Cell packaging and printing device and method capable of dynamically adjusting liquid components and concentration

Abstract

The invention relates to a cell packaging and printing device and method capable of dynamically adjusting liquid components and concentration, the cell packaging and printing device comprises a micro-fluidic chip, the micro-fluidic chip is vertically placed, the micro-fluidic chip at least comprises a micro-channel layer, and a micro-channel layer is arranged in the micro-channel layer; the micro-channel comprises at least one liquid inlet channel, at least one air inlet channel, at least one printing channel and at least one waste liquid channel, and the starting end of each liquid inlet channel and the starting end of each air inlet channel are connected with the corresponding pressure control end. The tail end of the liquid inlet channel, the tail end of the air inlet channel, the starting end of the printing channel and the starting end of the waste liquid channel intersect at the same position and form an extrusion area, and the thickness of the extrusion area is smaller than that of other areas of the micro-channel. A clamping structure is provided for the micro-fluidic chip, and it is guaranteed that the micro-fluidic chip is placed in the vertical direction and precisely matched with the piezoelectric device.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic chips, and in particular to a cell encapsulation and printing device and method capable of dynamically adjusting liquid components and concentrations. Background Art

[0002] In the field of biomedical research, such as gene sequencing, drug screening, protein microarray and other operations, it is often necessary to accurately, quickly and stably transfer trace amounts of biological reagents to specialized analytical vessels. However, the traditional manual reagent distribution method has disadvantages such as poor consistency, slow speed and easy waste of reagents. Therefore, how to achieve high-throughput and automated biological reagent distribution is of great significance to the development of these research fields.

[0003] A microfluidic chip is a miniaturized integrated system that integrates one or more analyses performed in a laboratory into one chip, and has good application prospects in the above-mentioned biomedical research field. Microfluidic chips mainly rely on their microchannels to process extremely small amounts of liquids and manipulate biochemical reactions in very small volumes. However, when the conditions required for biochemical reactions become complex, the types of liquids introduced and the operating steps become cumbersome, which will be detrimental to the success rate of the experiment. Therefore, how to quickly and accurately distribute the liquid in the microfluidic chip to an external container becomes important, and the present invention is designed to meet the needs of such liquid transfer operations.

[0004] At present, the transfer operations of liquids in microfluidic chips in the laboratory include pneumatic printing, pipe drainage, contact printing and other methods. These methods have high requirements for manual operation and chip production. For example, a microfluidic chip that can print out specific cells can capture cells through a special structure inside the chip, and then print the liquid containing cells in the form of droplets through pneumatic printing and eject them from the chip. Another example is the pipe drainage droplet printing method. After the liquid in the chip is screened by a pneumatic microvalve, the liquid is directly drained and inoculated into the microplate through a pipe inserted by a needle above the chip. Another example is to punch a hole under the chip and insert a capillary glass tube. When the gravity of the liquid is greater than the surface tension it is subjected to, droplets containing specific substances can be printed onto the collection substrate. Another example is Hand-Held Single-Cell Pipettes (hSCP) that can be used to print droplets containing single cells. This type of hSCP includes a dual-channel pipette and an hSCP tip. The chip at the tip of the hSCP is designed with a hook for capturing single cells, and the dual-channel pipette connected to the tip can print out the liquid containing single cells through four steps of preparation, capture, flushing, and release through positive and negative pressure operations. Some researchers also achieve the purpose of printing by forming tiny droplets that touch the micropores below to achieve passive dripping of droplets.

[0005] However, the pipette-type pressurized printing method cannot ensure a gentle fluid shear force, and the pressurization process will affect the fluid dynamic pressure distribution of the flow channel inside the chip, causing fluid reflux inside the chip, which is not suitable for high-throughput droplet printing; the method of pipetting and drainage is complicated to operate, takes a long time to print, and produces droplets with poor consistency, making it difficult to achieve efficient droplet printing; the contact printing method is prone to cross-contamination of reagents during liquid transfer. Summary of the invention

[0006] The present invention provides a cell encapsulation and printing device and method capable of dynamically adjusting liquid components and concentrations, aiming to solve at least one of the technical problems existing in the prior art.

[0007] The technical solution of the present invention is a cell encapsulation and printing device and method capable of dynamically adjusting liquid components and concentrations, wherein the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations comprises a microfluidic chip, the microfluidic chip is placed vertically, and the microfluidic chip comprises at least: A microchannel layer, wherein microchannels are arranged in the microchannel layer; The microchannel includes at least one liquid inlet channel, an air inlet channel, a printing channel and a waste liquid channel. The starting end of each of the liquid inlet channel and the starting end of the air inlet channel are respectively connected to a pressure control end. The end of the liquid inlet channel, the end of the air inlet channel, the starting end of the printing channel and the starting end of the waste liquid channel meet at one point to form an extrusion area. The thickness of the extruded area is less than the thickness of other areas of the microchannel.

[0008] Furthermore, it also includes at least one liquid storage tank, the number of which is consistent with the number of the liquid inlet channels. The outlet of each liquid storage tank is connected to the starting end of a single liquid inlet channel and a single pressure control end, and the pressure control end delivers the liquid in the liquid storage tank to the corresponding liquid inlet channel at a preset pressure and flow rate; The pressure control end is an air pressure control channel of the precision air pressure pump.

