Patent ID: 12251699

DETAIL DESCRIPTION OF EMBODIMENTS

In order that those skilled in the art will better understand the technical solutions of the present disclosure, the following detailed description is given with reference to the accompanying drawings and the specific embodiments.

In the present disclosure, two structures “disposed in a same layer” mean that they are formed by a same material layer through a photolithography process or the like, and therefore they are in the same layer in the stacking relationship; however, it does not mean that they are equidistant from the substrate, nor means that other layer structures interposed between the substrate and each of the two structures are the same.

In the present disclosure, two structures “disposed in different layers” mean that the two structures are not “disposed in the same layer” as defined above, but are disposed in different layers; however, it does not necessarily mean that their distances from the substrate are different.

In the present disclosure, the case where structure A is disposed on “a side of structure B away from the substrate” means that structure A and structure B are disposed on the same side of the substrate but in different layers, and the layer in which structure A is disposed is farther away from the substrate than the layer in which structure B is disposed. Therefore, if both structure A and structure B exist at the same position in a horizontal direction, structure A is necessarily farther from the substrate than structure B, but it does not mean that the distance between structure A and the substrate at any position in the horizontal direction is larger than the distance between structure B and the substrate at any position in the horizontal direction.

In the present disclosure, “row” and “column” merely mean two intersecting (especially orthogonal) and relative directions, regardless of the shape, placement, etc. of the substrate product.

As shown inFIG.1, a conventional micro-fluidic structure includes two opposing substrates, one of which is provided with an array of driving electrodes51, the other of which is provided with a common electrode52. Two respective sides of the two substrates, that face each other, are each provided with a lyophobic layer99(i.e., a layer having lyophobicity to a droplet), and the droplet9is between the two lyophobic layers99. When a predetermined common voltage is applied to the common electrode52, a predetermined driving electric field can be caused at and around the droplet9by applying different driving voltages to the driving electrodes51at different positions relative to the droplet9, which causes specific deformation and movement of the droplet9, thereby controlling the droplet9.

It is noted that, in order to avoid the electric conduction between different driving electrodes51, there is a gap space59between adjacent driving electrodes51, and no electric field is formed at the gap space59. Therefore, if the gap space59is too large, the droplet9cannot move continuously during the movement of the droplet9, and if the gap space is too small, adjacent driving electrodes51are liable to be electrically coupled, which results in failure of the fabricated micro-fluidic structure.

The present embodiment provides a micro-fluidic substrate including a substrate provided with a plurality of driving electrodes for driving a droplet to move. The driving electrodes are disposed in the same layer, and a gap space is between adjacent driving electrodes. The micro-fluidic substrate further includes at least one auxiliary electrode on the substrate and configured to drive the droplet to move, and the auxiliary electrode is at least partially disposed in the gap space and is in a different layer from the driving electrodes.

According to an embodiment of the present disclosure, the auxiliary electrode and the driving electrodes are in different layers, which may mean that the auxiliary electrode and the driving electrodes are spaced apart from each other in a thickness direction by an insulating layer.

In an embodiment of the present disclosure, as shown inFIG.13, the term “gap space” indicates a gap between adjacent driving electrodes51and all spaces vertically above and vertically under the gap (i.e., a gray region inFIG.13). That is, a portion between and surrounded by adjacent driving electrodes is the gap, and the gap and its extension portion in the direction perpendicular to the substrate is the gap space.

In the micro-fluidic substrate of the embodiment, the auxiliary electrode capable of driving the droplet to move is disposed at the gap space between the driving electrodes. The auxiliary electrode and the driving electrodes are in different layers, and thus the auxiliary electrode and the driving electrodes may overlap with each other. Therefore, the driving electric field can be formed at the gap space between the driving electrodes, thereby eliminating or reducing the space where the driving electric field cannot be formed, and controlling the droplet more smoothly.

