diagram between the droplet and the driving electrode P in the first stage.

[0049] S103, in a second stage t2, please refer to Figure 2 and Figure 5 the first signal provided to the Nth driving electrode P is cancelled, a second driving voltage V2 is formed between the Nth driving electrode P and the common electrode 11, and the absolute value of the second driving voltage is greater than 0 and less than the absolute value of the first driving voltage, wherein Figure 5Fig. 2 shows a diagram of a relative position relationship between the droplet and the driving electrode P in the second stage t2; it should be noted that the first signal provided to the Nth driving electrode P is cancelled, which means that the electric signal provided to the first driving electrode P is cancelled; alternatively, the first signal is a direct current voltage signal, and when the first signal provided to the Nth driving electrode P is cancelled, the direct current signal provided to the Nth driving electrode P is cancelled, that is, when the droplet has not completely left the position corresponding to the Nth driving electrode P, the electric signal provided to the Nth driving electrode P is cancelled, and the Nth electrode will not be provided with a continuous direct current signal.

[0050] S104, in the third stage t3, please refer to Figure 2 , Figure 5 to Figure 9 , the first signal is provided to the N+1th driving electrode P, and the first driving voltage is formed between the N+1th driving electrode P and the common electrode 11, wherein the second stage t2 and the third stage overlap, and wherein Figure 6 to Figure 9 Fig. 3 shows a diagram of a relative position relationship between the droplet and the driving electrode P in the third stage.

[0051] It should be noted that Figure 2 only a structure of the microfluidic device is shown, and does not represent the actual structure of the microfluidic device. Figure 4 to Figure 6 only the relative position relationship between the driving electrode P and the droplet is shown, and the actual shape and size of the driving electrode P and the droplet are not limited.

[0052] Specifically, please refer to Figure 1 to Figure 9 In the microfluidic device provided by the embodiment of the present application, the microfluidic device comprises a first substrate 00, a driving layer 10 arranged on the first substrate 00, and a microfluidic structure layer 20 arranged on the side of the driving layer 10 away from the first substrate 00, the microfluidic structure layer 20 comprises at least one first channel 21, and optionally, a plurality of first channels 21, the first channel 21 is used to accommodate a droplet that can be driven to flow. The driving layer 10 comprises a plurality of driving electrodes P and a common electrode 11 arranged opposite to the driving electrode P, and an electric signal is provided to the driving electrode P and the common electrode 11, so as to form a driving voltage for driving the droplet in the first channel 21 to move.

[0053] In the control method of the microfluidic device provided by the embodiment of the present application, after the droplet 30 is introduced into the first channel 21, the droplet 30 is driven through three stages, in the first stage t1, please refer to Figure 2 and Figure 4, first, the first signal is provided to the Nth driving electrode P overlapped with the droplet, and a constant signal is provided to the common electrode 11 to form the first driving voltage V1, so as to fix the droplet right above the Nth driving electrode P; in the second stage t2, the signal provided to the Nth driving electrode P is removed, and the voltage between the Nth driving electrode P and the common electrode 11 does not disappear suddenly, but gradually decreases to form the second driving voltage V2; please refer to Figure 2 and Figure 5 , in the third stage, the first signal is provided to the N+1th driving electrode P to form the first driving voltage V2 between the N+1th driving electrode P and the common electrode 11, and the third stage t3 overlaps with the second stage t2, that is, the second driving voltage provided by the Nth driving electrode P to the droplet and the first driving voltage provided by the N+1th driving electrode P to the droplet exist simultaneously, at this time, the front part of the droplet (the part adjacent to the N+1th driving electrode P) starts to move, please refer to Figure 5 , the tail part does not start to move, at this time, the moving speed of the droplet center is fast. Please refer to Figure 6 , as the droplet moves a distance towards the N+1th driving electrode P, the tail part of the droplet starts to move and forms a drag force to the front part of the droplet, and the overall speed of the droplet decreases. Please refer to Figure 7 to Figure 9 , when the tail part of the droplet catches up with the front part of the droplet, that is, the speeds of the two parts are consistent, the speed of the droplet increases under the driving voltage, moves towards the N+1th driving electrode P, and the contact area between the droplet and the N+1th driving electrode P becomes larger and larger. When the center of the droplet center coincides with the center of the N+1th driving electrode P, the first driving voltage fixes the droplet above the N+1th driving electrode P. In the second stage t2, even if the signal provided to the Nth driving electrode P is removed, the second driving voltage between the Nth driving electrode P and the common electrode 11 can still be maintained for a period of time to keep the shape of the droplet. When the first signal is applied to the N+1th driving electrode P in the third stage, the droplet still has a part located on the Nth driving electrode P, and the small second driving voltage V2 at the corresponding position of the Nth driving electrode P can still drive the droplet to move towards the N+1th driving electrode P, so that the first signal with a larger voltage value does not need to be continuously provided to the Nth driving electrode P in the driving process of the droplet, thereby ensuring the normal movement of the droplet and reducing the driving power consumption.