[0009] Furthermore, the air inlet channel comprises an air inlet and a serpentine channel connected in sequence, the air inlet is used to input a preset air pressure, the air inlet is connected to a pressure control end, and the end of the serpentine channel is connected to the extrusion area; The end of the printing channel is connected to an external container, and the end of the waste liquid channel is connected to a pressure control end for outputting negative pressure and a waste liquid pool.

[0010] Furthermore, the microfluidic chip further comprises a plane layer and a rigid glass layer arranged vertically, wherein the plane layer and the rigid glass layer are sequentially arranged behind the microchannel layer; The microchannel layer and the planar layer are made of polydimethylsiloxane (PDMS) or plastic.

[0011] Furthermore, the present invention also provides a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, comprising the microfluidic chip, and the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations further comprises: A three-axis displacement platform, wherein a microscope and a shooting device for high-speed shooting of a field image of an extrusion area of ​​a microfluidic chip are arranged on the three-axis displacement platform, and the shooting device is connected to an eyepiece of the microscope; A microfluidic chip clamping box, used for clamping the microfluidic chip in the vertical direction, the microfluidic chip clamping box is connected to the three-axis displacement platform; A piezoelectric actuating device, the piezoelectric actuating device comprising a piezoelectric device bracket and a piezoelectric device, the piezoelectric device bracket is mounted on the three-axis displacement platform, and the piezoelectric device is mounted on the piezoelectric device bracket; A precision air pressure pump, used to receive control signals from a host computer and control multiple air pressure outputs to the air inlet channel and the liquid inlet channel of the microfluidic chip, wherein the precision air pressure pump comprises a plurality of independent output channels, and a single output channel is respectively connected to the inlet of the air inlet channel or the inlet of the liquid inlet channel of the microfluidic chip; The host computer is used to output air pressure and control signals to the liquid inlet channel and the air inlet channel, and to output control signals to the shooting device and process the images taken by the shooting device. The microscope, the shooting device, the piezoelectric touch device and the precision air pressure pump are electrically connected to the host computer respectively.

[0012] Furthermore, the piezoelectric device, the host computer controls the voltage of the piezoelectric device to force the extrusion area of ​​the microfluidic chip to produce extrusion and deformation, The piezoelectric device is any one of a piezoelectric sheet, a piezoelectric stack and a piezoelectric actuator.

[0013] Furthermore, the film movement speed V of the microchannel layer of the microfluidic chip in the extrusion zone is p , the impacted area S of the extrusion zone p , fluid velocity V at the printing channel o and the cross-sectional area S at the printing channel o , satisfying the following relationship:

[0014] Among them, the film movement speed V of the microchannel layer of the microfluidic chip in the extrusion zone is pis the speed at which the striker head squeezes the squeeze zone, that is, the vibration frequency of the striker head, and the area S of the squeeze zone being impacted p is the smaller value of the cross-sectional area of ​​the striker tip and the area of ​​the extrusion zone, and the fluid velocity V at the printing channel is o It is related to the input gas pressure in the air inlet channel of the microfluidic chip, the serpentine channel flow resistance in the air inlet channel, the input gas pressure of all liquid inlet channels and the input liquid concentration.

[0015] Furthermore, the present invention also provides an operating method of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, which is applied to the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, and the operating method comprises: S100, at the inlet of each liquid inlet channel of the microfluidic chip, the corresponding liquid inlet channel inlet is connected to the corresponding liquid storage tank for storing the sample by means of an external pipe or an internal flow channel, and is also connected to the corresponding pressure control channel of the pressure control end; S200, connecting the inlet of the air inlet channel of the microfluidic chip to the corresponding pressure control channel of the pressure control end; S300, placing the microfluidic chip in a microfluidic chip clamping box of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations and clamping the microfluidic chip, and adjusting the position of the piezoelectric device so that the piezoelectric device just contacts the extrusion area on the microfluidic chip; S400, setting the waveform parameters of the pressure control signal, the sample ratio parameters of each liquid inlet channel and the pressure parameters of the air inlet channel in the host computer; S500, executing the droplet printing debugging program, the upper computer controls the pressure control end output pressure of the air inlet channel and the liquid inlet channel, and aligns the printing port of the microfluidic chip printing channel with the orifice plate below by printing out the droplet landing point. After the debugging is completed, the mixed droplet can be printed and prepared; S600: Execute a printing operation of the mixed liquid droplets.

[0016] Furthermore, the step S200 further includes: at the outlet of the waste liquid channel of the microfluidic chip, using an external pipe or an internal flow channel, connecting the corresponding waste liquid channel outlet to the waste liquid pool and connecting to the corresponding pressure control channel of the pressure control end; The steps S400 to S600 also include: the host computer controls the pressure control end connected to the waste liquid channel to output negative pressure.

[0017] The beneficial effects of the present invention are: The operating method of the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations can provide a clamping structure for the microfluidic chip to ensure that it is placed in the vertical direction and precisely matched with the piezoelectric device; the printing amount of a single liquid can be accurately controlled by controlling the piezoelectric device bracket and the supporting program; single printing and continuous printing of mixed droplets can be stably and accurately achieved, and the printing of droplets of different concentrations can be achieved by adjusting the liquid inlet pressure ratio, and at the same time, the encapsulation of microparticles such as microspheres and cells can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic diagram of an embodiment of a microchannel layer in a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0019] Figure 2 Shown is a schematic diagram of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0020] Figure 3 Shown is a schematic diagram of an air inlet channel and a printing channel in a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0021] Figure 4 Shown is a schematic diagram of the exploded structure of a microfluidic chip in a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0022] Figure 5 It is a schematic diagram of the simulation of the droplet printing principle and concentration control method of three liquid mixtures in the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0023] Figure 6 Shown is a flow chart of a cell encapsulation and printing method capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0024] Figure 7 Shown is a schematic diagram of the working process of the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0025] Figure 8 The figure shows a timing diagram of a pressure control signal waveform sample of a piezoelectric actuator in a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to the present invention.