As shown inFIGS.2to13, the present embodiment provides a micro-fluidic substrate, which includes:a substrate8;a plurality of driving electrodes51disposed on the substrate8and configured to drive the droplet9to move, the driving electrodes51being in a same layer with a gap space59between every two adjacent driving electrodes51; andat least one auxiliary electrode6disposed on the substrate8and configured to drive the movement of the droplet9, the auxiliary electrode6being at least partially provided in the gap space59and in a different layer from the driving electrodes51.

The substrate8is a substrate for carrying other structures, and may have a plate shape. The plurality of driving electrodes51are disposed in a same layer and arranged in an array (e.g., a rectangular array), and are configured to apply a driving voltage to drive the droplet9to move. It is noted that, since the driving electrodes51are disposed in the same layer with a gap space provided therebetween, the driving electrodes51cannot contact each other, so as to ensure that different driving electrodes51are insulated from each other.

In the micro-fluidic substrate of the embodiment, the auxiliary electrode6is further provided in the gap space59between the driving electrodes51. In the embodiment, the auxiliary electrode6is disposed on a side of the substrate8provided with the driving electrodes51. The auxiliary electrode6can also be applied with the driving voltage to drive the droplet9to move, thereby eliminating or reducing the space where the driving electric field cannot be formed, and controlling the droplet9more smoothly.

According to an embodiment of the present disclosure, an orthographic projection of the auxiliary electrode6on the substrate8at least covers an orthographic projection of the gap space59on the substrate8.

According to an embodiment of the present disclosure, the orthographic projection of the auxiliary electrode6on the substrate8coincides with the orthographic projection of the gap space59on the substrate8.

The auxiliary electrode6and the driving electrodes51are in different layers, and therefore, different driving electrodes51will be not electrically connected with each other even if the orthographic projection of the auxiliary electrode6on the substrate overlaps with the orthographic projection of the driving electrodes51on the substrate8. As shown inFIGS.2to4, the auxiliary electrode6(e.g., a first auxiliary electrode61and a second auxiliary electrode62described later) may cover the gap space59(e.g., a row gap space591and a column gap space592described later) where the auxiliary electrode6is located, for example, may extend beyond the gap space59, referring toFIG.6, to completely eliminate the space where the driving electric field cannot be formed. According to an embodiment of the present disclosure, in order to prevent the auxiliary electrode6from affecting the electric field caused by the driving electrodes51themselves, the orthographic projection of the auxiliary electrode6on the substrate8may completely overlap with the orthographic projection of the gap space59where the auxiliary electrode6is located.

According to the embodiment of the present disclosure, the auxiliary electrode6is disposed on the side of the driving electrodes51away from the substrate8.

As shown inFIGS.3and4, when the auxiliary electrode6and the driving electrodes51are disposed on the same side of the substrate8, the auxiliary electrode6can be farther away from the substrate8than the driving electrodes51, so that the process for fabricating the structure related to the driving electrodes51does not need to be changed, and the process can be easily implemented by adding a step of fabricating the auxiliary electrode6after the driving electrodes51are fabricated.

According to an embodiment of the present disclosure, the auxiliary electrode6may be made of a metal material.

According to an embodiment of the present disclosure, the driving electrodes51are arranged in an array, with a row gap space591between adjacent rows of driving electrodes51and a column gap space592between adjacent columns of driving electrodes51.

According to an embodiment of the present disclosure, the auxiliary electrode6includes a first auxiliary electrode61at least partially disposed in the row gap space591and having a strip shape, and a second auxiliary electrode62at least partially disposed in the column gap space592and having a strip shape, the second auxiliary electrode62being insulated from the first auxiliary electrode61.

As shown inFIG.2, the driving electrodes51are usually disposed in a matrix in a plurality of rows and columns, so that a plurality of “row gap spaces591” extending in a row direction and a plurality of “column gap spaces592” extending in the column direction may be formed therein, and the auxiliary electrodes6may include first auxiliary electrodes61arranged along the row gap spaces591and second auxiliary electrodes62arranged along the column gap spaces592. In this case, the first auxiliary electrodes61and the second auxiliary electrodes62are insulated to avoid signal interference therebetween.

