Microfluidic chip device and optical tweezer experimental method

Abstract

The application discloses a micro-fluidic chip device and an optical tweezer experiment method. The micro-fluidic chip device comprises a micro-fluidic chip, at least one inflow channel and at least one outflow channel, the micro-fluidic chip has an optical tweezer control and imaging area, the inflow channel is connected with the outflow channel through a fluid confluence structure, and the fluid confluence structure is at least partially located in the optical tweezer control and imaging area; a chip holder is fixed in an optical tweezer system through a mounting structure, the chip holder is further provided with a clamping structure, at least one fluid inlet and at least one fluid outlet, the micro-fluidic chip is clamped and fixed by the clamping structure, the inflow channel is connected with the corresponding fluid inlet, and the fluid outlet is connected with the corresponding outflow channel. The application can ensure the positioning accuracy of the micro-fluidic chip in the optical tweezer system and the stability of the micro-fluidic chip in the optical tweezer experiment, thereby being favorable for improving the capture efficiency and imaging effect in the optical tweezer experiment and improving the repeatability of the measurement result.

Description

TECHNICAL FIELD

[0001] The present application relates to the fields of microfluidic technology, optical tweezers technology and biomedical engineering technology, in particular, to a microfluidic chip device and an optical tweezers experimental method. BACKGROUND

[0002] Optical tweezers is a special tool based on the momentum transfer between light and matter, which can capture and manipulate microparticles of micro-nano size and measure pico-newton (pN) level force. The characteristics of non-contact and non-destructive manipulation of nanometer particles have irreplaceable effects on the research of biology, materials, mechanics, chemistry, environment and other disciplines, and also put forward higher requirements for research technology and method.

[0003] Microfluidic chip, also known as lab on a chip, is a micro-integrated technology based on micro-electro-mechanical technology and characterized by multi-dimensional network micro-flow channel, which can transfer and integrate the operation steps such as collection, reaction, preparation and detection of chemical or biological samples on the chip material. In recent years, microfluidic technology has been widely used in cell sorting, cell biochemical reaction and single cell analysis by combining with fluorescence, electrochemistry, Raman spectroscopy and other detection methods.

[0004] However, when the existing microfluidic chip is applied to the optical tweezers system, due to the differences in the design and construction of the optical tweezers system in different laboratories, the researchers need to make the sample chamber themselves in most cases, and it is difficult to find a unified standard or detailed manufacturing method, which increases the difficulty of carrying out such optical tweezers experiments in non-professional fields. In addition, due to the simple structure of the self-made sample chamber, problems such as sample deposition and adhesion, aggregation, liquid overflow or rapid loss, complex experimental environment and inability to achieve single control often occur during use, which further causes low optical tweezers capture efficiency, poor experimental result repeatability, and difficulty in reusing the sample chamber. SUMMARY

[0005] The purpose of the present application is to provide a microfluidic chip device and an optical tweezers experimental method to solve the technical problems of low capture efficiency, poor imaging effect and difficulty in repeating the measurement results when the existing sample chamber is applied to the optical tweezers system for optical tweezers experiments.

[0006] The above-mentioned purpose of the present application can be realized by using the following technical scheme:

[0007] This invention provides a microfluidic chip device, comprising: a microfluidic chip having at least one inflow channel and at least one outflow channel, the microfluidic chip having an optical tweezers manipulation and imaging region, the inflow channel being connected to the outflow channel via a fluid confluence structure, and the fluid confluence structure being at least partially located within the optical tweezers manipulation and imaging region; and a chip holder capable of being fixed to an optical tweezers system via a mounting structure, the chip holder further comprising a clamping structure, at least one fluid inlet and at least one fluid outlet, the microfluidic chip being clamped and fixed by the clamping structure, and the inflow channel being connected to the corresponding fluid inlet, and the fluid outlet being connected to the corresponding outflow channel.

[0008] In an embodiment of the present invention, the microfluidic chip is made of high-transmittance optical glass; the thickness of the microfluidic chip is less than or equal to 1.35 mm.

[0009] In embodiments of the present invention, the microfluidic chip includes a chip substrate and a chip cover plate, the chip cover plate being bonded to the chip substrate; wherein, the lower surface of the chip cover plate is provided with at least one channel, the upper surface of the chip cover plate is provided with at least one fluid outlet and at least one fluid inlet, the channel connecting the fluid outlet and the fluid inlet, thereby forming the outflow channel and the inflow channel in conjunction with the upper surface of the chip substrate; and / or the upper surface of the chip substrate is provided with at least one channel, the chip cover plate is provided with at least one fluid outlet and at least one fluid inlet, the channel connecting the fluid outlet and the fluid inlet, thereby forming the outflow channel and the inflow channel in conjunction with the lower surface of the chip cover plate.

[0010] In an embodiment of the present invention, the number of inflow channels is at least three; the fluid confluence structure includes at least three connecting channels corresponding to the at least three inflow channels and a confluence channel connecting the at least three connecting channels and the outflow channel, wherein the width of the confluence channel is greater than the width of each inflow channel.

[0011] In embodiments of the present invention, both the outflow channel and the inflow channel are provided in multiple ways. The fluid confluence structure includes multiple connecting structures, multiple connecting channels, and a confluence channel. The connecting structures connect the corresponding inflow channel and the outflow channel, and the connecting structures are connected to the confluence channel through the corresponding connecting channels.

[0012] In embodiments of the present invention, the width of the connecting channel is 50 micrometers to 1200 micrometers, and the depth of the connecting channel is 50 micrometers to 600 micrometers; the width of the inflow channel is greater than or equal to the width of the connecting channel, and the width of the outflow channel is greater than or equal to the width of the inflow channel.

[0013] In an embodiment of the present invention, the microfluidic chip further comprises at least one temperature control channel, the temperature control channel having a temperature control medium fluid inlet and a temperature control medium fluid outlet; the number of fluid inlets and the number of fluid outlets are both multiple, and at least one fluid inlet is connected to the temperature control medium fluid inlet of at least one temperature control channel, and at least one fluid outlet is connected to the temperature control medium fluid outlet of at least one temperature control channel; wherein, at least one temperature control channel is distributed on at least one side of the optical tweezers manipulation and imaging area.

[0014] In an embodiment of the present invention, the chip holder includes a cover plate and a base. The cover plate is detachably connected to the base. The clamping structure includes two clamping parts, which can clamp and fix both ends of the microfluidic chip. The cover plate and the base are provided with corresponding chip viewing windows, which are located between the two clamping parts. Both the cover plate and the base are provided with installation marking structures around their chip viewing windows. Each clamping part includes a positioning groove and a positioning boss. The positioning groove is located on the base, and the positioning boss is located on the cover plate.

[0015] In embodiments of the present invention, both the fluid inlet and the fluid outlet are disposed on the cover plate, the fluid inlet extending to a positioning boss, and the fluid outlet extending to a positioning boss; wherein, the fluid inlet, the fluid outlet, and the corresponding positioning boss are integrally formed on the cover plate; or the cover plate includes a detachably connected cover plate body and at least one replacement plate, the replacement plate integrally forming a positioning boss and a corresponding fluid inlet and / or fluid outlet; and / or the cover plate body integrally forming a positioning boss and a corresponding fluid inlet and / or fluid outlet.

