Pneumatically Actuated Micro Gripper

Abstract

The present invention discloses a pneumatically driven micro-gripper, comprising: a base; an airbag mechanism, the airbag mechanism is arranged on the base and is connected with the base, the airbag mechanism comprises at least one airbag; a clamping mechanism, the clamping mechanism comprises two clamping arms relatively arranged on the base, the airbag mechanism is located between the two clamping arms, the two clamping arms are respectively connected to the two opposite outer side walls of the airbag mechanism, and when the airbag mechanism is inflated or deflated, the airbag mechanism drives the two clamping arms to open or close. The pneumatically driven micro-gripper of the present invention utilizes high-precision micro-nano 3D printing technology, and adopts pneumatic expansion of the airbag to drive the clamping arms connected to both sides of the airbag to open, and has the advantages of simple, compact and miniaturized structure, large output force, high power density, large opening and closing amount, and the opening and closing amount resolution can reach sub-micron; it adopts pneumatic drive, has good applicability to biological environments and can be used in liquid environments, realizing fine operation of biological microstructures.

Description

Technical Field

[0001] The present invention relates to the field of micro-operation technology, and in particular to a pneumatically driven micro-gripper. Background Art

[0002] The rapid development of biological sciences has led to an increasing demand for manipulating entities at the micro- and nanoscale. In general, the manipulation of biological objects, such as single cells, embryos, etc., can be divided into contact and non-contact techniques. Non-contact techniques are mainly based on optics, in which highly focused laser beams are used to capture and move microorganisms, but this technology requires complex and expensive optical settings, and exposure to optical radiation may have long-term negative effects on the manipulated micro-objects. Micropipettes and grippers are the most commonly used contact techniques for manipulating microorganisms. Pipettes manipulate single cells through negative pressure applied by the nozzle. The control of negative pressure depends on the experience and proficiency of the operator. The operation process often cannot be carried out smoothly, the operation efficiency is low, it is difficult to limit the deformation of the cell, and the operation accuracy is low. In addition, the versatility of the pipette is limited. If the cell is smaller than the opening of the pipette nozzle, several cells may be sucked into the pipette instead of isolating only one.

[0003] The microgripper is the interface between the microgripper system and the object being gripped, and its performance will greatly affect the actual working efficiency of the micro-electromechanical system (MEMS). According to the different driving modes of the microgripper, it can be divided into electrostatically driven microgrippers, shape memory alloy driven microgrippers, piezoelectrically driven microgrippers, electrothermal driven microgrippers, electromagnetically driven microgrippers and fluid-driven microgrippers. Electrostatic drive produces satisfactory output force, but it is difficult to operate in ion-rich liquids. Although shape memory alloy drive produces high force and displacement, it is problematic in liquid environments due to heat loss associated with the high surface-to-volume ratio of microdevices, which may damage the biological environment. Moreover, the displacement of shape memory alloys is difficult to control due to their thermomechanical nonlinearity. Piezoelectric drive provides high speed and good motion resolution, but the displacement output is limited and the required applied voltage can damage the biological system. Electrothermal drive can provide large output force, but the jaw temperature is easily affected by the drive, thus affecting the biological environment. Electromagnetically actuated microgrippers have low output forces due to the unfavorable structure of the magnetic field, and their performance is also limited by the possibility of heat dissipation and leakage current from conductive materials. In addition, electromagnetic fields may have a disturbing effect on the very weak electrophysiological signals (in the picoampere range) from cells and organoids. Summary of the invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a pneumatically driven micro-gripper.

[0005] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0006] A pneumatically driven micro gripper, comprising:

[0007] Base;

[0008] An airbag mechanism, the airbag mechanism is disposed on the base and communicated with the base, and the airbag mechanism includes at least one airbag;

[0009] The clamping mechanism comprises two clamping arms arranged opposite to each other on the base, the airbag mechanism is located between the two clamping arms, the two clamping arms are respectively connected to two opposite outer side walls of the airbag mechanism, and when the airbag mechanism is inflated or deflated, the airbag mechanism drives the two clamping arms to open or close.

[0010] As a further improvement of the present invention, the airbag mechanism includes three airbags, which are arranged in parallel and interconnected, and the outer side walls of the two outermost airbags are respectively connected to the two clamping arms.

[0011] As a further improvement of the present invention, the smaller the wall thickness of the airbag is, the larger the distance between the two opposite inner walls of the airbag and the distance between adjacent airbags are.

[0012] As a further improvement of the present invention, the wall thickness of the airbag is 15-25 μm, the distance between two opposite inner walls of the airbag is 65-110 μm, and the distance between adjacent airbags is 65-90 μm.

[0013] As a further improvement of the present invention, adjacent airbags are connected with a transition portion, and the transition portion extends to the base.