[0054] Figure 10 Fig. 1 shows a driving timing diagram of the driving method of the micro-fluidic device provided by the embodiment of the present application, in an optional embodiment of the present application, the starting time of the second stage t2 coincides with the starting time of the third stage t3.

[0055] Specifically, in the second stage t2, the electrical signal provided to the Nth driving electrode P is canceled, and in the third stage t3, the first signal is started to be provided to the N+1th driving electrode P. When the starting time of the second stage t2 coincides with the starting time of the third stage t3, it means that the first signal is provided to the N+1th driving electrode P at the same time when the electrical signal provided to the Nth driving electrode P is canceled. That is, although the first driving voltage is no longer provided to the liquid drop through the Nth driving electrode P, the first driving voltage is still provided to the liquid drop through the N+1th driving electrode P, which is beneficial to ensure the continuity of the liquid drop during the movement from the position corresponding to the Nth driving electrode P to the position corresponding to the N+1th driving electrode P, and thus, the starting time of the second stage t2 and the starting time of the third stage coincide, which is beneficial to reduce the driving power consumption and improve the driving efficiency.

[0056] Figure 11 A schematic diagram of the driving electrode P and the connected switch control line G and data line S is shown, wherein each driving electrode P is connected with a first transistor T1, the gate of the first transistor T1 is connected with the switch control line G, the first electrode is connected with the data line S, and the second electrode is connected with the driving electrode P. When the signal on the switch control line G controls the first transistor T1 to be turned on, the signal on the data line S can be transmitted to the driving electrode P through the first transistor T1. The present embodiment takes the first transistor T1 as an N-type transistor as an example, which is turned on at a high level and turned off at a low level, but the type of the first transistor T1 is not limited, and in some other embodiments of the present application, the first transistor T1 can also be a P-type transistor, and the present application does not make specific limitation thereon. In an optional embodiment of the present application, in the second stage t2, the second driving voltage gradually decreases.

[0057] Figure 12 A variation of the driving signal generated by the Nth driving electrode P and the common electrode 11 is shown, please combine with Figure 2 , Figure 10 , Figure 11 and Figure 12In the first stage, when the first signal is provided to the Nth driving electrode P through the data line S, the driving signal corresponds to a high level signal, and the corresponding voltage is the first driving voltage. In the second stage t2, when the first signal provided to the Nth driving electrode P is cancelled, due to the characteristics of the driving circuit connected to the Nth driving electrode P itself, the driving signal applied to the liquid droplet in the region corresponding to the Nth driving electrode P will not directly disappear. In the process of driving the liquid droplet to move, after the driving of the liquid droplet from the first driving electrode to the last driving electrode in the first channel is completed, optionally, the next time the liquid droplet is driven, the signal on the data line will be polarized. In this process, a feedthrough voltage is generated, so that the driving voltage provided to the liquid droplet decreases by a certain value δVp from the first driving voltage, and even if the first signal is no longer provided to the Nth driving electrode P, the position corresponding to the Nth driving electrode P can still provide a smaller second driving voltage to the liquid droplet. Wherein, δVp = (Cgs + Cpg) * (VGH - VGL) / (C1 + Cgs + Cpg), wherein C1, Cgs and Cpg are the storage capacitance in the driving circuit (the capacitance C1 will be described in subsequent embodiments), the parasitic capacitance between the gate and the source of the first transistor T1, and the parasitic capacitance between the gate and the driving electrode P, VGH is the on-state voltage provided by the switch control line G to the first transistor T1, and VGL is the off-state voltage provided by the switch control line G to the first transistor T1. From the above formula, it can be seen that δVp is strongly related to Cgs and Cpg, and the two parameters can be appropriately increased through structural design.

[0058] When the first signal is applied to the N+1th driving electrode P, the liquid droplet is still located at the Nth driving electrode P, and if the driving voltage in the region corresponding to the Nth driving electrode P disappears, the liquid droplet will be deformed and locally changed, thereby reducing the moving speed of the liquid droplet when crossing the gap between the two adjacent driving electrodes P. In this application, after the first signal provided to the Nth electrode is cancelled in the second stage t2, it can be known from the above formula that the second driving voltage will still be generated in the region corresponding to the Nth electrode, so that the driving signal applied to the liquid droplet between the two adjacent driving electrodes P can be connected. After driving the liquid droplet to move, the first signal provided to the Nth driving electrode P is cancelled, so that the driving voltage applied to the liquid droplet at the position of the Nth driving electrode P gradually decreases, and the liquid droplet can still be driven to move, and the driving power consumption can be effectively reduced and the energy efficiency can be improved.

