A mobile drive mechanism and a microfluidic chip pressing device comprising the mechanism

Abstract

The present invention relates to a displacement driving device for a pressing device of a microfluidic chip, and a moving driving mechanism, including a driving mechanism. The driving mechanism includes a bracket, a horizontal moving structure and a longitudinal moving structure arranged on the bracket. A cover plate is connected to the bottom end of the longitudinal moving structure. It is characterized in that: the horizontal moving mechanism includes a lead screw transmission assembly, the lead screw transmission assembly includes a lead screw and a rotating block, the rotating block is sleeved on the lead screw, the rotating block is fixedly connected to a first connecting block, the lower end of the first connecting block is rotatably connected to a second connecting block, and the lower end of the second connecting block is rotatably provided with the cover plate. The longitudinal moving mechanism includes a third connecting block fixed to the lower side of the top plate fixing plate and a fourth connecting block slidably connected to the third connecting block. The fourth connecting block is fixedly connected to the cover plate. The present invention provides an actuating driving mechanism that can accurately realize the up and down movement of the floating pressing head, which has the advantages of high transmission accuracy and stable transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of pressing and sealing of microfluidic devices, and particularly to a moving drive structure of a pressing device for a microfluidic chip. Background Art

[0002] In a microfluidic pneumatic control system, to ensure that the fluid does not leak, the flow rate can be accurately adjusted and the adjustment range is wide, the pressing and sealing effect of the device is crucial. In a microfluidic device, the pressing and sealing of the chip is often achieved by the combination of the front-back displacement of the bottom chip and the up-down displacement of the top pressing member (press head). How to ensure the accuracy of the actuator for moving the press head during the process of downward pressing or horizontal movement is relatively important.

[0003] In addition, almost all the pressing members on the market are single-piece / monolithic and small-sized, which can only meet the pressing and sealing of single, small-sized microfluidic chips with a single slot. At the same time, the sealing effect has extremely high requirements for the surface processing flatness of the press head and the chip slot; therefore, it is very difficult for them to press microfluidic chips with multiple, large-sized and different-sized, and non-flat slots. In addition, with the long-term contact wear between the press head and the chip slot, the press head will also have problems such as surface unevenness, poor wear resistance, weak corrosion resistance, and short working life, all of which will lead to a decrease or failure of the sealing effect. This is also the main reason for the uneven performance of existing microfluidic operation devices in accurately controlling the flow rate and stably forming droplets. Summary of the Invention

[0004] Based on the above practical problems, one aspect of the purpose of the present technical solution is to provide an actuator that can accurately achieve the horizontal and vertical movements of the floating press head, which operates accurately during the movement process, has high adjustable precision, small error, and stable operation. On the other hand, a structure of a "floating press head" is provided, that is, a plurality of press heads are "suspended" under a pressing cover plate in the device, and each press head has degrees of freedom of tilting left and right, tilting front and back, and moving up and down. The press heads are relatively independent of each other, so as to be able to fully press the multiple slots of the chip below with multi-point contact. The above problems in the existing pressing and sealing technology field are successfully solved. The technical solution of the present invention realizes the complete pressing of microfluidic chips with multiple, large-sized slots of various sizes, well ensures the sealing effect, reduces the flatness requirements for the processing of the press head and the chip, and can ensure the accurate regulation of the flow rate with simple operation. To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A mobile drive mechanism, including a drive mechanism, the drive mechanism includes a bracket, a horizontal movement structure and a longitudinal movement structure arranged on the bracket, a cover plate is connected to the bottom end of the longitudinal movement structure, and is characterized in that: the horizontal movement mechanism includes a lead screw drive assembly, the lead screw drive assembly includes a lead screw and a rotating block, the rotating block is sleeved on the lead screw, the rotating block is fixedly connected to a first connecting block, the lower end of the first connecting block is rotatably connected to a second connecting block, and the lower end of the second connecting block is rotatably provided with the cover plate; the longitudinal movement mechanism includes a third connecting block fixed to the lower side of the top plate fixing plate and a fourth connecting block slidably connected to the third connecting block, and the fourth connecting block is fixedly connected to the cover plate.

[0006] Further, the bracket includes a left side plate, a right side plate and a top plate fixing plate arranged between the left side plate and the right side plate.

[0007] Further, a roller is arranged at the upper end of the first connecting block, and the roller is in contact with the lower side surface of the top plate fixing plate.

