阅读说明：本技术 一种可复位mems双稳态触发器 (Resettable MEMS bistable trigger ) 是由 张霞 张大成 于 2019-08-30 设计创作，主要内容包括：本发明提出一种可复位MEMS双稳态触发器,属于MEMS制造领域,包括两个固定端、一个触发机构和一个双稳态机构,可实现原始状态和置位状态,以及可重新复位至原始状态。本发明可与集成电路制造工艺兼容,每触发一次就实现一次位置状态的闪动翻转,可用任意能产生位移推力的执行器驱动触发,可与触点结构配合实现物理开关功能。(The invention provides a resettable MEMS bistable trigger, which belongs to the field of MEMS manufacturing and comprises two fixed ends, a trigger mechanism and a bistable mechanism, wherein the trigger mechanism can realize an original state and a set state and can reset to the original state again. The invention can be compatible with the integrated circuit manufacturing process, realizes the flashing turnover of the position state once triggered, can be driven and triggered by any actuator capable of generating displacement thrust, and can be matched with a contact structure to realize the physical switch function.)

1. A resettable MEMS bistable trigger comprising:

each fixed end comprises an anchor end protruding downwards, an elastic supporting beam connected to the inner side of the anchor end and a deformation space area located on the elastic supporting beam, the anchor end is connected with a substrate, and the deformation space area provides deformation space for the elastic supporting beam;

the trigger mechanism is arranged between the two fixed ends and comprises a driving block positioned in the middle and two first rigid connecting rods positioned on two sides of the driving block; one end of each first rigid connecting rod is connected with the driving block through a buffer structure and an elastic structure, the other end of each first rigid connecting rod is connected with the elastic supporting beam corresponding to the fixed end through another elastic structure, and the buffer structure provides a telescopic space between the driving block and the first rigid connecting rod;

the bistable mechanism is arranged between the two fixed ends and comprises an actuating block positioned in the middle and two second rigid connecting rods positioned at two sides of the actuating block; one end of each second rigid connecting rod is connected with the actuating block through an elastic structure, and the other end of each second rigid connecting rod is connected with the elastic supporting beam corresponding to the fixed end through another elastic structure;

the trigger mechanism and the bi-stable mechanism are in a same-direction V shape parallel to the substrate in an original state, when the trigger mechanism is driven by an external force to push the bi-stable mechanism actuating block to move to a critical point passing through an axial acting force of the bi-stable mechanism actuating block, the bi-stable mechanism is in a set state when the bi-stable mechanism is subjected to the action of the elastic supporting beam to generate flickering along the driving direction and stops in the V shape opposite to the original state, and when the external force is removed, the trigger mechanism returns to the original state, and the bi-stable mechanism stays in the set state.

2. The resettable MEMS bistable trigger of claim 1, wherein the deformation volume is a rectangular opening defined between the flexible support beam and the outer anchor, and the flexible support beam intermediate the edges of the trigger mechanism and the bistable mechanism is positioned where the flexible support beam connects the first rigid link and the second rigid link to the flexible support beam.

3. The resettable MEMS bistable trigger of claim 1, wherein the buffer structure is a rectangular frame having a first rigid connecting bar attached to the middle of one side of the rectangular frame and a resilient structure attached to the middle of the opposite side of the rectangular frame; when the driving block is close to the actuating block, the two sides of the rectangular frame deform inwards to realize the extension and contraction between the driving block and the first rigid connecting rod.

4. The resettable MEMS flip-flop of claim 1, wherein the actuating mass has an arrow shape with a protrusion on a side adjacent to the actuating mass that can be urged against the actuating mass by an external force and a recess on a side opposite to the actuating mass.

5. The resettable MEMS flip-flop of claim 1, wherein the actuator block is in the shape of an arrow, the recess being located on a side adjacent the actuator block and being abuttable by the actuator block being forced, the recess providing a pushing force from the actuator block in a line of the arrow, the projection being located on a side away from the actuator block.

6. The resettable MEMS bistable trigger of claim 1, wherein the trigger mechanism is actuatable by an actuation means having an actuation force and displacement.

