Micro-fluidic chip with photoelectric detection function

Abstract

The micro-fluidic chip with the photoelectric detection function comprises a substrate layer, a device layer, an insulating layer and a hydrophobic layer which are sequentially and fixedly connected from bottom to top, a micro-fluidic liquid drop driving array and an electrical interface are arranged in the device layer, the micro-fluidic liquid drop driving array is electrically connected with an external circuit through the electrical interface, and the insulating layer is electrically connected with the external circuit through the electrical interface. A plurality of liquid drop driving pixel units and an on-chip photoelectric detection area which are used for driving liquid drops to move are arranged in the microfluidic liquid drop driving array, the plurality of liquid drop driving pixel unit arrays are arranged in the device layer, and the on-chip photoelectric detection area is matched with the array formed by the liquid drop driving pixel units; a bright sensor and a dark sensor which are matched with each other are arranged in the on-chip photoelectric detection area, and a photodiode and two double-gate thin film transistors are arranged in each of the bright sensor and the dark sensor. The photoelectric detector has the beneficial effects that the photoelectric detection function with high detection sensitivity, wide dynamic response range and strong anti-interference performance can be realized, the structure is simple, the operation is convenient, and the integration level is improved.

Description

Technical Field

[0001] The 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 is a technology that integrates the basic operating units of sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes onto a micrometer-scale chip to automatically complete the entire analysis process. Due to its huge potential in the fields of biology, chemistry, and medicine, it has developed into a new research field that intersects biology, chemistry, medicine, fluids, electronics, materials, and mechanics.

[0003] A laboratory on a chip, also known as a chip lab, refers to a miniature chip 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-chip systems and achieve more miniaturized laboratory-on-chip.

[0004] The detection module in the microfluidic chip mainly collects information such as the concentration or composition of the sample to be tested, and is the core part of the microfluidic chip technology. The miniaturization or even micro-miniaturization of the detection module is the key and difficult point in the field of microfluidics. The ultimate goal of microfluidic technology is to achieve integrated detection and analysis. At present, the mainstream detection method used in existing microfluidic chips is optical detection, but most of them are implemented with the help of large and expensive external optical detection platforms. Not only is the operation complicated and costly, but the increase in the optical path may affect the accuracy of the final detection results, making it difficult to meet people's usage 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 an 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 realized. The structure is simple, the operation is convenient, the integration is improved, and the production cost of the microfluidic chip is reduced. In addition, real-time in-situ photoelectric detection can be performed, the detection efficiency and the accuracy of the detection results are improved, and 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] A microfluidic chip with a photoelectric detection function provided by the present invention comprises a substrate layer, a device layer, an insulating layer and a hydrophobic layer which are fixedly connected in sequence from bottom to top, wherein a microfluidic droplet drive array and an electrical interface are arranged in the device layer, wherein the microfluidic droplet drive array is electrically connected to an external circuit through the electrical interface, wherein a plurality of droplet drive pixel units and an on-chip photoelectric detection area for driving the movement of droplets are arranged in the microfluidic droplet drive array, wherein an array of a plurality of droplet drive pixel units is arranged in the device layer, wherein the on-chip photoelectric detection area cooperates with an array formed by the droplet drive pixel units, wherein a mutually cooperating bright sensor and a dark sensor are arranged in the on-chip photoelectric detection area, wherein a photodiode PD1, a double-gate thin film transistor TFT1 and a double-gate thin film transistor TFT2 are arranged in the bright sensor, wherein a light-shielded photodiode PD2, a double-gate thin film transistor TFT3 and a double-gate thin film transistor TFT4 are arranged in the dark sensor, wherein the bright sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area, and wherein the droplet drive pixel unit can drive the droplets located on the upper surface of the hydrophobic layer to move.

[0007] The present invention is further improved, the bright sensor is in the shape of a film, 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 a diagonally spaced arrangement, and the bright 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, the droplet driving pixel unit is provided 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.

[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 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 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 photoelectric detection 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 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 end of the transimpedance amplifier K3, the output end of the transimpedance amplifier K2 and the output end of the transimpedance amplifier K3 are connected to the input end of the differential amplifier K4, and the output end of the differential amplifier K4 can output the final differential voltage Vout.

[0012] The present invention is further improved, 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 by 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 or indium gallium zinc oxide or 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, 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 beneficial effects of the present invention are as follows: a microfluidic chip with a photoelectric detection function is provided, wherein a substrate layer, a device layer, an insulating layer and a hydrophobic layer that cooperate with each other are arranged on the microfluidic chip, a light sensor and a dark sensor are arranged in an 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, a droplet-driven pixel unit can drive the droplet located on the upper surface of the hydrophobic layer to move, and the differential output of the light sensor and the dark sensor is used as the result of the on-chip photoelectric detection area, so that a photoelectric detection function with high detection sensitivity, wide dynamic response range and strong anti-interference performance can be realized, the structure is simple, the operation is convenient, and the integration is improved, and the light sensor and the dark sensor based on thin film transistors are compatible with the preparation process of the microfluidic chip, and both can be prepared and processed by thin film transistor display panel technology, which 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 result, 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, the operation is complicated, 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 is 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 paying any creative work.

