MEMS (Micro Electro Mechanical System) micro clamp for micromanipulation

Abstract

The MEMS micro clamp for micromanipulation comprises a jaw and a driving module, the driving module comprises driving comb teeth and a camber beam, the driving comb teeth are used for deflecting according to the difference value of input first voltage and second voltage and driving the camber beam to drive a left clamp arm to move in the direction close to a right clamp arm or away from the right clamp arm according to the difference value, and the driving comb teeth are used for driving the camber beam to move in the direction close to the right clamp arm or away from the right clamp arm. Clamping or releasing of the micro-nano object is completed; according to the technical scheme, clamping or releasing of the micro-nano object can be achieved through low voltage, the problem that too high voltage needs to be used for achieving the large stroke of the jaw is avoided, and the micro clamp is endowed with the capacity of clamping objects of multiple sizes.

Description

Technical Field

[0001] The present application belongs to the field of micro-clamps, and in particular relates to a MEMS micro-clamp for micromanipulation. Background Art

[0002] With the rapid development of science and technology, human beings have gradually deepened their exploration of the microscopic world. Along with the in-depth exploration of the microscopic world, there are also a large number of related needs, especially in the operation and measurement of microscopic objects. To meet the relevant needs, different micromanipulation tools are constantly being developed and produced, and microgrippers are one of them. Microgrippers are usually used for picking up and placing biological targets of different sizes, such as biological tissues of various sizes, multicellular aggregates, single cells, etc. Microgrippers have a large number of applications in related microassembly fields due to their ability to perform flexible and high-precision operations in the microscopic field.

[0003] Micro-grippers have different production and driving methods depending on the application field and operation requirements. Micro-grippers produced using macro manufacturing methods, such as high-precision wire spark cutting and high-precision 3D printing, have short production cycles and low production costs. However, these micro-grippers are mostly made of various alloys, have a relatively large overall volume, and have low integration between different functional modules. They are not suitable for high-precision micro-force sensors and are currently difficult to apply to fragile application objects, especially biological targets, which reduces their scope of application. Another type of micro-gripper has greatly benefited from the progress of microelectronic production process technology. Microelectronic technology provides methods for manufacturing micro-components and micro-mechanical structures, such as using photolithography and thin film deposition technology. This type of micro-gripper has a long production cycle, high cost, high process requirements, and high requirements for structural design, but the overall size can be reduced to about a few millimeters, the operating resolution can reach the micron or even nanometer level, the entire system structure is almost integrated, and extremely high-precision force sensors can be integrated. The application range is very wide, but this type of micro-gripper wants to achieve a larger stroke of the jaw displacement, which depends to a large extent on the level of the driving voltage. However, the use of excessively high voltage will bring greater experimental risks and have an adverse effect on the long-term use of the device itself, increasing the cost of equipment use; more importantly, the use of high voltage has a great impact on the production process of the device, especially the growth thickness of the electrode; in addition, the clamping force of most micro-grippers depends on the theoretical calculation of the mechanical structure or cannot integrate high-precision force sensors, and lacks real-time and accurate force measurement and monitoring, resulting in the inability to clamp or non-destructive clamping for some soft and fragile objects. Summary of the invention

[0004] In order to solve the problem that the micro-gripper in the prior art cannot perform non-destructive gripping of soft and fragile objects, a MEMS micro-gripper for micromanipulation is proposed;

[0005] A MEMS micro-gripper for micromanipulation, comprising: a jaw and a driving module;

[0006] The jaws include a left jaw arm and a right jaw arm, and the driving module includes a driving comb tooth and a curved beam. One end of the curved beam is connected to the left jaw arm, and the driving comb tooth is used to deflect according to the difference between the first input voltage and the second input voltage, and drive the curved beam according to the difference to drive the left jaw arm to move toward or away from the right jaw arm; the curved beam is arc-shaped, and the driving comb tooth is fan-shaped. The arc-shaped side of the driving comb tooth is inscribed in the inner arc of the curved beam and is connected to the curved beam.