[0016] In an embodiment of the present invention, the mounting structure includes a plurality of magnetic fasteners, which are spaced apart on the circumferential side surface of the chip holder.

[0017] This invention also provides an optical tweezers experimental method using the aforementioned microfluidic chip device. The optical tweezers experimental method includes the following steps: Device installation: The chip holder clamps and fixes the microfluidic chip, and the chip holder is correctly fixed to the optical tweezers system through the mounting structure; A fluid inlet is connected to the sample inlet structure of the sample to be tested; The fluid outlet is connected to the waste liquid discharge structure; Obtaining the measurement object: The sample inlet structure of the sample to be tested is opened, allowing the sample to flow into the fluid confluence structure through the corresponding inflow channel, thereby allowing the sample to enter the optical tweezers manipulation and imaging area and obtain the measurement object; Optical tweezers measurement: The measurement object is moved to the target area of ​​the optical tweezers manipulation and imaging area for optical tweezers manipulation and mechanical measurement; Waste liquid discharge: During the experiment, while opening the inflow channel, the corresponding waste liquid discharge structure is opened to promptly discharge the fluid in the microfluidic chip.

[0018] In an embodiment of the present invention, the installation step of the device further includes connecting another fluid inlet to the microsphere injection structure; the acquisition of the measurement object specifically includes the following steps: microsphere injection: opening the microsphere injection structure, allowing the microsphere to flow into the fluid confluence structure through the corresponding inflow channel and enter the optical tweezers manipulation and imaging area; microsphere capture: capturing the microsphere in the optical tweezers manipulation and imaging area, and then moving the captured microsphere to the target area of ​​the optical tweezers manipulation and imaging area for mechanical correction; sample injection: opening the sample injection structure of the sample to be tested, allowing the sample to be tested to flow into the fluid confluence structure through the corresponding inflow channel and enter the optical tweezers manipulation and imaging area; establishing connection: moving the microsphere captured in the target area to the distribution area of ​​the sample to be tested, so that the sample to be tested and the microsphere establish a connection; wherein, the complex formed by the connection between the sample to be tested and the microsphere constitutes the measurement object.

[0019] In embodiments of the present invention, the number of inflow channels is at least three; the fluid confluence structure includes at least three connecting channels corresponding to the at least three inflow channels and a confluence channel connecting the at least three connecting channels and the outflow channels, the width of the confluence channel being greater than the width of each inflow channel; the installation step of the device further includes connecting a fluid inlet to the sample introduction structure of the buffer solution; the optical tweezers experimental method further includes the following steps: while performing the microsphere sample introduction step, the sample introduction structure of the buffer solution is turned on, so that the buffer solution enters the confluence channel of the fluid confluence structure in the form of laminar flow through the corresponding inflow channel and the microsphere and enters the optical tweezers manipulation and imaging area; while performing the sample sample introduction step, the sample introduction structure of the buffer solution is turned on, so that the buffer solution enters the confluence channel of the fluid confluence structure in the form of laminar flow through the corresponding inflow channel and the sample to be tested and enters the optical tweezers manipulation and imaging area; wherein, the distribution layer of the buffer solution in the laminar flow constitutes the target area; the distribution layer of the sample to be tested in the laminar flow constitutes the distribution area of ​​the sample to be tested.

[0020] In embodiments of the present invention, multiple outflow channels and multiple inflow channels are provided. The fluid confluence structure includes multiple connecting structures, multiple connecting channels, and a confluence channel. The outflow channel is connected to the corresponding inflow channel through the connecting structure, and the connecting structure is connected to the confluence channel through the corresponding connecting channel. In the installation step of the device, two fluid outlets are connected to two waste liquid discharge structures. The microsphere injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel, so that the microsphere flows into the corresponding connecting structure and / or the connecting channel and enters the optical tweezers manipulation and imaging area. The sample injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel, so that the sample to be tested flows into the corresponding connecting structure and / or the connecting channel and enters the optical tweezers manipulation and imaging area. The confluence channel of the fluid confluence structure constitutes the target area. The portion of the corresponding connecting structure and / or the connecting channel into which the sample to be tested flows constitutes the distribution area of ​​the sample to be tested.

[0021] The features and advantages of this invention are:

[0022] The microfluidic chip device and optical tweezers experimental method of the present invention utilize a chip holder to clamp and fix the microfluidic chip and install the chip holder on the optical tweezers system, thereby ensuring the positioning accuracy of the microfluidic chip in the optical tweezers system and the stability of the microfluidic chip in the optical tweezers experiment. This is beneficial to improving the capture efficiency and imaging effect in the optical tweezers experiment and improving the repeatability of measurement results. In addition, the chip holder can be used to disassemble and replace different types of microfluidic chips, and the operation is simple.

[0023] The microfluidic chip device of the present invention uses high-transparency optical glass to make microfluidic chips with an overall thickness of no more than 1.35 mm, which has better optical performance and is not easily deformed. Therefore, it can be applied to optical tweezers systems with high numerical aperture condensers (such as numerical aperture NA≥1.3) to ensure high-quality optical capture and imaging and minimize optical distortion.

[0024] The microfluidic chip device of the present invention has a connection channel width of 50 micrometers to 1200 micrometers and a fluid channel depth of 50 micrometers to 600 micrometers. The width of the inflow channel is greater than or equal to the width of the connection channel, and the width of the outflow channel is greater than or equal to the width of the inflow channel. This enables optical tweezers experiments on large-sized research objects such as cells, macromolecular polymers, or microbial aggregates with particle sizes of 0.5 micrometers to 20 micrometers.

[0025] An embodiment of the optical tweezers experimental method of the present invention, by designing the fluid confluence structure and the number of inflow and outflow channels, can achieve independent partitioning of microspheres, buffer solutions, and test samples, allowing them to flow into the confluence channel in a laminar flow form and enter the optical tweezers manipulation and imaging area. Within the optical tweezers manipulation and imaging area, the introduced substances can be captured, manipulated, and mechanically measured, thereby effectively avoiding problems such as sample deposition, adhesion, and the difficulty in achieving single control in complex experimental environments, thus ensuring the smooth progress of optical tweezers experiments and the repeatability of measurements.

[0026] Another embodiment of the optical tweezers experimental method of the present invention designs the fluid confluence structure and the number of inflow and outflow channels so that the microspheres flow into a connecting structure and enter the optical tweezers manipulation and imaging area, while the sample to be tested flows into another connecting structure and enters the optical tweezers manipulation and imaging area. First, the optical tweezers system is mechanically corrected using the confluence channel between the two connecting channels. Then, the connection between the sample to be tested and the microspheres is established through the connecting structure at the inflow end of the sample to be tested. Finally, the composite material formed by the sample to be tested and the microspheres is manipulated and mechanically measured using the confluence channel between the two connecting channels. This method can also effectively avoid problems such as sample deposition, adhesion, and difficulty in achieving single control due to the complexity of the experimental environment, thereby ensuring the smooth progress of the optical tweezers experiment and the repeatability of the measurement. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a top view of a microfluidic chip device according to an embodiment of the present invention.