[0014] As a further improvement of the present invention, the clamping arm includes two clamping arm bodies and a clamping claw connected to the top ends of the two clamping arm bodies, and a notch is formed on the clamping claw.

[0015] As a further improvement of the present invention, the cross section of the airbag is rectangular.

[0016] As a further improvement of the present invention, a recessed portion is provided at the center of the end of the clamping arm, and at least one through slot is provided at the end of the clamping arm, and the through slot is communicated with the recessed portion.

[0017] As a further improvement of the present invention, an air passage, a reduced diameter hole and a mounting hole which are connected in sequence are arranged in the base, and the air passage is connected to the airbag mechanism.

[0018] As a further improvement of the present invention, a flexible hinge is connected between each of the clamping arms and the base.

[0019] The beneficial effects of the present invention are:

[0020] (1) The structure of the pneumatically driven micro-gripper of the present invention can be well utilized for printing by high-precision micro-nano 3D printing technology. The overall size is about millimeters, and the structure is very simple, compact and small, which solves the disadvantage that the structure of the gripper of this driving mode is complex and difficult to miniaturize.

[0021] (2) Through structural layout, multiple problems such as adhesion, airbag failure, clamping arm breakage, and airway closure that occur during the printing process can be avoided, and the printing yield rate is high.

[0022] (3) The airbag is pneumatically inflated to drive the clamping arm to open, which is flexible and convenient to use and has the advantages of large output force, large driving displacement, high power density, and high resolution of opening and closing volume.

[0023] (4) It adopts pneumatic drive, has good applicability to biological environments and can be used in liquid environments, and has very broad application prospects.

[0024] (5) It can achieve a large limit of opening and closing under small size, and the opening and closing resolution can reach sub-micron, with high clamping accuracy. The clamping object is about micron and the clamping force reaches 14mN, which can realize fine operation of biological microstructures.

[0025] (6) It has important theoretical significance and academic value for improving the overall research level in the field of micro-manipulation, broadening the application scenarios of micro-manipulation, and promoting interdisciplinary development. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of a preferred embodiment 1 of the present invention;

[0028] Figure 2 It is a front view of a preferred embodiment 1 of the present invention;

[0029] Figure 3 It is a side view of a preferred embodiment 1 of the present invention;

[0030] Figure 4 A vertical cross-sectional view of a preferred embodiment 1 of the present invention;

[0031] Figure 5 It is a transverse cross-sectional view of a preferred embodiment 1 of the present invention;

[0032] Figure 6 It is a schematic structural diagram of the end of the clamping arm of the preferred embodiment 1 of the present invention;

[0033] Figure 7 This is a schematic structural diagram of the two clamping arms of the preferred embodiment 1 of the present invention being opened;

[0034] Figure 8 This is a simulation diagram of the overall deformation of the single-sided clamping arm of the preferred embodiment 1 of the present invention;

[0035] Fig. 9 This is a deformation simulation diagram along the X-axis of the preferred embodiment 1 of the present invention;

[0036] Fig.10 This is a simulation diagram of equivalent elastic strain of the first preferred embodiment of the present invention;

[0037] Fig.11 This is an equivalent stress simulation diagram of the preferred embodiment 1 of the present invention;

[0038] Fig.12 It is a structural schematic diagram of a preferred embodiment 2 of the present invention;

[0039] In the figure: 1. base, 11. airway, 12. reduced diameter hole, 13. mounting hole, 14. groove, 2. airbag, 3. clamping arm, 31. first inclined arm, 32. second inclined arm, 33. straight arm, 34. fourth inclined arm, 35. recessed portion, 36. through groove, 301. clamping arm body, 302. clamping claw, 303. notch, 4. transition portion, 5. first flexible hinge, 6. second flexible hinge. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] See also Figure 1-Figure 5 , the embodiment of the present application discloses a pneumatically driven micro-gripper, comprising: a base 1;

[0042] An airbag mechanism, the airbag mechanism is disposed on the base 1 and is connected to the base 1, and the airbag mechanism includes at least one airbag 2;

[0043] The clamping mechanism includes two clamping arms 3 arranged relatively on the base 1, the airbag mechanism is located between the two clamping arms 3, and the two clamping arms 3 are respectively connected to the two opposite outer side walls of the airbag mechanism. When the airbag mechanism is inflated or deflated, the airbag mechanism drives the two clamping arms 3 to open or close.

[0044] Preferably, the airbag mechanism includes three airbags 2, which are arranged in parallel and interconnected, and the outer side walls of the two outermost airbags 2 are respectively connected to the two clamping arms 3, so that the volume and opening and closing amount of the micro-clamp are optimized.

