A microfluidic chip with photoelectric detection function

Abstract

The present invention provides a microfluidic chip with a photoelectric detection function, comprising a substrate layer, a device layer, an insulating layer, and a hydrophobic layer fixedly connected in sequence from bottom to top. The device layer is provided with a microfluidic droplet drive array and an electrical interface. The microfluidic droplet drive array is electrically connected to an external circuit via the electrical interface. The microfluidic droplet drive array is provided with a plurality of droplet drive pixel units for driving droplet motion and an on-chip photoelectric detection area. The plurality of droplet drive pixel unit arrays are arranged in the device layer. The on-chip photoelectric detection area cooperates with the array formed by the droplet drive pixel units. The on-chip photoelectric detection area is provided with a mutually cooperating light sensor and dark sensor. The light sensor and dark sensor are each provided with a photodiode and two dual-gate thin-film transistors. The beneficial effects of the present invention are: it can realize a photoelectric detection function with high detection sensitivity, a wide dynamic response range, and strong anti-interference performance, and it has a simple structure, is easy to operate, and improves integration.

Description

Technical Field

[0001] The present invention relates to the technical field of detection circuits, and in particular to a microfluidic chip with a photoelectric detection function. Background Art

[0002] Microfluidics integrates the fundamental operational elements of biological, chemical, and medical analysis, including sample preparation, reaction, separation, and detection, onto a micron-scale chip, automating the entire analytical process. Due to its enormous potential in biology, chemistry, and medicine, it has developed into a new research field that intersects disciplines such as biology, chemistry, medicine, fluidics, electronics, materials, and mechanics.

[0003] A laboratory-on-a-chip, also known as a chip lab, refers to a microchip laboratory that can perform sample preparation, solution reaction, separation of target substances and other functions on a chip of a few square centimeters. The emergence of microfluidics technology helps to improve the integration of laboratory-on-a-chip systems and achieve further miniaturization of laboratory-on-a-chip.

[0004] The detection module in a microfluidic chip primarily collects information about the concentration or composition of the sample being tested, making it a core component of microfluidic chip technology. Miniaturization and even micro-scaling of the detection module are key challenges in the microfluidics field, and achieving integrated detection and analysis is the ultimate goal of microfluidics. Currently, optical detection is the mainstream detection method used in microfluidic chips, but most rely on large and expensive external optical detection platforms. This is not only complex and costly, but the increased optical path can affect the accuracy of the final detection results, making it difficult to meet user needs. Summary of the Invention

[0005] In order to solve the problems in the prior art, the present invention provides a microfluidic chip with a photoelectric detection function. By arranging a substrate layer, a device layer, an insulating layer and a hydrophobic layer that cooperate with each other on the microfluidic chip, a light sensor and a dark sensor are provided in the on-chip photoelectric detection area. The light sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area. The droplet-driven pixel unit can drive the droplets located on the upper surface of the hydrophobic layer to move. The differential output of the light sensor and the dark sensor is used as the result of the on-chip photoelectric detection area. The photoelectric detection function with high detection sensitivity, wide dynamic response range and strong anti-interference performance can be achieved. The structure is simple, the operation is convenient, the integration is improved, the production cost of the microfluidic chip is reduced, and real-time in-situ photoelectric detection can be performed, which improves the detection efficiency and the accuracy of the detection results. The problem that the microfluidic chip in the prior art generally uses external equipment to realize the photoelectric detection function, the operation is complicated, and the increased optical path affects the accuracy of the final detection result is solved.

[0006] The present invention provides a microfluidic chip with a photoelectric detection function, comprising a substrate layer, a device layer, an insulating layer, and a hydrophobic layer fixedly connected in sequence from bottom to top. The device layer is provided with a microfluidic droplet drive array and an electrical interface, the microfluidic droplet drive array being electrically connected to an external circuit via the electrical interface. The microfluidic droplet drive array is provided with a plurality of droplet drive pixel units for driving droplet motion and an on-chip photoelectric detection area. An array of the plurality of droplet drive pixel units is arranged in the device layer. The on-chip photoelectric detection area cooperates with the array formed by the droplet drive pixel units. The on-chip photoelectric detection area is provided with a mutually cooperating bright sensor and dark sensor. The bright sensor is provided with a photodiode PD1, a dual-gate thin-film transistor TFT1, and a dual-gate thin-film transistor TFT2. The dark sensor is provided with a light-shielded photodiode PD2, a dual-gate thin-film transistor TFT3, and a dual-gate thin-film transistor TFT4. The bright sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area. The droplet drive pixel unit can drive the movement of droplets located on the upper surface of the hydrophobic layer.