[0029] Figure 2 This is a top view of a microfluidic chip device according to another embodiment of the present invention.

[0030] Figure 3 This is a top view of the microfluidic chip according to the first embodiment of the present invention.

[0031] Figure 4 This is a top view of the microfluidic chip according to the second embodiment of the present invention.

[0032] Figure 5 This is a front oblique view of the cover plate of a chip holder according to an embodiment of the present invention.

[0033] Figure 6 This is a front view of the cover plate of a chip holder according to an embodiment of the present invention.

[0034] Figure 7 This is a front oblique view of the base of a chip holder according to an embodiment of the present invention.

[0035] Figure 8 This is a rear oblique view of the base of a chip holder according to an embodiment of the present invention.

[0036] Figure 9 This is a top view of a chip holder according to another embodiment of the present invention holding a microfluidic chip device according to the first embodiment.

[0037] Figure 10 This is a perspective view of a chip holder holding a microfluidic chip device according to another embodiment of the present invention.

[0038] Figure 11 This is a top view of a chip holder holding a microfluidic chip device according to another embodiment of the present invention.

[0039] Figure 12 This is a perspective view of the cover plate of a chip holder according to another embodiment of the present invention.

[0040] Figure 13 This is a perspective view of the base of a chip holder according to another embodiment of the present invention.

[0041] Figure 14This is a perspective view of a replacement plate according to an embodiment of the present invention.

[0042] Figure 15 This is a perspective view of a replacement plate according to another embodiment of the present invention.

[0043] In the picture:

[0044] 1. Microfluidic chip;

[0045] 11. Optical tweezers manipulation and imaging area; 12. Imaging area marking structure;

[0046] 100. Inflow channel; 101. First inflow channel; 102. Second inflow channel; 103. Third inflow channel; 104. Fluid inlet;

[0047] 110. Outflow channel; 111. First outflow channel; 112. Second outflow channel; 113. Third outflow channel; 114. Fluid outlet;

[0048] 120. Fluid merging structure; 121. First connecting channel; 122. Second connecting channel; 123. Third connecting channel; 124. Fourth connecting channel; 125. Fifth connecting channel; 126. First merging channel; 127. Second merging channel; 128. First connecting structure; 129. Second connecting structure;

[0049] 130. Temperature control channel; 131. Temperature control medium fluid inlet; 132. Temperature control medium fluid outlet;

[0050] 2. Chip holder;

[0051] 21. Cover plate; 211. Cover plate body; 212. Replacement plate; 214. Fluid inlet; 215. Fluid outlet; 214'. Fluid inlet; 215'. Fluid outlet; 216. Upper mounting groove; 217. Mounting port; 218. Second bolt; 219. Second threaded hole; 22. Base; 221. Lower mounting groove; 23. Clamping structure; 231. Clamping part; 232. Positioning boss; 233. Positioning groove; 24. Mounting structure; 241. Magnetic fixing hole; 25. Chip viewing window; 26. Threaded connection structure; 261. First threaded hole; 262. First bolt; 27. Mounting marking structure. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Implementation Method 1

[0054] like Figure 1 and Figure 2 As shown, the present invention provides a microfluidic chip device, comprising: a microfluidic chip 1 having at least one inflow channel 100 and at least one outflow channel 110, the microfluidic chip 1 having an optical tweezers manipulation and imaging region 11 for optical tweezers manipulation and imaging, the inflow channel 100 being connected to the outflow channel 110 via a fluid confluence structure 120, and the fluid confluence structure 120 being at least partially located within the optical tweezers manipulation and imaging region 11; and a chip holder 2, which can be mounted and fixed in an optical tweezers system via a mounting structure 24, the chip holder 2 further comprising a clamping structure 23, at least one fluid inlet 214 and at least one fluid outlet 215, the microfluidic chip 1 being clamped and fixed by the clamping structure 23, the inflow channel 100 being connected to the corresponding fluid inlet 214, and the at least one fluid outlet 215 being connected to the corresponding outflow channel 110.

[0055] The microfluidic chip device of the present invention uses a chip holder 2 to clamp and fix the microfluidic chip 1 and install the chip holder 2 on the optical tweezers system, thereby ensuring the positioning accuracy of the microfluidic chip 1 in the optical tweezers system and the stability of the microfluidic chip 1 in the optical tweezers experiment. This is beneficial to improving the capture efficiency and imaging effect in the optical tweezers experiment and improving the repeatability of the measurement results. In addition, the chip holder 2 can be used to disassemble and replace different types of microfluidic chips 1, and the operation is simple.

[0056] Specifically, such as Figure 1 and Figure 2 As shown, the inflow channels 100 of the microfluidic chip 1 can be respectively introduced into different reagents or samples for optical tweezers experiments. Each fluid inlet 214 can be connected to a sample introduction structure for different reagents or samples, such as a syringe pump, pressure pump, or other injection structure, to control the introduction of different reagents or samples; the fluid outlets 215 are connected to a waste liquid collection structure to control the discharge and collection of waste liquid. The number of fluid inlets 214 can be greater than or equal to the number of inflow channels 100. Fluid inlets 214 at corresponding positions are selectively used according to the position and number of inflow channels 100 of different microfluidic chips 1, and excess fluid inlets 214 are not connected to the sample introduction structure. Similarly, the number of fluid outlets 215 can be greater than or equal to the number of outflow channels 110. Fluid outlets 215 at corresponding positions are selectively used according to the position and number of outflow channels 110 of different microfluidic chips 1, and excess fluid outlets 215 are not connected to the waste liquid collection structure. The fluid inlet 214 and fluid outlet 215 are, but are not limited to, connected to the output pipe connector of the sample injection structure and the input pipe connector of the waste liquid collection structure by means of threaded connection.

[0057] like Figure 1 and Figure 2 As shown, in the embodiments of the present invention, the material of the microfluidic chip 1 is preferably high-transparency optical glass; the thickness of the microfluidic chip 1 is preferably less than or equal to 1.35 mm; by using high-transparency optical glass to make the microfluidic chip 1, the thickness of the microfluidic chip 1 can not exceed 1.35 mm, which has better optical performance and is not easily deformed, thereby further improving the optical imaging and optical tweezers capture effect, and can be applied to optical tweezers systems with high numerical aperture condenser lenses (such as numerical aperture NA ≥ 1.3, especially numerical aperture NA of 1.4), to ensure high-quality optical capture and imaging and minimize optical distortion.

[0058] Specifically, such as Figure 3 and Figure 4 As shown, the microfluidic chip 1 includes a chip substrate and a chip cover plate, with the chip cover plate placed on the chip substrate. By first creating a channel structure and corresponding fluid interfaces on the chip substrate and / or the chip cover plate, including but not limited to a fluid outlet 114 and a fluid inlet 104, the chip substrate and the chip cover plate are then bonded together, thereby forming a circumferentially closed fluid channel. Both the chip substrate and the chip cover plate are made of high-transmittance optical glass.