7. A resettable MEMS flip-flop according to claim 1 wherein a fixed structure is provided as a contact at a location accessible to the actuator block of the bistable mechanism and an extraction electrode is provided on the substrate to which the contact is connected, the extraction electrode and the contact forming a physical switch in the circuit for mechanical logic control.

8. The resettable MEMS bistable trigger of claim 1, wherein the spring support beam, the trigger mechanism, and the spring and buffer structures of the bistable mechanism have successively decreasing stiffness.

9. The resettable MEMS bistable trigger of claim 1, wherein the first rigid connecting rod fully compresses the buffer structure without compressing the resilient support beam when the bistable mechanism is set.

10. The resettable MEMS bistable trigger of claim 1, wherein when the bistable mechanism is in the set state, the triggering mechanism is driven by an external force to press the resilient support beam outwards through the first rigid connecting rod, so that the resilient support beam loses its set locking effect on the bistable mechanism, and the bistable mechanism resets to the original state under the action of its own resilience.

Technical Field

The invention belongs to the field of MEMS manufacturing, and particularly relates to a resettable flashing on-chip MEMS bistable trigger.

Background

The bistable structure is an important basic logic unit in an automatic control system, and the switch is a typical bistable device. The history of mechanical flip-flop structures dates back to hundreds of years ago as rat trap clips, and electronic flip-flops are represented by D flip-flops manufactured using integrated circuit technology, which has also been known for about 60 years. Electronic flip-flops suffer from the need for quiescent current maintenance and the inability to physically switch off the current. The micro-electro-mechanical system (MEMS) technology breaks through the limitation of traditional mechanical manufacturing, can manufacture a mechanical structure on an integrated circuit chip, and provides technical feasibility for realizing physical power failure of a certain subsystem when a system-on-chip works. However, due to the special manufacturing method, the MEMS chip structure has a series of technical limitations such as small space volume, no friction among microstructures, difficulty in assembling and the like, so that the chip structure design is full of challenges.

Disclosure of Invention

The invention aims to provide a resettable MEMS bistable trigger which is compatible with an integrated circuit manufacturing process, can realize the flashing and overturning of a position state once triggered, can be driven and triggered by any actuator capable of generating displacement thrust, and can be matched with a contact structure to realize a physical switch function.

In order to achieve the purpose, the invention adopts the following technical scheme:

a resettable MEMS bistable trigger, comprising:

each fixed end comprises an anchor end protruding downwards, an elastic supporting beam connected to the inner side of the anchor end and a deformation space area located on the elastic supporting beam, the anchor end is connected with a substrate, and the deformation space area provides deformation space for the elastic supporting beam;

the trigger mechanism is arranged between the two fixed ends and comprises a driving block positioned in the middle and two first rigid connecting rods positioned on two sides of the driving block; one end of each first rigid connecting rod is connected with the driving block through a buffer structure and an elastic structure, the other end of each first rigid connecting rod is connected with the elastic supporting beam corresponding to the fixed end through another elastic structure, and the buffer structure provides a telescopic space between the driving block and the first rigid connecting rod;

the bistable mechanism is arranged between the two fixed ends and comprises an actuating block positioned in the middle and two second rigid connecting rods positioned at two sides of the actuating block; one end of each second rigid connecting rod is connected with the actuating block through an elastic structure, and the other end of each second rigid connecting rod is connected with the elastic supporting beam corresponding to the fixed end through another elastic structure;

the trigger mechanism and the bi-stable mechanism are in a same-direction V shape parallel to the substrate in an original state, when the trigger mechanism is driven by an external force to push the bi-stable mechanism actuating block to move to a critical point passing through an axial acting force of the bi-stable mechanism actuating block, the bi-stable mechanism is in a set state when being subjected to the action of the elastic supporting beam to generate flickering along the driving direction and stop in the V shape opposite to the original state, when the external force is removed, the trigger mechanism returns to the original state, and the bi-stable mechanism stays in the set state until the driving mechanism starts again and then returns to the original state.