[0007] The present invention is further improved in that the light sensor is in the shape of a thin film, the dark sensor is in the shape of a thin film, the light sensor and the dark sensor are arranged in a horizontally spaced arrangement, a vertically spaced arrangement, or an obliquely spaced arrangement, and the light sensor and the dark sensor are arranged and combined to form the on-chip photoelectric detection area.

[0008] The present invention is further improved in that a plurality of on-chip photoelectric detection areas are provided in the microfluidic droplet driving array, and the plurality of on-chip photoelectric detection areas do not contact each other but cooperate with each other.

[0009] The present invention is further improved. A single-gate thin film transistor TFT5 and a capacitor C1 are provided in the droplet-driven pixel unit. The drain of the single-gate thin film transistor TFT5 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded.

[0010] The present invention is further improved, the on-chip photodetection area also includes a transimpedance amplifier K1 arranged outside the device layer, the bottom gate of the dual-gate thin-film transistor TFT1 is connected to the drain of the dual-gate thin-film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the dual-gate thin-film transistor TFT2, the negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT1 is grounded, and the drain of the dual-gate thin-film transistor TFT2 is connected to the transimpedance amplifier K1. the input end of the dual-gate thin-film transistor TFT3 is connected; the bottom gate of the dual-gate thin-film transistor TFT3 is connected to the drain of the dual-gate thin-film transistor TFT3, the anode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4, the cathode of the photodiode PD2 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss, the bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT3 is grounded, the drain of the dual-gate thin-film transistor TFT4 is connected to the input end of the transimpedance amplifier K1, and the output end of the transimpedance amplifier K1 can output the final differential voltage Vout.

[0011] The present invention is further improved, the on-chip photodetection area also includes a transimpedance amplifier K2, a transimpedance amplifier K3 and a differential amplifier K4 arranged outside the device layer, the bottom gate of the dual-gate thin-film transistor TFT1 is connected to the drain of the dual-gate thin-film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the dual-gate thin-film transistor TFT2, the negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT1 is grounded, and the drain of the dual-gate thin-film transistor TFT2 is connected to the input end of the transimpedance amplifier K2; the dual-gate thin-film transistor The bottom gate of the body transistor TFT3 is connected to the drain of the dual-gate thin-film transistor TFT3, the anode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4. The cathode of the photodiode PD2 is connected to the bias voltage source Vdd. The top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1. The source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss. The bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2. The source of the dual-gate thin-film transistor TFT3 is grounded. The drain of the dual-gate thin-film transistor TFT4 is connected to the input of the transimpedance amplifier K3. The output of the transimpedance amplifier K2 and the output of the transimpedance amplifier K3 are connected to the input of the differential amplifier K4. The output of the differential amplifier K4 can output a final differential voltage Vout.

[0012] The present invention is further improved, and the dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are prepared in the device layer through a large-area display thin film process.

[0013] The present invention is further improved, and the manufacturing materials of the dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are amorphous silicon materials, indium gallium zinc oxide, organic semiconductors, or polycrystalline silicon materials.

[0014] The present invention is further improved, and the channel shapes of the dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are planar channels, π-type channels, or 3D fin-type channels.

[0015] The present invention is further improved and also includes an upper plate, which includes an upper substrate layer, an upper conductive layer and an upper hydrophobic layer fixedly connected in sequence from top to bottom, and a droplet movement space layer is provided between the upper hydrophobic layer and the hydrophobic layer, and the substrate layer and the upper substrate layer are both glass substrates or printed circuit board substrates or silicon-based substrates.

[0016] Compared with the prior art, the present invention has the following beneficial effects: providing a microfluidic chip with a photoelectric detection function. By providing a substrate layer, a device layer, an insulating layer, and a hydrophobic layer that cooperate with each other on the microfluidic chip, an on-chip photoelectric detection area is provided with a light sensor and a dark sensor. The light sensor and the dark sensor can perform on-chip photoelectric signal detection in the on-chip photoelectric detection area. The droplet-driven pixel unit can drive the droplet located on the upper surface of the hydrophobic layer to move. The differential output of the light sensor and the dark sensor is used as the output of the on-chip photoelectric detection area. This can achieve a photoelectric detection function with high detection sensitivity, a wide dynamic response range, and strong anti-interference performance. The structure is simple, the operation is convenient, and the integration is improved. Moreover, the light sensor and the dark sensor based on thin-film transistors are compatible with the preparation process of the microfluidic chip and can both be prepared and processed using thin-film transistor display panel technology. This not only improves the system integration of the on-chip laboratory and reduces the production cost of the microfluidic chip, but also enables real-time in-situ photoelectric detection, improves the detection efficiency and the accuracy of the detection results. It has broad application value and market potential, and solves the problem that the microfluidic chip in the prior art generally uses external equipment to achieve the photoelectric detection function, which is complicated to operate and the increased optical path affects the accuracy of the final detection result. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 This is a schematic diagram of the structure of the microfluidic chip with photoelectric detection function of the present invention;

