Ultrasonic phased array multi-droplet automatic control and detection system and method

Abstract

The invention discloses an ultrasonic phased array multi-droplet automatic control and detection system and method, and the system comprises an ultrasonic phased array driving device which comprises an optical flat plate, and a phased array circuit board and a droplet detection platform which are sequentially and fixedly installed on the optical flat plate from top to bottom; the liquid drop detection platform comprises a super-hydrophobic surface, and the phased array circuit board is used for capturing liquid drops on the super-hydrophobic surface and moving the liquid drops to required positions; the multi-liquid-drop automatic titration device is fixedly arranged on the optical flat plate and is used for generating liquid drops with required volumes; the ultrasonic phased array driving device further comprises an acquisition module which is used for acquiring liquid drop related information so as to carry out liquid drop detection. According to the invention, a plurality of sound field focuses are generated through computer control, and non-contact control of a plurality of liquid drops is realized; liquid drops are generated in an automatic control mode, the accuracy of liquid drop control is improved, and high-throughput detection of liquid drop samples is achieved in cooperation with a fluorescence detection sensor and a biological probe.

Description

Technical Field

[0001] The present invention relates to multi-droplet generation and multi-droplet manipulation technology, and in particular to an ultrasonic phased array multi-droplet automatic manipulation and detection system and method. Background Art

[0002] Droplet manipulation technology refers to the precise control of the movement, merging, splitting or arrangement of droplets in an internal or external environment by external control means (such as electric field, magnetic field, light field, acoustic field, etc.). The goals of droplet manipulation usually include precise control of the distribution, size, shape and interaction of droplets, and are widely used in medical diagnosis, chemical synthesis, single molecule experiments and other fields. Droplet manipulation in the internal environment refers to the manipulation of droplets in a microfluidic device. However, this method has problems such as uneven droplet distribution, limited operation accuracy, and cost caused by complex equipment, which directly affects the rate of high-throughput biochemical detection of droplets. Droplet manipulation in the external environment does not rely on the fluid dynamics in microfluidic channels and microchannels, but mainly manipulates droplets by physical or chemical means. This type of technology is suitable for macroscopic or larger-scale droplet manipulation, and usually uses external physical fields or chemical environments to change the shape, position, size or motion state of droplets. This technology does not involve fine flow control in microfluidics, but uses more direct external intervention. It is more suitable for high-throughput biochemical detection.

[0003] As one of the droplet manipulation technologies, the electric field requires a higher voltage during the driving process and the equipment is relatively large. The magnetic field is used to manipulate magnetic droplets, and the added magnetic substances may affect the subsequent chemical detection results. The light field changes the phototropism of the droplets to achieve droplet control, and the heat energy generated by the light will cause damage to the sample to be tested.

[0004] As a method of droplet manipulation, the acoustic field is widely used. Its basic principle is: when the distance between the ultrasonic source and the target to be measured is an integer multiple of half the wavelength, the radiated sound pressure generates an acoustic radiation force parallel to the ultrasonic source. If the sound source is placed above the droplet, the generated acoustic radiation force can offset part of the effect of gravity. If the acoustic radiation force is greater than or equal to gravity, the droplet will suspend, and the position of the droplet will be changed by dragging the position of the sound source.

[0005] At present, the droplets required for droplet manipulation and detection are mostly manually titrated using a pipette. If you need to titrate droplets of different volumes at different locations on the detection platform, you need to repeatedly adjust the pipette parameters. If the droplets are of different types, you also need to drain the original solution and then absorb another solution. This results in a decrease in the droplet detection rate. In addition, long-term use of a pipette can cause damage to the joints of the human hand. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art.

[0007] The technical solution adopted by the present invention to solve the technical problem is: to provide an ultrasonic phased array multi-droplet automatic control and detection system, comprising:

[0008] An ultrasonic phased array driving device comprises an optical plate made of metal material and a phased array circuit board and a droplet detection platform fixedly mounted on the optical plate from top to bottom; the droplet detection platform comprises a super-hydrophobic surface, and the phased array circuit board is used to capture droplets on the super-hydrophobic surface and move the droplets to a desired position;

[0009] A multi-droplet automatic titration device is fixedly mounted on the optical plate; the multi-droplet automatic titration device is used to generate droplets of a required volume and titrate them on the super-hydrophobic surface;

[0010] A waste liquid recovery device is fixedly installed next to the droplet detection platform on the optical plate, and is used to capture and recover the droplets on the droplet detection platform after the detection is completed;

[0011] A communication module, connected to the host computer, the ultrasonic phased array driving device and the multi-droplet automatic titration device respectively to realize the communication between the host computer and the ultrasonic phased array driving device and the communication between the host computer and the multi-droplet automatic titration device;

[0012] The ultrasonic phased array driving device also includes a collection module, which is used to collect droplet-related information and send it to a host computer for droplet detection.