[0059] Continue to refer to Figure 6 to Figure 7In an alternative embodiment of the present application, a first gap is included between the Nth driving electrode P and the N+1th driving electrode P, and in the second stage t2, the liquid drop overlaps the Nth driving electrode P and the N+1th driving electrode P, and the center of gravity of the liquid drop overlaps the first gap, or the center of gravity of the liquid drop overlaps the N+1th driving electrode P.

[0060] Specifically, when the liquid drop moves from the Nth electrode to the N+1th electrode, when the center of gravity of the liquid drop crosses the gap between the adjacent two driving electrodes P, the driving force at the tail of the liquid drop starts to move backward, i.e., the liquid drop does not move forward, and the liquid drop starts to decelerate. At this time, the driving voltage of the region corresponding to the Nth driving electrode P has little effect on the speed of the liquid drop, and therefore, the time when the center of gravity of the liquid drop overlaps the first gap or the time when the center of gravity of the liquid drop overlaps the N+1th driving electrode P is taken as the starting time of the second stage t2, and even if the first signal provided to the Nth driving electrode P is canceled, the lower second driving voltage generated at the position of the Nth driving electrode P will not affect the speed of the liquid drop. Instead, if the first signal (e.g., a direct current voltage) is still provided to the Nth driving electrode P in the second stage t2, it will cause waste of power consumption. Therefore, the present application selects to cancel the first signal provided to the Nth driving electrode P at the time when the center of gravity of the liquid drop overlaps the first gap or overlaps the N+1th driving electrode P, which can ensure the normal movement of the liquid drop and is beneficial to reduce the driving power consumption.

[0061] Figure 13 Fig. 1 shows a schematic diagram of a driving circuit corresponding to the micro-fluid driving device in the present application, Figure 14 Fig. 2 shows a driving timing diagram corresponding to the driving circuit in the present application, Figure 13 Fig. 3 shows a driving timing diagram corresponding to the driving circuit in the present application, wherein PN represents the driving voltage applied to the liquid drop by the position of the Nth driving electrode P, PN+1 represents the driving voltage applied to the liquid drop by the position of the N+1th driving electrode P, GN represents the signal on the switch control line G corresponding to the first transistor T1 connected to the Nth driving electrode P, and GN+1 represents the signal on the switch control line G corresponding to the first transistor T1 connected to the N+1th driving electrode P. The present embodiment only shows the connection relationship of the driving circuit corresponding to the adjacent two driving electrodes P, and does not show the actual driving circuit, and alternatively, one driving circuit is provided for each driving electrode P.

[0062] Please refer to Figure 13 and Figure 14In an optional embodiment of the present application, the driving layer 10 comprises a plurality of switch control lines G, a plurality of data lines S, and a plurality of driving circuits corresponding to the driving electrodes P, the driving circuit comprises a first transistor T1 and a first capacitor C1; in the driving circuits corresponding to the Nth driving electrode P and the N+1th driving electrode P, the gates of the first transistors T1 are respectively connected to different switch control lines G, the first poles of the first transistors T1 are connected to the same data line S, the second poles of the first transistors T1 are respectively connected to different driving electrodes P, the driving electrode P is connected to the first pole of the first capacitor C1, and the second pole of the first capacitor C1 receives a fixed voltage signal;

[0063] In the first stage t1, the switch control line G corresponding to the Nth driving electrode P provides an opening signal to the first transistor T1 corresponding to the Nth driving electrode P;

[0064] In the third stage t3, the switch control line G corresponding to the N+1th driving electrode P provides an opening signal to the first transistor T1 corresponding to the N+1th driving electrode P;

[0065] The first stage t1 and the third stage t3 do not overlap.

[0066] Optionally, the driving electrodes P in the same column are connected to the same data line S. In this embodiment, the first transistor T1 is taken as an N-type transistor for illustration, but the type of the first transistor T1 is not limited. Taking the Nth driving electrode P and the N+1th driving electrode P as an example, the first stage and the third stage do not overlap, which means that the first signal is not provided to the N+1th driving electrode P when the first signal is provided to the Nth driving electrode P to generate the first driving voltage for driving the liquid droplet, and the first signal is provided to the N+1th driving electrode P after the first signal provided to the Nth driving electrode P is canceled. In this way, the total time for providing the first signal to the driving electrode P during the liquid droplet driving process is reduced, that is, the time for providing the direct current voltage to the driving electrode P is reduced. Compared with the way of continuously providing the direct current voltage to the driving electrode P in the related art, the present application can reduce the driving power consumption while ensuring the normal driving of the liquid droplet.