[0007] Beneficial Effects

[0008] A MEMS micro-gripper for micromanipulation of the present application can realize the clamping of a series of micro-nano objects, including but not limited to microbeads, human hair, cells and cell aggregates; compared with other related micro-grippers, the MEMS micro-gripper for micromanipulation of the present application can realize the clamping of micro-nano objects with extremely low voltage, avoiding the problem of using excessively high voltage to achieve a larger stroke, thereby reducing the requirements for process production, especially reducing the requirements for the thickness of the electrode grown on the device layer; the micro-gripper of the present application can provide the operator with real-time force measurement during the clamping process, thereby realizing accurate non-destructive clamping and measurement of the mechanical properties of the sample; it is suitable for large-scale industrial production and reduces manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A structural diagram of a MEMS micro-fixture for micromanipulation according to a specific embodiment of the present application;

[0010] Figure 2 This is a diagram of the drive comb structure of a specific implementation method of this application;

[0011] Figure 3 A schematic diagram of comb teeth of fixed comb teeth and movable comb teeth according to a specific embodiment of the present application;

[0012] Figure 4 It is a partial enlarged view of the comb teeth of the fixed comb teeth and the movable comb teeth according to the specific implementation mode of the present application;

[0013] Figure 5 This is an enlarged view of the connection between the right clamp arm and the crossbeam of the specific implementation method of the present application;

[0014] Figure 6 A schematic diagram of a curved beam according to a specific embodiment of the present application;

[0015] Figure 7 The present invention is a flowchart of a MEMS micro-fixture for micromanipulation according to a specific embodiment of the present application. DETAILED DESCRIPTION

[0016] The following will be combined Figures 1 to 6 , describing the present embodiment,

[0017] A MEMS micro-gripper for micromanipulation, comprising: a jaw and a driving module;

[0018] The jaws include a left arm 1 and a right arm 2, and the driving module includes a driving comb tooth 3 and a curved beam 13. One end of the curved beam 13 is connected to the left arm 1, and the driving comb tooth 3 is used to deflect according to the difference between the first input voltage and the second input voltage, and drive the curved beam according to the difference to drive the left arm 1 to move toward or away from the right arm 2; the curved beam 13 is arc-shaped, and the driving comb tooth 3 is fan-shaped. The arc side of the driving comb tooth 3 is inscribed in the inner arc of the curved beam 13 and is connected to the curved beam 13.

[0019] Specifically, when the jaws are not driven, the left jaw arm 1 and the right jaw arm 2 will be spaced a certain distance apart. When driven, the driving comb teeth will shift according to the difference between the first voltage and the second voltage. By changing the difference between the positive voltage inputs of the first voltage and the second voltage, the offset angle of the driving comb teeth can be controlled, so that the driving comb teeth drive the left jaw arm 1 to move toward the right jaw arm 2 through the bent beam to complete the clamping action, and the driving comb teeth drive the left jaw arm 1 to move away from the right jaw arm 2 through the bent beam to complete the release action, thereby adapting to different target sizes and ultimately realizing the functions of clamping and releasing. A MEMS micro-gripper for micromanipulation in the present application can achieve a larger jaw displacement at a relatively low voltage, thereby avoiding a series of problems caused by excessively high driving voltage in some existing micro-grippers.

[0020] Further, a MEMS micro-fixture for micromanipulation also includes a sensing module and a monitoring module;

[0021] The sensing module includes a cantilever structure, a first comb tooth capacitor and a second comb tooth capacitor. The right clamp arm 2 is connected to the first comb tooth capacitor and the second comb tooth capacitor through the cantilever structure. When the right clamp arm is deformed by force, the comb tooth spacing of the first comb tooth capacitor and the second comb tooth capacitor changes, thereby changing the first comb tooth capacitance value and the second comb tooth capacitance value. The monitoring module is used to obtain the changed first comb tooth capacitance value and the second comb tooth capacitance value, and obtain the force value of the right clamp arm 2 based on the first comb tooth capacitance value and the second comb tooth capacitance value.

[0022] Specifically, deformation of the right pliers arm 2 will cause the first comb-tooth capacitance value and the second comb-tooth capacitance value to change, and the monitoring device can complete the force monitoring of the right pliers arm 2 according to the first capacitance value and the second capacitance value.

