Fiber type acceleration sensor based on gradient spiral structure and application thereof

Abstract

The application discloses a kind of gradient spiral structure-based fiber type acceleration sensor and application, including packaging layer, spiral main body, lead and dielectric layer;Packaging layer is located in the outermost side of fiber type acceleration sensor, the two sides of packaging layer are closed, and are connected with the two endpoints of spiral main body respectively;Spiral main body includes matrix skeleton, electrode layer, insulating layer;Lead one end is connected with the electrode layer at the endpoint of spiral main body, the other end passes through packaging layer and is exposed to the outside of fiber type acceleration sensor;Dielectric layer fills the remaining space in fiber type acceleration sensor.The sensor provided by the application can produce capacitance change under acceleration, and is not disturbed by axial tension and normal pressure, thereby realizing high-reliability acceleration detection;The sensor of the application is woven, and a wearable acceleration sensing fabric can be further obtained.The sensor of the application is also suitable for human-computer interaction, humanoid robot, intelligent prosthesis and other application scenarios.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flexible electronic devices, in particular to a fiber type acceleration sensor based on gradient spiral structure and application. BACKGROUND

[0002] The acceleration sensor is a kind of micro-inertial device that can measure acceleration, and the main body is mass block and elastic element. Its principle is based on Newton's second law, that is, when external acceleration occurs, due to the inequality of inertia between the mass block and the elastic element, the elastic element will be elastically deformed, which will change the capacitance, resistance, current and other signals of the sensor. It has excellent application prospect in the field of human-computer interaction and flexible robot.

[0003] However, the current acceleration sensor is usually composed of rigid components, and its wearability, detection stability and portability are poor. The research on full flexible acceleration sensor is in a blank state. The main reason is that the full flexible acceleration sensor is easily affected by external invalid pressure and stretch signal crosstalk, and has low reliability. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a fiber type acceleration sensor based on gradient spiral structure and application. The full flexible acceleration sensor is realized, and the crosstalk of invalid pressure signal and stretch signal is eliminated by spiral structure and packaging layer respectively, solving the problem that the full flexible acceleration sensor is easily affected by external invalid pressure and stretch signal crosstalk.

[0005] The purpose of the present application is realized by the following technical scheme:

[0006] A fiber type acceleration sensor based on gradient spiral structure, comprising a packaging layer, a spiral main body, a lead wire and a dielectric layer; the packaging layer is located at the outermost side of the fiber type acceleration sensor, the two sides of the packaging layer are closed, and are respectively connected with the two end points of the spiral main body; the spiral main body comprises a base skeleton, an electrode layer and an insulating layer; the spiral main body is divided into dense area, small pitch area and large pitch area according to different pitch; one end of the lead wire is connected with the electrode layer at the end point of the spiral main body, and the other end is exposed outside the fiber type acceleration sensor through the packaging layer; the dielectric layer fills the remaining space in the fiber type acceleration sensor.

[0007] Further, the pitch P1 of the dense area is h, wherein h is the line height of the spiral main body; the pitch P2 of the small pitch area is greater than h and less than Wherein ε is the dielectric constant of the dielectric layer, r is the radius of the spiral main body, and d is the line width of the spiral main body; the pitch P3 of the large pitch area is greater than

[0008] Further, the base skeleton is located in the innermost layer of the spiral body.

[0009] Further, the electrode layer is compounded on the upper and lower sides of the base skeleton along the spiral line direction.

[0010] Further, the insulating layer completely covers the electrode layer and the base skeleton along the spiral line direction.

[0011] Further, the lead wire connects the electrode layer on the upper and lower sides of the spiral body with the positive and negative electrodes of the capacitance measuring device.

[0012] Further, the radius of the spiral body is between 100 mu m and 2 cm, the line width and the line height are between 50 mu m and 1 cm, the length is between 0.1 cm and 1000 cm, and the elastic modulus is between 0.1 Mpa and 10 Gpa.

[0013] Further, the dielectric layer can be any one of transformer oil, rapeseed oil, castor oil, air, ionic elastomer, Ecoflex, and PDMS.

[0014] The application of the above-mentioned fiber type acceleration sensor based on the gradient spiral structure in the preparation of a smart sensing device.