[0067] Figure 15 Fig. 1 shows a schematic diagram of a driving circuit corresponding to the microfluidic driving device in the present application, Figure 16 Fig. 2 shows a driving timing diagram corresponding to the driving circuit in the present application, Figure 15 Fig. 3 shows a driving timing diagram corresponding to the driving circuit in the present application, Figure 13 Compared with the embodiment shown in Fig. 2, the embodiment shown in Fig. 3 introduces a second capacitor C1' in part of the driving circuits.

[0068] In an optional embodiment of the present invention, the driving layer 10 includes multiple switch control lines G, multiple data lines S, and multiple driving circuits corresponding to driving electrodes P. The driving circuits include a first transistor T1, a first capacitor C1, and a second capacitor C1'. In the driving circuits corresponding to the Nth driving electrode P and the (N+1)th driving electrode P, the gate of the first transistor T1 is connected to different switch control lines G, the first electrode of the first transistor T1 is connected to the same data line S, and the second electrodes of different first transistors T1 are connected to different driving electrodes P. The driving electrode P is connected to the first electrode of the first capacitor C1, and the second electrode of the first capacitor C1 receives a fixed voltage signal. The Nth driving electrode P is electrically connected to the switch control line G corresponding to the (N+1)th driving electrode P through the second capacitor C1'. In the third stage, an enable signal is provided to the first transistor T1 corresponding to the (N+1)th driving electrode P through the switch control line G, and the enable signal is coupled to the Nth driving electrode P through the second capacitor C1'.

[0069] Specifically, this embodiment provides another driving circuit for driving the driving electrode P in a microfluidic device, and... Figure 13 and Figure 14 Compared to the illustrated embodiment, a second capacitor C1' is introduced between the switch control line G corresponding to the Nth driving electrode P and the (N+1)th driving electrode P. In the third stage, after the switch control line G provides an enable signal to the first transistor T1 corresponding to the (N+1)th driving electrode P, since the switch control line G is connected to the Nth driving electrode P through the second capacitor C1', when the signal on the switch control line G becomes a high-level signal, the voltage on the Nth driving electrode P will also increase due to the capacitive coupling effect. This helps to increase the driving voltage at the position corresponding to the Nth driving electrode P, thus improving the driving efficiency of the droplet.

[0070] Please refer to Figure 15 and Figure 16 In an optional embodiment of the present invention, in the first stage t1, the switch control line G corresponding to the Nth driving electrode P provides an enable signal to the first transistor T1 corresponding to the Nth driving electrode P; the third stage t3 overlaps with the first stage t1, and the start time of the third stage t3 is after the start time of the first stage t1.

[0071] Continue to refer to Figure 15 and Figure 16, the first stage t1 is a stage of providing the first signal to the Nth driving electrode P, and the third stage t3 is a stage of providing the first signal to the N+1th driving electrode P, in the embodiment, the third stage t3 overlaps the first stage t1, and the starting moment of the third stage t3 is after the starting moment of the first stage t1. It can be understood that during the period of providing the first signal to the Nth driving electrode P, the first transistor T1 corresponding to the N+1th driving electrode P is turned on, and the first signal is provided to the N+1th driving electrode P. Since the switch control line G corresponding to the N+1th driving electrode P is connected to the Nth driving electrode P through the second capacitor C1', when the first transistor T1 corresponding to the N+1th driving electrode P is provided with a high-level opening signal through the switch control line G, due to the coupling effect of the second capacitor C1', the driving voltage originally applied to the Nth driving electrode P will be raised, which is equivalent to increasing the value of the first driving voltage in the part of the first stage t1 overlapping with the third stage t3. In this way, without increasing the voltage value of the first signal provided to the Nth driving electrode P through the data line S, the driving voltage of the region corresponding to the Nth driving electrode P on the liquid droplet can be increased through capacitive coupling, so as to improve the driving efficiency of the liquid droplet and reduce the overall driving power consumption.