[0023] Furthermore, the sensing module further includes a third sensing unit 12, the cantilever structure includes a cross beam 6 and a plurality of cantilever beams; the first comb-tooth capacitor includes a first movable comb tooth, a first fixed comb tooth, and a first sensing unit 10; the second comb-tooth capacitor includes a second movable comb tooth, a second fixed comb tooth, and a second sensing unit 11;

[0024] The right clamp arm 2 is connected to the crossbeam 6, the upper side of the crossbeam 6 is connected to two cantilever beams and the first movable comb teeth, and the two cantilever beams on the upper side of the crossbeam are arranged on the left and right sides of the first movable comb teeth; the lower side of the crossbeam is connected to the two cantilever beams and the second movable comb teeth, and the two cantilever beams on the lower side of the crossbeam are arranged on the left and right sides of the second movable comb teeth; the comb teeth of the first fixed comb teeth and the first movable comb teeth are arranged in parallel and staggered, and the comb teeth of the second fixed comb teeth and the second movable comb teeth are arranged in parallel and staggered; the first movable comb teeth and the second movable comb teeth are respectively connected to the third sensing unit 12, the first fixed comb teeth are connected to the first sensing unit 10, and the second fixed comb teeth are connected to the second sensing unit 11;

[0025] When the right clamp arm is deformed by force, the crossbeam 6 and the first movable comb teeth and the second movable comb teeth connected to the crossbeam are displaced, causing the comb tooth spacing of the first comb tooth capacitor and the second comb tooth capacitor to change, thereby changing the first capacitance value of the first comb tooth capacitor and the second capacitance value of the second comb tooth capacitor.

[0026] Specifically, when the right clamp arm 2 is deformed, the crossbeam connected to the right clamp arm is displaced, and the movement of the right clamp arm will drive the four cantilever beams (attached Figure 3 7-1, 7-2, 7-3 and 7-4), the positions of the first movable comb teeth and the second movable comb teeth change; Figure 4 As shown, since the first fixed comb teeth and the second fixed comb teeth are arranged parallel and staggered with the comb teeth of the first movable comb teeth and the second movable comb teeth respectively, when the positions of the first movable comb teeth and the second movable comb teeth change, the distance d1 between the two adjacent comb teeth of the first fixed comb teeth and the first movable comb teeth and the distance d2 between the two adjacent comb teeth of the second fixed comb teeth and the second movable comb teeth change; the first sensing unit 10 and the third sensing unit 12 are connected, the first fixed comb teeth are connected to the first sensing unit 10, and the second fixed comb teeth are connected to the second sensing unit 11; the first sensing unit 10, the first fixed comb teeth and the first movable comb teeth form a first comb teeth capacitor, and the second sensing unit 11, the second fixed comb teeth and the second movable comb teeth form a second comb teeth capacitor; the change of the distance d1 and the distance d2 will change the first comb teeth capacitance value and the second comb teeth capacitance value.

[0027] Furthermore, the driving module also includes a first voltage input unit 4 and a second voltage input unit 5, and the driving comb teeth include an upper comb tooth 3-1, a lower comb tooth 3-2 and a middle comb tooth 3-3; the upper comb tooth 3-1 is connected to the second voltage input unit 5 for receiving a second voltage; the lower comb tooth 3-2 is connected to the first voltage input unit 4 for receiving a first voltage; the upper comb tooth 3-1 is arranged on one side of the middle comb tooth 3-3, and the lower comb tooth 3-2 is arranged on the other side of the middle comb tooth 3-3, and the upper comb tooth 3-1 and the lower comb tooth 3-2 are respectively arranged alternately with the comb teeth of the middle comb tooth 3-3; the upper comb tooth 3-1 and the lower comb tooth 3-2 are used to generate an electrostatic force according to the difference between the first voltage and the second voltage, and the middle comb tooth 3-3 is deflected according to the generated electrostatic force, and the middle comb tooth 3-3 is fixedly connected to the bending beam 13.

[0028] Furthermore, the driving module also includes a straight beam 14, one end of which is connected to the curved beam 13, and the straight beam 14 is fixed to the middle of the middle comb teeth 3-3, and is driven by the middle comb teeth 3-3 to perform the same deflection around the other end.