According to an embodiment of the present disclosure, each row gap space591is provided with one first auxiliary electrode61having a strip shape, and each column gap space592is provided with one second auxiliary electrode62having a strip shape.

That is, the first auxiliary electrodes61may be disposed in all of the row gap spaces591, there is only one first auxiliary electrode61in each row gap space591, and the one first auxiliary electrode61fills the row gap space591; similarly, there is only one second auxiliary electrode62in each column gap space592and the one second auxiliary electrode62fills the column gap space592. In other words, the auxiliary electrode6completely occupies the space of the gap space59when viewed in a plan view. In this way, all of the gap spaces51may be filled with the auxiliary electrodes6, thereby completely eliminating the space where the driving electric field cannot be formed, and improving the driving accuracy. Since only one auxiliary electrode6is provided in each gap space59, the total number of auxiliary electrodes6is not too large, which facilitates the control thereof. For example, a signal can be directly provided to one auxiliary electrode6through each port of a driving chip (IC).

According to an embodiment of the present disclosure, the second auxiliary electrode62and the first auxiliary electrode61are in different layers with an overlap therebetween, and an insulating layer is disposed between the second auxiliary electrode62and the first auxiliary electrode61at least at the overlap.

When the first auxiliary electrode61and the second auxiliary electrode62fill the row gap space591and the column gap space592, respectively, they must overlap, as shown inFIG.2, at the intersection of the row gap space591and the column gap space592. To simplify the structure, the first auxiliary electrode61and the second auxiliary electrode62may be in different layers, and as shown inFIG.5, they may be separated by an insulating layer (e.g., a fourth passivation layer808) at the overlap.

According to an embodiment of the present disclosure, the micro-fluidic substrate further includes a plurality of first gate lines31extending in the row direction, a plurality of driving lines41extending in the column direction, and a plurality of driving transistors D1. In an embodiment, each of the driving electrodes51and each of the driving transistors D1are disposed between adjacent first gate lines31and between adjacent driving lines41. The driving transistor D1is configured to control the driving voltage applied to the driving electrode51to drive the droplet9on the driving electrode to move. In the embodiment, the driving electrode51corresponds to the driving transistor D1that controls the driving electrode51.

According to an embodiment of the present disclosure, the driving electrodes51are arranged in an array, with a row gap space591between adjacent rows of the driving electrodes51and a column gap space592between adjacent columns of the driving electrodes51.

According to an embodiment of the present disclosure, referring toFIG.2andFIG.14showing details of a part ofFIG.2, each driving electrode51is coupled to a first electrode of the driving transistor D1corresponding thereto, gate electrodes of respective driving transistors D1corresponding to each row of driving electrodes51are coupled to one of the first gate lines31, and second electrodes of respective driving transistors D1corresponding to each column of driving electrodes51are coupled to one of the driving lines41.

As shown inFIG.2, since the number of the driving electrodes51is large, they can be controlled by a transistor array. That is, a turn-on signal is provided to respective first gate lines31in turn, so that respective rows of the driving transistors D1are turned on in turn. When a certain row of the driving transistors D1are turned on, driving voltages can be provided to the row of respective driving electrodes51through respective driving lines41. Thus, a large number of driving electrodes51can be controlled with a few lead wires.

According to an embodiment of the present disclosure, the auxiliary electrode6includes the first auxiliary electrode61and the second auxiliary electrode62. The first gate line31is disposed in the row gap space591, the first auxiliary electrode61is also disposed in the row gap space591where the first gate line31is disposed, and the first auxiliary electrode61is on a side of the first gate line31away from the substrate8(seeFIG.3). The driving line41is disposed in the column gap space592, and the second auxiliary electrode62is disposed in the column gap space592where the driving line41is disposed, and the second auxiliary electrode62is located on a side of the driving line41away from the substrate8(seeFIG.4).