[0045] Specifically, the clamping arm 3 includes a first inclined arm 31, a second inclined arm 32, a vertical arm 33 and a fourth inclined arm 34 which are connected in sequence. The first inclined arm 31 is connected to the base 1 and is inclined outwardly relative to the airbag 2. The second inclined arm 32 and the fourth inclined arm 34 are both inclined inwardly relative to the airbag 2. An outwardly protruding V-shape is formed between the first inclined arm 31 and the second inclined arm 32, so that a containing space is formed between the first inclined arm 31 and the second inclined arm 32, so as to avoid the clamping arm 3 blocking the airbag 2 when the airbag 2 is expanded, and ensure the expansion and deformation of the airbag 2.

[0046] The smaller the wall thickness d1 of the airbag 2 is, the larger the distance d2 between the two opposite inner walls of the airbag 2 and the distance d3 between adjacent airbags 2 are, so as to avoid adhesion during printing and ensure the printing yield.

[0047] The wall thickness d1 of the airbag 2 is preferably 15-25 μm, the spacing d2 between the two opposite inner walls of the airbag 2 is 65-110 μm, and the spacing d3 between adjacent airbags 2 is 65-90 μm, which can avoid the airbag 2 from rupturing, ensure that the airbag 2 can be printed and formed, improve the yield rate, and ensure that the airbag 2 has a large deformation so that the driving stroke is large. In order to ensure the stable deformation and large deformation of the airbag 2, the wall thickness of the airbag 2 is preferably 20 μm. In order to better avoid the adhesion between the two opposite inner walls of the airbag 2 and ensure the compactness of the structure between the airbags 2, the spacing between the two opposite inner walls of the airbag 2 is preferably 100 μm, and the spacing between adjacent airbags 2 is 90 μm.

[0048] Preferably, the cross section of the airbag 2 is rectangular, which increases the deformation of the airbag 2 and thus increases the driving stroke of the airbag 2 .

[0049] Preferably, adjacent airbags 2 are connected with transition portions 4 , which extend to the base 1 , so that airflow can flow quickly between adjacent airbags 2 while ensuring deformation of the airbags 2 .

[0050] In order to facilitate the deformation of the airbag 2 to drive the clamping arm 3 to move, a first flexible hinge 5 is preferably connected between the outer wall of the airbag 2 and the clamping arm 3. Specifically, the first flexible hinge 5 is connected to the connection between the second inclined arm 32 and the vertical arm 33, so as to improve the smoothness and rapidity of the deformation of the airbag 2 to drive the clamping arm 3 to move.

[0051] See also Figure 6 In order to facilitate the clamping operation of cells in the solution, it is preferred that a recessed portion 35 is provided at the center of the end of the clamping arm 3, and at least one through slot 36 is provided at the end of the clamping arm 3, and the through slot 36 is connected to the recessed portion 35. In this way, the cells are accommodated in the recessed portion 35 during clamping, and the solution can leak from the through slot 36, thereby improving the stability of the clamped cells. Specifically, the number of through slots 36 is two. It is further preferred that the recessed portion 35 is in an arc shape, which is convenient for matching with the cell shape and further improving the stability of clamping.

[0052] In order to facilitate ventilation, the base 1 is preferably provided with an airway 11, a reduced diameter hole 12 and a mounting hole 13 which are connected in sequence, and the airway 11 is connected to the airbag mechanism. The mounting hole 13 is used for inserting the trachea to assemble the trachea, and the setting of the reduced diameter hole 12 can pre-tighten the inserted trachea to avoid the glue flowing into the airway 11 and blocking the airway 11 when the glue is used to fix the trachea, thereby ensuring the smoothness of ventilation. Specifically, the airway 11 faces the inner cavity of the airbag 2 located in the middle, so that the airflow can quickly enter the two airbags 2 located on the outside.

[0053] The upper cross-section of the base 1 is hexagonal, and a groove 14 is formed on the upper side wall of the base 1. When assembling the air pipe, the base 1 can be clamped at multiple angles, which is convenient for assembly. The lower part of the base 1 is cylindrical.

[0054] In order to facilitate the movement of the clamping arm 3 , preferably a second flexible hinge 6 is connected between each clamping arm 3 and the base 1 .

[0055] The micro-gripper of this embodiment is printed by a micro-nano 3D printer based on sub-pixel scanning technology (SMS) and light-curing initiation principle. Preferably, a micro-nano 3D printer of the MP series of Prismlab is used, and the model may be MP-36-3L or MP-200-17DL. The parameters of the 3D printers of the MP-36-3L and MP-200-17DL models are shown in Table 1. Preferably, the MP-36-3L model is used, with a printing accuracy of 3.2 μm and a printing resolution of 1.6 μm, which improves the printing quality and yield rate.

[0056] Table 1 Parameters of micro-nano 3D printer

[0057]

[0058] In order for the microgripper to be used in biological operations and to provide sufficient deformation to drive the clamping arm 3 to open without rupturing the airbag 2, it is necessary to select the molding material. The material needs to be biocompatible and have a low elastic modulus. The preferred materials are shown in Table 2.