[0019] Figure 2 This is a principle block diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0020] Figure 3 This is a principle block diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0021] Figure 4 This is a principle block diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0022] Figure 5 This is a principle block diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0023] Figure 6 A comparison diagram of the output current of the light sensor and the photodiode of the present invention;

[0024] Figure 7 A comparison diagram of the photoelectric gain of the bright sensor and the photodiode of the present invention;

[0025] Figure 8 is a circuit diagram of the on-chip photodetection area of ​​the present invention;

[0026] Figure 9 The graph is a graph showing the change of the differential current of the bright sensor and the dark sensor with different light intensities;

[0027] Figure 10 This is a comparison chart of the temperature characteristics of the combination of the bright sensor and the dark sensor of the present invention and a single 2T1D sensor;

[0028] Figure 11 is a circuit diagram of the on-chip photodetection area of ​​the present invention;

[0029] Figure 12 This is a schematic diagram of the bipolar plate structure of the microfluidic chip with photoelectric detection function of the present invention. DETAILED DESCRIPTION

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0031] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0033] like Figures 1-12 As shown, the present invention provides a microfluidic chip with a photoelectric detection function, including a substrate layer, a device layer, an insulating layer and a hydrophobic layer fixedly connected in sequence from bottom to top, a microfluidic droplet drive array and an electrical interface are provided in the device layer, the microfluidic droplet drive array is electrically connected to the external circuit through the electrical interface, the microfluidic droplet drive array is provided with a plurality of droplet drive pixel units for driving the movement of droplets and an on-chip photoelectric detection area, a plurality of droplet drive pixel unit arrays are arranged in the device layer, the on-chip photoelectric detection area is coordinated with the array formed by the droplet drive pixel units, the on-chip photoelectric detection area is provided with a bright sensor and a dark sensor that cooperate with each other, the bright sensor is provided with a photodiode PD1, a dual-gate thin film transistor TFT1 and a dual-gate thin film transistor TFT2, and the dark sensor is provided with a shielded photodiode PD2, a dual-gate thin film transistor TFT3 and a dual-gate thin film transistor TFT4. In this embodiment, the light sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area, and the droplet-driven pixel unit can drive the movement of the droplet located on the upper surface of the hydrophobic layer. The differential output of the light sensor and the dark sensor is used as the result of the on-chip photoelectric detection area, which can achieve a photoelectric detection function with high detection sensitivity, wide dynamic response range, and strong anti-interference performance. It has a simple structure, convenient operation, and improved integration. Moreover, the light sensor and dark sensor based on thin film transistors are compatible with the preparation process of the microfluidic chip, and can be prepared and processed using thin film transistor display panel technology. It not only improves the system integration of the on-chip laboratory and reduces the production cost of the microfluidic chip, but also can perform real-time in-situ photoelectric detection, improves the detection efficiency and the accuracy of the detection results, and has broad application value and market potential.

[0034] like Figure 2-Figure 5As shown, the light sensor is thin-film-shaped, and the dark sensor is thin-film-shaped. The light sensors and dark sensors are arranged in a horizontally spaced, vertically spaced, or diagonally spaced arrangement. The light sensors and dark sensors are arranged to form an on-chip photoelectric detection area. The microfluidic droplet drive array is equipped with multiple on-chip photoelectric detection areas, which do not contact each other but cooperate with each other. The droplet drive pixel unit is equipped with a single-gate thin-film transistor TFT5 and a capacitor C1. The drain of the single-gate thin-film transistor TFT5 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded. In this embodiment, multiple droplet drive pixel units are arranged in certain rows and columns to form an array for controlling droplet movement, generation, merging, and separation operations. The on-chip photoelectric detection area is used to perform on-chip photoelectric signal detection in specific areas of the microfluidic chip, improving the system integration of the on-chip lab. The shape and size of the on-chip photoelectric detection area are mainly determined by the arrangement of the light sensors and dark sensors. The shape and size of the on-chip photoelectric detection area can be set to square, circular, diamond, or other polygonal shapes according to actual needs. Multiple on-chip photoelectric detection areas 51, 52...5n can be prepared on a microfluidic chip, and the microfluidic droplet drive array is used to drive the sample to move to different on-chip photoelectric detection intervals for optical signal detection. Multi-channel detection can be performed simultaneously to improve detection efficiency.