[0072] Based on the same inventive concept, the present application also provides a microfluidic device, for example, please refer to Figure 3 and Figure 17 , Figure 17 Figure 1 shows a schematic diagram of a film layer of a driving layer 10 in a microfluidic device, the microfluidic device comprising: a first substrate 00, a driving layer 10 and a microfluidic structure layer 20, the driving layer 10 being located between the first substrate 00 and the microfluidic structure layer 20, the driving layer 10 comprising a plurality of driving electrodes P and a common electrode 11 arranged opposite to the driving electrodes P, the microfluidic structure layer 20 comprising at least one first channel 21, the first channel 21 comprising M driving electrodes P arranged in sequence;

[0073] Please refer to Figure 15The driving layer 10 further comprises a plurality of switch control lines G, a plurality of data lines S and a plurality of driving circuits corresponding to the driving electrodes P; at least part of the driving circuits comprises a first transistor T1, a first capacitor C1 and a second capacitor C1'; in the same first channel 21, in the driving circuits corresponding to the Nth driving electrode P and the N+1th driving electrode P, the gates of the first transistors T1 are respectively connected to different switch control lines G, the first poles of the first transistors T1 are connected to the same data line S, and the second poles of different first transistors T1 are respectively connected to different driving electrodes P; the driving electrode P is connected to the first pole of the first capacitor C1, and the second pole of the first capacitor C1 receives a fixed voltage signal; the Nth driving electrode P is electrically connected to the switch control line G corresponding to the N+1th driving electrode P through the second capacitor C1', and 1≤N

[0074] Specifically, in the microfluidic device provided by the embodiment of the present application, a first substrate 00 is oppositely arranged, a driving layer 10 is arranged on the first substrate 00, and a microfluidic structure layer 20 is arranged on the side of the driving layer 10 away from the first substrate 00. The microfluidic structure layer 20 comprises at least one first channel 21, and optionally, a plurality of first channels 21. The first channel 21 is used for accommodating a droplet that can be driven to flow. The driving layer 10 comprises a plurality of driving electrodes P and a common electrode 11 oppositely arranged with the driving electrodes P. An electrical signal is provided to the driving electrodes P and the common electrode 11, so as to form a driving voltage for driving the droplet in the first channel 21 to move. Optionally, the signal provided to the common electrode 11 is a constant voltage signal. When another signal different from the constant voltage signal is provided to the driving electrode P, a driving voltage for driving the droplet to move is formed between the driving electrode P and the common electrode 11.

[0075] The driving layer 10 is provided with a switch control line G, a data line S and a driving circuit. The driving circuit comprises a first transistor T1, a first capacitor C1 and a second capacitor C1'. The Nth driving electrode P is connected to the switch control line G corresponding to the N+1th driving electrode P through the second capacitor C1'. When an opening signal is provided to the first transistor T1 corresponding to the N+1th driving electrode P through the switch control line G in the third stage, the switch control line G corresponding to the N+1th driving electrode P is connected to the Nth driving electrode P through the second capacitor C1'. When the signal on the switch control line G becomes a high-level signal, the voltage on the Nth driving electrode P is also increased due to the coupling effect of the second capacitor C1', for example, please refer to Figure 16 Thus, the driving voltage of the position corresponding to the Nth driving electrode P is improved, and the driving efficiency of the droplet is improved.

[0076] Please refer to Figure 15 and Figure 16In an alternative embodiment of the present application, the time when the switch control line G corresponding to the N+1th driving electrode P sends an effective pulse overlaps with the time when the switch control line G corresponding to the Nth driving electrode P sends an effective pulse.

[0077] In the present embodiment, the time when the switch control line G corresponding to the N+1th driving electrode P sends an effective pulse overlaps with the time when the switch control line G corresponding to the Nth driving electrode P sends an effective pulse can be understood as that during the time when the first signal is provided to the Nth driving electrode P, the first transistor T1 corresponding to the N+1th driving electrode P is turned on and the first signal is provided to the N+1th driving electrode P. Since the switch control line G corresponding to the N+1th driving electrode P is connected to the Nth driving electrode P through the second capacitor C1', when the first transistor T1 corresponding to the N+1th driving electrode P is provided with a high-level turn-on signal through the switch control line G, due to the coupling effect of the second capacitor C1', the driving voltage originally applied to the Nth driving electrode P will be raised, which is equivalent to increasing the value of the first driving voltage in the part of the first stage overlapping with the third stage. In this way, without increasing the voltage value of the first signal provided to the Nth driving electrode P through the data line S, the driving voltage of the region corresponding to the Nth driving electrode P to the liquid drop can be increased through capacitive coupling, thus being beneficial to improving the driving efficiency to the liquid drop and reducing the overall driving power consumption.