[0059] In some embodiments of the present invention, the lower surface of the chip cover is provided with at least one channel, and the upper surface of the chip cover is provided with at least one fluid outlet 114 and at least one fluid inlet 104. The channel connects the fluid outlet 114 and the fluid inlet 104, thereby forming an outflow channel 110 and an inflow channel 100 with the upper surface of the chip substrate. The thickness of the chip substrate is approximately 0.16 mm to 0.18 mm, preferably around 0.17 mm.

[0060] In other embodiments of the present invention, the upper surface of the chip substrate is provided with at least one channel, and the chip cover is provided with at least one fluid outlet 114 and at least one fluid inlet 104. The channel connects the fluid outlet 114 and the fluid inlet 104, so that the channel, in conjunction with the lower surface of the chip cover, forms an outflow channel 110 and an inflow channel 100. The thickness of the chip cover is approximately 0.16 mm to 0.18 mm, preferably around 0.17 mm.

[0061] In some other embodiments of the present invention, the chip cover is provided with at least one fluid outlet 114 and at least one fluid inlet 104, and at least one conduit is installed between the chip substrate and the chip cover, the conduit connecting the fluid outlet 114 and the fluid inlet 104, thereby forming an inflow channel 100 and an outflow channel 110 inside the conduit.

[0062] In addition, such as Figure 3 and Figure 4As shown, the microfluidic chip 1 has an imaging area marking structure 12 in the optical tweezers manipulation and imaging area 11, so that the optical tweezers manipulation and imaging area 11 is accurately positioned with the imaging device of the optical tweezers system. That is, the imaging area marking structure 12 serves as a reference mark, so that the optical tweezers manipulation and imaging area 11 matches or is located within the optimal image acquisition area of ​​the imaging device, thereby facilitating software control by the user.

[0063] like Figure 1 and Figure 2 As shown, in the embodiments of the present invention, the number of outflow channels 110 and inflow channels 100 is not specifically limited. For example, only one or multiple channels can be provided, and they can be used selectively. The number of channels can be determined according to the reagents and samples required for the optical tweezers experiment. Different reagents or samples for the optical tweezers experiment can be introduced, including but not limited to microspheres, buffer solutions, culture media, cells, macromolecular polymers, or microbial aggregates. The positions of the outflow channels 110 and inflow channels 100 are also not specifically limited. That is, under suitable conditions, any fluid interface on the microfluidic chip 1 can be selectively used as a fluid inlet 104, and the channel connected to that fluid interface can be selectively used as an inflow channel 100. Similarly, any fluid interface can be selectively used as a fluid outlet 114, and the channel connected to that fluid interface can be selectively used as an outflow channel 110. The specific structure of the fluid confluence structure 120 is determined according to the number and position of the outflow channels 110 and inflow channels 100. The fluid confluence structure 120 may be entirely located within the optical tweezers manipulation and imaging region 11, or it may be only partially located within the optical tweezers manipulation and imaging region 11.

[0064] like Figure 1 and Figure 3 As shown, in the first embodiment of the present invention, there is one outflow channel 110, defined as the first outflow channel 111; there are three inflow channels 100, defined as the first inflow channel 101, the second inflow channel 102 and the third inflow channel 103 respectively; the fluid confluence structure 120 includes three connecting channels (defined as the first connecting channel 121, the second connecting channel 122 and the third connecting channel 123 respectively) that are connected to the three inflow channels 100 respectively, and a confluence channel (defined as the first confluence channel 126) that connects the three connecting channels and the outflow channel 110. The width of the first confluence channel 126 is greater than the width of each inflow channel 100.

[0065] The first inflow channel 101 is used to introduce microspheres, the third inflow channel 103 is used to introduce buffer solution, and the second inflow channel 102 is used to introduce the sample to be tested. During the optical tweezers experiment, in the microsphere capture stage, microspheres and buffer solution can be introduced simultaneously. The microspheres flow sequentially into the first confluence channel 126 through the first inflow channel 101 and the first connecting channel 121, while the buffer solution flows sequentially into the first confluence channel 126 through the third inflow channel 103 and the third connecting channel 123. This allows the microspheres and buffer solution to meet in the first confluence channel 126 in a laminar flow and flow into the portion of the first confluence channel 126 located in the optical tweezers manipulation and imaging area 11. The user can then capture the microspheres in the laminar flow microsphere distribution layer in the optical tweezers manipulation and imaging area 11 and move the captured microspheres to the buffer solution distribution layer in the laminar flow. After stopping the introduction of microspheres and buffer solution, mechanical correction is performed, such as obtaining relevant information such as the optical trap stiffness. Subsequently, buffer solution and the test sample are simultaneously introduced. The test sample passes sequentially through the second inflow channel 102 and the second connecting channel 122, allowing the test sample and buffer solution to meet in the first confluence channel 126 in a laminar flow manner and flow into the portion of the first confluence channel 126 located in the optical tweezers manipulation and imaging area 11. The user can then move the captured microspheres to the test sample distribution layer in the laminar flow. After stopping the introduction of the test sample and buffer solution, the microspheres are allowed to establish a connection with the test sample, such as the test sample binding with the microspheres to form a complex. After successful connection, the microspheres and the test sample complex are moved to the laminar flow buffer distribution layer for optical tweezers manipulation and mechanical measurement. During the experiment, when any inflow channel 100 is opened, the outflow channel 110 must also be connected to the waste liquid collection structure to ensure timely discharge of waste liquid.

[0066] By allowing microspheres and buffer solutions, as well as the test sample and buffer solution, to flow into the confluence channel and enter the optical tweezers manipulation and imaging area 11 in a laminar flow manner, multiple introduced substances can be independently partitioned and manipulated. This effectively avoids problems such as sample deposition, adhesion, and difficulty in achieving single control due to complex experimental environments, thereby ensuring the smooth progress of optical tweezers experiments and the repeatability of measurements.

[0067] Specifically, the depths of the inflow channel 100, outflow channel 110, connecting channel, and converging channel are all equal; the width of the first inflow channel 101 is similar to the width of the third inflow channel 103 and is smaller than the width of the second inflow channel 102; the first connecting channel 121 connects the first inflow channel 101 and the first converging channel 126, and the width of the first connecting channel 121 is smaller than the width of the first inflow channel 101; the third connecting channel 123 connects the third inflow channel 103 and the first converging channel 126, and the width of the third connecting channel 123 is equal to the width of the third inflow channel 103; the second connecting channel 122 connects the second inflow channel 102 and the first converging channel 126, and the width of the second connecting channel 122 is smaller than the width of the second inflow channel 102.

[0068] The connecting channel can be tapered or straight along a portion of its end. The left and right sides of the ends where the connecting channel connects to the merging channel can be at the same height or at different heights. Preferably, the left side of the end of the first connecting channel 121 is lower than the right side, forming a stepped shape that connects to the third connecting channel 123 and the first merging channel 126 respectively. The right side of the end of the second connecting channel 122 is lower than the left side, also forming a stepped shape that connects to the third connecting channel 123 and the first merging channel 126 respectively.