[0026] Fig. 9 It is a schematic diagram showing the initial state (A), printing execution (B), droplet formation (C) and restoration of the initial state (D) in the first printing experiment of two liquid mixtures according to the present invention.

[0027] Fig.10It is a schematic diagram showing the initial state (A), printing execution (B), droplet formation (C) and restoration of the initial state (D) in the second printing experiment of two liquid mixtures according to the present invention.

[0028] Fig.11 It is a schematic diagram showing the initial state (A), printing execution (B), droplet formation (C) and restoration of the initial state (D) in the third printing experiment of two liquid mixtures according to the present invention.

[0029] Fig.12 Shown are schematic diagrams of the initial state (A), printing execution (B), droplet formation (C) and recovery to the initial state (D) in a three-liquid mixed printing experiment according to the present invention.

[0030] Fig.13 Shown are schematic diagrams of the initial state (A), identification of target particles (B), execution of printing (C) and droplet formation (D) in a particle encapsulation printing experiment of a three-liquid mixture according to the present invention.

[0031] 100, microfluidic chip; 110, microchannel layer; 120, liquid inlet channel; 130, air inlet channel; 131, air inlet; 132, serpentine channel; 140, printing channel; 150, waste liquid channel; 160, extrusion area; 170, plane layer; 180, rigid glass layer; 200, pressure control end; 300, piezoelectric device; 400, host computer. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0033] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, top, bottom, etc. used in the present invention are only relative to the relative positional relationship of the components of the present invention in the drawings.

[0034] In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. The terms used in this specification are only for describing specific embodiments, not for limiting the present invention. The term "and / or" used herein includes any combination of one or more related listed items.

[0035] It should be understood that, although the terms first, second, third, etc. may be used to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0036] Reference Figures 1 to 13 In some embodiments, the present invention provides a cell encapsulation and printing device and method capable of dynamically adjusting liquid components and concentrations, wherein the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations comprises a microfluidic chip 100, referring to Figures 1 to 4 , the microfluidic chip 100 is placed vertically, and the microfluidic chip 100 at least comprises: A microchannel layer 110, wherein the microchannel layer 110 is provided with microchannels; The microchannel includes at least one liquid inlet channel 120, an air inlet channel 130, a printing channel 140 and a waste liquid channel 150. The starting end of each of the liquid inlet channel 120 and the starting end of the air inlet channel 130 are connected to a pressure control end 200 respectively. The end of the liquid inlet channel 120, the end of the air inlet channel 130, the starting end of the printing channel 140 and the starting end of the waste liquid channel 150 meet at one point to form a squeezing area 160. The thickness of the extruded area 160 is less than the thickness of other areas of the microchannel.

[0037] The beneficial effects of the present invention are: The operating method of the cell encapsulation and printing device capable of dynamically adjusting the liquid components and concentration can provide a clamping structure for the microfluidic chip 100 to ensure that it is placed in the vertical direction and precisely matched with the piezoelectric device 300; the printing volume of a single liquid can be precisely controlled by controlling the piezoelectric device bracket and the supporting program; the single printing and continuous printing of mixed droplets can be stably and accurately realized, and the printing of droplets of different concentrations can be realized by adjusting the liquid inlet pressure ratio, and the encapsulation of microparticles such as microspheres and cells can be realized at the same time. Through the cooperation of the piezoelectric device 300 and the microfluidic chip 100, a low-risk contamination operation of transferring the liquid in the microfluidic chip 100 to an external specific container is realized, providing an important guarantee for the precise processing and analysis of subsequent reagent samples.

[0038] Specifically, the purpose of the present invention is to design a set of trace reagent dispensing devices combined with a microfluidic chip 100 to achieve high-precision and high-efficiency printing of tiny droplets and to achieve printing of mixed droplets and printing of mixed droplets encapsulating particles. Design a microfluidic chip 100 that can realize the function of tiny droplet injection, realize the precise transfer of trace liquids and the printing of mixed droplets containing different liquid concentrations; design a piezoelectric droplet printing device that can realize microfluidic plug-and-play and can flexibly adjust the initial position of the piezoelectric device 300, to facilitate the research and debugging of droplet and particle printing functions. The designed device has good integration and versatility, can be adapted to a variety of different microfluidic chips 100, and provide a platform for more in-depth chip research and development.

[0039] By replacing the conventional flat placement of the microfluidic chip 100 with a combination of hard glass and the groove of the microfluidic chip 100, the microfluidic chip 100 can be compatible with the use of an inverted microscope and a side-viewing microscope. At the same time, this design method can also reduce the energy loss in the process of transferring external energy to the internal fluid of the chip, enhance the local vibration of the microfluidic chip 100, and make it easier to generate droplets. Compared with other types of droplet printing technology, the droplets generated by the piezoelectric droplet printing technology have higher consistency, and the controllability of the printing process is higher. The droplet printing of a variety of liquid mixtures can be completed through the design of the chip, providing a new idea for the concentration control of the mixed liquid. Moreover, the liquid mixing and matching particle printing by the microfluidic method is more efficient than the traditional method of manually configuring the solution and then placing the particles into the configured solution. The amount of sample used is small, which is more suitable for the processing of rare samples and has better economic benefits. This device is compatible with a variety of chips, providing a simpler and more reliable experimental platform for the research of piezoelectric microfluidic chips 100.