[0029] Furthermore, the driving module further includes a first protection circuit 8 and a second protection circuit 9;

[0030] The other end of the straight beam 14 is connected to the positive electrode of the second protection circuit 9, the right clamp arm 2 is connected to the positive electrode of the first protection circuit 8, and the negative electrodes of the second protection circuit 9 and the first protection circuit 8 are connected to the ground wire at the same time.

[0031] Furthermore, the first voltage and the second voltage are in the range of 50V to 100V; the first capacitance value and the second capacitance value are in the range of 5pF to 8pF; and the difference between the first capacitance value and the second capacitance value is in the range of 10fF to 100fF.

[0032] Specifically, the displacement of the middle beam is generally tens to hundreds of nanometers, which is much smaller than the spacing of the teeth of the comb. Therefore, the first capacitance value and the second capacitance value are several picofarads when they are stationary, and the change in the first capacitance value and the second capacitance value is expected to be hundreds or even tens of picofarads.

[0033] Furthermore, the thickness and the inter-comb tooth spacing of the upper comb teeth 3 - 1 , the lower comb teeth 3 - 2 and the middle comb teeth 3 - 3 are the same.

[0034] Furthermore, the first voltage input unit 4, the second voltage input unit 5, the second protection circuit 9, the first protection circuit 8, the first sensing unit 10, the second sensing unit 11 and the third sensing unit 12 are made of metal aluminum; the jaws, the driving comb teeth, the cantilever structure, the movable comb teeth and the fixed comb teeth are made of doped silicon material.

[0035] Specifically, the first voltage input unit 4, the second voltage input unit 5, the second protection circuit 9, the first protection circuit 8, the first sensing unit 10, the second sensing unit 11 and the third sensing unit 12 are electrode layers with aluminum as the main metal, a growth thickness of about 500 nanometers, and are responsible for the input and output of the working voltage.

[0036] Furthermore, the distance over which the beam 6 is displaced is in the range of 10 nm to 1000 nm.

[0037] Combination Figure 7 The present invention provides a method for manufacturing a MEMS micro-fixture for micromanipulation, comprising:

[0038] Step 1: Select a doped silicon wafer as a raw material for the micro-jig. The doped silicon wafer comprises a device layer, a sacrificial layer and a silicon substrate layer from top to bottom. The silicon substrate layer comprises a shallow silicon substrate layer and a deep silicon substrate layer. The shallow silicon substrate layer is located above the deep silicon substrate layer.

[0039] Step 2: Depositing a silicon dioxide layer on the bottom of the doped silicon wafer;

[0040] Step 3: Patterning the bottom silicon dioxide layer using reactive ion etching technology;

[0041] Step 4: etching the deep silicon substrate layer using deep reactive ion etching technology, and after the deep silicon substrate layer is etched, the silicon dioxide layer is removed at the same time;

[0042] Step 5: After the deep silicon substrate layer is etched, the shallow silicon substrate layer is etched to achieve a height difference;

[0043] Step 6: Etching the sacrificial layer using reactive ion etching technology;

[0044] Step 7: After the sacrificial layer is etched, an electrode layer of a certain thickness is set above the device layer, and a support wafer is bonded to the bottom of the deep silicon substrate layer;

[0045] Step 8: Etch the device layer through deep reactive ion etching technology, and etch the boundary around the micro-jig to release the micro-jig on the supporting wafer.

[0046] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A MEMS micro-chuck for micromanipulation, characterized in that: include: Jaw and drive module; The jaws include a left clamp arm 1 and a right clamp arm, and the driving module includes a driving comb tooth and a curved beam. One end of the curved beam is connected to the left clamp arm, and the driving comb tooth is used to deflect according to the difference between the first input voltage and the second input voltage, and drive the curved beam to drive the left clamp arm to move toward or away from the right clamp arm according to the difference; the curved beam is arc-shaped, and the driving comb tooth is fan-shaped. The arc side of the driving comb tooth is inscribed in the inner arc of the curved beam and is connected to the curved beam.