[0069] In one specific embodiment, the third connecting channel 123 is generally located between the two side walls of the first merging channel 126. One side wall of the first connecting channel 121 extends into the first merging channel 126 and connects with one side wall of the third connecting channel 123. The other side wall of the first connecting channel 121 connects with one side wall of the first merging channel 126. One side wall of the second connecting channel 122 extends into the first merging channel 126 and connects with the other side wall of the third connecting channel 123. The other side wall of the second connecting channel 122 connects with the other side wall of the first merging channel 126. The connection points of the first connecting channel 121, the third connecting channel 123, and the first confluence channel 126 form a stepped structure, which facilitates the flow of microspheres and buffer solution into the first confluence channel 126 to form a stable laminar flow structure and prevents microspheres from entering other fluid channels. Similarly, the connection points of the second connecting channel 122, the third connecting channel 123, and the first confluence channel 126 also form a stepped structure, which facilitates the flow of the sample to be tested and buffer solution into the first confluence channel 126 to form a stable laminar flow structure and prevents the sample to be tested from entering other fluid channels. In addition, it also helps to maintain an independent and stable laminar flow structure between each fluid channel when all three inflow channels 100 (such as the first inflow channel 101, the second inflow channel 102, and the third inflow channel 103) are opened simultaneously.

[0070] like Figure 2 and Figure 4As shown, in the second embodiment of the present invention, there are two inflow channels 100, namely a first inflow channel 101 and a second inflow channel 102; there are two outflow channels 110, namely a second outflow channel 112 and a third outflow channel 113; the fluid confluence structure 120 includes two connecting structures (defined as a first connecting structure 128 and a second connecting structure 129, respectively), two connecting channels (defined as a fourth connecting channel 124 and a fifth connecting channel 125, respectively) and a confluence channel (defined as a second confluence channel 127). The connecting structures connect the corresponding outflow channels 110 and inflow channels 100, and the connecting structures are connected to the second confluence channel 127 through the corresponding connecting channels. That is, the two ends of the second confluence channel 127 are connected to the fourth connecting channel 124 and the fifth connecting channel 125, respectively. The fourth connecting channel 124 is connected to the first connecting structure 128, and the fifth connecting channel 125 is connected to the second connecting structure 129.

[0071] The first inflow channel 101 is used to introduce microspheres, and the second inflow channel 102 is used to introduce the sample to be tested. During the optical tweezers experiment, in the microsphere capture stage, microspheres are first introduced. The microspheres flow through the first inflow channel 101 into the first connecting structure 128 and enter the optical tweezers manipulation and imaging area 11. The user can capture the microspheres in this area and move them to the second confluence channel 127 through the fourth connecting channel 124. Then, after stopping the microsphere injection, mechanical correction is performed, such as obtaining relevant information like the optical trap stiffness. Subsequently, the sample access channel is opened, and the sample flows through the second inflow channel 102 into the second connecting structure 129 and enters the optical tweezers manipulation and imaging area 11. The user can move the captured microspheres to the sample distribution area near the second connecting structure 129 through the fifth connecting channel 125, so that the microspheres and the sample to be tested are connected. After successful connection, the composite of the microspheres and the sample to be tested is moved back to the second confluence channel 127 through the fifth connecting channel 125 for optical tweezers manipulation and mechanical measurement. During the experiment, the waste liquid collection structure was connected to both the second outflow channel 112 and the third outflow channel 113 so that the waste liquid could be discharged in a timely manner.

[0072] By allowing microspheres to flow into a connecting structure and enter the optical tweezers manipulation and imaging region 11, while the sample to be tested flows into another connecting structure and enters the optical tweezers manipulation and imaging region 11, the optical tweezers system is first mechanically corrected using the confluence channel between the two connecting channels. Then, the connection between the sample to be tested and the microspheres is established through the connecting structure at the inflow end of the sample to be tested. Finally, the composite material formed by the sample to be tested and the microspheres is manipulated and mechanically measured using optical tweezers using the confluence channel between the two connecting channels. This method can effectively avoid problems such as sample deposition, adhesion, and the difficulty in achieving single control due to the complexity of the experimental environment, thereby ensuring the smooth progress of the optical tweezers experiment and the repeatability of the measurement.

[0073] Specifically, the depths of the inflow channel 100, the outflow channel 110, the connecting structure, the connecting channel, and the merging channel are all equal; the width of the first inflow channel 101 is less than the width of the second inflow channel 102; and the widths of the fourth connecting channel 124 and the fifth connecting channel 125 are both less than the widths of the inflow channel 100 and the outflow channel 110.

[0074] In this system, multiple inflow channels 100 and multiple outflow channels 110 are symmetrically and correspondingly arranged with respect to the fluid confluence structure 120. The inflow channels 100 and outflow channels 110 are connected to form a unified fluid channel. The positions of the corresponding fluid inlet 104 and fluid outlet 114 can be interchanged, and the positions of the two connecting channels can also be interchanged. The confluence channel has a certain spatial range (e.g., its width is greater than the width of the connecting channels). Its two ends are connected to the two connecting channels. Its two sides can be open structures (e.g., its two sides can be connected to other fluid channels or to fluid channels with independent inlets and outlets), or they can be closed structures (e.g., semi-arc, rectangular, or any other geometric shape). This allows the measured object to have a better independent control environment when performing mechanical correction, optical tweezers manipulation, and mechanical measurement within the second confluence channel 127, avoiding interference from other introduced substances.

[0075] In one specific embodiment, both the upper and lower fluid channels are connected to the corresponding connecting channels through a connecting structure. The part of the connecting structure connected to the connecting channel is tapered. The longitudinal cross-section of the second converging channel 127 is generally circular or elliptical.

[0076] like Figure 1 and Figure 2 As shown, in order to perform optical tweezers experiments on large-sized research objects such as cells, macromolecular polymers, or microbial aggregates with particle sizes ranging from 0.5 micrometers to 20 micrometers, in the embodiments of the present invention, the minimum width of the connecting channel is 50 micrometers to 1200 micrometers, preferably 200 micrometers to 600 micrometers; the depth of the connecting channel is 50 micrometers to 600 micrometers, preferably 100 micrometers to 500 micrometers. The width of the inflow channel 100 is greater than or equal to the width of the connecting channel, and the width of the outflow channel 110 is greater than or equal to the width of the inflow channel 100.