[0059] Table 2 Selected material parameters

[0060]

[0061] The micro-gripper of this embodiment has a length L of 1.8 mm, a width W of 1.8 mm, a height H1 of 2.86 mm, and a height H2 of 4.17 mm.

[0062] When in use, when the amount of opening and closing of the two clamping arms 3 in the natural state is greater than or equal to the size of the clamped object, stable clamping is achieved by generating negative pressure in the airbag 2; if the amount of opening and closing of the two clamping arms 3 in the natural state is less than the size of the clamped object, clamping is achieved by generating positive pressure in the airbag 2. The air pressure control in the airbag 2 can be connected to the trachea using a syringe, and the air pressure in the airbag 2 can be changed by pushing and pulling the piston of the syringe. The control accuracy of the opening and closing amount of the clamping arms 3 can reach 1μm, but it is not limited to this method, and other control structures that can change the air pressure in the airbag 2 are also possible.

[0063] The airbag 2 of the micro-gripper is expanded so that the two clamping arms 3 are opened. Figure 7 The micro-gripper of this embodiment is simulated below, and the simulation results are all based on the results obtained under the pressure drive of one atmosphere. The simulation diagram is shown in Figure 8-Figure 11 In practical applications, when the driving pressure is greater than one atmosphere, the amount of opening and closing will also increase. Experiments have shown that the amount of opening and closing of the micro-gripper can reach 1 mm at this size.

[0064] Figure 8 It reflects the total deformation of the single-sided clamping arm 3, and the maximum deformation is 193.66 μm. Fig. 9 It reflects that the maximum deformation along the X-axis is 192.81 μm. Fig.10 It reflects that the maximum equivalent elastic strain is 0.039. When the tension is large enough, that is, Figure 8 and Fig. 9 When the maximum value of is large enough, the airbag 2 will not rupture. Fig.11 This reflects that the maximum equivalent stress is 94 MPa, and the airbag 2 will not rupture.

[0065] Embodiment 2

[0066] The difference between the first embodiment and the second embodiment is that:

[0067] See also Fig.12 The clamping arm 3 includes two clamping arm bodies 301, and a clamping claw 302 connected to the top of the two clamping arm bodies 301. A notch 303 is provided on the clamping claw 302. The notch 303 can reduce the weight of the clamping arm 3 and facilitate the movement of the clamping arm 3. The two clamping arms 301 can increase the clamping width of the clamping arm 3, facilitate the clamping of a long workpiece, and clamp stably. A second flexible hinge 6 is connected between each clamping arm body 301 and the base 1.

[0068] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0069] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A pneumatically driven micro gripper, characterized in that: Printed using micro-nano 3D printing technology, including: Base; An airbag mechanism, the airbag mechanism is disposed on the base and communicated with the base, and the airbag mechanism includes at least one airbag; The clamping mechanism comprises two clamping arms which are arranged relatively on the base, the airbag mechanism is located between the two clamping arms, the two clamping arms are respectively connected to the two opposite outer side walls of the airbag mechanism, a first flexible hinge is connected between the outer side wall of the airbag and the clamping arm, a recess is arranged at the center of the end of the clamping arm, at least one through groove is opened at the end of the clamping arm, the through groove is connected to the recess, a second flexible hinge is connected between each clamping arm and the base, and when the airbag mechanism is inflated or deflated, the airbag mechanism drives the two clamping arms to open or close.

2. The pneumatically driven micro-gripper according to claim 1, characterized in that: The airbag mechanism comprises three airbags, which are arranged in parallel and connected to each other, and the outer side walls of the two outermost airbags are respectively connected to the two clamping arms.

3. The pneumatically driven micro-gripper according to claim 2, characterized in that: The smaller the wall thickness of the airbag is, the larger the distance between the two opposite inner side walls of the airbag and the distance between adjacent airbags are.

4. The pneumatically driven micro-gripper according to claim 3, characterized in that: The wall thickness of the airbag is 15-25 μm, the distance between two opposite inner walls of the airbag is 65-110 μm, and the distance between adjacent airbags is 65-90 μm.

5. The pneumatically driven micro-gripper according to claim 2, characterized in that: A transition portion is connected between adjacent airbags, and the transition portion extends to the base.

6. The pneumatically driven micro-gripper according to claim 2, characterized in that: The clamping arm comprises two clamping arm bodies and clamping claws connected to the top ends of the two clamping arm bodies, and a notch is provided on the clamping claws.

7. The pneumatically driven micro-gripper according to claim 1 or 2, characterized in that: The cross section of the airbag is rectangular.

8. The pneumatically driven micro-gripper according to claim 1 or 2, characterized in that: An air passage, a reduced diameter hole and a mounting hole which are connected in sequence are arranged in the base, and the air passage is connected to the airbag mechanism.

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