[0013] Preferably, the circuit arranged on the phased array circuit board includes:

[0014] The microcontroller is used to generate a control sequence according to the instructions of the host computer and decompose it into a number of clock signals, which are output through a number of output terminals;

[0015] A plurality of shift registers, each of which has an input terminal connected to an output terminal of a microcontroller and outputs multiple parallel signals through multiple output terminals;

[0016] A plurality of driving amplifiers, each of which has an input terminal connected to an output terminal of the shift register and outputs an amplified signal through the output terminal;

[0017] There are several ultrasonic generators, each of which has an input end connected to an output end of a driving amplifier and generates ultrasonic waves through the output end. The ultrasonic waves generated by the multiple ultrasonic generators are focused to form multiple sound field foci to control multiple droplets respectively.

[0018] Preferably, the microcontroller is an FPGA chip, comprising at least 32 output terminals for outputting clock signals; each output terminal is electrically connected to an input terminal of a shift register;

[0019] There are 32 shift registers, each of which includes 1 input terminal and 8 output terminals, and each output terminal is electrically connected to the input terminal of a driving amplifier;

[0020] There are 128 driving amplifiers, each of which includes 2 input terminals and 2 output terminals, and each output terminal is electrically connected to the positive input terminals of two ultrasonic generators;

[0021] There are 256 ultrasonic generators distributed in a 16×16 array; each ultrasonic generator includes two input terminals and one output terminal, the negative input terminal is grounded, and the output terminal generates ultrasonic waves according to the input signal.

[0022] Preferably, the multi-droplet automatic titration device comprises:

[0023] A liquid storage module, used for storing a titration solution;

[0024] A titration module for generating droplets;

[0025] A droplet pumping module is used to pump the titration solution to the titration module; the input end is connected to the liquid storage module, and the output end is connected to the titration module;

[0026] The first driving circuit is connected to the titration module and the droplet pumping module respectively to supply power.

[0027] Preferably, the liquid storage module includes a plurality of cryotubes, and the cryotubes are fixed on the optical plate through a cryotube bracket; a plurality of through holes are reserved on the cryotube bracket to place a plurality of cryotubes correspondingly, and the cryotube bracket is fixed on the optical plate through screws;

[0028] The titration module includes a servo motor, a servo motor connecting rod, a plurality of PP adapters and a plurality of dispensing needles; the servo motor connecting rod includes a cross bar and two legs extending from both ends of the cross bar in a direction perpendicular to the cross bar, and the two legs are parallel and equal in length; the servo motor is fixed on a metal plate through a motor bracket, and the metal plate is fixed on an optical flat plate through a metal plate bracket and is located above the freezing tube; a servo motor arm is installed on the output shaft of the servo motor, and the servo motor arm is connected to one of the legs of the servo motor connecting rod, and an adapter bracket is fixedly connected to the servo motor connecting rod, and the adapter is provided with a plurality of through holes; each PP adapter consists of an inverted cone joint and a Luer male head, and the inverted cone joint and the Luer male head are respectively located at the two ends of the through hole of the adapter bracket, one end of the Luer male head is screwed with the inverted cone joint to be fixed on the adapter bracket, and a dispensing needle is installed on the other end of the Luer male head for generating droplets.

[0029] Preferably, two limit cross bars extend outward from the two legs of the servo motor connecting rod in a direction parallel to the cross bar, and the two limit cross bars respectively pass through the slots of two limit brackets, and the two limit brackets are fixed on the metal plate; one of the limit brackets is provided with a bearing circular hole, and a bearing is installed in the bearing circular hole, and a bearing cross bar also extends from the leg connected to the limit bracket and passes through the middle of the bearing.

[0030] Preferably, the acquisition module includes a fluorescence detector and an industrial camera fixedly mounted on the edge of the optical plate; the camera head of the industrial camera has a field of view of up to 120° and is fixedly mounted on the optical plate with the lens facing upward, below the super-hydrophobic surface of the droplet detection platform.

[0031] Preferably, the waste liquid recovery device comprises:

[0032] A second liquid storage module, used for storing recovered droplets;

[0033] A second droplet pumping module, used to pump the droplets captured by the recovery module to the second liquid storage module; the input end is connected to the output end of the recovery module, and the output end is connected to the second liquid storage module;

[0034] A recovery module, the input end of which is flush with the super-hydrophobic surface of the droplet detection platform, and the output end of which is connected to the second droplet pumping module;

[0035] The second driving circuit is connected to the second droplet pumping module and the recovery module to supply power.