[0078] Figure 18 A schematic diagram of the driving circuit corresponding to the M driving electrodes P is shown. Please refer to Figure 3 and Figure 18 In an alternative embodiment of the present application, the driving circuit corresponding to the first to M-1th driving electrodes P in the first channel 21 all includes the first transistor T1, the first capacitor C1 and the second capacitor C1', and the driving circuit corresponding to the Mth driving electrode P includes the first transistor T1 and the first capacitor C1.

[0079] Specifically, when the first channel 21 includes M driving electrodes P, the driving circuit corresponding to the first driving electrode P to the M-1th driving electrode P is provided with a second capacitor C1', which is used to electrically connect the switch control line G corresponding to the current driving electrode P with the last driving electrode P. In this way, when the first signal is provided to the current driving electrode P, due to the coupling effect of the second capacitor C1', the driving signal value corresponding to the last driving electrode P will be raised, and the driving voltage applied to the liquid drop will also be increased, thereby facilitating the improvement of the driving ability of the liquid drop by the driving electrode P except for the last driving electrode P. Since it is not necessary to raise the voltage value of the first signal provided to the driving electrode P through the data line S, the driving voltage of the liquid drop can be improved, thereby facilitating the improvement of the overall driving ability of the liquid drop while reducing power consumption.

[0080] It should be noted that since the liquid drop has reached the edge of the driving area when it moves to the last driving electrode P in the first channel 21, it does not need to move further, and thus it is not necessary to provide an additional signal to the last driving electrode P in the first channel 21 to drive the liquid drop to move further. Therefore, the driving circuit corresponding to the last driving electrode P in the first channel 21 does not need to be provided with a second capacitor C1', thereby facilitating the simplification of the structure of the driving circuit corresponding to the last driving electrode P.

[0081] Continuing to refer to Figure 17 In an optional embodiment of the present application, the driving layer 10 includes a first metal layer M1, a second metal layer M2 and an electrode layer T0, the second metal layer M2 is located between the first metal layer M1 and the electrode layer T0, and the second metal layer M2 is insulated from the first metal layer M1 and the electrode layer T0; the gate of the first transistor T1 is located on the first metal layer M1, the source and the drain of the first transistor T1 and the common electrode 11 are located on the second metal layer M2, and the driving electrode P is located on the electrode layer T0.

[0082] Optionally, the driving layer 10 is arranged on the first substrate 00, and the electrode layer T0 is located on the side of the second metal layer M2 away from the first substrate 00. That is, the film layer in which the driving electrode P is arranged is arranged close to the liquid drop, so as to reduce the distance between the driving electrode P and the liquid drop, thereby improving the driving ability of the driving voltage generated by the driving electrode P and the common electrode 11 on the liquid drop.

[0083] Optionally, please refer to Figure 17 and Figure 18The switch control line G in the driving layer 10 is located in the first metal layer M1, the data line is located in the second metal layer M2, and the common electrode 11 is also located in the second metal layer M2. In this way, when the switch control line G, the data line S and the first transistor T1 are introduced in the driving layer 10, only two metal layers need to be arranged on the driving layer 10 to realize the layout, thus effectively reducing the number of masks required for manufacturing these film layers, reducing the process required for manufacturing the driving layer 10, and thus facilitating the simplification of the manufacturing process of the microfluidic device.

[0084] With reference to the foregoing description Figure 17 In an optional embodiment of the present application, the array layer further comprises a first auxiliary conductive block K1 arranged in the first metal layer M1 and a second auxiliary conductive block K2 arranged in the second metal layer M2. In the thickness direction of the microfluidic device, the first auxiliary conductive block K1 overlaps with the common electrode 11 to form a first capacitor C1, and the second auxiliary conductive block K2 overlaps with the gate of the first transistor T1 in the driving circuit corresponding to the N+1th driving electrode P to form a second capacitor C1'. The Nth driving electrode P is electrically connected to the first auxiliary conductive block K1 and the second auxiliary conductive block K2 through the connection hole.