[0015] Further, the smart sensing device is a human-computer interaction device, a humanoid robot, a flexible robot, or an intelligent prosthesis.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] The application provides a fiber type acceleration sensor based on a gradient spiral structure, which is characterized in that a packaging layer, a spiral body and a dielectric layer located in the packaging layer are arranged, the spiral body can freely expand and contract in the packaging layer, the turn-to-turn capacitance of adjacent turns of the spiral body changes with the pitch, and the greater the pitch, the smaller the capacitance change rate. In this way, when the acceleration sensor is used, the spiral body elastically deforms due to the inequality of inertia of the large-pitch area, the dense area and the small-pitch area when the sensor detects acceleration. The capacitance of the dense area does not change because the pitch is constant; the capacitance change rate of the large-pitch area is small because the pitch is large; the capacitance change rate of the small-pitch area is large because the pitch is small; and the acceleration sensor can be regarded as being in parallel connection with the dense area, the large-pitch area and the small-pitch area, and the capacitance is the sum of the three. Therefore, the size and direction of acceleration can be determined by measuring the capacitance value change at both ends of the lead wire. In this process, when the fiber is subjected to pressure perpendicular to the pitch direction, the spiral structure releases the compression strain, the pitch does not change, and the capacitance value does not change. At the same time, because the packaging layer cannot be stretched, the fiber will not be subjected to tensile strain under the tensile force in the parallel pitch direction, and the capacitance value does not change. The application realizes full-flexible acceleration sensing, eliminates the crosstalk of invalid pressure signals and tensile signals through the spiral structure and the packaging layer respectively, and thus realizes high-reliability acceleration detection. In addition, the fiber acceleration sensor provided by the application can be woven to obtain a wearable acceleration sensing fabric. The fiber type acceleration sensor based on the gradient spiral structure provided by the application is suitable for application scenarios such as human-computer interaction, humanoid robots and intelligent prostheses. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 A structural schematic diagram of a fiber type acceleration sensor based on a gradient spiral structure is provided.

[0020] Figure 2 An equivalent circuit schematic diagram of a fiber type acceleration sensor based on a gradient spiral structure is provided.

[0021] Figure 3 A relationship diagram of the pitch of the spiral body and the capacitance change rate is provided.

[0022] Figure 4 A change diagram of a fiber type acceleration sensor based on a gradient spiral structure under the action of acceleration in the +x direction is provided.

[0023] Figure 5 Fig. 2 is a schematic diagram showing the change of a fiber type acceleration sensor based on a gradient spiral structure under the action of acceleration in the -x direction according to the present application;

[0024] Figure 6 Fig. 3 is a schematic diagram showing the change of a fiber type acceleration sensor based on a gradient spiral structure under the action of pressure according to the present application;

[0025] In the figure, 1 is a packaging layer; 2 is a spiral main body; 21 is a base skeleton; 22 is an electrode layer; 23 is an insulating layer; 3 is a lead wire; and 4 is a dielectric layer. DETAILED DESCRIPTION

[0026] The exemplary embodiments will be described in detail herein below with reference to the drawings. In the following description, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0028] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various information, these terms are not intended to denote a temporal or chronological order. Rather, these terms are used only to distinguish one from another. For example, a first information can be termed a second information, and similarly, a second information can also be termed a first information, without departing from the scope of the present application. The word "if' as used herein means "when" or "upon" or "in response to the determination" depending on the context.

[0029] It is to be understood that the present application can be carried out by using many different forms without departing from the spirit of the application. Rather, these embodiments are provided so that this disclosure will be complete and full, and will fully convey the scope of the application to those skilled in the art. Further, the technical features involved in the respective embodiments described below can be combined with each other as long as there is no conflict.

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present application.