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

[0019] Figure 2 The schematic diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0020] Figure 3 The schematic diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0021] Figure 4 The schematic diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0022] Figure 5 The schematic diagram of the microfluidic chip with photoelectric detection function of the present invention;

[0023] Figure 6 This is a comparison diagram of the output current of the bright 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 photoelectric detection area of ​​the present invention;

[0026] Fig. 9 The graph is a variation curve of the differential current of the bright sensor and the dark sensor of the present invention with different light intensities;

[0027] Fig.10 This is a temperature characteristic comparison diagram of a combination of a bright sensor and a dark sensor of the present invention and a single 2T1D sensor;

[0028] Fig.11 is a circuit diagram of the on-chip photoelectric detection area of ​​the present invention;

[0029] Fig.12 The bipolar plate structure schematic diagram 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 meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein 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] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood 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 Figure 1-Figure 12 As shown, a microfluidic chip with a photoelectric detection function provided by the present invention comprises a substrate layer, a device layer, an insulating layer and a hydrophobic layer which are fixedly connected in sequence from bottom to top, a microfluidic droplet drive array and an electrical interface are arranged in the device layer, the microfluidic droplet drive array is electrically connected to an external circuit through the electrical interface, a plurality of droplet drive pixel units and an on-chip photoelectric detection area for driving the movement of droplets are arranged in the microfluidic droplet drive array, a 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, a bright sensor and a dark sensor which cooperate with each other are arranged in the on-chip photoelectric detection area, a photodiode PD1, a dual-gate thin film transistor TFT1 and a dual-gate thin film transistor TFT2 are arranged in the bright sensor, and a light-shielded photodiode PD2, a dual-gate thin film transistor TFT3 and a dual-gate thin film transistor TFT4 are arranged in the dark sensor. 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 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, which can achieve a photoelectric detection function with high detection sensitivity, wide dynamic response range, and strong anti-interference performance. The structure is simple, the operation is convenient, and the integration is improved. Moreover, the thin-film transistor-based light sensor and dark sensor are compatible with the preparation process of the microfluidic chip, and both can 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 can perform real-time in-situ photoelectric detection, thereby improving the detection efficiency and the accuracy of the detection results. It has broad application value and market potential.

[0034] like Figure 2-Figure 5As shown, the shape of the light sensor is a thin film, the shape of the dark sensor is a thin film, the arrangement and combination of the light sensor and the dark sensor is a horizontal spacing arrangement, a vertical spacing arrangement, or an oblique spacing arrangement, and the light sensor and the dark sensor are arranged to form an on-chip photoelectric detection area; a plurality of on-chip photoelectric detection areas are provided in the microfluidic droplet drive array, and the plurality of on-chip photoelectric detection areas do not contact each other and cooperate with each other; a single-gate thin-film transistor TFT5 and a capacitor C1 are provided in the droplet drive 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. In this embodiment, a plurality of droplet drive pixel units can form an array for controlling the movement, generation, merging and separation of droplets through a certain combination of rows and columns. The on-chip photoelectric detection area is used to perform on-chip photoelectric signal detection on a specific area of ​​the microfluidic chip, thereby improving the system integration of the on-chip laboratory. The shape and size of the on-chip photoelectric detection area are mainly determined by the arrangement and combination of the light sensor and the dark sensor. The shape and size of the on-chip photoelectric detection area can be set to a square, a circle, a diamond, or other polygons according to actual needs. A plurality of on-chip photoelectric detection areas 51, 52...5n can be prepared on a microfluidic chip, and a microfluidic droplet drive array can be used to drive the sample to be tested 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 Figure 6-Figure 10As shown, the on-chip photodetection area also includes a transimpedance amplifier K1 disposed outside the device layer, the bottom gate of the double-gate thin film transistor TFT1 is connected to the drain of the double-gate thin film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the double-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 double-gate thin film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the double-gate thin film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the double-gate thin film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the double-gate thin film transistor TFT1 is grounded, and the drain of the double-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 end of the transimpedance amplifier K1. The output end of the transimpedance amplifier K1 can output the final differential voltage Vout. In this embodiment, the bright sensor is composed of a photodiode (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 microfluidic chips, which can improve the integration of the system and reduce the preparation cost of microfluidic chips. The dark sensor is based on the bright sensor, but 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, such as Figure 8 The light sensor L and the dark sensor are firstly current-differentiated, and then output to the peripheral readout system P2 for current-voltage conversion and amplification, and finally the differential voltage Vout is output. Fig. 9 This is a curve showing the difference in current between the bright sensor and the dark sensor as the light intensity changes. Figure 6 and Fig. 9It can be seen that the differential output has better linearity than a single 2T1D sensor output, and therefore has a wider dynamic response range and higher sensitivity. Fig.10 The temperature characteristics of the combination of bright sensor and dark sensor and single 2T1D sensor are compared. Fig.10 It can be seen that the combined output of the bright sensor and the dark sensor has smaller changes in different temperatures, so it has more stable temperature characteristics and stronger resistance to temperature interference. In summary, the combined design of the bright sensor and the dark sensor has higher detection sensitivity, wider dynamic response range and better anti-interference performance, which can improve the efficiency of detection and the accuracy of detection results.