[0040] Further, refer to Figure 1 , further comprising at least one liquid storage tank, the number of the liquid storage tanks being consistent with the number of the liquid inlet channels 120, The outlet of each liquid storage tank is connected to the starting end of a single liquid inlet channel 120 and a single pressure control end 200, and the pressure control end 200 delivers the liquid in the liquid storage tank to the corresponding liquid inlet channel 120 at a preset pressure and flow rate; The pressure control end 200 is an air pressure control channel of the precision air pressure pump.

[0041] Further, refer to Figures 1 to 4 The air inlet channel 130 includes an air inlet 131 and a serpentine channel 132 connected in sequence, the air inlet 131 is used to input a preset air pressure, the air inlet 131 is connected to a pressure control end 200, and the end of the serpentine channel 132 is connected to the extrusion area 160; The end of the printing channel 140 is connected to an external container, and the end of the waste liquid channel 150 is connected to a pressure control terminal 200 for outputting negative pressure and a waste liquid pool.

[0042] Specifically, the pressure control end 200 for outputting negative pressure may be a negative pressure output port of a negative pressure pump or a precision air pressure pump.

[0043] Further, refer to Figure 4 , the microfluidic chip 100 further includes a plane layer 170 and a rigid glass layer 180 arranged vertically, and the plane layer 170 and the rigid glass layer 180 are sequentially arranged behind the microchannel layer 110; The microchannel layer 110 and the planar layer 170 are made of polydimethylsiloxane (PDMS) or plastic.

[0044] Specifically, the microchannel layer 110 and the planar layer 170 are made of materials with good light transmittance such as polydimethylsiloxane (PDMS) or plastic.

[0045] In addition, the main component of the microfluidic chip 100 is the flow channel inside the microfluidic chip 100, and the material of the microfluidic chip 100 can be any transparent material that meets the flow channel precision requirements. The microfluidic chip 100 in the present invention contains two or more original sample channels, which are connected to the liquid reservoir storing the original samples by means of external pipes or internal flow channels at the corresponding entrances; after connecting these liquid reservoir precision air pressure pumps, the proportion of different samples can be controlled by controlling the pressure given to each liquid reservoir, thereby controlling the proportion of different components in the droplets during printing. The microfluidic chip 100 is placed in the device and connected to the piezoelectric device 300, so that the extended striker connected to the actuator just contacts the extrusion area 160 on the chip. Set the required waveform parameters and sample ratio parameters in the main control computer (host computer 400); execute the droplet printing debugging program, align the print port of the microfluidic chip 100 with the orifice plate below by printing out the droplet landing point, and after the debugging is completed, the printing preparation of the mixed droplets can be carried out; if it is necessary to print particles of droplet mixing, the recognition algorithm program must be enabled at the same time.

[0046] Reference Figure 1 The microfluidic chip 100 includes three independent liquid inlet channels 120, and the number of the liquid inlet channels 120 can be flexibly adjusted according to needs; in addition, Figure 1 In the figure, the black part represents air and the blue part represents liquid.

[0047] Specifically, the microfluidic chip 100 is composed of a three-layer structure, and combined with a special pipeline flow resistance, the external vibration can be transmitted to the fluid in the chip. The complete transmission of external energy to the internal fluid of the microfluidic chip 100 is an important guarantee for the controllability of droplet injection, so the fixing method of the microfluidic chip 100 is important, and the microfluidic chip 100 is mostly made of soft polydimethylsiloxane PDMS material. When the thickness of the polydimethylsiloxane PDMS is too large, it is easy to absorb the tiny vibration energy of the piezoelectric device 300, so that the complete transmission of external energy cannot be guaranteed; and the traditional microfluidic chip 100 is bonded by polydimethylsiloxane PDMS and a glass sheet. Since these two materials have different hydrophilic and hydrophobic properties for droplets, the dripping direction of droplets may be inconsistent during printing. Therefore, the microfluidic chip 100 designed by the present invention is composed of a three-layer structure, which is a polydimethylsiloxane PDMS layer with a microchannel.

[0048] Further, refer to Figure 1 and Figure 7 The present invention also provides a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, comprising the microfluidic chip 100, and the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations further comprises: A three-axis displacement platform, on which a microscope and a shooting device for high-speed shooting of a field image of the extrusion area 160 of the microfluidic chip 100 are arranged, and the shooting device is connected to the eyepiece of the microscope; A microfluidic chip clamping box, used for clamping the microfluidic chip 100 in the vertical direction, the microfluidic chip clamping box is connected to the three-axis displacement platform; A piezoelectric actuating device, the piezoelectric actuating device comprising a piezoelectric device bracket and a piezoelectric device 300, the piezoelectric device bracket being mounted on the three-axis displacement platform, and the piezoelectric device 300 being mounted on the piezoelectric device bracket; A precision air pressure pump, used to receive control signals from the host computer 400 and control the multi-channel air pressure output to the air inlet channel 130 and the liquid inlet channel 120 of the microfluidic chip 100, wherein the precision air pressure pump includes a plurality of independent output channels, and a single output channel is respectively connected to the inlet of the air inlet channel 130 or the inlet of the liquid inlet channel 120 of the microfluidic chip 100; The host computer 400 is used to output air pressure and control signals to the liquid inlet channel 120 and the air inlet channel 130, as well as to output control signals to the shooting device and process images taken by the shooting device. The microscope, the shooting device, the piezoelectric touch device and the precision air pressure pump are electrically connected to the host computer 400 respectively.