[0008] Further, one end of the lead screw is connected to the output end of the drive motor, and the other end passes through and is rotatably fixed on a lead screw fixing plate. The lead screw fixing plate is arranged between the left side plate and the right side plate and is parallel to the two.

[0009] Further, the first connecting block and the second connecting block are connected by a second rotating shaft, and the upper end of the first connecting block and the roller are connected by a first rotating shaft.

[0010] Further, limiting plates are respectively arranged on both sides of the first connecting block. The limiting plates are respectively in contact with or slidably connected to the front and rear sides of the first connecting block, and the two ends of the limiting plates are respectively fixed on the housing of the drive motor and the lead screw fixing plate.

[0011] Further, the left side plate includes a first vertical portion, a first horizontal portion is arranged at the upper end of the first vertical portion, a first threaded hole is arranged on the first horizontal portion, a row of through holes is arranged on the part of the upper end of the first vertical portion close to the lower side of the first horizontal portion, second threaded holes are arranged on the end faces at both ends of the top plate fixing plate, and bolts pass through the through holes and cooperate with the second threaded holes to complete the fixation. The diameter of the through holes is smaller than the bolt head and larger than the bolt rod. In this solution, the through holes can be arranged in multiple rows at intervals up and down.

[0012] Further, the through holes may not be arranged in a regular circle, or may be vertically long strips. The width of the vertically long strip through holes is smaller than the bolt head and larger than the bolt rod. In the above two design solutions, the up and down adjustment of the top plate fixing plate can be achieved by connecting bolts through the side through holes and cooperating with the second threaded holes. Further, the fixation is strengthened by the bolts passing through the second threaded holes and pressing against the upper side surface of the top plate fixing plate.

[0013] Further, a slide rail or a slider is provided on the third connection block, and a slider or a slide rail cooperating therewith is provided on the fourth connection block.

[0014] Further, a press head groove is provided on the bottom side of the cover plate, and the floating press head is arranged in the press head groove.

[0015] A microfluidic chip pressing device includes a driving mechanism described above, a pressing device connected to the driving mechanism. The pressing device includes a floating cover plate, a plurality of groups of floating press heads arranged on the lower side of the cover plate, and the floating cover plate and the floating press heads are connected by springs.

[0016] Further, an air inlet is provided on the circumferential side surface of each group of floating press heads, and an air outlet is provided on the bottom side surface. The air inlet is communicated with the air outlet, and the air inlet is connected to an air inlet pipe.

[0017] Further, a first air inlet is provided on one circumferential side surface of each group of floating press heads, a first air outlet is provided on the other circumferential side surface, and a second air outlet is provided on the bottom side surface. The air inlet is communicated with the air outlet, and the first air outlet and the first air inlet between adjacent two groups of floating press heads are connected by an air guide pipe.

[0018] Further, the adaptive floating pressing device further includes a soft material gasket independently arranged between the pressing device and the notch of the chip sample pool. Through holes are provided on the soft material gasket, and the arrangement positions of the through holes correspond to the second air outlets on the floating press heads distributed on the lower side of the cover plate.

[0019] Further, a press head fixing frame, a fixing frame limiting block, and a floating press head are sequentially arranged on the lower side of the cover plate. The fixing frame limiting block includes a first table block and a second table block arranged on the lower side of the first table block. The upper side surface of the first table block is fixedly connected to the lower side surface of the cover plate. The press head fixing frame is a square frame with openings on both the upper and lower side surfaces. The area of the square opening on the upper side surface of the press head fixing frame is larger than the upper surface area of the first table block and smaller than the lower surface area of the second table block, so that the first table block can freely enter and exit the square opening on the upper side surface. The area of the opening on the lower side surface of the press head fixing frame is larger than the lower surface area of the second table block. The floating press head is fixedly connected to the press head fixing frame. A spring sleeving column is arranged on the upper side surface of the floating press head. A column accommodating cavity for accommodating the spring sleeving column is arranged on the lower side of the second table block, and a spring is arranged on the spring sleeving column. The press head fixing frame and the floating press head wrap the fixing frame limiting block in the connection space between the two and leave a certain activity space.

[0020] Further, screw holes are provided on the periphery of the indenter fixing frame, and screw holes are also provided on the periphery of the floating indenter. When the floating indenter is fixed to the indenter fixing frame, the floating indenter is placed inside the indenter fixing frame, and the screw holes are connected by screws. In the above solution, the fixing frame limiting block is fixed to the floating pressing plate, and the indenter fixing frame and the floating indenter wrap it and can move appropriately under its limited fixing. This fixing method can greatly stabilize the floating indenter during the working process of the floating indenter, avoid deviation, and avoid excessive movement and poor working effect.