According to an embodiment of the disclosure, the first gate line31, the driving line41, the first auxiliary electrode61and the second auxiliary electrode62may be disposed on the same side of the substrate, as shown inFIGS.2,3and4, the first gate line31and the driving line41may also be respectively in the row gap space591and the column gap space592. At this time, the corresponding first auxiliary electrode61and the corresponding second auxiliary electrode62are respectively above the first gate line31and the driving line41, so as to shield the signals in the first gate line31and the driving line41from affecting the droplet9.

According to an embodiment of the present disclosure, referring toFIG.6, the auxiliary electrodes6each have block shape, and each auxiliary electrode6is located in the gap space59between two adjacent driving electrodes51and is electrically coupled to one driving electrode51adjacent thereto.

That is, as shown inFIG.6, the auxiliary electrode6may not have a shape of strip, but may have a shape of “small block”, and each auxiliary electrode6is only located between two adjacent driving electrodes51, and at the same time, the auxiliary electrode6is also electrically coupled to one of the driving electrodes51adjacent to the auxiliary electrode (for example, electrically coupled through a via hole penetrating through an insulating layer between the auxiliary electrode6and the one driving electrode51, and a black dot inFIG.6represents a via hole), so that the signal via the auxiliary electrode6is the same as the signal via the one driving electrode51. Thus, the driving electrode51is “expanded” into the gap space59, and thus, the space where the driving electric field cannot be formed can be reduced.

It is noted that, respective sides of one driving electrode51are provided with the gap spaces59. The auxiliary electrodes6having a block shape may be provided in each of the gap spaces59, or only some of the gap spaces59are provided with the auxiliary electrode6, or none of the gap spaces59provided with the auxiliary electrode6. Each of the driving electrodes51may be coupled to only one auxiliary electrode6adjacent thereto, may be coupled to a plurality of auxiliary electrodes6, or may not be coupled to any of the auxiliary electrodes6.

It is noted that, in view of a regular layout, each driving electrode51is coupled to the auxiliary electrodes6at gap spaces59on the same side of the driving electrode51. For example, each of the driving electrodes51may be coupled to the auxiliary electrodes6on the right and upper sides thereof, as shown inFIG.6.

According to an embodiment of the present disclosure, the micro-fluidic substrate further includes a plurality of photosensitive elements D3on the substrate8.

In the micro-fluidic technology, in many cases, only the position of the droplet9is determined can the droplet be driven. In addition, in some cases, the concentration, composition, etc. of the droplet9need to be detected, which can be implemented by setting the photosensitive element D3(which may be disposed on a side of the substrate8provided with the driving electrodes51), and therefore the photosensitive element D3may be disposed on the substrate8.

According to an embodiment of the present disclosure, as shown inFIG.10(for simplicity, part of the structure is not shown in the figure), light can be transmitted to the substrate8of the micro-fluidic substrate through an optical waveguide layer55and the like provided on the counter substrate. It is noted that, since parameters such as the intensities of light passing through the droplet9and light not passing through the droplet9are different, as shown inFIG.11, it can be determined which photosensitive elements D3have the droplet9above them by analyzing the light detected by each photosensitive element D3, that is, the positioning of the droplet9can be achieved.

Similarly, after light passes through the droplet9, parameters of the light, such as the intensity of light, become varied with the concentration, composition, and the like of the droplets9. Therefore, the detection of the concentration, composition, and the like of the droplets9can be achieved by analyzing the light detected by the photosensitive element D3.

In an embodiment, as shown inFIG.3, the photosensitive element D3may be a photodiode or the like, which will not be described in detail herein.

The photosensitive elements D3may be in one-to-one correspondence with the driving electrodes51as shown inFIG.2. Alternatively, as shown inFIG.10, the number of the photosensitive elements D3and the number of the driving electrodes51may be different.