Furthermore, the deformation space area is a rectangular through hole formed between the elastic support beam and the outer anchor end, and the elastic support beam is connected with the first rigid connecting rod and the second rigid connecting rod at the middle of the side, close to the trigger mechanism and the bi-stable mechanism, of the elastic support beam.

Furthermore, the buffer structure is a rectangular frame, the middle of one side of the rectangular frame is connected with the first rigid connecting rod, and the middle of the opposite side of the rectangular frame is connected with the elastic structure; when the driving block is close to the actuating block, the two sides of the rectangular frame are bent inwards to deform, so that the driving block and the first rigid connecting rod can stretch and retract.

Furthermore, the elasticity of the buffer structure is smaller than that of the elastic supporting beam, so that the elastic supporting beam cannot be extruded in the process that the trigger mechanism pushes the bistable mechanism to be set, and the bistable mechanism is prevented from being triggered to flicker to the original state.

Furthermore, the driving block is in an arrow shape, the convex part of the driving block is positioned at one side close to the actuating block and can be abutted against the actuating block under the driving of external force, and the concave part of the driving block is positioned at one side far away from the actuating block.

Furthermore, the actuating block is in an arrow shape, the concave part of the actuating block is positioned on one side close to the driving block and can be abutted by the driving block driven by force, the concave part enables the pushing force from the driving block to be on the straight line pointed by the arrow without twisting, and the convex part of the actuating block is positioned on one side away from the driving block.

Further, the trigger mechanism may be driven by a drive means having sufficient drive force and displacement.

Furthermore, a fixed structure can be arranged at the position where the actuating block of the bistable mechanism can reach as a contact, an extraction electrode connected with the contact is arranged on the substrate, and the extraction electrode and the contact form a physical switch in a circuit for mechanical logic control.

Furthermore, the hardness of the elastic support beam, the elastic structure of the trigger mechanism and the bistable mechanism and the hardness of the buffer structure are reduced in sequence.

Further, upon setting the bistable mechanism, the first rigid connecting rod fully compresses the cushioning structure without compressing the resilient support beam.

Further, when the bistable mechanism is in a set state, the triggering mechanism is driven by external force to extrude the elastic supporting beam outwards through the first rigid connecting rod, so that the elastic supporting beam loses the set locking effect on the bistable mechanism, and the bistable mechanism resets to an original state (reset state) under the action of self resilience force.

For the resettable MEMS bistable trigger, the setting of the bistable mechanism is directly driven by a driving block on the trigger mechanism, and the resetting is realized by extruding an elastic supporting beam by the trigger mechanism so as to lose the locking of the setting state of the bistable mechanism. The elastic supporting beam is fixed on the anchor end at one side and is in a suspension state at the other side. The bistable mechanism relies on the resilience of the elastic structure at the end of the second rigid connecting rod to effect the change in position. After the trigger mechanism acts on the bistable mechanism through a critical position (namely the position when the trigger mechanism is changed from the V shape to the reverse V shape), or the elastic support beam loses the locking force on the bistable mechanism in a set state, the bistable mechanism can be flicked to a corresponding state position.

Drawings

Fig. 1A-1B are top and cross-sectional views of a resettable MEMS flip-flop of this embodiment.

Fig. 2A-2B are set and reset state diagrams of the resettable MEMS flip-flop of this embodiment.

1-fixed end, 11-anchor end, 12-elastic supporting beam, 13-deformation space region, 2-trigger mechanism, 21-elastic structure, 22-first rigid connecting rod, 23-driving block, 24-buffer structure, 3-bistable mechanism, 31-elastic structure, 32-second rigid connecting rod and 33-actuating block.

Detailed Description

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

The present embodiment proposes a resettable MEMS bistable flip-flop, which is a micro-mechanical structure fabricated on a substrate material by MEMS process, as shown in fig. 1A-1B, and is composed of the following basic structural components.

