A microfluidic chip

Abstract

The application provides a microfluidic chip, comprising: a substrate for receiving a microdroplet, wherein a TFT array is arranged on the substrate for controlling movement of the microdroplet; a cover plate configured with a control electrode; and at least one pair of detection electrodes arranged on the substrate and the cover plate respectively for detecting an electrical impedance parameter of the microdroplet. The application improves the pixel density and integration of the microfluidic chip through TFT array driving, and can also make the reaction of the detection substance and the detection be carried out simultaneously. The application can also control driving signals through the TFT array circuit, and can simultaneously carry out electrical impedance detection of the microdroplet through the capacitance method and the resistance method, so that the detection precision can be improved.

Description

Technical Field

[0001] This invention relates to the field of microfluidics, and more specifically, to a microfluidic chip. Background Technology

[0002] Currently, there are two main methods for impedance testing. One method involves placing the object under test between two insulating layers and detecting changes in capacitance. This method typically uses an AC excitation signal and is called the capacitance method. The other method involves placing the object under test in contact with electrodes, acting as a variable resistor. This method can use either a DC or AC excitation signal and is called the resistance method.

[0003] Currently, the primary method for impedance detection in microfluidics is the first method, namely the capacitance method. This is because microfluidic electrodes need to be coated with insulating and hydrophobic layers to control the movement of microdroplets. Due to the barrier effect of the insulating layer, the sensitivity of the capacitance method is relatively lower than that of the resistance method, which can directly contact the electrode. Furthermore, the capacitance method can only use crosslinking excitation signals, and it also places certain requirements on the design of the driving circuit.

[0004] In addition, the reaction products of current electrical impedance detection need to be carried out on other platforms, that is, the detection substance is moved to the detection platform after the reaction is completed, which is relatively inefficient. Summary of the Invention

[0005] Therefore, the purpose of this disclosure is to provide a microfluidic chip to solve the above-mentioned problems.

[0006] This disclosure provides a microfluidic chip, comprising: a substrate for receiving microdroplets, wherein a TFT array is disposed on the substrate for controlling the movement of the microdroplets; a cover plate on which control electrodes are disposed; and at least one pair of detection electrodes respectively disposed on the substrate and the cover plate for detecting the impedance parameters of the microdroplets. The microfluidic chip provided by this disclosure can achieve microfluidic manipulation of reaction products on the microfluidic chip through the TFT array, enabling merging or separation of reaction products. After completion, the microdroplets to be detected are then transferred to the detection electrodes for impedance detection via microfluidics.

[0007] In some possible implementations, an insulating layer and a hydrophobic layer are also included, located on the upper surface of the substrate and the lower surface of the cover plate, respectively. The design of the insulating and hydrophobic layers allows for smoother and more fluid movement of microdroplets between the substrate and the cover plate.

[0008] In some possible implementations, the positive and negative electrodes of each pair of detection electrodes are covered by an insulating layer and a hydrophobic layer. When the positive and negative electrodes of each pair of detection electrodes are covered by an insulating layer and a hydrophobic layer, the impedance detection of microdroplets can be performed by capacitance method.

[0009] In some possible implementations, through-holes are formed in the insulating or hydrophobic layer, allowing one of the positive and negative electrodes of each pair of detection electrodes to directly contact the microdroplet. When one of the positive and negative electrodes of each pair of detection electrodes is in direct contact with the microdroplet, the measurement of its resistance parameters will be more accurate after the microdroplet comes into contact with the detection electrode.

[0010] In some possible implementations, through-holes are formed in both the insulating layer and the hydrophobic layer, allowing the positive and negative electrodes of each pair of detection electrodes to be in direct contact with the microdroplets. When both the positive and negative electrodes of each pair of detection electrodes are in direct contact with the microdroplets, the measurement of their resistance parameters will be more accurate after the microdroplets come into contact with the detection electrodes.

[0011] In some possible implementations, when the number of detection electrodes is greater than one pair, through-holes are formed in the insulating and hydrophobic layers of some detection electrodes, allowing both the positive and negative electrodes of these electrodes to directly contact the microdroplet. This arrangement, where the positive and negative electrodes of some detection electrodes are in direct contact with the microdroplet while the remaining electrodes are not, enables simultaneous capacitance and resistance impedance detection of the same microdroplet, thus improving detection accuracy.