According to an embodiment of the present disclosure, the orthographic projection of the photosensitive element D3on the substrate8is covered by the orthographic projection of the driving electrode51on the substrate8;

the driving electrode51is on the side of the photosensitive element D3away from the substrate8, and is made of a transparent conductive material.

The photosensitive element D3only needs to receive light without causing an electric field, and thus, as shown inFIGS.2and3, it may be disposed under the driving electrodes51(in this case, the driving electrodes51are transparent), so that the area of the driving electrodes51is not reduced, and the electric field caused by the driving electrodes51is not affected.

According to an embodiment of the present disclosure, the micro-fluidic substrate further includes a plurality of second gate lines32extending in the row direction, a plurality of detection lines42extending in the column direction, and a plurality of detection transistors D2corresponding to the photosensitive elements D3in one-to-one correspondence.

Referring toFIGS.2and14, the plurality of photosensitive element D3are arranged in an array, each photosensitive element D3is coupled to a first electrode of detection transistor D2corresponding thereto, gate electrodes of respective detection transistors D2corresponding to each row of photosensitive elements D3are coupled to one second gate line32, and second electrodes of respective detection transistors D2corresponding to each column of photosensitive elements D3are coupled to one detection line42.

That is, as shown inFIG.2, the photosensitive elements D3may also be controlled by a transistor array (where the second gate line32and the detection line42may or may not be in the gap space59). When a turn-on signal is provided through one of the second gate lines32, a corresponding row of the detection transistors D2are turned on, so that the light intensity signals detected by the photosensitive elements D3in the corresponding row can be respectively output through the corresponding detection lines42.

According to an embodiment of the present disclosure, in order to simplify the process, many structures may be disposed in the same layer. For example, referring toFIGS.3to5, the second gate line32and the first gate line31may be disposed in the same layer, the gate electrodes of the detection transistor D2and the driving transistor D1may be disposed in the same layer as the second gate line32and the first gate line31, the source electrodes and the drain electrodes of the detection transistor D2and the driving transistor D1may be disposed in the same layer, and the driving line41and the detection line42may be disposed in the same layer.

According to an embodiment of the present disclosure, the micro-fluidic substrate may further have other desired structures, such as an insulating layer for separating different conductive structures, a planarization layer (or resin layer) for eliminating a step difference, a lyophobic layer99on the uppermost layer, and the like.