[0049] Specifically, the clamping structure of the microfluidic chip 100 is simple, and can realize fast and reliable connection of microfluidic chips 100 of various thicknesses. In order to give full play to the consumables of the microfluidic chip 100 and realize the plug-and-play of the chip, the clamping structure is mainly composed of the microfluidic chip 100 clamping groove and the piezoelectric device bracket (i.e., the piezoelectric device displacement fixture). After the microfluidic chip 100 is installed in the clamping groove, the piezoelectric device 300 is aligned with the extrusion chamber (extrusion area 160) on the microfluidic chip 100 through the displacement platform, thereby realizing high-precision connection. At the same time, in order to facilitate the adaptation of different microfluidic chips 100, the clamping groove and the device are separated. When facing microfluidic chips 100 of different sizes, the corresponding clamping groove can be replaced.

[0050] At the same time, the supporting software can be used to achieve precise adjustment of the single liquid printing amount. The extended striker installed at the head of the piezoelectric device 300 can achieve the staggered arrangement of the head structure of the piezoelectric device 300 and the microfluidic chip 100. There is a threaded seat on the top of the striker, and striker heads with different impact areas can be installed to adjust the contact area between the piezoelectric device 300 and the extrusion area 160 of the microfluidic chip 100. At the same time, the supporting software is used to adjust the voltage given to the piezoelectric device 300 according to the different areas of the striker head, thereby achieving precise adjustment of the single droplet amount.

[0051] Under the control of the supporting software of the device, stable and accurate single droplet printing and continuous droplet printing can be achieved. The extrusion zone 160 is introduced with gas for printing and different liquid inlet pressure ratios are adjusted to achieve quantitative and accurate mixed printing of different liquids, and the particles flowing through the printing zone can be wrapped and printed. The entire device can achieve single droplet and continuous droplet printing at different rates through external drive adjustment of different waveforms, voltage amplitudes, and waveform frequencies; droplets mixed with multiple liquids can be printed through the design of the number of channels of the microfluidic chip 100, and different pressure ratios are set at the liquid inlet and gas is used as the squeezed fluid in the extrusion zone 160 to achieve the adjustment of various liquid concentrations in the droplets; through the supporting algorithm software, the samples containing particles can be mixed with droplets of different concentrations and then wrapped and printed for subsequent research on the particles.

[0052] In a specific embodiment, the three-axis displacement platform includes an XY-axis displacement platform and a Z-axis displacement platform, the XY-axis displacement platform includes an XY-platform mounting seat, and the Z-axis displacement platform includes a Z-axis platform bracket. After selecting a suitable piezoelectric device 300, the cell encapsulation and printing device that can dynamically adjust the liquid component and concentration is mainly composed of a microfluidic chip clamping box, a piezoelectric device 300, a piezoelectric device bracket, an extended striker, a Z-axis platform bracket and a Z-axis displacement platform, an XY-platform mounting seat and an XY-axis displacement platform.

[0053] The clamping groove of the microfluidic chip clamping box is designed to be as wide as the glass sheet used for bonding. The chip is anchored by a spring pressure plate above the groove to ensure that the microfluidic chip 100 is firmly installed. The piezoelectric device 300 is the main power source of the microfluidic piezoelectric injection device. The application of driving voltages of different frequencies and amplitudes can cause the head structure to produce corresponding micro-displacements. In addition, the threaded base of the actuator head can be installed with strikers of different contact areas to achieve the purpose of adjusting the contact area, thereby regulating the driving volume and the liquid flow rate. The positioning bracket of the piezoelectric device 300 is installed on a total displacement platform composed of three linear displacement platforms, so that it can be precisely aligned for different chips. The pre-pressure degree of the striker and the extrusion area 160 of the microfluidic chip 100 can be adjusted by adjusting the Z axis of the displacement platform.

[0054] Further, refer to Figure 7 The piezoelectric device 300 and the host computer 400 control the voltage of the piezoelectric device 300 to force the extrusion area 160 of the microfluidic chip 100 to produce extrusion and deformation. The piezoelectric device 300 is any one of a piezoelectric sheet, a piezoelectric stack, and a piezoelectric actuator.

[0055] In addition, in a specific embodiment, the piezoelectric actuator includes an extended striker, and a threaded seat is provided on the top of the extended striker, and the threaded seat is used to install striker heads with different impact areas. The striker head controls the extension amount of the striker head based on the pressure control signal of the piezoelectric actuator. When the striker head extends, it touches and squeezes the squeezing area 160 of the microfluidic chip 100 , thereby outputting pressure to the squeezing area 160 of the microfluidic chip 100 .

[0056] Further, refer to Figure 3 , the film movement speed V of the microchannel layer 110 of the microfluidic chip 100 in the squeezing zone 160 p , the impacted area S of the squeeze zone 160 p , the fluid velocity V at the printing channel 140 o and the cross-sectional area S at the printing channel 140 o , satisfying the following relationship:

[0057] The film movement speed V of the microchannel layer 110 of the microfluidic chip 100 in the extrusion zone 160 is p is the speed at which the striker head squeezes the squeezing area 160, that is, the vibration frequency of the striker head, and the area S of the squeezing area 160 being impacted p is the smaller value of the cross-sectional area of ​​the striker head and the area of ​​the extrusion zone 160, the fluid velocity V at the printing channel 140 oIt is related to the input gas pressure in the air inlet channel 130 of the microfluidic chip 100, the flow resistance of the serpentine channel 132 in the air inlet channel 130, the input gas pressure of all the liquid inlet channels 120 and the input liquid concentration.