[0031] The present application discloses a fiber type acceleration sensor based on gradient spiral structure, referring to Figure 1 The structure schematic diagram of the fiber type acceleration sensor refers to Figure 1 The structure schematic diagram of the fiber type acceleration sensor, including a packaging layer 1, a spiral main body 2, a lead wire 3 and a dielectric layer 4. The packaging layer 1 is located at the outermost side of the fiber type acceleration sensor, and the two sides of the packaging layer 1 are closed and connected with the two end points of the spiral main body 2 respectively; the packaging layer 1 is in a fiber shape, and the packaging layer 1 can be made of non-stretchable acrylic organic glass material, so that the sensor itself is not stretchable, and the signal crosstalk under stretching is eliminated. The spiral main body 2 includes a base skeleton 21, an electrode layer 22 and an insulating layer 23; the base skeleton 21 is located at the innermost layer of the spiral main body 2; the electrode layer 22 is compounded on the upper and lower sides of the base skeleton 21 along the spiral line direction; and the insulating layer 23 completely covers the electrode layer 22 and the base skeleton 21 along the spiral line direction. One end of the lead wire 3 is connected with the electrode layer 22 at the end point of the spiral main body 2, and the other end of the lead wire 3 is exposed to the outside of the fiber type acceleration sensor through the packaging layer 1; the lead wire 3 is used to connect the electrode layers 22 on the upper and lower sides of the spiral main body 2 with the positive and negative electrodes of the capacitance measuring device. The dielectric layer 4 fills the remaining space in the fiber type acceleration sensor. When the sensor is manufactured, the spiral main body 2 can be prepared by synchronous rotation of the preform during the fiber drawing tower drawing process, and the spiral pitch can be controlled in situ by adjusting the drawing conditions.

[0032] Specifically, the spiral main body 2 is located in the packaging layer 1, and the spiral main body 2 can be divided into a dense area, a small pitch area and a large pitch area according to different pitches; the pitch direction is parallel to the fiber orientation of the packaging layer 1. The large pitch area and the small pitch area are located on the two sides of the dense area respectively.

[0033] In the embodiment, the radius of the spiral main body 2 is between 100 μm and 2 cm, the line width and the line height of the spiral main body 2 are between 50 μm and 1 cm, the length of the spiral main body 2 is between 0.1 cm and 1000 cm, and the elastic modulus of the spiral main body 2 is between 0.1 Mpa and 10 Gpa.

[0034] In this embodiment, the dielectric layer 4 can be any one of transformer oil, rapeseed oil, castor oil, air, ion elastomer, Ecoflex, and PDMS.

[0035] In this embodiment, the base skeleton 21 is made of SEBS elastomer; SEBS elastomer has good anti-aging performance and can maintain stable performance under long-term use.

[0036] In this embodiment, the electrode layer 22 is made of a composite material of silver nanoparticles and SEBS, the surface energy of which matches the SEBS elastomer skeleton, and the composite is relatively tight.

[0037] In this embodiment, the insulating layer 23 is made of air, which has a relatively small resistance to the spiral body 2 and is conducive to the elastic deformation of the spiral body 2 under acceleration.

[0038] Reference Figure 2 Schematic diagram of the equivalent circuit of the fiber-type acceleration sensor. The fiber-type acceleration sensor of this embodiment can be regarded as an equivalent circuit composed of multiple parallel plate capacitors in parallel, and the distance between the plates of each parallel plate capacitor is equal to the pitch of the spiral structure.

[0039] When using the above-mentioned fiber-type acceleration sensor to detect the acceleration of the object to be measured, it is necessary to first fix the sensor to the object to be measured, and connect the two leads 3 to the positive and negative electrodes of the capacitance test device respectively. When the object to be measured generates acceleration, the sensor follows the object to generate acceleration. Due to the unequal inertia of the large pitch area, dense area, and small pitch area, the spiral body 2 undergoes elastic deformation, causing its pitch to change, thereby changing the capacitance value of the parallel plate capacitor in its equivalent circuit. Figure 3 Schematic diagram of the relationship between the pitch of the spiral body and the capacitance change rate. The capacitance value of each parallel plate capacitor can be described by the following formula:

[0040]

[0041] Wherein, C represents the capacitance value, ε represents the dielectric constant of the dielectric layer 4 , r represents the radius of the spiral body 2 , d represents the line width of the spiral body 2 , P represents the pitch of the spiral body 2 , and h represents the line height of the spiral body 2 .

[0042] Therefore, its capacitance change rate can be described by the following formula:

[0043]

[0044] It can be seen that the capacitance change rate is inversely correlated with the spring pitch. The capacitance does not change in the dense area due to the constant pitch; the capacitance change rate is small in the large pitch area due to the large pitch; the capacitance change rate is large in the small pitch area due to the small pitch. The pitch P2 in the small pitch area is greater than h and less than The pitch P3 in the large pitch area is greater than

[0045]

[0046] Preferably, in this embodiment, the pitch P1 of the dense area is equal to the line height h of the spiral body 2; the pitch P2 of the small pitch area is equal to Where r represents the radius of the helical body 2; the pitch P3 of the large pitch region is equal to Since P3 is much larger than P2, the capacitance change in the large pitch area can be ignored, so the capacitance change value of the acceleration sensor is equal to the capacitance change value in the small pitch area.