[0021] In the technical solution adopted by the present invention, the pressing and sealing of the chip are realized by driving the driving mechanism by the motor, and the driving mechanism drives the pressing device to move up and down, so that the indenter closely adheres to the notch of the chip sample cell. In the technical solution adopted by the present invention, the actuator is only a lead screw transmission assembly, which is connected through the mutual cooperation of the first connecting block, the second connecting block, the third connecting block and the fourth connecting block, so that the driven component cover plate moves in the vertical direction and provides power for it. During this process, through the setting of the roller, the lead screw is not affected by the vertical force during the downward pressing process. Through the setting of the two limiting plates, the lead screw is not affected by the horizontal offset force during the downward pressing process, and at the same time, the problem of the indenter being deflected in other directions due to the downward force is also avoided. In the technical solution provided by the present invention, the driving mechanism has high transmission accuracy and stable transmission. In the technical solution provided by the present invention, when the second connecting block and the first connecting block are both in the vertical state, a stable state can be achieved. At this time, even if the power is cut off or the driving motor is turned off, the actuator can still maintain a stable state at this position when the cover plate is still subject to the reaction force.

[0022] The floating indenter in the pressing device provided by the present invention is independently processed, and multiple floating indenters are suspended and installed under the same cover plate to form a "floating indenter". The advantages of the floating indenter are reflected in: each indenter has a certain degree of freedom of left and right inclination, front and back inclination, and up and down movement; and each indenter is relatively independent. Therefore, each indenter can generate an independent adaptive offset amount (adjustment in horizontal angle or height) of its own indenter according to the downward force given by the connecting rod and the processing conditions (notch shape, size and flatness) of the contact surface between the floating indenter and the chip notch during the downward pressing process, presenting multi-point contact with the microfluidic chip, thereby realizing complete pressing and sealing. At the same time, the air inlet interface and the gas path part of the device are completely processed at the independent indenter to ensure that the input air flow does not leak and accurately control the flow rate. In addition, in actual assembly operations, a soft material gasket such as rubber is placed between the indenter and the chip sample cell notch, which can reduce the wear during the pressing process of the indenter and the chip, and improve the compactness during contact. The present invention can realize the complete pressing and sealing of microfluidic chips with multiple notches and large-size apertures, and at the same time greatly reduce the requirements for the processing flatness of the indenter and the chip sample cell notch. Description of the Drawings

[0023] Figure 1 This is a schematic structural diagram of a specific embodiment of the present invention.

[0024] Figure 2 This is a schematic structural diagram of a specific embodiment of the present invention.

[0025] Figure 3 This is a schematic partial structural diagram of a specific embodiment of the present invention.

[0026] Figure 4 This is a schematic structural diagram of another perspective of a partial specific embodiment of the present invention.

[0027] Figure 5 This is a schematic structural diagram of a floating chuck of a specific embodiment of the present invention.

[0028] Figure 6 This is a schematic structural diagram of a driving mechanism of a specific embodiment of the present invention. Specific Embodiments

[0029] The following further explains the technical solution of the present invention with reference to the accompanying drawings.

[0030] Embodiment 1:

[0031] A mobile driving mechanism includes a driving mechanism. The driving mechanism includes a bracket 1, a horizontal moving structure and a longitudinal moving structure provided on the bracket 1. A cover plate 5 is connected to the bottom end of the longitudinal moving structure. The characteristics are as follows: The horizontal moving mechanism includes a lead screw transmission assembly. The lead screw transmission assembly includes a lead screw 97 and a rotating block 98. The rotating block 98 is sleeved on the lead screw 97. The rotating block 98 is fixedly connected to a first connecting block 99. The lower end of the first connecting block 99 is rotatably connected to a second connecting block 102. The lower end of the second connecting block 102 is rotatably provided with the cover plate 5. The longitudinal moving mechanism includes a third connecting block 109 fixed to the lower side of a top plate fixing plate 96 and a fourth connecting block 110 slidably connected to the third connecting block. The fourth connecting block 110 is fixedly connected to the cover plate 5.

[0032] The bracket 1 includes a left side plate 94, a right side plate 95 and a top plate fixing plate 96 provided between the left side plate 94 and the right side plate 95.

[0033] A roller 101 is provided at the upper end of the first connecting block 99. The roller 101 is in contact with the lower side surface of the top plate fixing plate 96.