[0058] Specifically, refer to Figure 8 , t1 is the waveform jump time, which is a fixed value under a fixed voltage peak; t2 is the peak duration, and t3 is the waveform fall time. These two times and voltage peaks can be adjusted to obtain different waveforms during use.

[0059] Specifically, the microfluidic chip 100 can achieve control of the fluid by combining special channel design and external energy input. From the simulation analysis of the droplet ejection process, it can be seen that for the microfluidic chip 100 with a fixed nozzle diameter, whether the droplet ejection experiment is successful is closely related to the regulation of the flow rate and the liquid drive volume. Therefore, the designed microfluidic chip 100 needs to set an experimental control group on these two factors, so that the optimal droplet printing chip design parameters can be determined by experimental means. The liquid is regarded as an incompressible Newtonian fluid in the chip channel. When the chip extrusion area 160 is deformed by external energy impact, the liquid is accelerated in the channel. The chip uses the large flow resistance of the serpentine channel 132 to make the flow resistance of the flow channel in the upper half of the extrusion area 160 much greater than the flow resistance of the lower half. Therefore, the accelerated liquid can be approximately considered to flow to the ejection port to complete the droplet ejection process.

[0060] Based on this design, the film movement speed V in the extrusion zone is 160 p and the cross-sectional area S at the injection port o Under fixed conditions, the area S of the squeeze zone 160 that is impacted can be adjusted p To change the velocity V of the fluid at the jet o , and by adjusting the extension of the piezoelectric device 300, the amount of liquid squeezed can be changed, thereby achieving the purpose of changing the liquid injection volume. Figure 8 and Fig.10 On the basis of the above-mentioned droplet squeezing area 160, channels (liquid inlets 1-3) for introducing other liquids are added. By adjusting the input pressures at the three liquid inlets respectively, mixed droplets of different liquid (liquid 1, liquid 2, liquid 3) concentrations can be printed, thereby realizing the printing of trace mixed droplets.

[0061] Further, refer to Figure 6 The present invention also provides an operating method of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, which is applied to the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations. The operating method comprises: S100, at the inlet of each liquid inlet channel 120 of the microfluidic chip 100, the corresponding inlet of the liquid inlet channel 120 is connected to the corresponding liquid storage tank for storing the sample by using an external pipe or an internal flow channel, and is also connected to the corresponding pressure control channel of the pressure control end 200; S200, connecting the inlet of the air inlet channel 130 of the microfluidic chip 100 to the corresponding pressure control channel of the pressure control end 200; S300, placing the microfluidic chip 100 into a microfluidic chip clamping box of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations and clamping it, adjusting the position of the piezoelectric device 300 so that the extended striker of the piezoelectric device 300 just contacts the squeezing area 160 on the microfluidic chip 100; S400, setting the waveform parameters of the pressure control signal, the sample ratio parameters of each liquid inlet channel 120 and the pressure parameters of the air inlet channel 130 in the host computer 400; S400, executing the droplet printing debugging program, the upper computer 400 controls the pressure control end 200 of the air inlet channel 130 and the liquid inlet channel 120 to output the pressure, and aligns the printing port of the printing channel 140 of the microfluidic chip 100 with the orifice plate below by printing out the droplet landing point. After the debugging is completed, the printing preparation of the mixed droplet can be carried out; S500: Execute a printing operation of the mixed liquid droplets.

[0062] Specifically, it also includes the realization principle and simulation of mixed droplet printing function. In the microfluidic mixed droplet printing chip, Figure 6 Taking three liquid inlets as an example, liquids are introduced into the three liquid inlets respectively. By increasing negative pressure in the waste channel to ensure that no liquid flows out of the printing port, by adjusting the flow rate of the liquid inlet, mixed droplets composed of a combination of multiple liquids (the type of liquid is determined by the number of liquid inlets) can be printed, and in order to ensure that the ratio of the droplet mixture is not disturbed, the actuator is used in the extrusion area 160 to squeeze the gas for printing. The principle of this droplet printing function will be explained in conjunction with the simulation result diagram of the COMSO finite element simulation software. The volume ratio of different types of liquids is mainly determined by the pressure ratio at each liquid inlet and the position of the boundary line of various liquids at the intersection. When the concentration of each component in the mixed droplet composed of three liquids is mainly controlled, the driving flow ratio at the three liquid inlets can be adjusted to achieve the printing of various mixed droplets, thereby completing the concentration ratio control of the three liquids in the mixed droplet. This adjustment method for mixed droplet printing is simple, convenient, flexible and controllable. When the liquid introduced contains particles, the particles can be identified through the recognition algorithm of the supporting software and then printed. In this way, a particle sample containing a liquid with a fixed ratio can be obtained, and further research on the particles can be carried out.

[0063] Further, refer to Figure 1 , the step S200 further includes: at the outlet of the waste liquid channel 150 of the microfluidic chip 100, using an external pipe or an internal flow channel, connecting the corresponding outlet of the waste liquid channel 150 to the waste liquid pool, and at the same time connecting to the corresponding pressure control channel of the pressure control end 200; The steps S400 to S600 further include: the host computer 400 controls the pressure control end 200 connected to the waste liquid channel 150 to output negative pressure.