According to an embodiment of the present disclosure, as shown inFIGS.2and12, a method of fabricating a micro-fluidic substrate may include steps S01to S20.Step S01includes forming a first gate line31, a second gate line32, and gate electrodes of a detection transistor D2and a driving transistor D1on a substrate8.Step S02includes forming a gate insulating layer801of the detection transistor D2and the driving transistor D1. The gate insulating layer801covers the first gate line31, the second gate line32, and the gate electrodes of the detection transistor D2and the driving transistor D1, and the first gate line31, the second gate line32, and the gate electrodes of the detection transistor D2and the driving transistor D1are spaced apart from each other by the gate insulating layer801.Step S03includes forming active regions of the detection transistor D2and the driving transistor D1on the gate insulating layer801.Step S04includes forming source electrodes and drain electrodes of the detection transistor D2and the driving transistor D1, the driving line41and the detection line42on the gate insulating layer801.Step S05includes forming a first passivation layer (PVX)802, and the first passivation layer802covers the source electrodes and the drain electrodes of the detection transistor D2and the driving transistor D1, the driving line41, and the detection line42and insulates them from each other.Step S06includes etching the first passivation layer802to expose a first electrode (which may be a source electrode or a drain electrode) of the detection transistor D2and a first electrode (which may be a source electrode or a drain electrode) of the driving transistor D1. Step S06further includes forming an anode of a photodiode (an example of the photosensitive element D3) on the first electrode of the detection transistor D2and forming a first connection structure CT1for assisting the connection between the driving electrode51and the driving transistor D1on the first electrode of the driving transistor D1. The anode and the first connection structure CT1are, for example, portions defined by thick solid lines inFIG.3and may be made of metal materials.Step S07includes forming a semiconductor layer of the photodiode on the anode. The photodiode may be a PIN photodiode.Step S08includes forming a cap layer of the photodiode on the semiconductor layer, which may be made of transparent conductive material such as Indium Tin Oxide (ITO).Step S09includes forming a cover layer803to cover the photodiode and the first passivation layer.Step S10includes forming a first resin layer804cover the cover layer803.Step S11includes forming a second passivation layer805to cover the first resin layer804. The formation of the second passivation layer805may include processes such as etching and deposition, which will not be described in detail herein.Step S12includes forming a cathode of the photodiode and a lead wire for supplying power thereto, while forming a second connection structure CT2for assisting the connection between the driving electrode51and the driving transistor D1. The formation of the second connection structure CT2may include a process such as deposition.Step S13includes forming a barrier layer806on a portion of the second passivation layer805not covered by the second connection structure CT2.Step S14includes forming driving electrodes51spaced apart from each other on the barrier layer806and the second connection structure CT2.Step S15includes forming a third passivation layer807, the third passivation layer807covering the driving electrodes51and insulating the driving electrodes51from each other.Step S16includes forming a first auxiliary electrode61on the third passivation layer807.Step S17includes forming a fourth passivation layer808on the third passivation layer807and the first auxiliary electrode61, the fourth passivation layer808serving as the insulating layer for separating the first auxiliary electrode61from the second auxiliary electrode62as described above.Step S18includes forming the second auxiliary electrode62on the fourth passivation layer808(seeFIG.4).Step S19includes forming a second resin layer809to cover the second auxiliary electrode62.Step S20includes forming a lyophobic layer99on the second resin layer809.

The structure and the fabricating method of the micro-fluidic substrate of the embodiment may have various modifications. For example, each transistor can also be a top-gate structure. For another example, and the positions of the layers in which the first auxiliary electrode61and the second auxiliary electrode62are located can be interchanged, and the details thereof will not be described herein. In addition, a lead wire for connecting the auxiliary electrode6(e.g., a lead wire621for connecting the second auxiliary electrode62) may be formed.

As shown inFIGS.2to13, the present embodiment provides a micro-fluidic structure, which includes: a micro-fluidic substrate according to an embodiment of the present disclosure; and a counter substrate opposite to the micro-fluidic substrate. A side of the micro-fluidic substrate provided with the driving electrodes51faces the counter substrate, a side of the counter substrate facing the micro-fluidic substrate is provided with a common electrode facing each of the driving electrodes51, and a space for accommodating the droplet9is between the micro-fluidic substrate and the counter substrate.

That is, the above micro-fluidic substrate and the counter substrate can be disposed opposite to each other to form a micro-fluidic structure, in which the counter substrate has the common electrode52, so that a required driving electric field can be formed between the two substrates to drive the droplet9therebetween to move.

According to an embodiment of the present disclosure, a lyophobic layer99is disposed on a side of the micro-fluidic substrate closest to the counter substrate; and a lyophobic layer99is disposed on a side of the counter substrate closest to the micro-fluidic substrate.

That is, the lyophobic layers99(i.e., layers having liquid repellency to the droplet9) are provided on the opposite sides of the above two substrates so that a predetermined contact angle can be formed between the lyophobic layers99and the droplet9contacting them, which facilitates the movement of the droplet. In an embodiment, the lyophobic layers99may be made of a material such as teflon.

According to an embodiment of the present disclosure, when the micro-fluidic substrate is a micro-fluidic substrate having a photosensitive element D3, the counter substrate further includes an optical waveguide layer55for guiding and directing light towards the micro-fluidic substrate.