Two fixing ends 1 for connecting the substrate and the trigger, which includes an anchor end 11 protruding downward to connect the substrate, an elastic supporting beam 12 connected to the inside of the anchor end 11, and a deformation space region 13 on the elastic supporting beam 12. The elastic support beam 12 is an important component of the trigger, and provides self-adaptive stabilizing force for the bistable mechanism 3 by using resilience force. The deformation space region 13 is a rectangular through hole formed in the elastic supporting beam 12, and the middle of the rectangular through hole, which is close to the sides of the triggering mechanism 2 and the bistable mechanism 3, is the position where the elastic supporting beam 12 is connected with the first rigid connecting rod 22 and the second rigid connecting rod 32 connected with the elastic supporting beam 12, so as to provide a bending deformation space without obstacle when the elastic supporting beam 12 is extruded by the triggering mechanism 2.

The trigger mechanism 2 is arranged between the two fixed ends 1 and comprises a driving block 23 positioned in the middle and two first rigid connecting rods 22 positioned at two sides of the driving block 23; one end of each first rigid connecting rod 22 is connected with the driving block 23 through a buffer structure 24 and an elastic structure 21, the other end is connected with the elastic supporting beam 12 corresponding to the fixed end 1 through another elastic structure 21, and the driving block 23 and the two first rigid connecting rods 22 are in a V shape on a plane parallel to the substrate when not stressed. Wherein the elastic structure 21 provides an elastic connection between the first rigid connecting rod 22 and the elastic supporting beam 12 and the driving block 23 when the triggering mechanism 2 is driven to move towards the bistable mechanism 3. The first rigid connecting rod 22 provides a rigid connection for the resilient support beam 12 and the drive block 23. This buffer structure 24 is a rectangular frame, first rigid connection rod 22 is connected to the middle department on a limit of this rectangular frame, elastic structure 21 is connected to the middle department on its opposite side, when the driving block 23 is close to when acting as the piece 33, the above-mentioned both sides of this rectangular frame are inside to be deformed, in order to realize the flexible between driving block 23 and the first rigid connection rod 22, for first rigid connection rod 22 provides the flexible volume of length, when guaranteeing to drive the setting to bistable mechanism 3, shorten through axial length, can not exert axial thrust to elastic support beam 12 and influence bistable mechanism 3's setting. The concave portion of the driving block 23 receives an external displacement driving force, and the convex portion transmits the displacement driving force to the actuating block 33.

A bistable mechanism 3, which is arranged between the two fixed ends 1 and on the side of the trigger mechanism 2 facing the V-shaped opening, comprises an actuating block 33 in the middle and two second rigid connecting rods 32 on two sides of the actuating block 33; each second rigid connecting rod 32 has one end connected to the actuating block 33 through an elastic structure 31 and the other end connected to the elastic supporting beam 12 corresponding to the fixed end 1 through another elastic structure 31, the actuating block 33 and the two second rigid connecting rods 32 are in a V-shape on a plane parallel to the substrate, the V-shape is in the same direction as the V-shape of the trigger mechanism 2, and the V-shaped included angle is larger than that of the latter. The actuating block 33 is used as the bistable position output end of the trigger, the concave part receives the displacement driving force of the driving block 23, and the convex part can transmit the displacement driving force to other actuator structures. The resilient structure 31 provides a resilient connection between the second rigid link 32 and the resilient support beam 12 and the actuator block 33 when the actuator block 33 is actuated between two stable states. The second rigid connecting rod 32 provides a rigid connection between the resilient support beam 12 and the actuator block 33.