[0085] Specifically, Figure 17 The relative position relationship and connection relationship of the Nth driving electrode Pn, the first transistor T1 corresponding to the Nth driving electrode P, and the first transistor T1 corresponding to the N+1th driving electrode P are shown. Please refer to Figure 17 and Figure 18 The driving circuit corresponding to the driving electrode P, the switch control line G and the data line S are distributed in the film layer between the electrode layer T0 and the first substrate 00. In this embodiment, the first auxiliary conductive block K1 is introduced in the first metal layer M1, which is used to overlap with the common electrode 11 on the second metal layer M2 to form the first capacitor C1; and the second auxiliary conductive block K2 is introduced in the second metal layer M2, which is used to overlap with the gate of the first transistor T1 corresponding to the N+1th driving electrode P to form the second capacitor C1', i.e. the second capacitor C1' is arranged between the switch control line G corresponding to the N+1th driving electrode P and the Nth driving electrode P. When a high-level signal is provided to the switch control line G corresponding to the N+1th driving electrode P to control the corresponding first transistor T1 to be turned on, due to the coupling effect of the second capacitor C1', the potential on the Nth driving electrode P will also be raised, thereby facilitating the enhancement of the driving ability of the region corresponding to the Nth driving electrode P to the liquid droplet. In this embodiment, the first capacitor C1 and the second capacitor C1' are formed by utilizing the existing film layer structure in the driving layer 10, without the need to introduce a new film layer structure in the driving layer 10, thus facilitating the simplification of the manufacturing process of the driving layer 10 and improving the production efficiency of the microfluidic device while enhancing the driving ability to the liquid droplet.

[0086] Figure 19 Fig. 1 shows a structural schematic diagram of the driving electrode P provided by the embodiment of the present application, and the embodiment takes the edge of the driving electrode P as a wave shape for example. Figure 4 and Figure 19 In an alternative embodiment of the present application, the shape of the driving electrode P is the same, and in the first channel 21, the first edge B1 of the Nth driving electrode P and the second edge B2 of the N+1th driving electrode P are adjacent, and the width of the first gap between the first edge B1 and the second edge B2 is equal everywhere.

[0087] Figure 4 to Figure 9 and Figure 19 respectively show two shapes of the driving electrode P, Figure 4 to Figure 9 the driving electrode P is square in the embodiment, Figure 19 In the embodiment, the four edges of the driving electrode P are all wave-shaped, but the actual structure of the driving electrode P is not limited, and in some other embodiments of the present application, the driving electrode P can also be in other shapes, for example, the edge is sawtooth-shaped, and the like.

[0088] In the embodiment, the first edge B1 of the Nth driving electrode P and the second edge B2 of the N+1th driving electrode P are adjacent, and the width of the interval between the first edge B1 and the second edge B2 is equal everywhere, so that when the liquid drop reaches the interval between the adjacent two driving electrodes P, it is beneficial to avoid the phenomenon that the liquid drop is obviously unevenly stressed due to the different width of the first gap.

[0089] Please combine Figure 15 and Figure 16 In an alternative embodiment of the present application, the first transistor T1 in the driving circuit is an amorphous silicon thin film transistor or an oxide transistor. When the amorphous silicon thin film transistor or the oxide transistor is used, its gate is turned on when receiving a high-level signal, and when the second capacitor C1' is introduced between the switch control line G corresponding to the Nth driving electrode P and the N+1th driving electrode P, due to the coupling effect of the second capacitor C1', when a high-level signal is provided to the switch control line G of the N+1th driving electrode P, the voltage signal on the Nth driving electrode P will also be coupled to be increased, thereby being beneficial to improve the driving ability of the Nth driving electrode P on the liquid drop, and also being beneficial to reduce the driving power consumption.

[0090] In summary, the driving method of the microfluidic device and the microfluidic device provided by the present application at least achieve the following beneficial effects:

[0091] The microfluidic device provided by the embodiment of the present application comprises a driving layer and a microfluidic structure layer, wherein the microfluidic structure layer comprises at least one first channel for accommodating a liquid drop; the driving layer comprises oppositely arranged driving electrodes and a common electrode; when an electric signal is provided to the driving electrodes and the common electrode, a driving voltage for driving the liquid drop to move is formed between the driving electrodes and the common electrode. In the control method of the microfluidic device provided by the embodiment of the present application, after the liquid drop is introduced into the first channel, the liquid drop is driven through three stages. In the first stage, a first signal is first provided to an Nth driving electrode overlapping the liquid drop, and a constant signal is provided to the common electrode to form a first driving voltage, so as to fix the liquid drop directly above the Nth driving electrode; in the second stage t2, the signal provided to the Nth driving electrode is cancelled, and the voltage between the Nth driving electrode and the common electrode does not suddenly disappear, but gradually decreases to form a second driving voltage; in the third stage, a first signal is provided to an N+1th driving electrode to form a first driving voltage between the N+1th driving electrode and the common electrode, the third stage overlaps the second stage t2, that is, the second driving voltage provided by the Nth driving electrode to the liquid drop and the first driving voltage provided by the N+1th driving electrode to the liquid drop exist at the same time, at this time, the front part (the part adjacent to the N+1th driving electrode) of the liquid drop starts to move, and the tail part does not start to move, at this time, the moving speed of the gravity center of the liquid drop is relatively fast. With the movement of the liquid drop to the N+1th driving electrode by a distance, the tail part of the liquid drop starts to move and forms a drag force to the front part of the liquid drop, and the overall speed of the liquid drop is reduced. When the gravity center of the liquid drop coincides with the center of the N+1th driving electrode, the first driving voltage fixes the liquid drop above the N+1th driving electrode. In the second stage t2, even if the electric signal provided to the Nth driving electrode is removed, the second driving voltage between the Nth driving electrode and the common electrode can still be maintained for a period of time to maintain the shape of the liquid drop. When the first signal is applied to the N+1th driving electrode in the third stage, part of the liquid drop is still located on the Nth driving electrode, and the smaller second driving voltage at the corresponding position of the Nth driving electrode can still drive the liquid drop to move to the direction of the N+1th driving electrode, so that the first signal with a larger voltage value does not need to be continuously provided to the Nth driving electrode in the driving process of the liquid drop, thereby ensuring the normal movement of the liquid drop and reducing the driving power consumption.