As shown inFIG.10(for simplicity, part of the structure is not shown), when the micro-fluidic substrate has the photosensitive element D3, a corresponding optical waveguide layer55may be disposed in the counter substrate to guide light incident from a right or left side and direct the light toward the micro-fluidic substrate.

According to an embodiment of the present disclosure, the optical waveguide layer may not be provided, and the light may be emitted toward the micro-fluidic substrate by a light source located on a side of the transparent counter substrate away from the micro-fluidic substrate.

As shown inFIGS.2to13, the present embodiment provides a method for driving a micro-fluidic structure, including:

applying a common voltage to the common electrode52, applying a driving voltage to the driving electrode51at a first position, and applying the driving voltage to the auxiliary electrode6at a second position to form a driving electric field to drive the droplet9to move, wherein the first position represents a position of the driving electrode51to which the droplet9is to be moved in a moving direction of the droplet9, and the second position represents a position of the auxiliary electrode to which the droplet9is to be moved in the moving direction of the droplet9.

That is, when the droplet9is driven using the above micro-fluidic structure, it is necessary to form an electric field at a position where the droplet9is expected to reach. Since the auxiliary electrode6is provided, if there is an auxiliary electrode6at least a part of which is located at the position where the droplet is expected to reach, the driving voltage may be applied to the auxiliary electrode6to assist driving of the droplet9, in addition to applying the driving voltage to the driving electrode51located at the position where the droplet is expected to reach.

According to an embodiment of the present disclosure, in the case where the auxiliary electrode6has the elongated strip shape shown inFIG.2, the same driving voltage as that applied to the driving electrode51at the first position may be applied to the auxiliary electrode6through the lead wire coupled to the auxiliary electrode6at the second position (as shown inFIG.2, the lead wire621coupled to the second auxiliary electrode62). In the case where the auxiliary electrode6has a block shape as shown inFIG.6, since the auxiliary electrode6is electrically coupled to the driving electrode51through the via hole, the same driving voltage as that applied to the driving electrode51may be applied to the auxiliary electrode6.

For example, when the droplet9inFIG.7needs to move to the right, a high voltage may be applied to the second auxiliary electrode62and the driving electrode51on the right side thereof (marked by a dashed line frame in the figure). When the droplet9inFIG.8needs to move downward, a high voltage may be applied to the first auxiliary electrode61and the driving electrode51on the lower side thereof (marked by a dashed line frame in the figure). When the droplet9inFIG.9needs to move to the lower left, a high voltage may be applied to the first auxiliary electrode61on the lower side thereof, the second auxiliary electrode62on the left side thereof, and the driving electrode51on the lower left side thereof (marked by the dashed line in the figure).

When the above first auxiliary electrode61and second auxiliary electrode62are employed, as shown inFIG.2, the end(s) of each auxiliary electrode6may be directly coupled to a driving chip (IC), so that they may be directly supplied with a driving voltage by the driving chip.

When the above block-shaped auxiliary electrode6is employed, the voltage on the auxiliary electrode6is supplied through the driving electrode51coupled thereto.

According to the embodiment of the present disclosure, the driving voltage applied to the auxiliary electrode6is equal to the driving voltage applied to at least one driving electrode51adjacent to the auxiliary electrode6.

In the embodiment of the present disclosure, the auxiliary electrode6can be regarded as an extension of the driving electrode51, so the driving voltage on the auxiliary electrode6may be equal to the driving voltage of a certain driving electrode51that is also being driven.

According to an embodiment of the present disclosure, the driving voltage applied to the auxiliary electrode6may be different from the driving voltages applied to the driving electrodes51, for example, the driving voltages applied to the driving electrodes may be varied, and the specific driving voltages thereto may be obtained according to the driving requirement for the droplet9, and will not be described in detail herein.

It will be understood that the above embodiments are merely exemplary embodiments employed to illustrate the principles of the present disclosure, and the present disclosure is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the disclosure, and these changes and modifications are to be considered within the scope of the disclosure.