[0064] Specifically, applying negative pressure on the waste liquid channel 150 as needed can promote the flow of liquid in the microfluidic chip 100 .

[0065] The following is a description of the cell encapsulation and printing device that can dynamically adjust the liquid composition and concentration in various working states: (1), reference Fig. 9 , which is a schematic diagram of the first experiment of two liquid mixing and printing, shows the process of two different liquids being mixed and then printed into droplets. The dividing line between the upper and lower layers in the four sub-figures is the dividing line between the two liquids. Fig. 9 This is the case when the proportions of the two liquids are the same. It can be seen that the dividing line is basically in the middle of the channel. Among them, sub-figure (A) is the initial state of the microfluidic chip 100, sub-figure (B) is the host computer 400 issuing a command to drive the piezoelectric actuator to start the printing action to hit the extrusion area 160 of the microfluidic chip 100, sub-figure (C) is a schematic diagram of droplet generation, and sub-figure (D) is a schematic diagram of the internal flow field of the microfluidic chip 100 returning to the initial state.

[0066] (2), reference Fig.10 , is a schematic diagram of the second experiment of two liquid mixing and printing, which shows the process of two different liquids being mixed and then printed into droplets. The dividing line between the upper and lower layers in the four sub-figures is the dividing line between the two liquids. Fig.10 This is the case when the proportions of the two liquids are different. At this time, the dividing line is at the lower part of the channel, indicating that the proportion of the upper layer liquid is greater than that of the lower layer. Among them, sub-figure (A) is the initial state of the microfluidic chip 100, sub-figure (B) is the host computer 400 issuing an instruction to drive the piezoelectric actuator to start the printing action and hit the extrusion area 160 of the microfluidic chip 100, sub-figure (C) is a schematic diagram of droplet generation, and sub-figure (D) is a schematic diagram of the internal flow field of the microfluidic chip 100 returning to the initial state.

[0067] (3), reference Fig.11 , is a schematic diagram of the two liquid mixing printing experiment three, which shows the process of two different liquids being mixed and then printed into droplets. The dividing line between the upper and lower layers in the four sub-figures is the dividing line between the two liquids. Fig.11This is the case when the proportions of the two liquids are different. At this time, the dividing line is located at the upper part of the channel, indicating that the proportion of the lower layer of liquid is greater than that of the upper layer. Among them, sub-figure (A) is the initial state of the microfluidic chip 100, sub-figure (B) is the host computer 400 issuing an instruction to drive the piezoelectric actuator to start the printing action and hit the extrusion area 160 of the microfluidic chip 100, sub-figure (C) is a schematic diagram of droplet generation, and sub-figure (D) is a schematic diagram of the internal flow field of the microfluidic chip 100 returning to the initial state.

[0068] (4), reference Fig.12 , is a schematic diagram of the three-liquid mixed printing experiment. When the three liquids are mixed and printed, the three liquids can be clearly seen to be layered in the channel. Among them, the process is as follows: sub-image (A) is the initial state, sub-image (B) is the start of the printing process, sub-image (C) is the droplet generation, and sub-image (D) is the flow field inside the chip restored to the initial state.

[0069] (5), reference Fig.13 , is a schematic diagram of a particle encapsulation printing experiment with a mixture of three liquids. When the three liquids are mixed and encapsulated to print, the three liquids can be clearly seen to be layered in the channel. The process is as follows: Sub-image (A) is the initial state, where the red dotted circle is the target particle; Sub-image (B) is the movement of the particle to the printing area, where the red dotted circle is the target particle; the recognition program of the host computer 400 continuously monitors the state of the printing area; Sub-image (C) shows that the host computer 400 recognizes the target particle and issues a command to drive the piezoelectric actuator to perform printing; Sub-image (D) shows that the droplet encapsulates the particle to complete printing.

[0070] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the scope of protection of the present disclosure. All should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A microfluidic chip, characterized in that: The microfluidic chip (100) is placed vertically, and the microfluidic chip (100) comprises at least: A microchannel layer (110), wherein microchannels are arranged in the microchannel layer (110); The microchannel comprises at least one liquid inlet channel (120), an air inlet channel (130), a printing channel (140) and a waste liquid channel (150). The starting end of each of the liquid inlet channels (120) and the starting end of the air inlet channels (130) are respectively connected to a pressure control end (200). The end of the liquid inlet channel (120), the end of the air inlet channel (130), the starting end of the printing channel (140) and the starting end of the waste liquid channel (150) meet at one point to form a squeezing area (160). The thickness of the extrusion zone (160) is less than the thickness of other regions of the microchannel.

2. The microfluidic chip according to claim 1, characterized in that: It also includes at least one liquid storage tank, the number of the liquid storage tanks being consistent with the number of the liquid inlet channels (120). The outlet of each liquid storage tank is connected to the starting end of a single liquid inlet channel (120) and a single pressure control end (200), and the pressure control end (200) delivers the liquid in the liquid storage tank to the corresponding liquid inlet channel (120) at a preset pressure and flow rate; The pressure control end (200) is an air pressure control channel of a precision air pressure pump.

3. The microfluidic chip according to claim 1, characterized in that: The air inlet channel (130) comprises an air inlet (131) and a serpentine channel connected in sequence, the air inlet (131) is used to input a preset air pressure, the air inlet (131) is connected to a pressure control end (200), and the end of the serpentine channel (132) is connected to the extrusion zone (160); The end of the printing channel (140) is connected to an external container, and the end of the waste liquid channel (150) is connected to a pressure control end (200) for outputting negative pressure and a waste liquid pool.