[0012] In some possible implementations, when the number of detection electrodes is greater than one pair, through-holes are formed in the insulating or hydrophobic layer of some detection electrodes, allowing one of the positive or negative electrodes of that portion of the detection electrode to directly contact the microdroplet. This arrangement, where one of the positive or negative electrodes is in direct contact with the microdroplet while the remaining electrodes are not, enables simultaneous capacitance and resistance impedance detection of the same microdroplet, thus improving detection accuracy.

[0013] In some possible implementations, the detection electrodes are located on the substrate or cover plate.

[0014] In some possible implementations, the control electrode is made of conductive glass.

[0015] In some possible implementations, the substrate and cover are made of glass, printed circuit boards, or thermoplastic polyester.

[0016] Based on the above technical solution, it can be seen that this disclosure has the following advantages:

[0017] 1. This disclosure improves the pixel density and integration of microfluidic chips by using TFT array driving;

[0018] 2. This disclosure uses a microfluidic chip to control the movement of microdroplets, enabling the reaction and detection of the target substance to occur simultaneously;

[0019] 3. This disclosure uses a TFT array circuit to control the driving signal, which can simultaneously perform capacitance and resistance impedance detection on the same microdroplet, thereby improving detection accuracy;

[0020] 4. By combining a microfluidic chip and a TFT array, this disclosure can improve the integration of the microfluidic platform and control the input of electrical signals through the TFT. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a circuit layout diagram of a substrate according to an embodiment of the present disclosure;

[0023] Figure 2 This is a circuit diagram of a cover plate according to an embodiment of the present disclosure;

[0024] Figure 3 A longitudinal cross-sectional view of a microfluidic chip according to an embodiment of this disclosure;

[0025] Figure 4 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0026] Figure 5 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0027] Figure 6 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0028] Figure 7 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0029] Figure 8 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0030] Figure 9 This is a longitudinal cross-sectional view of a microfluidic chip according to another embodiment of the present disclosure;

[0031] Figure 10 This is an electrode distribution diagram of a substrate according to another embodiment of the present disclosure;

[0032] Figure 11 This is an electrode distribution diagram of a cover plate according to another embodiment of the present disclosure. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] An embodiment provides a microfluidic chip, comprising: a substrate for receiving microdroplets, wherein a TFT array is disposed on the substrate for controlling the movement of the microdroplets; a cover plate on which control electrodes are disposed; and at least one pair of detection electrodes disposed on the substrate and the cover plate respectively for detecting the impedance parameters of the microdroplets.

[0035] In some embodiments, an insulating layer and a hydrophobic layer are further included, the insulating layer and the hydrophobic layer being located on the upper surface of the substrate and the lower surface of the cover plate, respectively.

[0036] In some embodiments, the positive and negative electrodes of each pair of detection electrodes are covered by an insulating layer and a hydrophobic layer.

[0037] In some embodiments, through-holes are formed in the insulating layer or hydrophobic layer, so that one of the positive and negative electrodes of each pair of detection electrodes is in direct contact with the microdroplet.

[0038] In some embodiments, through holes are provided on both the insulating layer and the hydrophobic layer, so that the positive and negative electrodes of each pair of detection electrodes are in direct contact with the microdroplets.

[0039] In some embodiments, when the number of detection electrodes is greater than one pair, the insulating layer and hydrophobic layer of some detection electrodes are provided with through holes, so that the positive and negative electrodes of these detection electrodes are in direct contact with the microdroplets.

[0040] In some embodiments, when the number of detection electrodes is greater than one pair, the insulating layer or hydrophobic layer of some detection electrodes is provided with through holes, so that one of the positive and negative electrodes of this portion of the detection electrodes is in direct contact with the microdroplet.

[0041] In some embodiments, the detection electrodes are located on a substrate or a cover plate.

[0042] In some embodiments, the control electrode is made of conductive glass.

[0043] In some embodiments, the substrate and cover are made of glass, printed circuit board, or thermoplastic polyester.

[0044] In one embodiment, the microfluidic chip includes a pair of detection electrodes for detecting the impedance of microdroplets, wherein the cathode and anode of the detection electrodes 6 are located on the substrate and the cover plate, respectively (e.g., ...). Figures 1-2 (As shown). The positions of the anode and cathode can be interchanged. A pair of detection electrodes 6 on the substrate and cover plate are positioned correspondingly. Multiple microfluidic electrodes are arranged around the detection electrodes 6 to move the microdroplet to be detected between the detection electrodes 6 so that the resistance or capacitance parameters of the microdroplet can be detected.