[0036] Preferably, the second liquid storage module includes a freezing tube, which is fixed on the optical plate through a recovery bracket; the recovery bracket reserves a through hole for placing the freezing tube and is fixed on the optical plate by screws; the second droplet pumping module includes a micro peristaltic pump, the positive and negative power lines of the micro peristaltic pump are connected to the second drive circuit, and a BPT hose is sleeved on the rotor of the micro peristaltic pump, one end of the BPT hose is connected to the freezing tube of the second liquid storage module, and the other end of the BPT hose is connected to the adapter of the recovery module; the recovery module includes a PP adapter and a dispensing needle, and the dispensing needle is connected to the BPT hose of the second droplet pumping module through the PP adapter; the dispensing needle is flush with the super hydrophobic surface of the droplet detection platform;

[0037] The number of the freezing tubes, the number of micro peristaltic pumps, the number of PP adapters and the number of dispensing needles are consistent. Several freezing tubes are connected one-to-one with one end of several BPT hoses, and the other ends of several BPT hoses are connected one-to-one with several PP adapters. A dispensing needle is fixedly installed at the end of each PP adapter.

[0038] The present invention also provides an ultrasonic phased array multi-droplet automatic control and detection method, using any of the above-mentioned systems, comprising the following steps:

[0039] Turn on the multi-droplet automatic titration device to generate multiple droplets with volumes meeting expected requirements on the droplet detection platform;

[0040] The acquisition module is used to detect the current positions of multiple droplets, and the phased array circuit board is turned on to generate multiple acoustic field focal points to capture multiple droplets;

[0041] According to the preset end position of the droplet, the shortest path for the multiple droplets to move to the end position is calculated, and the multiple acoustic field focal points are controlled to move the multiple droplets along the shortest path;

[0042] After multiple droplets have reached the target detection position, the collection module is used to collect droplet-related information and upload it to the host computer, which analyzes the droplet composition based on the relevant information uploaded by the collection module;

[0043] After the host computer completes the analysis of the droplet composition, it moves multiple droplets to the recovery area through multiple acoustic field foci generated by the phased array circuit board;

[0044] The second droplet pumping module of the recovery device is turned on to recover the droplets and store them in the second liquid storage module.

[0045] The present invention has the following beneficial effects:

[0046] (1) The present invention can control the ultrasonic phased array to generate multiple acoustic field foci without contacting the droplets, capture and manipulate multiple droplets to move simultaneously, and the ultrasonic phased array method of manipulating droplets significantly increases the distance over which the droplets can be manipulated;

[0047] (2) Due to the introduction of an automatic droplet titration device, the generation of controlled droplets is automated; and a waste liquid recovery system is added to avoid droplet contamination caused during the detection process;

[0048] (3) By introducing a fluorescence detection module, it is easy to obtain the composition information of the droplet sample. The entire invention realizes automated operation and analysis, reduces human intervention, and can improve the efficiency of droplet manipulation.

[0049] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the system structure of an embodiment of the present invention;

[0051] Figure 2 It is the exploded and overall installation diagram of the embodiment of the present invention;

[0052] Figure 3 This is the disassembly and overall installation diagram of the ultrasonic phased array drive device;

[0053] Figure 4 It is a connection diagram of the ultrasonic phased array driving device;

[0054] Figure 5 This is the disassembly and overall installation diagram of the multi-droplet automatic titration device;

[0055] Figure 6 Design drawing of the upper metal plate of the multi-droplet automatic titration device;

[0056] Figure 7 A first driving circuit connection diagram of a multi-droplet automatic titration device;

[0057] Figure 8 It is a schematic diagram of a first driving circuit of a multi-droplet automatic titration device;

[0058] Fig. 9 This is the disassembly and overall installation diagram of the waste liquid recovery device;

[0059] Fig.10 The figure is a flow chart of a method according to an embodiment of the present invention.

[0060] Description of the accompanying drawings: 100-ultrasonic phased array driving device, 101-phased array circuit board, 102-phased array circuit fixing metal plate, 103-TDT-2020 aluminum profile-250mm, 104-2020 angle code, 105-TDT-2020 aluminum profile-300mm, 106-droplet detection platform, 107-industrial camera, 108-optical flat plate, 109-fluorescence detection module bracket, 110-fluorescence detector; 200-multi-droplet automatic titration device, 201-first driving circuit, 202-TDT-2020 aluminum profile-135mm, 203-peristaltic pump pressure plate, 204-limiting bracket (with bearing hole), 205-bearing (606ZZ 6*17*6), 206-upper metal plate, 207-first micro peristaltic pump, 208-first freezing tube, 209-freezing tube bracket, 210-limiting bracket (without bearing hole), 211-servo motor bracket, 212-servo motor arm, 213-servo motor arm, 214-servo motor connecting rod, 215-first Luer male head, 216-adapter bracket, 217-first inverted cone joint; 300-waste liquid recovery device, 301-second freezing tube, 302-waste liquid recovery bracket, 303-second Luer male head, 304-second inverted cone joint, 305-second micro peristaltic pump. DETAILED DESCRIPTION