4. The microfluidic chip according to claim 1, characterized in that: The microfluidic chip (100) further comprises a plane layer (170) and a rigid glass layer (180) arranged vertically, wherein the plane layer (170) and the rigid glass layer (180) are arranged in sequence behind the microchannel layer (110); The microchannel layer (110) and the planar layer (170) are made of polydimethylsiloxane (PDMS) or plastic.

5. A cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations, comprising a microfluidic chip as claimed in any one of claims 1 to 4, characterized in that: The cell encapsulation and printing device for dynamically adjusting liquid components and concentrations also includes: A three-axis displacement platform, wherein a microscope and a shooting device for shooting a field image of an extrusion area (160) of a microfluidic chip (100) at high speed are arranged on the three-axis displacement platform, and the shooting device is connected to an eyepiece of the microscope; A microfluidic chip clamping box, used for clamping the microfluidic chip (100) in a vertical direction, the microfluidic chip clamping box being connected to the three-axis displacement platform; A piezoelectric actuating device, the piezoelectric actuating device comprising a piezoelectric device bracket and a piezoelectric device (300), the piezoelectric device bracket being mounted on the three-axis displacement platform, and the piezoelectric device (300) being mounted on the piezoelectric device bracket; A precision air pressure pump, used for receiving control signals from a host computer (400) and controlling multiple air pressure outputs to the air inlet channel (130) and the liquid inlet channel (120) of the microfluidic chip (100), wherein the precision air pressure pump comprises a plurality of independent output channels, and a single output channel is respectively connected to an inlet of the air inlet channel (130) or an inlet of the liquid inlet channel (120) of the microfluidic chip (100); The host computer (400) is used to output air pressure and control signals to the liquid inlet channel (120) and the air inlet channel (130), and to output control signals to the shooting device and process images taken by the shooting device. The microscope, the shooting device, the piezoelectric actuator and the precision air pressure pump are electrically connected to the host computer (400) respectively.

6. The cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to claim 5, characterized in that: The piezoelectric device (300) and the host computer (400) control the voltage of the piezoelectric device (300) to force the extrusion area (160) of the microfluidic chip (100) to produce extrusion and deformation. The piezoelectric device (300) is any one of a piezoelectric sheet, a piezoelectric stack and a piezoelectric actuator.

7. The cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to claim 5, characterized in that: The film movement speed V of the microchannel layer (110) of the microfluidic chip (100) in the extrusion zone (160) is p , the impacted area S of the extrusion zone (160) p , the fluid velocity V at the printing channel (140) o and the cross-sectional area S at the printing channel (140) o , satisfying the following relationship: ； The film movement speed V of the microchannel layer (110) of the microfluidic chip (100) in the extrusion zone (160) is p is the speed at which the striker head squeezes the squeezing area (160), that is, the vibration frequency of the striker head, and the area S of the squeezing area (160) being impacted p is the smaller value of the cross-sectional area of ​​the striker head and the area of ​​the extrusion zone (160), and the fluid velocity V at the printing channel (140) is o It is related to the input gas pressure in the air inlet channel (130) of the microfluidic chip (100), the flow resistance of the serpentine channel (132) in the air inlet channel (130), the input gas pressure of all liquid inlet channels (120) and the input liquid concentration.

8. A method for operating a cell encapsulation and printing device capable of dynamically adjusting liquid composition and concentration, characterized in that: Applied to the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations as described in any one of claims 5 to 7, the operation method comprises: S100, at the inlet of each liquid inlet channel (120) of the microfluidic chip (100), the corresponding inlet of the liquid inlet channel (120) is connected to the corresponding liquid storage tank for storing the sample by using an external pipe or an internal flow channel, and is also connected to the corresponding pressure control channel of the pressure control end (200); S200, connecting the inlet of the air inlet channel (130) of the microfluidic chip (100) to the corresponding pressure control channel of the pressure control end (200); S300, placing the microfluidic chip (100) in a microfluidic chip clamping box of a cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations and clamping the microfluidic chip (100), and adjusting the position of the piezoelectric device (300) so that the piezoelectric device (300) just contacts the extrusion area (160) on the microfluidic chip (100); S400, setting the waveform parameters of the pressure control signal, the sample ratio parameters of each liquid inlet channel (120), and the pressure parameters of the air inlet channel (130) in the host computer (400); S500, executing the droplet printing debugging program, the upper computer (400) controls the pressure control end (200) of the air inlet channel (130) and the liquid inlet channel (120) to output pressure, and aligns the printing port of the printing channel (140) of the microfluidic chip (100) with the orifice plate below by printing out the droplet landing point, and after the debugging is completed, the printing preparation of the mixed droplet can be carried out; S600: Execute a printing operation of the mixed liquid droplets.

9. The method for operating the cell encapsulation and printing device capable of dynamically adjusting liquid components and concentrations according to claim 8, characterized in that: The step S200 further comprises: at the outlet of the waste liquid channel (150) of the microfluidic chip (100), using an external pipe or an internal flow channel, connecting the corresponding outlet of the waste liquid channel (150) to the waste liquid pool, and at the same time connecting to the corresponding pressure control channel of the pressure control end (200); The steps S400 to S600 further include: the host computer (400) controls the pressure control end (200) connected to the waste liquid channel (150) to output negative pressure.

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