[0047] Reference Figure 4 Schematic diagram of the changes in the fiber-type acceleration sensor under the action of acceleration in the +x direction. In this embodiment, the fiber is placed along the x-axis. When the fiber is subjected to acceleration in the +x direction, the pitch of the small pitch area becomes shorter, the capacitance value becomes larger, and the overall capacitance of the acceleration sensor becomes larger. Conversely, referring to Figure 5 A diagram shows how a fiber-type accelerometer changes under acceleration in the -x direction. When the fiber is accelerated in the -x direction, the pitch length and capacitance of the small-pitch area decrease, reducing the overall capacitance of the accelerometer. The magnitude of the acceleration can be determined by the rate of change in capacitance, and the direction of the acceleration can be determined by the sign of the change in capacitance.

[0048] Reference Figure 6 Schematic diagram of the capacitance change of a fiber-type acceleration sensor under pressure. In this embodiment, when the fiber is subjected to pressure in the direction perpendicular to the x-axis, the spiral structure is compressed, but the plate spacing and plate area of ​​the parallel plate capacitor in its equivalent circuit remain unchanged. Therefore, the acceleration sensor of this embodiment is not affected by pressure signal crosstalk.

[0049] To further explain, Figure 1 The fiber-type acceleration sensor based on the gradient spiral structure shown can also be used in the preparation of intelligent sensing devices such as human-computer interaction devices, humanoid robots, flexible robots, and intelligent prostheses.

[0050] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

[0051] Those skilled in the art can easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fiber-type acceleration sensor based on a gradient spiral structure, characterized in that: The invention comprises a packaging layer (1), a spiral body (2), a lead (3) and a dielectric layer (4); the packaging layer (1) is located at the outermost side of the fiber-type acceleration sensor, and the two sides of the packaging layer (1) are closed and respectively connected to the two end points of the spiral body (2); the spiral body (2) comprises a base skeleton (21), an electrode layer (22) and an insulating layer (23); the spiral body (2) is divided into a dense area, a small pitch area and a large pitch area according to different pitches; one end of the lead (3) is connected to the electrode layer (22) at the end point of the spiral body (2), and the other end passes through the packaging layer (1) and is exposed to the outside of the fiber-type acceleration sensor; the dielectric layer (4) fills the remaining space in the fiber-type acceleration sensor.

2. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The pitch P1 of the dense area is equal to h, where h is the height of the spiral body (2); the pitch P2 of the small pitch area is greater than h and less than Wherein ε is the dielectric constant of the dielectric layer (4), r is the radius of the spiral body (2), and d is the line width of the spiral body (2); the pitch P3 of the large pitch region is greater than 3. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The base skeleton (21) is located in the innermost layer of the spiral body (2).

4. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The electrode layer (22) is compounded on the upper and lower sides of the base skeleton (21) along the spiral line direction.

5. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The insulating layer (23) completely covers the electrode layer (22) and the matrix skeleton (21) along the spiral direction.

6. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The lead wires (3) connect the electrode layers (22) on the upper and lower sides of the spiral body (2) to the positive and negative electrodes of a capacitance measuring device.

7. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The spiral body (2) has a radius of 100 μm-2 cm, a line width and a line height of 50 μm-1 cm, a length of 0.1 cm-1000 cm, and an elastic modulus of 0.1 Mpa-10 Gpa.

8. The fiber-type acceleration sensor based on a gradient spiral structure according to claim 1, characterized in that: The dielectric layer (4) comprises transformer oil, rapeseed oil, castor oil, air, ion elastomer, Ecoflex, and PDMS.

9. Use of a fiber-type acceleration sensor based on a gradient spiral structure according to any one of claims 1 to 8 in preparing an intelligent sensing device.

10. The use according to claim 9, characterized in that The intelligent sensing device includes a human-computer interaction device, a humanoid robot, a flexible robot, and an intelligent prosthesis.

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