[0061] See also Figure 1 and Figure 2As shown, it is a system structure diagram decomposition and overall installation diagram of an embodiment of the present invention, and the system includes:

[0062] The ultrasonic phased array driving device 100 comprises an optical plate 108 and a phased array circuit board 101 and a droplet detection platform 103 fixedly mounted on the optical plate 108 from top to bottom; the droplet detection platform 106 comprises a super-hydrophobic surface, and the phased array circuit board 101 is used to capture droplets on the super-hydrophobic surface and move the droplets to a desired position; the ultrasonic phased array driving device 100 also comprises a collection module for collecting droplet-related information for droplet detection; the collection module comprises an industrial camera 107 and a fluorescence detection device 110;

[0063] A multi-droplet automatic titration device 200, fixedly mounted on the optical plate 108, for generating droplets of a desired volume;

[0064] The waste liquid recovery device 300 is fixedly installed beside the droplet detection platform 106 on the optical plate 108, and is used to capture and recover the droplets on the droplet detection platform 106 after the detection is completed; the waste liquid recovery device 300 includes: a second liquid storage module, which is used to store the recovered droplets; a second droplet pumping module, whose input end is connected to the recovery module, and whose output end is connected to the second liquid storage module; a recovery module, whose input end is flush with the super-hydrophobic surface of the droplet detection platform 106, and whose output end is connected to the second droplet pumping module; a second driving circuit, which is connected to the second droplet pumping module and the recovery module for power supply;

[0065] And auxiliary supporting metal parts, including: aluminum profiles, optical flat plate 108, metal angle code, phased array circuit fixing metal plate.

[0066] Specifically, the ultrasonic phased array driving device 100 includes a phased array circuit fixing metal plate 102, which is fixed to an optical flat plate 108 through a column structure composed of aluminum profiles, a beam structure composed of aluminum profiles, and a metal angle bracket. The multi-droplet automatic titration device 200 includes an upper metal plate 206, which is fixed to the optical flat plate 108 through a column structure composed of aluminum profiles.

[0067] See also Figure 3As shown, the ultrasonic phased array driving device 100 includes an optical flat plate 108 at the bottom, four 300mm aluminum profiles 105 form columns fixed on the optical flat plate, and two 250mm aluminum profiles 103 form a crossbeam structure fixed by angle code 104. The phased array circuit fixing metal plate is fixed on the crossbeam, and the phased array circuit board 101 is placed on the metal iron sheet, all of which are fixed with screws and nuts. The industrial camera 107 is fixed in the center of the optical flat plate 108 with the lens facing upward. The droplet detection platform 106 is placed directly below the phased array circuit board 101 and fixed on the optical flat plate 108. The fluorescence detection module includes a fluorescence detector 110 and a fluorescence detection module bracket 109, and the fluorescence detection module bracket 109 is fixed to the edge of the optical flat plate 108 by screws. Two sets of fluorescence detectors 110 are fixed to the fluorescence detection module bracket 109 by screws and bolts. The end of the fluorescence detection module bracket 109 has a certain tilt angle, which is conducive to the light beam irradiating on the hydrophobic surface.

[0068] Specifically, the phased array circuit board 101 is an ultrasonic phased array PCB circuit board, which includes a main control module integrating a main control chip and a communication module, a signal processing module connected to the signal output end of the main control module, and an ultrasonic generator at the output end of the signal processing module. The above modules are all connected by electrical connection. The PCB circuit board is placed on a metal iron sheet and fixed by screws.

[0069] The ultrasonic generator used in the embodiment of the present invention has a center frequency of 40kHz and is distributed in an array in a 16×16 manner, with a spacing of 1mm between two adjacent probes. The main control chip model used is FPGA CoreEP4CE6, which is used to generate a clock control sequence, and the communication module is Arduino Nano. The signal processing module used includes a 74HC595D shift register and a MIC4127YME driver amplifier. The function of the signal processing module is that the shift register converts the serial clock signal generated by the FPGA into an eight-way parallel output signal (amplitude 5V) acting on the input end of the driver amplifier, and the driver amplifier amplifies the input signal to a pulse signal with the same amplitude as the input voltage (amplitude 6V~15V). By adjusting the phase difference of the output pulse signal amplitude, the focus position of the sound field can be changed, thereby capturing the movement of the droplet.