[0036] like Fig.11 As shown, the on-chip photoelectric detection 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 double-gate thin film transistor TFT1 is connected to the drain of the double-gate thin film transistor TFT1, the positive electrode of the photodiode PD1, and the top gate of the double-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 double-gate thin film transistor TFT1 is connected to the bias voltage source Vtg1, the source of the double-gate thin film transistor TFT2 is connected to the bias voltage source Vds, the bottom gate of the double-gate thin film transistor TFT2 is connected to the bias voltage source Vbg2, the source of the double-gate thin film transistor TFT1 is grounded, and the drain of the double-gate thin film transistor TFT2 is connected to the input end of the transimpedance amplifier K2; the double-gate thin film transistor TFT1 is connected to the input end of the transimpedance amplifier K2; ...2 is connected to the input end of the transimpedance amplifier K2; the double-gate thin film transistor TFT1 is connected to the input end of the transimpedance amplifier K2; the double-gate thin film 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: Fig.11 The output currents of the bright sensor and the 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 Vout1 and Vout2 are differentiated to obtain the final differential voltage Vout.

[0037] like Fig.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 materials 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 are amorphous silicon materials or indium gallium zinc oxides or organic semiconductors or polycrystalline silicon materials; the channel shapes 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 are planar channels or π-type channels or 3D fin-type channels. In this embodiment, the microfluidic chip can also be in the form of a bipolar plate, such as Fig.12 As shown. Compared with the monopolar plate mode, the bipolar plate mode adds an upper plate including an upper conductive layer, while the lower plate is the same. Therefore, the microfluidic chip has a high degree of integration and adopts mature large-area display panel technology, with a low preparation 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 an 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, so that a photoelectric detection function with high detection sensitivity, wide dynamic response range and strong anti-interference performance can be realized. 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 both can be prepared and processed by thin film transistor display panel technology. Not only the system integration of the on-chip laboratory is improved, the production cost of the microfluidic chip is reduced, but also real-time in-situ photoelectric detection can be performed, the detection efficiency and the accuracy of the detection results are improved, and 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, the operation is complicated, and the increased optical path affects the accuracy of the final detection result.

[0039] The specific implementation modes described above are preferred implementation modes of the present invention, and are not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to the specific implementation modes, and all equivalent changes made according to 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 which are fixedly connected in sequence from bottom to top, wherein a microfluidic droplet drive array and an electrical interface are arranged in the device layer, wherein the microfluidic droplet drive array is electrically connected to an external circuit through the electrical interface, wherein a plurality of droplet drive pixel units and an on-chip photoelectric detection area for driving the movement of droplets are arranged in the microfluidic droplet drive array, wherein an array of a plurality of droplet drive pixel units is arranged in the device layer, wherein the on-chip photoelectric detection area cooperates with an array formed by the droplet drive pixel units, wherein a mutually cooperating bright sensor and dark sensor are arranged in the on-chip photoelectric detection area, wherein a photodiode PD1, a double-gate thin film transistor TFT1 and a double-gate thin film transistor TFT2 are arranged in the bright sensor, wherein a light-shielded photodiode PD2, a double-gate thin film transistor TFT3 and a double-gate thin film transistor TFT4 are arranged in the dark sensor, wherein the bright sensor and the dark sensor can perform on-chip photoelectric signal detection on the on-chip photoelectric detection area, and wherein the droplet drive pixel unit can drive the droplets located on the upper surface of the hydrophobic layer to move.

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, 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, and 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 arranged 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 disposed 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 cathode of the photodiode PD1 is connected to a bias voltage source Vdd, the top gate of the dual-gate thin film transistor TFT1 is connected to a bias voltage source Vtg1, the source of the dual-gate thin film transistor TFT2 is connected to a bias voltage source Vds, the bottom gate of the dual-gate thin film transistor TFT2 is connected to a 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, 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 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 a bias voltage source Vdd, the top gate of the dual-gate thin film transistor TFT1 is connected to a bias voltage source Vtg1, the source of the dual-gate thin film transistor TFT2 is connected to a bias voltage source Vds, the bottom gate of the dual-gate thin film transistor TFT2 is connected to a 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 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 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 end of the transimpedance amplifier K3, the output end of the transimpedance amplifier K2 and the output end of the transimpedance amplifier K3 are connected to the input end of the differential amplifier K4, and the output end of the differential amplifier K4 can output the 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 prepared in the device layer by 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, 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.

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