[0035] like Figures 6-10As shown, the on-chip photodetection area also includes a transimpedance amplifier K1 arranged outside the device layer, the bottom gate of the dual-gate thin film transistor TFT1 is connected to the drain of the dual-gate thin film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the dual-gate thin film transistor TFT2, the negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin film transistor TFT1 is grounded, and the drain of the dual-gate thin film transistor TFT2 is connected to the input terminal of the transimpedance amplifier K1. The bottom gate of the dual-gate thin-film transistor TFT3 is connected to the drain of the dual-gate thin-film transistor TFT3, the positive electrode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4. The negative electrode of the photodiode PD2 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss, the bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT3 is grounded, and the drain of the dual-gate thin-film transistor TFT4 is connected to the input of the transimpedance amplifier K1. The output of the transimpedance amplifier K1 can output the final differential voltage Vout. In this embodiment, the bright sensor is composed of a photodiode (PD) and two dual-gate thin-film transistors TFT, that is, a 2T1D sensor circuit. Figure 6 and Figure 7 It can be seen that the output current of 2T1D is 1 to 2 orders of magnitude higher than that of the photodiode, the detection limit is reduced by 1 to 2 orders of magnitude, and the photoelectric gain is also increased by 2 to 3 orders of magnitude. Therefore, compared with a single photodiode, 2T1D has higher sensitivity in weak light, which can improve the accuracy of the detection results, and its preparation process is compatible with the preparation process of the microfluidic chip, which can improve the integration of the system and reduce the preparation cost of the microfluidic chip. The dark sensor is based on the bright sensor, and the photodiode is shielded from light to make it insensitive to light. The bright sensor and the dark sensor use the output of the dark sensor as the background noise, and the output of the bright sensor is differentiated from the output of the dark sensor, and the differential output is used as the final output result, as shown in Figure 8 As shown, the current difference between the bright sensor L and the dark sensor is first performed, and then output to the peripheral readout system P2 for current-voltage conversion and amplification, and finally the differential voltage Vout is output. Figure 9 This is a graph showing the change in the differential current of the bright sensor and the dark sensor with different light intensities. Figure 6 and Figure 9It can be seen that the differential output has better linearity than the single 2T1D sensor output, resulting in a wider dynamic response range and higher sensitivity. Figure 10 The temperature characteristics of the combination of bright sensor, dark sensor and single 2T1D sensor are compared. Figure 10 As can be seen, the output of the combined bright and dark sensors varies less with temperature, resulting in more stable temperature characteristics and greater resistance to temperature interference. In summary, the combined bright and dark sensor design offers higher detection sensitivity, a wider dynamic response range, and improved anti-interference performance, improving detection efficiency and accuracy.

[0036] like Figure 11 As shown, the on-chip photodetection area also includes a transimpedance amplifier K2, a transimpedance amplifier K3 and a differential amplifier K4 arranged outside the device layer. The bottom gate of the dual-gate thin-film transistor TFT1 is connected to the drain of the dual-gate thin-film transistor TFT1, the anode of the photodiode PD1, and the top gate of the dual-gate thin-film transistor TFT2. The negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT1 is grounded, and the drain of the dual-gate thin-film transistor TFT2 is connected to the input terminal of the transimpedance amplifier K2; the dual-gate thin-film transistor TFT The bottom gate of T3 is connected to the drain of the dual-gate thin-film transistor TFT3, the positive electrode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4. The negative electrode of the photodiode PD2 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss, the bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT3 is grounded, the drain of the dual-gate thin-film transistor TFT4 is connected to the input of the transimpedance amplifier K3, the output of the transimpedance amplifier K2 and the output of the transimpedance amplifier K3 are connected to the input of the differential amplifier K4, and the output of the differential amplifier K4 can output the final differential voltage Vout. In this embodiment, the combination design of the light sensor and the dark sensor can also be as follows: Figure 11 The output currents of the bright sensor and dark sensor in P1 are first read out to the peripheral readout system P2 for current-voltage conversion and amplification to obtain voltages Vout1 and Vout2, and then the difference between Vout1 and Vout2 is obtained to obtain the final differential voltage Vout.