[0070] The ultrasonic phased array PCB circuit board designed in the embodiment of the present invention includes 1 main control module, 32 shift registers, 128 drive amplifiers, and 256 ultrasonic generators. The ultrasonic generators are distributed in 16×16. Figure 4As shown in the figure, one of the topologies is used as an example: when the FPGA receives the host computer instruction, it generates a clock signal according to the instruction. The clock signal is used as the input of the shift register, and the clock signal is output in parallel and acts on the driver amplifier. The driver amplifier amplifies the input signal and acts on the ultrasonic generator to generate a sound wave signal with sufficient amplitude. By adjusting the trigger time of the clock signal, the phase of the sound wave signal generated by the ultrasonic generator is finally realized, thereby realizing the change of the focal position of the generated sound field.

[0071] Specifically, the droplet detection platform 106 is composed of a platform bracket and a super-hydrophobic surface. The platform bracket is a hollow structure inside, which is made by an integrated molding method and is placed on the optical flat plate 108, 16 cm below the phased array circuit board 101. The super-hydrophobic surface is made of glass as a substrate, after spraying a hydrophobic material (XN-204L hydrophobic coating) on ​​the surface, heating at 150°C for 1h and cooling; it is placed flat at the center of the platform bracket as a droplet motion control platform.

[0072] Specifically, the industrial camera 107 is fixed at the center of the optical plate 108 and is used to collect images of droplet motion. When in use, the industrial camera 107 sends droplet image information to the host computer at fixed time intervals to implement a feedback function. The host computer determines whether the droplet is successfully captured based on the image information, compares the expected preset position of the droplet with the actual position, and corrects the droplet motion trajectory.

[0073] Specifically, the fluorescence detection module is composed of two fluorescence detectors 110 and a fluorescence detection module bracket 109. The fluorescence detector 110 is fixed to the fluorescence detection module bracket 109 by bolts. Since the bracket itself has a certain tilt angle, the light beam emitted by the fluorescence detector 110 is better irradiated on the hydrophobic surface. When in use, the fluorescence detection module sends the droplet composition information to the host computer in the form of an electrical signal for detection and analysis. The specific principle is: the fluorescence detection module emits a laser, which is irradiated on the sample to be tested (i.e., the droplet). The sample to be tested reflects a certain fluorescence wavelength. After the fluorescence is filtered, it is focused on the photoelectric detector integrated inside by the fluorescence collection lens. After photoelectric conversion and amplification, the corresponding electrical signal is obtained, and finally the electrical signal is sent to the host computer through serial communication. This information is sent uninterruptedly and at a certain time interval. The host computer analyzes these electrical signals and then obtains the droplet composition. The model of the fluorescence detector used in the embodiment of the present invention is MNS-MFD-365.

[0074] See also Figure 5As shown in FIG. 1 , the multi-droplet automatic titration device 200 is decomposed and installed as a whole, which can be divided into a first driving circuit, a droplet pumping module, a liquid storage module, a titration module and auxiliary metal parts; the titration module also includes a servo motor. The multi-droplet automatic titration device 200 is fixed on the optical plate 108 as a whole, and the auxiliary metal parts used include six aluminum profiles 202 (TDT-2020 aluminum profile - 135mm) and an upper metal plate 206 (specifications refer to Figure 6 ).

[0075] The droplet pumping device is composed of four first micro peristaltic pumps 207. The embodiment of the present invention adopts a micro peristaltic pump of model LFP101ADB, with a rated flow rate of 0.1 ml / min and a rated input voltage of 6 V; the four first micro peristaltic pumps 207 are respectively placed in holes with a diameter of 19 mm in the upper metal plate 206 and fixed with screws through a peristaltic pump pressure plate 203.

[0076] The liquid storage module is composed of four 5ml first cryotubes 208 and a cryotube holder 209. The cover of each first cryotube 208 is reserved with a hole of 1.5mm to 2mm. The four first cryotubes 208 can store different types of solutions to be titrated and are placed in the cryotube holder 209. The cryotube holder 209 is formed in an integrated manner, which includes four slots with a diameter of 16.4mm, which is convenient for placing and removing the cryotubes. Four fixing holes are reserved on the base of the holder, which are fixed to the edge of the optical plate 108 with screws.

[0077] The titration module includes a servo motor (TD8115), a servo motor bracket 211, a servo motor connecting rod 214, a limit bracket (with a bearing side 204, without a bearing side 210), a bearing 205 (606ZZ, 6*17*6), a first PP adapter, an adapter bracket 214 and a dispensing needle. Figure 7 The rotor of the first micro peristaltic pump 207 is covered with a BPT hose, wherein the liquid output end is connected to the first inverted cone connector 217 of the titration module, and the liquid input end is connected to the first freezing tube 208, and enters the first freezing tube 208 through the reserved hole on the cover of the first freezing tube 208. The positive and negative wires of the first micro peristaltic pump 207 are respectively connected to the positive and negative electrodes of the peristaltic pump terminal of the first driving circuit.