The working principle of the resettable MEMS bistable trigger is as follows:

1. FIG. 1A shows the original state, in an unstressed state.

2. Fig. 2A shows a set state, and the process from the original state to the set state is as follows:

a) the driving block 23 is driven by a downward force, moves toward the actuating block 33, and moves downward by abutting against the actuating block 33.

b) The first rigid connecting rod 22 extends and contracts axially, the buffer structure 24 deforms and contracts under pressure, the elongation of the second rigid connecting rod 32 caused by angle change when the driving block 23 moves towards the actuating block 33 is absorbed, and the elastic supporting beam 12 is basically not subjected to extrusion deformation.

c) When the actuating block 33 moves to a position where the central axis of the second rigid connecting rod 32 is perpendicular to the central axis of the elastic supporting beam 12 (the included angle between the central axis and the horizontal axis is changed from a positive angle to zero degree), the maximum extrusion force is generated on the elastic supporting beam 12, so that the elastic supporting beam is subjected to maximum bending deformation, and the bistable mechanism 3 is located at a critical point position.

i. The resilient force of the elastic support beam 12 will drive the bistable mechanism 3 back to the original state upon the withdrawal of the driving force.

And ii, continuing to drive the actuating block 33 to pass through a critical point, changing an included angle between the central axis of the second rigid connecting rod 32 and the horizontal axis from zero degrees to a negative angle, extruding the second rigid connecting rod 32 from two sides by the resilience force of the elastic supporting beam 12 to enable the elastic structure 21 to generate torsional deformation, increasing the negative included angle between the central axis of the second rigid connecting rod 32 and the horizontal axis under the extrusion action of the resilience force of the elastic supporting beam 12 of the bistable mechanism 3, flashing without being pushed by the driving block 23, rapidly moving to a setting state, and stopping moving.

3. As shown in fig. 2B, the reset state, the reset from the set state to the original state, is as follows:

a) the driving block 23 is driven by the downward force to move the actuating block 33 downward until the first rigid connecting rod 22 is axially extended and retracted and the buffer structure 21 is fully compressed, at which time the first rigid connecting rod 22 has not yet reached the parallel with the horizontal axis.

b) The driving block 23 is continuously applied with displacement driving force, the first rigid connecting rod 22 starts to extrude the elastic supporting beam 12 while the included angle between the first rigid connecting rod and the horizontal shaft is reduced, so that the bistable mechanism 3 loses the resilience extrusion force of the elastic supporting beam 12 and flicks back to the original position under the resilience force of the elastic structure 31.

c) The actuating block 23 is pushed to generate extrusion deformation, so that the trigger mechanism 2 is ensured to execute the driving action.

In order to ensure the normal operation of the resettable MEMS bistable trigger, the structural design of each part meets the following requirements:

1. among several flexible structures, the cushioning structure is softest, the elastic structure and the elastic structure are second-softer, and the elastic support beam is harder.

2. The angle and length design of the first rigid connecting rod should ensure that:

a) when the bistable mechanism is set, the buffer structure is just completely compressed when the first rigid connecting rod axially stretches, and the first rigid connecting rod does not extrude the elastic support beam.

b) When the bistable mechanism resets, when the first rigid connecting rod stretches out and draws back in the axial direction, the buffer structure is compressed completely, the driving block can continue to move, so that the first rigid connecting rod extrudes the elastic support beam, until the bistable mechanism begins to rebound and reset, the included angle between the first rigid connecting rod and the horizontal shaft is greater than zero, and the tip position of the driving block can not block the actuating block from returning to one side of the original position of the critical position.

In the fabrication of the resettable MEMS flip-flop, most MEMS chip processes are aimed at fabricating a movable structure on a substrate, and therefore, the manufacturing method of the flip-flop will be described below by taking a process of a silicon structure on a glass plate or a silicon wafer with an insulating medium on the surface as an example, as long as the MEMS process capable of fabricating a movable structure on a substrate is suitable for fabricating the resettable MEMS flip-flop. The manufacturing steps comprise:

1. photoetching and connecting anchor end structure patterns on a monocrystalline silicon piece, and etching for 2-4 mu m to form a raised anchor end structure;

2. bonding the monocrystalline silicon wafer and a substrate;

3. thinning the monocrystalline silicon wafer to 60-100 μm by KOH corrosion or lapping equipment;

4. and photoetching the bistable trigger structure, and deeply etching silicon until the silicon penetrates to release the bistable trigger structure.

The above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person skilled in the art can modify the technical solution of the present invention or substitute the same without departing from the spirit and scope of the present invention, and the scope of the present invention should be determined by the claims.