[0037] like Figure 12As shown, the microfluidic chip also includes an upper board, which includes an upper substrate layer, an upper conductive layer and an upper hydrophobic layer fixedly connected in sequence from top to bottom, a droplet movement space layer is provided between the upper hydrophobic layer and the hydrophobic layer, and the substrate layer and the upper substrate layer are all glass substrates or printed circuit board substrates or silicon-based substrates; the double-gate thin film transistor TFT1, the double-gate thin film transistor TFT2, the double-gate thin film transistor TFT3, the double-gate thin film transistor TFT4 and the single-gate thin film transistor TFT5 are prepared in the device layer by a large-area display thin film process; the manufacturing material of the double-gate thin film transistor TFT1, the double-gate thin film transistor TFT2, the double-gate thin film transistor TFT3, the double-gate thin film transistor TFT4 and the single-gate thin film transistor TFT5 is amorphous silicon material or indium gallium zinc oxide or organic semiconductor or polycrystalline silicon material; the channel shape of the double-gate thin film transistor TFT1, the double-gate thin film transistor TFT2, the double-gate thin film transistor TFT3, the double-gate thin film transistor TFT4 and the single-gate thin film transistor TFT5 is a planar channel or a π-type channel or a 3D fin-type channel. In this embodiment, the microfluidic chip can also be in the form of a bipolar plate, such as Figure 12 Compared to the unipolar plate model, the bipolar plate model adds an upper plate containing an upper conductive layer, while the lower plate remains the same. Therefore, the microfluidic chip has a high degree of integration and utilizes mature large-area display panel technology, resulting in a low manufacturing cost.

[0038] As can be seen from the above, the present invention provides a microfluidic chip with a photoelectric detection function. By arranging a substrate layer, a device layer, an insulating layer and a hydrophobic layer that cooperate with each other on the microfluidic chip, a light sensor and a dark sensor are provided in the on-chip photoelectric detection area. The light sensor and the dark sensor can perform on-chip photoelectric signal detection in the on-chip photoelectric detection area. The droplet drive pixel unit can drive the droplet located on the upper surface of the hydrophobic layer to move. The differential output of the light sensor and the dark sensor is used as the result of the on-chip photoelectric detection area. The photoelectric detection function with high detection sensitivity, wide dynamic response range, and strong anti-interference performance can be achieved. The structure is simple, the operation is convenient, and the integration is improved. Moreover, the light sensor and the dark sensor based on thin film transistors are compatible with the preparation process of the microfluidic chip and can both be prepared and processed using thin film transistor display panel technology. This not only improves the system integration of the on-chip laboratory and reduces the production cost of the microfluidic chip, but also enables real-time in-situ photoelectric detection, improves the detection efficiency and the accuracy of the detection results. It has broad application value and market potential, and solves the problem that the microfluidic chip in the prior art generally uses external equipment to realize the photoelectric detection function, which is complicated to operate and the increased optical path affects the accuracy of the final detection result.

[0039] The specific implementation manner described above is a preferred implementation manner of the present invention, and is not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to this specific implementation manner. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A microfluidic chip with photoelectric detection function, characterized in that: The invention comprises a substrate layer, a device layer, an insulating layer and a hydrophobic layer fixedly connected in sequence from bottom to top, wherein the device layer is provided with a microfluidic droplet drive array and an electrical interface, the microfluidic droplet drive array is electrically connected to an external circuit through the electrical interface, the microfluidic droplet drive array is provided with a plurality of droplet drive pixel units and an on-chip photoelectric detection area for driving the movement of droplets, an array of a plurality of droplet drive pixel units is arranged in the device layer, the on-chip photoelectric detection area cooperates with the array formed by the droplet drive pixel units, the on-chip photoelectric detection area is provided with a mutually cooperating bright sensor and dark sensor, the bright sensor is provided with a photodiode PD1, a dual-gate thin-film transistor TFT1 and a dual-gate thin-film transistor TFT2, the dark sensor is provided with a shielded photodiode PD2, a dual-gate thin-film transistor TFT3 and a dual-gate thin-film transistor TFT4, the bright sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area, and the droplet drive pixel unit can drive the movement of droplets located on the upper surface of the hydrophobic layer.