[0034] One end of the lead screw 97 is connected to the output end of a driving motor 92, and the other end passes through and is rotatably fixed on a lead screw fixing plate 100. The lead screw fixing plate 100 is provided between the left side plate 94 and the right side plate 95 and is parallel to the two.

[0035] The first connecting block 99 and the second connecting block 102 are connected by a second rotating shaft 103, and the upper end of the first connecting block 99 and the roller 101 are connected by a first rotating shaft 104.

[0036] Limit plates 105 are respectively arranged on both sides of the first connecting block 99. The limit plates 105 are respectively in contact with or slidably connected to the front and rear sides of the first connecting block 99, and both ends of the limit plates 105 are respectively fixed on the housing of the driving motor 92 and the lead screw fixing plate 100.

[0037] The left side plate 94 includes a first vertical portion. A first horizontal portion 106 is arranged at the upper end of the first vertical portion. A first threaded hole 107 is arranged on the first horizontal portion 106. A through hole 108 is arranged on the upper end of the first vertical portion near the lower side of the first horizontal portion 106. Second threaded holes are arranged on the end faces of both ends of the top plate fixing plate 96. Bolts pass through the through hole 108 and cooperate with the second threaded holes to complete the fixation. The diameter of the through hole 108 is smaller than the bolt head and larger than the bolt rod. In this solution, the through holes can be arranged in multiple rows at intervals up and down.

[0038] The through hole 108 may not be arranged as a perfect circle, but may also be a vertical long strip shape. The width of the long strip through hole is smaller than the bolt head and larger than the bolt rod. In the above two design solutions, the up and down adjustment of the top plate fixing plate can be achieved by connecting bolts through the side through holes and the second threaded holes. Further, the fixation is strengthened by the bolts passing through the second threaded holes and pressing against the upper side of the top plate fixing plate.

[0039] A slide rail 112 is arranged on the third connecting block 109, and a slider 111 that cooperates with it is arranged on the fourth connecting block 110.

[0040] A microfluidic chip pressing device includes a driving mechanism described above, and a pressing device connected to the driving mechanism. The pressing device includes a cover plate 5, and multiple groups of floating pressing heads 6 arranged on the lower side of the cover plate 5. The cover plate 5 and the floating pressing heads 6 are connected by springs.

[0041] An air inlet 7 is arranged on the circumferential side surface of each group of floating pressing heads 6, and an air outlet 9 is arranged on the bottom side surface. The air inlet 7 is communicated with the air outlet 9, and the air inlet 7 is connected to an air inlet pipe.

[0042] A first air inlet is arranged on the circumferential side surface of each group of floating pressing heads 6, a first air outlet is arranged on the other circumferential side surface, and a second air outlet is arranged on the bottom side surface. The air inlet is communicated with the air outlet. The first air outlet and the first air inlet between adjacent two groups of floating pressing heads are connected by a guide pipe 14.

[0043] The adaptive suspension pressing device further includes a soft material gasket 11 independently arranged between the pressing device and the notch 10 of the chip sample cell. A through hole 12 is provided on the soft material gasket 11, and the position of the through hole 12 corresponds to the second air outlet 9 on the suspension pressing head 6 distributed on the lower side of the cover plate 5.

[0044] A pressing head fixing frame 51, a fixing frame limiting block 52, and a suspension pressing head 6 are sequentially arranged on the lower side of the cover plate 5. The fixing frame limiting block 52 includes a first table block 522 and a second table block 521 arranged on the lower side of the first table block 522. The upper side surface of the first table block 522 is fixedly connected to the lower side surface of the cover plate 5. The pressing head fixing frame 51 is a square frame with openings on both the upper and lower side surfaces. The area of the square opening on the upper side surface of the pressing head fixing frame 51 is larger than the upper surface area of the first table block and smaller than the lower surface area of the second table block, so that the first table block 522 can freely enter and exit the square opening on the upper side surface. The area of the opening on the lower side surface of the pressing head fixing frame 51 is larger than the lower surface area of the second table block 521. The suspension pressing head 6 is fixedly connected to the pressing head fixing frame 51. A spring sleeving column 55 is arranged on the upper side surface of the suspension pressing head 6. A sleeve column accommodating cavity is provided on the lower side of the second table block 521 for accommodating the spring sleeving column 55, and a spring is arranged on the spring sleeving column 55. The pressing head fixing frame 51 and the suspension pressing head 6 wrap the fixing frame limiting block 52 in the connection space between the two and leave a certain amount of movement space.