[0077] like Figure 3As shown, in some embodiments of the present invention, the microfluidic chip 1 is further provided with at least one temperature control channel 130. The temperature control channel 130 has two fluid interfaces, which serve as a temperature control medium fluid inlet 131 and a temperature control medium fluid outlet 132, respectively. Correspondingly, at least one fluid inlet 214' on the chip holder 2 is connected to the temperature control medium fluid inlet 131 of the at least one temperature control channel 130, and at least one fluid outlet 215' is connected to the temperature control medium fluid outlet 132 of the at least one temperature control channel 130, so as to connect an external temperature control device to form a temperature control medium circulation loop. The number and distribution of the temperature control channels 130 are not specifically limited and can be set as needed. For example, at least one temperature control channel 130 can be distributed on at least one side of the optical tweezers manipulation and imaging area 11, so that the optical tweezers manipulation and imaging area 11 can maintain a certain temperature, which is beneficial to maintaining a certain physiological state of the sample to be tested. Preferably, a temperature control channel 130 is provided on each side of the optical tweezers manipulation and imaging area 11. Optionally, the two temperature control channels 130 are distributed on both sides of the inflow channel 100. Optionally, the two temperature control channels 130 are distributed on both sides of the outflow channel 110. Optionally, the two temperature control channels 130 are distributed on both sides of the fluid confluence structure 120.

[0078] like Figure 1 and Figure 2 as well as Figures 5 to 8 As shown, in an embodiment of the present invention, the chip holder 2 includes a cover plate 21 and a base 22. The cover plate 21 covers the base 22 and is detachably connected to the base 22. The clamping structure 23 includes two clamping parts 231, which can clamp and fix both ends of the microfluidic chip 1. The cover plate 21 and the base 22 are provided with corresponding chip viewing windows 25, which are located between the two clamping parts 231. The clamping part 231 includes a positioning groove 233 and a positioning boss 232. The positioning groove 233 is provided on the base 22, and the positioning boss 232 is provided on the cover plate 21.

[0079] Specifically, the detachable connection between the cover plate 21 and the base 22 includes, but is not limited to, the threaded connection structure 26 in this embodiment. That is, the cover plate 21 and the base 22 are provided with corresponding first threaded holes 261, and then the cover plate 21 and the base 22 are connected by passing through multiple first bolts 262. Both the cover plate 21 and the base 22 are generally frame-shaped plate structures, with a positioning boss 232 on the lower surface of the cover plate 21 and a positioning groove 233 on the upper surface of the base 22. Both the fluid inlet 214 and the fluid outlet 215 are located on the cover plate 21. The fluid inlet 214 extends to a positioning boss 232, and the fluid outlet 215 extends to a positioning boss 232. This allows the two ends of the microfluidic chip 1 to be clamped and fixed between the two positioning bosses 232 and the two positioning grooves 233. The fluid inlet 104 at one end of the microfluidic chip 1 is connected to the fluid inlet 214, and the fluid outlet 114 at the other end of the microfluidic chip 1 is connected to the fluid outlet 215. The optical tweezers manipulation and imaging area 11 located in the middle of the microfluidic chip 1 corresponds to the chip viewing window 25 of the cover plate 21 and the base 22. In addition, when the temperature control channel 130 is needed, it is connected to the fluid inlet 214' and the fluid outlet 215'. A sealing structure (such as an O-ring) or a hole boss is provided between the cover plate 21 and the microfluidic chip 1. The sealing structure or hole boss is located at the hole docking point between the cover plate 21 and the microfluidic chip 1, such as the docking point between the fluid inlet 214 and the fluid inlet 104, or the docking point between the fluid outlet 215 and the fluid outlet 114, to ensure that a good sealing state can be maintained even under pressure conditions.

[0080] In addition, such as Figures 5 to 8 As shown, the cover plate 21 and the base 22 are provided with corresponding installation marking structures 27. The orientation of the cover plate 21 and the base 22 can be distinguished according to the installation marking structures 27. On the one hand, it is easier to position and install the microfluidic chip 1 on the chip holder 2. On the other hand, it is easier to correctly install the chip holder 2 on the worktable of the optical tweezers system.

[0081] like Figure 7 and Figure 8 As shown, in this embodiment of the invention, the mounting structure 24 includes multiple magnetic fasteners, which are spaced apart on the circumferential side surface of the chip holder 2. Specifically, multiple magnetic fastening holes 241 are spaced apart on the circumferential side surface of the chip holder 2, and each magnetic fastener is embedded in one of the multiple magnetic fastening holes 241. The magnetic fasteners can be magnets. In this embodiment, the multiple magnetic fasteners are mounted on the circumferential side surface of the base 22. Optionally, the multiple magnetic fasteners are mounted on the circumferential side surface of the cover plate 21. Optionally, multiple magnetic fasteners are mounted on the circumferential side surfaces of both the cover plate 21 and the base 22.

[0082] likeFigures 5 to 8 As shown, in some embodiments of the present invention, the fluid inlet 214, the fluid outlet 215, and the corresponding positioning boss 232 are all integrally formed on the cover plate 21. In one specific embodiment, there are three fluid inlets 214 and three fluid outlets 215. The corresponding fluid inlet 214 can be connected to the inflow channel 100, and the fluid outlet 215 can be connected to the outflow channel 110 as needed.

[0083] like Figures 9 to 15 As shown, in some other embodiments of the present invention, the cover plate 21 includes a detachably connected cover plate body 211 and at least one replacement plate 212. The replacement plate 212 has an integrally formed positioning boss 232 and corresponding fluid inlet 214 and / or fluid outlet 215 and / or fluid inlet 214' and / or fluid outlet 215'. Specifically, the cover plate body 211 is provided with an upper mounting groove 216, and the bottom surface of the upper mounting groove 216 is provided with a mounting opening 217. The replacement plate 212 and the cover plate body 211 are provided with corresponding multiple second threaded holes 219. The replacement plate 212 can be fixed in the upper mounting groove 216 by multiple second bolts 218 passing through the second threaded holes 219, and the positioning boss 232 passes through the mounting opening 217 to cooperate with the positioning groove 233. Furthermore, lower mounting grooves 221 can be provided on both sides of the positioning groove 233 to cooperate with the two ends of the replacement plate 212. The base 22 may also be provided with a number of corresponding second threaded holes 219, so as to connect the replacement plate 212 to the cover plate body 211 and the base 22 by a number of second bolts 218.

[0084] In some specific embodiments, the cover plate body 211 is detachably connected to a replacement plate 212. The cover plate body 211 has an integrally formed positioning boss 232 and a corresponding fluid inlet 214 or fluid outlet 215. The replacement plate 212 has an integrally formed positioning boss 232 and a corresponding fluid inlet 214 or fluid outlet 215.

[0085] like Figure 9 , Figure 10 as well as Figure 14 As shown, in a specific embodiment, the replacement plate 212 is provided with a fluid outlet 215, two fluid inlets 214' and two fluid outlets 215'. The fluid outlet 215 is connected to the first outflow channel 111 of the microfluidic chip 1 in the first embodiment, and the two fluid inlets 214' and two fluid outlets 215' are connected to the two temperature control channels 130 of the microfluidic chip 1 in the first embodiment.

[0086] like Figure 11 as well as Figure 15As shown, in another specific embodiment, the replacement plate 212 is provided with two fluid outlets 215, which are connected to the second outflow channel 112 and the third outflow channel 113 of the microfluidic chip 1 in the second embodiment.