[0092] While certain specific embodiments of the application have been described in detail herein for the purposes of exemplification and to provide a thorough and enabling disclosure, it will be understood that the application is not limited to the particular embodiments described. Any modifications of the methods and materials described herein, which come within the scope and spirit of the application, are to be considered within the scope of the application. The scope of the application is to be determined by the claims appended hereto, which are to be construed in accordance with the principles of patent law.

Claims

1. A microfluidic device, characterized in that, The application relates to a microfluidic device. The microfluidic device comprises a first substrate, a driving layer and a microfluidic structure layer, the driving layer is arranged between the first substrate and the microfluidic structure layer, the driving layer comprises a plurality of driving electrodes and a common electrode arranged opposite to the driving electrodes, and the microfluidic structure layer comprises at least one first channel, and the first channel comprises M driving electrodes arranged in sequence. The driving layer further comprises a plurality of switch control lines, a plurality of data lines and a plurality of driving circuits corresponding to the driving electrodes; at least part of the driving circuits comprises a first transistor, a first capacitor and a second capacitor; in the same first channel, in the driving circuits corresponding to the Nth driving electrode and the N+1th driving electrode, the gates of the first transistors are respectively connected to different switch control lines, the first poles of the first transistors are connected to the same data line, and the second poles of different first transistors are respectively connected to different driving electrodes. The driving electrodes are connected to the first poles of the first capacitors, and the second poles of the first capacitors receive a fixed voltage signal; the Nth driving electrode is electrically connected to the switch control line corresponding to the N+1th driving electrode through the second capacitor, and 1<=N The time when the switch control line corresponding to the N+1th driving electrode sends an effective pulse overlaps with the time when the switch control line corresponding to the Nth driving electrode sends an effective pulse.

2. The microfluidic device of claim 1, wherein, In the first channel, the driving circuits corresponding to the first to M-1th driving electrodes all comprise the first transistor, the first capacitor and the second capacitor, and the driving circuit corresponding to the Mth driving electrode comprises the first transistor and the first capacitor.

3. The microfluidic device of claim 1, wherein, The driving layer comprises a first metal layer, a second metal layer and an electrode layer, the second metal layer is arranged between the first metal layer and the electrode layer, and the second metal layer is isolated from the first metal layer and the electrode layer by an insulating layer; The gate of the first transistor is located in the first metal layer, the source and the drain of the first transistor and the common electrode are located in the second metal layer, and the driving electrode is located in the electrode layer.

4. The microfluidic device of claim 3, wherein, Further comprising a first auxiliary conductive block arranged in the first metal layer and a second auxiliary conductive block arranged in the second metal layer, along the thickness direction of the microfluidic device, the first auxiliary conductive block overlaps with the common electrode to form the first capacitor, and the second auxiliary conductive block overlaps with the gate of the first transistor in the driving circuit corresponding to the N+1th driving electrode to form the second capacitor; the Nth driving electrode is electrically connected to the first auxiliary conductive block and the second auxiliary conductive block through a connecting hole.

5. The microfluidic device of claim 1, wherein, The shapes of the driving electrodes are the same, in the first channel, the first edge of the Nth driving electrode and the second edge of the N+1th driving electrode are adjacent, and the width of the first gap between the first edge and the second edge is equal everywhere.

6. The microfluidic device of claim 1, wherein, The first transistor is an amorphous silicon thin film transistor or an oxide transistor.

7. The microfluidic device of claim 1, wherein, The edge of the driving electrode is wavy.

8. The microfluidic device of claim 1, wherein, The edge of the driving electrode is zigzag.

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