[0045] In one embodiment, the distribution of the detection electrodes in the microfluidic chip is as follows: Figure 3 As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. One of a pair of detection electrodes 6 is located on the cover plate 1 and communicates with the control electrode 2, and the other is located on the substrate 5 and communicates with the TFT array 4. The surfaces of the pair of detection electrodes 6 are respectively covered by the hydrophobic layer 3 and the insulating layer 8, forming a capacitance between the hydrophobic layer 3 and the insulating layer 8. The impedance of the microdroplet located between the hydrophobic layer 3 and the insulating layer 8 can be detected by applying an AC signal to the detection electrode. After the microdroplet reaction is complete, the TFT array controls the microdroplet to move to the detection electrode 6. Since the presence of the microdroplet affects the capacitance between the hydrophobic layer 3 and the insulating layer 8, the impedance of the microdroplet can be detected by detecting the capacitance between the detection electrodes 6.

[0046] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 4As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. One of a pair of detection electrodes 6 is located on the cover plate 1 and communicates with the control electrode 2, while the other is located on the substrate 5 and communicates with the TFT array 4. The surfaces of the pair of detection electrodes 6 are respectively covered by the hydrophobic layer 3 and the insulating layer 8. Through-holes are formed in the hydrophobic layer 3 and the insulating layer 8 at the locations where the detection electrodes 6 are disposed, allowing microdroplets to directly contact the pair of detection electrodes 6. After the microdroplet's reaction is complete, the TFT array controls the microdroplet to move to the detection electrode 6, where the microdroplet directly contacts the pair of detection electrodes 6. At this point, the microdroplet acts as a variable resistor for detection.

[0047] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 5 As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. One of a pair of detection electrodes 6 is located on the cover plate 1 and communicates with the control electrode 2, while the other is located on the substrate 5 and communicates with the TFT array 4. The surfaces of the pair of detection electrodes 6 are respectively covered by the hydrophobic layer 3 and the insulating layer 8. The hydrophobic layer 3 has through holes at the locations where the detection electrodes 6 are located, allowing microdroplets to directly contact the detection electrodes 6 located on the cover plate. After the microdroplet's reaction is complete, the TFT array controls the microdroplet to move to the detection electrode 6, where the microdroplet directly contacts the detection electrode 6 located on the cover plate. At this point, the microdroplet acts as a variable resistor for detection.

[0048] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 6As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. One of a pair of detection electrodes 6 is located on the cover plate 1 and communicates with the control electrode 2, while the other is located on the substrate 5 and communicates with the TFT array 4. The surfaces of the pair of detection electrodes 6 are respectively covered by the hydrophobic layer 3 and the insulating layer 8. The hydrophobic layer 3 has through holes at the locations where the detection electrodes 6 are located, allowing microdroplets to directly contact the detection electrodes 6 located on the substrate. After the microdroplet's reaction is complete, the TFT array controls the microdroplet to move to the detection electrode 6, where the microdroplet directly contacts the detection electrode 6 located on the substrate. At this point, the microdroplet acts as a variable resistor for detection.

[0049] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 7 As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. Two pairs of detection electrodes (6 and 7) are disposed between the cover plate 1 and the substrate 5, with the anode and cathode of each pair of detection electrodes connected to the control electrode 2 and the TFT array 4, respectively. Furthermore, the surfaces of one pair of detection electrodes 7 are covered by the hydrophobic layer 3 and the insulating layer 8, respectively, and both the hydrophobic layer 3 and the insulating layer 8 have through-holes at the other pair of detection electrodes 6, allowing microdroplets to directly contact the detection electrodes 6. After the microdroplet reaction is complete, the TFT array controls the microdroplet to move to the detection area of ​​the two pairs of detection electrodes. The pair of detection electrodes 7, whose surfaces are covered by a hydrophobic layer 3 and an insulating layer 8, detects the impedance of the microdroplet by detecting the capacitance between the detection electrodes 7. The pair of detection electrodes 6, which are in direct contact with the microdroplet, detects the impedance by using the microdroplet as a variable resistor. The two impedance detection methods can be performed simultaneously. The number of detection electrodes can be two or more.