[0045] Screw holes are provided on the periphery of the pressing head fixing frame 51, and screw holes are also provided on the periphery of the suspension pressing head 6. When the suspension pressing head 6 is fixed to the pressing head fixing frame 51, the suspension pressing head 6 is placed inside the pressing head fixing frame 51, and the screw holes can be connected by screws. In the above solution, the fixing frame limiting block 52 is fixed to the cover plate 5, and the pressing head fixing frame 51 and the suspension pressing head 6 wrap it and can move appropriately under its limited fixation. This fixing method can greatly stabilize the suspension pressing head 6 during the working process of the suspension pressing head 6, avoid deviation, and avoid excessive movement, which may cause poor working effects.

[0046] In summary, the driving mechanism adopted by the present invention has stable downward pressure, no deviation during the downward pressure process, high downward pressure accuracy and stable pressure, a very small adjustable stroke distance, and is convenient for high-precision adjustment actions. The pressing device provided by the present invention can adaptively adjust according to the pressed surface, the components are wear-resistant, anti-loosening, anti-extrusion, and are convenient for installation and use.

Claims

1. A microfluidic chip pressing device, comprising a driving mechanism and a pressing device connected to the driving mechanism. The pressing device includes a floating cover plate and multiple groups of floating pressing heads arranged on the lower side of the cover plate. The floating cover plate and the floating pressing heads are connected by springs. A pressing head fixing frame, a fixing frame limiting block, and a floating pressing head are sequentially arranged on the lower side of the cover plate. The fixing frame limiting block includes a first table block and a second table block arranged on the lower side of the first table block. The upper side surface of the first table block is fixedly connected to the lower side surface of the cover plate. The pressing head fixing frame is a square frame with openings on both the upper and lower side surfaces. The area of the square opening on the upper side surface of the pressing head fixing frame is larger than the upper surface area of the first table block and smaller than the lower surface area of the second table block, so that the first table block can freely enter and exit the square opening on the upper side surface. The area of the opening on the lower side surface of the pressing head fixing frame is larger than the lower surface area of the second table block. The floating pressing head is fixedly connected to the pressing head fixing frame. A spring sleeving column is arranged on the upper side surface of the floating pressing head. A column accommodating cavity for accommodating the spring sleeving column is arranged on the lower side of the second table block. The spring is arranged on the spring sleeving column. The pressing head fixing frame and the floating pressing head enclose the fixing frame limiting block in the connection space between the two and leave a certain movement space. The driving mechanism includes a bracket, a horizontal movement structure, and a vertical movement structure arranged on the bracket. The cover plate is connected to the bottom end of the vertical movement structure. The bracket includes a left side plate, a right side plate, and a top plate fixing plate arranged between the left side plate and the right side plate. The horizontal movement structure includes a lead screw transmission assembly. The lead screw transmission assembly includes a lead screw and a rotating block. One end of the lead screw is connected to the output end of the driving motor, and the other end passes through and is rotatably fixed on the lead screw fixing plate. The lead screw fixing plate is arranged between the left side plate and the right side plate and is parallel to the two. The left side plate includes a first vertical portion. A first horizontal portion is arranged at the upper end of the first vertical portion. A first threaded hole is arranged on the first horizontal portion. A through hole is arranged on the upper end of the first vertical portion near the lower side of the first horizontal portion. The through hole includes multiple rows of through holes and a vertical long strip through hole. The diameter of the through hole is smaller than the bolt head and larger than the bolt rod. Second threaded holes are arranged on the end faces at both ends of the top plate fixing plate. The bolt passes through the through hole and cooperates with the second threaded hole to complete the fixation. The rotating block is sleeved on the lead screw. The rotating block is fixedly connected to the first connecting block. A roller is arranged at the upper end of the first connecting block. The roller is in contact with the lower side surface of the top plate fixing plate. Limiting plates are respectively arranged on both sides of the first connecting block. The limiting plates are respectively in contact with or slidably connected to the front and rear sides of the first connecting block. The two ends of the limiting plate are respectively fixed on the driving motor housing and the lead screw fixing plate. The lower end of the first connecting block is rotatably connected to a second connecting block. The lower end of the second connecting block is rotatably provided with the cover plate. The vertical movement structure includes a third connecting block fixed to the lower side of the top plate fixing plate and a fourth connecting block slidably connected to the third connecting block. The fourth connecting block is fixedly connected to the cover plate.

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