2. A MEMS micro-chuck for micromanipulation according to claim 1, characterized in that: It also includes a sensing module and a monitoring module; The sensing module includes a cantilever structure, a first comb-tooth capacitor and a second comb-tooth capacitor, and the right clamp arm is connected to the first comb-tooth capacitor and the second comb-tooth capacitor through the cantilever structure; when the right clamp arm is deformed by force, the comb-tooth spacing of the first comb-tooth capacitor and the second comb-tooth capacitor changes, thereby changing the capacitance value of the first comb-tooth capacitor and the second comb-tooth capacitor; The monitoring module is used to obtain the changed first comb tooth capacitance value and the second comb tooth capacitance value, and obtain the force value of the right clamp arm according to the first comb tooth capacitance value and the second comb tooth capacitance value.

3. A MEMS micro-chuck for micromanipulation according to claim 2, characterized in that: The sensing module further includes a third sensing unit, the cantilever structure includes a crossbeam and a plurality of cantilever beams; the first comb-tooth capacitor includes a first movable comb tooth, a first fixed comb tooth and a first sensing unit; the second comb-tooth capacitor includes a second movable comb tooth, a second fixed comb tooth and a second sensing unit; The right clamp arm is connected to the crossbeam, and the upper side of the crossbeam is connected to the first movable comb teeth through two cantilever beams, and the two cantilever beams on the upper side of the crossbeam are arranged on the left and right sides of the first movable comb teeth; the lower side of the crossbeam is connected to the second movable comb teeth through two cantilever beams, and the two cantilever beams on the lower side of the crossbeam are arranged on the left and right sides of the second movable comb teeth; the comb teeth of the first fixed comb teeth and the first movable comb teeth are arranged in parallel and staggered, and the comb teeth of the second fixed comb teeth and the second movable comb teeth are arranged in parallel and staggered; the first movable comb teeth and the second movable comb teeth are respectively connected to the third sensing unit, the first fixed comb teeth are connected to the first sensing unit, and the second fixed comb teeth are connected to the second sensing unit.

4. A MEMS micro-chuck for micromanipulation according to claim 1, characterized in that: The driving module also includes a first voltage input unit and a second voltage input unit, and the driving comb teeth include upper comb teeth, lower comb teeth and middle comb teeth; the upper comb teeth are connected to the second voltage input unit for receiving the second voltage; the lower comb teeth are connected to the first voltage input unit for receiving the first voltage; the upper comb teeth are arranged on one side of the middle comb teeth, and the lower comb teeth are arranged on the other side of the middle comb teeth, and the upper comb teeth and the lower comb teeth are respectively arranged alternately with the comb teeth of the middle comb teeth; the upper comb teeth and the lower comb teeth are used to generate electrostatic force according to the difference between the first voltage and the second voltage, the middle comb teeth are deflected according to the generated electrostatic force, and the middle comb teeth are fixedly connected to the bending beam.

5. A MEMS micro-chuck for micromanipulation according to claim 4, characterized in that: The driving module also includes a straight beam, one end of which is connected to the curved beam. The straight beam is fixed at the middle of the middle comb teeth and performs the same deflection around the other end under the drive of the middle comb teeth.

6. A MEMS micro-chuck for micromanipulation according to claim 4, characterized in that: The driving module also includes a first protection circuit and a second protection circuit; The other end of the straight beam is connected to the positive electrode of the second protection circuit, the right clamp arm is connected to the positive electrode of the first protection circuit, and the negative electrodes of the second protection circuit and the first protection circuit are connected to the ground wire at the same time.

7. A MEMS micro-chuck for micromanipulation according to claim 1, characterized in that: The first voltage and the second voltage are in the range of 50V to 100V; the first capacitance value and the second capacitance value are in the range of 5pF to 8pF; and the difference between the first capacitance value and the second capacitance value is in the range of 10fF to 100fF.

8. A MEMS micro-chuck for micromanipulation according to claim 4, characterized in that: The thickness and tooth spacing of the upper, lower and middle comb teeth are the same.

9. A MEMS micro-chuck for micromanipulation according to claim 6, characterized in that: The first voltage input unit, the second voltage input unit, the second protection circuit, the first protection circuit, the first sensing unit, the second sensing unit and the third sensing unit are made of metal aluminum; the jaws, the driving comb teeth, the cantilever structure, the first movable comb teeth, the second movable comb teeth, the first fixed comb teeth and the second fixed comb teeth are made of doped silicon material.

10. A MEMS micro-chuck for micromanipulation according to claim 5, characterized in that: The distance over which the beam is displaced is in the range of 10nm to 1000nm.

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