[0050] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 8As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. Two pairs of detection electrodes (6 and 7) are disposed between the cover plate 1 and the substrate 5, with the anode and cathode of each pair of detection electrodes connected to the control electrode 2 and the TFT array 4, respectively. Furthermore, the surfaces of one pair of detection electrodes 7 are covered by the hydrophobic layer 3 and the insulating layer 8, respectively, and the hydrophobic layer 3 has through-holes at the other pair of detection electrodes 6, allowing microdroplets to directly contact the detection electrodes 6 located on the cover plate 1. After the microdroplet reaction is complete, the TFT array controls the microdroplet to move to the detection area of ​​the two pairs of detection electrodes. The pair of detection electrodes 7, whose surfaces are covered by a hydrophobic layer 3 and an insulating layer 8, detects the impedance of the microdroplet by detecting the capacitance between the electrodes 7. The pair of detection electrodes 6, whose side electrode is in direct contact with the microdroplet, detects the impedance using the microdroplet as a variable resistor. Both impedance detection methods can be performed simultaneously. The number of detection electrodes can be two or more.

[0051] The detection electrode distribution of the microfluidic chip in another embodiment is as follows: Figure 9 As shown, the microfluidic chip includes a cover plate 1 and a substrate 5. A hydrophobic layer 3 is disposed on the cover plate 1, and a control electrode 2 is disposed between the hydrophobic layer 3 and the cover plate 1. The cover plate 1 and the substrate 5 are made of materials such as glass, printed circuit board, or thermoplastic polyester, while the control electrode 2 is made of conductive glass or other conductive materials. A TFT array 4 is disposed on the substrate 5, and the TFT array also has an insulating layer 8. Two pairs of detection electrodes (6 and 7) are disposed between the cover plate 1 and the substrate 5, with the anode and cathode of each pair of detection electrodes connected to the control electrode 2 and the TFT array 4, respectively. Furthermore, the surfaces of one pair of detection electrodes 7 are covered by the hydrophobic layer 3 and the insulating layer 8, respectively, and the hydrophobic layer 3 has through-holes at the other pair of detection electrodes 6, allowing microdroplets to directly contact the detection electrodes 6 located on the substrate 5. After the microdroplet reaction is complete, the TFT array controls the microdroplet to move to the detection area of ​​two pairs of detection electrodes. A pair of detection electrodes 7, whose surfaces are covered by a hydrophobic layer 3 and an insulating layer 8, detects the impedance of the microdroplet by detecting the capacitance between the electrodes. Another pair of detection electrodes 6, with one electrode directly in contact with the microdroplet, detects the impedance using the microdroplet as a variable resistor. Both impedance detection methods can be performed simultaneously. The number of detection electrodes can be two or more.

[0052] In another embodiment, the detection electrodes 6 of the microfluidic chip are all located on the substrate 5 (e.g., Figure 10 As shown), the control electrode circuit on cover plate 1 is as follows: Figure 11As shown, a microdroplet to be detected is moved to the detection area where the detection electrode 6 is located using microfluidics. The resistance or capacitance parameters of the microdroplet can then be detected within this detection area, which can contain one or more detection electrodes. The cathodes and anodes of the detection electrodes 6 are arranged in alternating rows or columns, and the TFT device 4 controls the detection electrodes 6 to be turned on alternately. By moving the microdroplet to be detected to the corresponding detection electrode 6, its resistance or capacitance parameters can be detected.

[0053] Although the present invention has been further described and illustrated in detail with reference to preferred embodiments, the invention is not limited to the disclosed examples, and those skilled in the art can derive other modifications therefrom without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A microfluidic chip, characterized in that, include: A substrate for receiving microdroplets, wherein a TFT array is disposed on the substrate for controlling the movement of the microdroplets; A cover plate, configured to have control electrodes; At least two pairs of detection electrodes are respectively disposed on the substrate and the cover plate for detecting the impedance parameters of the microdroplets. The detection electrodes on the substrate are electrically connected to the TFT array, and the detection electrodes on the cover plate are electrically connected to the control electrodes. An insulating layer and a hydrophobic layer are respectively located on the upper surface of the substrate and the lower surface of the cover plate; The positive and negative electrodes of the first pair of detection electrodes are covered by the insulating layer and the hydrophobic layer, respectively, so as to detect the impedance parameters of the microdroplets by capacitance method. Through holes are formed on both the insulating layer and the hydrophobic layer in the area where the second pair of detection electrodes are located, so that the positive and negative electrodes of the second pair of detection electrodes are in direct contact with the microdroplet, so as to detect the impedance parameter of the microdroplet by resistance method.

2. The microfluidic chip according to claim 1, characterized in that, The control electrode is made of conductive glass.

3. The microfluidic chip according to claim 2, characterized in that, The substrate and cover plate are made of glass, printed circuit board, or thermoplastic polyester.

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