[0087] In other specific embodiments, the cover plate body 211 is detachably connected to two replacement plates 212. One replacement plate 212 has an integrally formed positioning boss 232 and a corresponding fluid inlet 214, and the other replacement plate 212 has an integrally formed positioning boss 232 and a corresponding fluid outlet 215.

[0088] Implementation Method 2

[0089] The present invention also provides an optical tweezers experimental method, which uses the microfluidic chip device in Embodiment 1.

[0090] The optical tweezers experimental method includes the following steps: Device installation: The chip holder 2 clamps and fixes the microfluidic chip 1, and the chip holder 2 is correctly fixed to the optical tweezers system through the mounting structure 24; A fluid inlet 214 is connected to the sample inlet structure of the sample to be tested; A fluid outlet 215 is connected to the waste liquid discharge structure; Obtaining the measurement object: The sample inlet structure of the sample to be tested is opened, so that the sample to be tested flows into the fluid confluence structure 120 through the corresponding inflow channel 100, and then the sample to be tested enters the optical tweezers manipulation and imaging area 11 and the measurement object is obtained; Optical tweezers measurement: The above-mentioned measurement object is moved to the target area for optical tweezers manipulation and mechanical measurement; Waste liquid discharge: During the experiment, while opening the inflow channel 100, the corresponding waste liquid discharge structure is opened to discharge the fluid in the microfluidic chip 1 in a timely manner.

[0091] In some embodiments of the present invention, the installation steps of the device further include connecting a fluid inlet 214 to the microsphere injection structure; obtaining the measurement object specifically includes the following steps: microsphere injection: opening the microsphere injection structure, allowing the microsphere to flow into the fluid confluence structure 120 through the corresponding inflow channel 100 and enter the optical tweezers manipulation and imaging area 11; microsphere capture: capturing the microsphere in the optical tweezers manipulation and imaging area 11, and then moving the captured microsphere to the target area of ​​the optical tweezers manipulation and imaging area 11 for mechanical correction; sample injection: opening the sample injection structure of the sample to be tested, allowing the sample to flow into the fluid confluence structure 120 through the corresponding inflow channel 100 and enter the optical tweezers manipulation and imaging area 11; establishing connection: moving the captured microsphere in the target area to the distribution area of ​​the sample to be tested, so that the sample to be tested and the microsphere establish a connection; wherein, the composite formed by the connection between the sample to be tested and the microsphere constitutes the measurement object.

[0092] In one specific embodiment of the present invention, the number of inflow channels 100 is set to at least three and correspondingly connected to at least three fluid inlets 214; the fluid confluence structure 120 includes at least three connecting channels corresponding to the at least three inflow channels 100 and a confluence channel connecting the at least three connecting channels and the outflow channel 110, the width of the confluence channel being greater than the width of each inflow channel 100; the installation step of the device further includes connecting a fluid inlet 214 to the sample introduction structure of the buffer solution; the optical tweezers experimental method further includes the following steps: while performing the microsphere sample introduction step, opening... The buffer injection structure is activated, allowing the buffer solution to flow through the corresponding inflow channel 100 and into the confluence channel of the fluid confluence structure 120 in a laminar flow manner, and then into the optical tweezers manipulation and imaging area 11. Simultaneously with the sample injection step, the buffer injection structure is activated, allowing the buffer solution to flow through the corresponding inflow channel 100 and into the confluence channel of the fluid confluence structure 120 in a laminar flow manner, and then into the optical tweezers manipulation and imaging area 11. The buffer solution distribution layer in the laminar flow constitutes the target area; the sample distribution layer in the laminar flow constitutes the sample distribution area. Preferably, the steps of simultaneously injecting the microspheres and buffer solution and simultaneously injecting the sample and buffer solution are performed separately, which helps to save on samples with low concentrations and high value. Alternatively, the microspheres, sample, and buffer solution can be injected simultaneously.

[0093] In another specific embodiment of the present invention, the number of outflow channels 110 and inflow channels 100 are both set to multiple and correspondingly connected to multiple fluid inlets 214 and multiple fluid outlets 215. The fluid confluence structure 120 includes multiple connecting structures, multiple connecting channels, and a confluence channel. The connecting structures connect the corresponding inflow channels 100 and outflow channels 110, and the connecting structures connect to the confluence channel through the corresponding connecting channels. In the device installation step, the two fluid outlets 215 are connected to the two waste liquid discharge structures. The microsphere injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel 110, so that the microspheres flow into the corresponding connecting structure and / or connecting channel and enter the optical tweezers manipulation and imaging area 11. The sample injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel 110, so that the sample to be tested flows into the corresponding connecting structure and / or connecting channel and enters the optical tweezers manipulation and imaging area 11. The confluence channel of the fluid confluence structure 120 constitutes the target area. The portion of the corresponding connecting structure and / or connecting channel into which the sample to be tested flows into the optical tweezers manipulation and imaging area constitutes the distribution area of ​​the sample to be tested. The microsphere injection step and the sample injection step described above are preferably performed separately, which helps to save samples with small content and high value. Of course, the microsphere injection step and the sample injection step can also be performed simultaneously.

[0094] In other embodiments of the present invention, in some experiments that do not require the introduction of microspheres, the capture and mechanical measurement of the sample to be tested can be performed within the optical tweezers manipulation and imaging area of ​​any fluid channel. That is, only the sample to be tested is introduced, and the sample to be tested is directly used as the measurement object. For example, in droplet fusion experiments, it is not necessary to go through all the above operation steps. The appropriate method should be selected according to the specific experimental content.

[0095] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A microfluidic chip device, characterized in that, include: A microfluidic chip has at least one inflow channel and at least one outflow channel. The microfluidic chip has an optical tweezers manipulation and imaging region. The inflow channel is connected to the outflow channel through a fluid confluence structure, and the fluid confluence structure is at least partially located within the optical tweezers manipulation and imaging region. A chip holder that can be fixed to an optical tweezers system by a mounting structure. The chip holder also has a clamping structure, at least one fluid inlet and at least one fluid outlet. The microfluidic chip is clamped and fixed by the clamping structure, and the inflow channel is connected to the corresponding fluid inlet, and the fluid outlet is connected to the corresponding outflow channel. The number of inflow channels is at least two; the fluid confluence structure includes at least two connecting channels corresponding to the at least two inflow channels and a confluence channel connecting the at least two connecting channels and the outflow channel, wherein the width of the inflow channel is greater than or equal to the width of the connecting channel.

2. The microfluidic chip device as described in claim 1, characterized in that, The microfluidic chip is made of high-transmittance optical glass; the thickness of the microfluidic chip is less than or equal to 1.35 mm.

3. The microfluidic chip device as described in claim 1, characterized in that, The microfluidic chip includes a chip substrate and a chip cover plate, wherein the chip cover plate is bonded to the chip substrate; The lower surface of the chip cover is provided with at least one channel, and the upper surface of the chip cover is provided with at least one fluid outlet and at least one fluid inlet. The channel connects the fluid outlet and the fluid inlet, thereby forming the outflow channel and the inflow channel with the upper surface of the chip substrate; and / or The upper surface of the chip substrate is provided with at least one channel, and the chip cover is provided with at least one fluid outlet and at least one fluid inlet. The channel connects the fluid outlet and the fluid inlet, so that the channel cooperates with the lower surface of the chip cover to form the outflow channel and the inflow channel.