[0078] The servo motor is fixed to the upper metal plate 206 with screws and nuts, specifically fixed to the 3.2mm inner diameter hole of the upper metal plate 206 by the servo motor bracket 211. The servo motor output shaft is connected to the servo motor arms 212 and 213, and the servo motor arms 212 and 213 are connected to the servo motor connecting rod 214. The limit bracket is divided into a bearing side and a non-bearing side. The bearing side is installed on the 61mm long slot hole of the upper metal plate, and the bearing is installed in the bearing hole of the limit bracket 204. The non-bearing side is installed in the 64mm long slot hole of the upper metal plate. The rod extending from the servo motor connecting rod 214 passes through the slot holes reserved in the bearing 205 and the limit bracket 204 respectively. The adapter bracket 216 is installed in the slot hole at the end of the servo motor connecting rod 214, and the installation position is adjusted by adapting the height of the droplet detection platform 106. The first PP adapter is divided into two parts: a first inverted cone connector 217 and a first Luer male head 215, wherein the liquid output end of the first micro peristaltic pump 207 is connected to the first inverted cone connector 217. The first inverted cone connector 217 passes through the upper part of the adapter bracket 216, and the first Luer male head 215 passes through the lower part of the adapter bracket 216, and the two parts are tightened and fixed; a dispensing needle is fixed at the end of the first Luer male head 215.

[0079] The first drive circuit 201 is fixed on the upper metal plate 206 through the aluminum profile 202. The first drive circuit includes a core module (the main control chip is Arduino nano), two power conversion chips (TPS5450), four switch devices (S9012 and JQC-3FF-005-SZ relay), and input and output terminals. Figure 7 and Figure 8 , which is the first drive circuit connection diagram and schematic diagram of the multi-droplet automatic titration device; the main control chip generates I / O signals and interacts with the communication module data. The two-way power conversion chip is used to stabilize the external input voltage at 5V and 6V. The 5V voltage is used to power the relay, and the 6V voltage is used to power the servo motor and the pumping device in the titration module. The peristaltic pump terminal and the external voltage input interface use KF301-2PIN terminals, the communication interface uses KF301-3PIN terminals, and the servo motor interface uses 3PIN pins with a spacing of 2.54mm. When the host computer sends a serial port instruction, the microprocessor controls the relay switch by outputting the level signal of the corresponding time, thereby controlling the switching time of the peristaltic pump. During the titration process, the microprocessor outputs a pulse signal to the servo motor to keep the servo motor connecting rod parallel to the working platform; when the titration operation is completed, the microprocessor outputs a pulse signal again to put the servo motor connecting rod in a vertical state to avoid the obstruction of the transfer tube bracket affecting the generation of the sound field focus.

[0080] See also Fig. 9As shown, the waste liquid recovery device includes two second micro peristaltic pumps 305, a BPT hose, a PP adapter, a recovery device bracket 302 and two sets of 5ml second freezing tubes 301. The recovery device bracket 302 is fixed to the optical plate 108 by screws, and the PP adapter includes a second inverted cone joint 304 and a second Luer male head 303, and the end of the second Luer male head 303 is connected to a dispensing needle. The PP adapter is placed on the fixed notch reserved in the recovery device bracket 302, and the dispensing needle after installation is flush with the hydrophobic surface. The BPT hose is sleeved on the rotor of the second micro peristaltic pump 305, and its input end is connected to the second inverted cone joint 304, and the output end is connected to the second freezing tube 301. The second micro peristaltic pump 305 is placed in the upper hole of the recovery device bracket 302. The freezing tube is placed in the lower hole. When the droplet detection is completed, the focus of the acoustic field is manipulated to move the droplet to the vicinity of the dispensing needle of the recovery device. At this time, the power of the second micro peristaltic pump 305 is turned on to pump the droplet back into the second freezing tube 301.