2. The microfluidic chip with photoelectric detection function according to claim 1, characterized in that: The bright sensor is in the shape of a film, and the dark sensor is in the shape of a film. The bright sensor and the dark sensor are arranged in a horizontally spaced arrangement, a vertically spaced arrangement, or an obliquely spaced arrangement. The bright sensor and the dark sensor are arranged and combined to form the on-chip photoelectric detection area.

3. The microfluidic chip with photoelectric detection function according to claim 2, characterized in that: A plurality of on-chip photoelectric detection areas are provided in the microfluidic droplet driving array, and the plurality of on-chip photoelectric detection areas do not contact each other but cooperate with each other.

4. The microfluidic chip with photoelectric detection function according to claim 3, characterized in that: A single-gate thin film transistor TFT5 and a capacitor C1 are provided in the droplet driving pixel unit. The drain of the single-gate thin film transistor TFT5 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded.

5. The microfluidic chip with photoelectric detection function according to claim 4, characterized in that: The on-chip photodetection area also includes a transimpedance amplifier K1 arranged outside the device layer, the bottom gate of the dual-gate thin film transistor TFT1 is connected to the drain of the dual-gate thin film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the dual-gate thin film transistor TFT2, the negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin film transistor TFT1 is grounded, and the drain of the dual-gate thin film transistor TFT2 is connected to the input end of the transimpedance amplifier K1. The bottom gate of the dual-gate thin-film transistor TFT3 is connected to the drain of the dual-gate thin-film transistor TFT3, the anode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4. The cathode of the photodiode PD2 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss, the bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT3 is grounded, the drain of the dual-gate thin-film transistor TFT4 is connected to the input end of the transimpedance amplifier K1, and the output end of the transimpedance amplifier K1 can output the final differential voltage Vout.

6. The microfluidic chip with photoelectric detection function according to claim 4, characterized in that: The on-chip photodetection area further includes a transimpedance amplifier K2, a transimpedance amplifier K3 and a differential amplifier K4 arranged outside the device layer. The bottom gate of the dual-gate thin-film transistor TFT1 is connected to the drain of the dual-gate thin-film transistor TFT1, the anode of the photodiode PD1 and the top gate of the dual-gate thin-film transistor TFT2. The negative electrode of the photodiode PD1 is connected to the bias voltage source Vdd, the top gate of the dual-gate thin-film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the dual-gate thin-film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the dual-gate thin-film transistor TFT1 is grounded, and the drain of the dual-gate thin-film transistor TFT2 is connected to the input terminal of the transimpedance amplifier K2; the dual-gate thin-film transistor TFT The bottom gate of the dual-gate thin-film transistor TFT3 is connected to the drain of the dual-gate thin-film transistor TFT3, the anode of the photodiode PD2, and the top gate of the dual-gate thin-film transistor TFT4. The cathode of the photodiode PD2 is connected to the bias voltage source Vdd. The top gate of the dual-gate thin-film transistor TFT3 is connected to the bias voltage source Vtg1. The source of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vss. The bottom gate of the dual-gate thin-film transistor TFT4 is connected to the bias voltage source Vbg2. The source of the dual-gate thin-film transistor TFT3 is grounded. The drain of the dual-gate thin-film transistor TFT4 is connected to the input of the transimpedance amplifier K3. The output of the transimpedance amplifier K2 and the output of the transimpedance amplifier K3 are connected to the input of the differential amplifier K4. The output of the differential amplifier K4 can output a final differential voltage Vout.

7. The microfluidic chip with photoelectric detection function according to claim 5 or 6, characterized in that: The dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are manufactured in the device layer through a large-area display thin film process.

8. The microfluidic chip with photoelectric detection function according to claim 7, characterized in that: The manufacturing materials of the dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are amorphous silicon materials, indium gallium zinc oxide, organic semiconductors, or polycrystalline silicon materials.

9. The microfluidic chip with photoelectric detection function according to claim 8, characterized in that: The channel shapes of the dual-gate thin film transistor TFT1, the dual-gate thin film transistor TFT2, the dual-gate thin film transistor TFT3, the dual-gate thin film transistor TFT4, and the single-gate thin film transistor TFT5 are planar channels, π-type channels, or 3D fin-type channels.

10. The microfluidic chip with photoelectric detection function according to claim 9, characterized in that: It also includes an upper plate, which includes an upper substrate layer, an upper conductive layer and an upper hydrophobic layer fixedly connected in sequence from top to bottom, and a droplet movement space layer is provided between the upper hydrophobic layer and the hydrophobic layer. The substrate layer and the upper substrate layer are both glass substrates, printed circuit board substrates or silicon-based substrates.

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