4. The microfluidic chip device as described in claim 1, characterized in that, The width of the merging channel is greater than the width of each of the inflow channels.

5. The microfluidic chip device as described in claim 1, characterized in that, The outflow channels are configured in multiple ways, and the fluid confluence structure includes multiple connecting structures. The connecting structures connect the corresponding inflow channels and the outflow channels, and the connecting structures are connected to the confluence channels through the corresponding connecting channels.

6. The microfluidic chip device as described in claim 1, characterized in that, The width of the connecting channel is 50 micrometers to 1200 micrometers, and the depth of the connecting channel is 50 micrometers to 600 micrometers; the width of the outflow channel is greater than or equal to the width of the inflow channel.

7. The microfluidic chip device as described in claim 1, characterized in that, The microfluidic chip also has at least one temperature control channel, which has a temperature control medium fluid inlet and a temperature control medium fluid outlet; there are multiple fluid inlets and multiple fluid outlets, and at least one fluid inlet is connected to the temperature control medium fluid inlet of at least one temperature control channel, and at least one fluid outlet is connected to the temperature control medium fluid outlet of at least one temperature control channel; wherein, at least one temperature control channel is distributed on at least one side of the optical tweezers manipulation and imaging area.

8. The microfluidic chip device as described in claim 1, characterized in that, The chip holder includes a cover plate and a base. The cover plate is detachably connected to the base. The clamping structure includes two clamping parts that can clamp and fix both ends of the microfluidic chip. The cover plate and the base are provided with corresponding chip viewing windows, which are located between the two clamping parts. Both the cover plate and the base are provided with installation marking structures around their chip viewing windows. Each clamping part includes a positioning groove and a positioning boss. The positioning groove is located on the base, and the positioning boss is located on the cover plate.

9. The microfluidic chip device as described in claim 8, characterized in that, Both the fluid inlet and the fluid outlet are located on the cover plate. The fluid inlet extends through to a positioning boss, and the fluid outlet extends through to the positioning boss. The fluid inlet, the fluid outlet, and the corresponding positioning boss are all integrally formed on the cover plate; or The cover plate includes a detachably connected cover plate body and at least one replacement plate. The replacement plate has an integrally formed positioning boss and a corresponding fluid inlet and / or fluid outlet; and / or the cover plate body has an integrally formed positioning boss and a corresponding fluid inlet and / or fluid outlet.

10. The microfluidic chip device as described in claim 1, characterized in that, The mounting structure includes multiple magnetic fasteners, which are spaced apart on the circumferential side of the chip holder.

11. A method for optical tweezers experiments, characterized in that, Using the microfluidic chip device as described in any one of claims 1-10, the optical tweezers experimental method includes the following steps: Device installation: The chip holder clamps and fixes the microfluidic chip, and the mounting structure correctly installs and fixes the chip holder to the optical tweezers system; a fluid inlet is connected to the sample inlet structure; and the fluid outlet is connected to the waste liquid discharge structure. Acquiring the measurement object: Open the sample introduction structure of the sample to be tested, so that the sample to be tested flows into the fluid confluence structure through the corresponding inflow channel, thereby allowing the sample to enter the optical tweezers manipulation and imaging area and acquiring the measurement object; Optical tweezers measurement: The object to be measured is moved to the target area of ​​the optical tweezers manipulation and imaging area for optical tweezers manipulation and mechanical measurement; Waste liquid discharge: During the experiment, while opening the inflow channel, the corresponding waste liquid discharge structure is also opened to discharge the fluid in the microfluidic chip in a timely manner.

12. The optical tweezers experimental method as described in claim 11, characterized in that, The installation steps of the device also include connecting another fluid inlet to the sample introduction structure of the microspheres; The specific steps for obtaining the measurement object are as follows: Microsphere injection: The microsphere injection structure is opened, allowing the microsphere to flow into the fluid confluence structure through the corresponding inflow channel and enter the optical tweezers manipulation and imaging area; Microsphere capture: The microsphere is captured in the optical tweezers manipulation and imaging area, and then the captured microsphere is moved to the target area of ​​the optical tweezers manipulation and imaging area for mechanical correction; Sample introduction: The sample introduction structure of the sample to be tested is opened, so that the sample to be tested flows into the fluid confluence structure through the corresponding inflow channel and enters the optical tweezers manipulation and imaging area; Establishing a connection: The microspheres captured in the target area are moved to the distribution area of ​​the sample to be tested, so that the sample to be tested and the microspheres are connected; wherein, the complex formed by the connection between the sample to be tested and the microspheres constitutes the measurement object.

13. The optical tweezers experimental method as described in claim 12, characterized in that, The number of inflow channels is at least three; the fluid confluence structure includes at least three connecting channels corresponding to the at least three inflow channels and a confluence channel connecting the at least three connecting channels and the outflow channel, wherein the width of the confluence channel is greater than the width of each inflow channel; The installation steps of the device also include connecting one of the fluid inlets to the sample injection structure of the buffer solution; The optical tweezers experimental method also includes the following steps: While performing the microsphere injection step, the buffer injection structure is activated, allowing the buffer to enter the confluence channel of the fluid confluence structure and the optical tweezers manipulation and imaging area in a laminar flow with the microsphere through the corresponding inflow channel. While performing the sample injection step, the buffer injection structure is activated, so that the buffer and the sample to be tested enter the confluence channel of the fluid confluence structure in a laminar flow form through the corresponding inflow channel and enter the optical tweezers manipulation and imaging area. Wherein, the distribution layer of the buffer solution in the laminar flow constitutes the target region; the distribution layer of the sample to be tested in the laminar flow constitutes the distribution region of the sample to be tested.

14. The optical tweezers experimental method as described in claim 12, characterized in that, Both the outflow channel and the inflow channel are provided in multiple ways. The fluid confluence structure includes multiple connecting structures, multiple connecting channels, and a confluence channel. The outflow channel is connected to the corresponding inflow channel through the connecting structure, and the connecting structure is connected to the confluence channel through the corresponding connecting channel. In the installation steps of the device, the two fluid inlets are connected to the two waste liquid discharge structures; The microsphere injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel, so that the microsphere flows into the corresponding connection structure and / or the connection channel and enters the optical tweezers manipulation and imaging area; The sample injection step further includes: opening the waste liquid discharge structure connected to the corresponding outflow channel, so that the sample to be tested flows into the corresponding connection structure and / or the connection channel and enters the optical tweezers manipulation and imaging area; Wherein, the confluence channel of the fluid confluence structure constitutes the target region; the portion of the sample to be tested flowing into the corresponding connection structure and / or connection channel located in the optical tweezers manipulation and imaging region constitutes the distribution region of the sample to be tested.

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