[0081] See also Fig.10 As shown, when using the embodiment of the present invention to manipulate and detect multiple droplets, the micro peristaltic pump of the titration module works to generate droplets on the droplet detection platform until the droplet volume meets the expected requirements. When the droplet is generated, the servo motor works so that the servo motor connecting rod is in a vertical state. Then the current position of multiple droplets is detected in real time by visual detection. There are many such algorithms. The embodiment of the present invention uses a droplet target detection method based on deep learning; the phased array circuit is turned on to generate multiple sound field foci to capture multiple droplets. When the droplet is successfully captured, since the end position of the droplet movement is pre-set, the A* algorithm (8 directions) can be used to generate the shortest path from multiple droplets to the end point, and then the multiple sound field foci are controlled to move along the shortest path. During the movement, the visual feedback method is used to determine whether the droplet is captured successfully, that is, the difference between the droplet position coordinates and the sound field focus position coordinates is compared in real time to see whether it is kept within 10 pixels. If so, it means that the droplet is successfully captured. Otherwise, it means that the capture fails, and then the current droplet position is returned to recapture and sent to the target detection position. After the droplet reaches the target detection position, the information collected by the fluorescence detection module is used to detect the droplet composition. Different substances reflect different fluorescence wavelengths, so the electrical signals obtained through the photoelectric converter are also different. The electrical signals are continuously sent back to the host computer at a certain time interval and displayed, and the droplet composition is determined based on the size of the electrical signal. After the detection is completed, the droplet is moved to the recovery area, the peristaltic pump power of the recovery device is turned on, and the droplet is recovered.

[0082] The present invention discloses an ultrasonic phased array multi-droplet automatic control device, which can control the ultrasonic phased array to generate multiple sound field foci without contacting the droplets, and capture and manipulate multiple droplets to move simultaneously. The ultrasonic phased array controls the droplets so that the distance of the controllable droplets is significantly increased. The automatic titration device for the droplets is introduced, and the generation of the controlled droplets is automated. The introduction of the fluorescence detection module facilitates the acquisition of the droplet sample composition information. The waste liquid recovery system is added to avoid droplet contamination caused during the detection process. The entire invention realizes automated operation analysis, reduces human intervention, and can improve the efficiency of droplet manipulation.

[0083] It can be seen that the present invention generates multiple acoustic field foci through computer control, which can realize non-contact manipulation of multiple droplets. In addition, the generation of controlled droplets is generated by automatic control, replacing the traditional manual operation mode, thereby improving the accuracy of droplet manipulation. In combination with fluorescence detection sensors and biological probes, high-throughput detection of droplet samples can be achieved.

[0084] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultrasonic phased array multi-droplet automatic control and detection system, characterized in that: include: An ultrasonic phased array driving device comprises an optical plate made of metal material and a phased array circuit board and a droplet detection platform fixedly mounted on the optical plate from top to bottom; the droplet detection platform comprises a super-hydrophobic surface, and the phased array circuit board is used to capture droplets on the super-hydrophobic surface and move the droplets to a desired position; A multi-droplet automatic titration device is fixedly mounted on the optical plate; the multi-droplet automatic titration device is used to generate droplets of a required volume and titrate them on the super-hydrophobic surface; A waste liquid recovery device is fixedly installed next to the droplet detection platform on the optical plate, and is used to capture and recover the droplets on the droplet detection platform after the detection is completed; A communication module, connected to the host computer, the ultrasonic phased array driving device and the multi-droplet automatic titration device respectively to realize the communication between the host computer and the ultrasonic phased array driving device and the communication between the host computer and the multi-droplet automatic titration device; The ultrasonic phased array driving device also includes a collection module, which is used to collect droplet-related information and send it to a host computer for droplet detection.

2. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 1, characterized in that: The circuit arranged on the phased array circuit board includes: The microcontroller is used to generate a control sequence according to the instructions of the host computer and decompose it into a number of clock signals, which are output through a number of output terminals; A plurality of shift registers, each of which has an input terminal connected to an output terminal of a microcontroller and outputs multiple parallel signals through multiple output terminals; A plurality of driving amplifiers, each of which has an input terminal connected to an output terminal of the shift register and outputs an amplified signal through the output terminal; There are several ultrasonic generators, each of which has an input end connected to an output end of a driving amplifier and generates ultrasonic waves through the output end. The ultrasonic waves generated by the multiple ultrasonic generators are focused to form multiple sound field foci to control multiple droplets respectively.

3. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 2, characterized in that: The microcontroller is an FPGA chip, comprising at least 32 output terminals for outputting clock signals; each output terminal is electrically connected to an input terminal of a shift register; There are 32 shift registers, each of which includes 1 input terminal and 8 output terminals, and each output terminal is electrically connected to the input terminal of a driving amplifier; There are 128 driving amplifiers, each of which includes 2 input terminals and 2 output terminals, and each output terminal is electrically connected to the positive input terminals of two ultrasonic generators; There are 256 ultrasonic generators distributed in a 16×16 array; each ultrasonic generator includes two input terminals and one output terminal, the negative input terminal is grounded, and the output terminal generates ultrasonic waves according to the input signal.

4. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 1, characterized in that: The multi-droplet automatic titration device comprises: A liquid storage module, used for storing a titration solution; A titration module for generating droplets; A droplet pumping module is used to pump the titration solution to the titration module; the input end is connected to the liquid storage module, and the output end is connected to the titration module; The first driving circuit is connected to the titration module and the droplet pumping module respectively to supply power.

5. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 4, characterized in that: The liquid storage module includes a plurality of cryotubes, which are fixed on the optical plate through a cryotube bracket; a plurality of through holes are reserved on the cryotube bracket to place a plurality of cryotubes correspondingly, and the cryotube bracket is fixed on the optical plate through screws; The titration module includes a servo motor, a servo motor connecting rod, a plurality of PP adapters and a plurality of dispensing needles; the servo motor connecting rod includes a cross bar and two legs extending from both ends of the cross bar in a direction perpendicular to the cross bar, and the two legs are parallel and equal in length; the servo motor is fixed on a metal plate through a motor bracket, and the metal plate is fixed on an optical flat plate through a metal plate bracket and is located above the freezing tube; a servo motor arm is installed on the output shaft of the servo motor, and the servo motor arm is connected to one of the legs of the servo motor connecting rod, and an adapter bracket is fixedly connected to the servo motor connecting rod, and the adapter is provided with a plurality of through holes; each PP adapter consists of an inverted cone joint and a Luer male head, and the inverted cone joint and the Luer male head are respectively located at the two ends of the through hole of the adapter bracket, one end of the Luer male head is screwed with the inverted cone joint to be fixed on the adapter bracket, and a dispensing needle is installed on the other end of the Luer male head for generating droplets.

6. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 5, characterized in that: Two limit cross bars extend outward from the two legs of the servo motor connecting rod in a direction parallel to the cross bar, and the two limit cross bars pass through the slots of the two limit brackets respectively, and the two limit brackets are fixed on the metal plate; one of the limit brackets is provided with a bearing circular hole, and a bearing is installed in the bearing circular hole, and a bearing cross bar also extends from the leg connected to the limit bracket and passes through the middle of the bearing.

7. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 1, characterized in that: The acquisition module includes a fluorescence detector and an industrial camera fixedly mounted on the edge of the optical plate; the camera head of the industrial camera can reach a field of view of 120° and is fixedly mounted on the optical plate with the lens facing upward and below the super-hydrophobic surface of the droplet detection platform.

8. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 1, characterized in that: The waste liquid recovery device comprises: A second liquid storage module, used for storing recovered droplets; A second droplet pumping module, used to pump the droplets captured by the recovery module to the second liquid storage module; the input end is connected to the output end of the recovery module, and the output end is connected to the second liquid storage module; A recovery module, the input end of which is flush with the super-hydrophobic surface of the droplet detection platform, and the output end of which is connected to the second droplet pumping module; The second driving circuit is connected to the second droplet pumping module and the recovery module to supply power.

9. The ultrasonic phased array multi-droplet automatic manipulation and detection system according to claim 8, characterized in that: The second liquid storage module includes a freezing tube, which is fixed on the optical plate through a recovery bracket; the recovery bracket has a reserved through hole for placing the freezing tube and is fixed on the optical plate by screws; the second droplet pumping module includes a micro peristaltic pump, the positive and negative power lines of the micro peristaltic pump are connected to the second drive circuit, and a BPT hose is sleeved on the rotor of the micro peristaltic pump, one end of the BPT hose is connected to the freezing tube of the second liquid storage module, and the other end of the BPT hose is connected to the adapter of the recovery module; the recovery module includes a PP adapter and a dispensing needle, and the dispensing needle is connected to the BPT hose of the second droplet pumping module through the PP adapter; the dispensing needle is flush with the super hydrophobic surface of the droplet detection platform; The number of the freezing tubes, the number of micro peristaltic pumps, the number of PP adapters and the number of dispensing needles are consistent. Several freezing tubes are connected one-to-one with one end of several BPT hoses, and the other ends of several BPT hoses are connected one-to-one with several PP adapters. A dispensing needle is fixedly installed at the end of each PP adapter.

10. An ultrasonic phased array multi-droplet automatic control and detection method, using the system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Turn on the multi-droplet automatic titration device to generate multiple droplets with volumes meeting expected requirements on the droplet detection platform; The acquisition module is used to detect the current positions of multiple droplets, and the phased array circuit board is turned on to generate multiple acoustic field focal points to capture multiple droplets; According to the preset end position of the droplet, the shortest path for the multiple droplets to move to the end position is calculated, and the multiple acoustic field focal points are controlled to move the multiple droplets along the shortest path; After multiple droplets have reached the target detection position, the collection module is used to collect droplet-related information and upload it to the host computer, which analyzes the droplet composition based on the relevant information uploaded by the collection module; After the host computer completes the analysis of the droplet composition, it moves multiple droplets to the recovery area through multiple acoustic field foci generated by the phased array circuit board; The second droplet pumping module of the recovery device is turned on to recover the droplets and store them in the second liquid storage module.

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