阅读说明：本技术 一种基于负泊松比结构的测量方法及系统 (Measurement method and system based on negative Poisson ratio structure ) 是由 温庆国 张征凯 李鹏举 于 2021-07-23 设计创作，主要内容包括：本发明公开了一种基于负泊松比结构的测量方法及系统,将光源、负泊松比结构和光电池依次平行设置,将负泊松比结构作为基底与被测物接触,当被测物产生变形后对负泊松比结构施加力的作用,负泊松比结构产生弹性变形,光源发出的光线经弹性变形后的负泊松比结构照射在光电池上,通过数据采集设备采集光电池的电信号,利用电信号与被测量之间的关系获取被测量大小。本发明可选结构灵活多样,整体设计简便；组成部分相互独立,没有物理连接,能有效减少干扰和噪声的传递,测量精度较高。(The invention discloses a measuring method and a system based on a negative Poisson ratio structure, wherein a light source, the negative Poisson ratio structure and a photocell are sequentially arranged in parallel, the negative Poisson ratio structure is used as a substrate to be contacted with a measured object, when the measured object deforms, the negative Poisson ratio structure exerts force on the negative Poisson ratio structure, the negative Poisson ratio structure generates elastic deformation, light emitted by the light source irradiates the photocell through the elastically deformed negative Poisson ratio structure, electric signals of the photocell are collected through data collecting equipment, and the size of a measured object is obtained by utilizing the relation between the electric signals and the measured object. The invention has flexible and various selectable structures and simple and convenient integral design; the components are mutually independent, and are not physically connected, so that the transmission of interference and noise can be effectively reduced, and the measurement precision is higher.)

1. A measurement method based on a negative Poisson ratio structure is characterized by comprising the following steps:

the method comprises the steps that a light source, a negative Poisson ratio structure and a photocell are sequentially arranged in parallel, the negative Poisson ratio structure is used as a substrate to be in contact with a measured object, after the measured object exerts force on the negative Poisson ratio structure, the negative Poisson ratio structure generates elastic deformation, light emitted by the light source irradiates the photocell through the elastically deformed negative Poisson ratio structure, electric signals of the photocell are collected through data collection equipment, and the size of a measured object is obtained through the relation between the electric signals and the measured object.

2. The method of claim 1, wherein the electrical signal output by the photocell is related to the measured d by:

d＝aU+b

wherein a and b are constants, and U is the electrical signal output by the photocell.

3. The method of claim 2, wherein the electrical signal output by the photocell is related to the amount of light received by the photocell from the light source by:

U＝kQ_v

wherein k is a proportionality coefficient, U is an electrical signal output by the photocell, and Q_vThe light entering amount of the photocell.

4. The method of claim 1, wherein the amount of light entering the photovoltaic cell from the light source through the negative poisson's ratio structure is varied by varying the porosity of the negative poisson's ratio structure, and the amount of light entering the photovoltaic cell is Q_vComprises the following steps:

Q_v＝Q_v0P

wherein Q is_v0P is the amount of light entering when the photovoltaic cell is not shaded, and P is the porosity.

5. The method of claim 1, wherein the negative poisson's ratio structure has a porosity P that changes after the negative poisson's ratio structure is deformed such that an amount of light entering the photovoltaic cell from the light source through the negative poisson's ratio structure changes, the porosity P being:

P＝(s-s_c)/s

wherein s is the area of the photocell exposed to light when the photocell is not shielded, s_cThe area of the photovoltaic cell exposed to light is shielded by the negative Poisson ratio structure.

6. The method of claim 1, wherein the light source comprises a planar or non-planar light source, a visible light source, or infrared.

7. The method of claim 1, wherein the negative poisson's ratio structure is a cellular porous structure, and wherein the y-direction expands laterally within an elastic range when the x-direction is stretched and contracts when the x-direction is compressed.

8. The method of claim 7, wherein the negative poisson's ratio structure has a poisson's ratio of-1 to-8.

9. A measurement system based on a negative poisson's ratio structure, characterized in that, with the method of claim 1, it comprises a negative poisson's ratio structure (2), the negative poisson's ratio structure (2) is in contact with the object to be measured, the negative poisson's ratio structure (2) is arranged between a light source (1) and a photocell (3), and the photocell (3) is electrically connected with a data acquisition device (4).

Technical Field

The invention belongs to the technical field of measurement, and particularly relates to a measurement method and a measurement system based on a negative Poisson ratio structure.

Background

The existing force measuring method or system generally comprises a sensing element, a conversion element and a post-processing circuit, and the principle is that the deformation of the sensing element after force is applied to the sensing element is converted into the change of an electric signal by the conversion element, a one-to-one correspondence relationship is established between the force and the electric signal, and the size of the force to be measured is obtained by acquiring the electric signal. The existing displacement measurement method or system is partially similar to the force measurement, and the principle of the method is that the relationship between displacement and capacitance, eddy current or inductance is utilized, the displacement is converted into the change of the capacitance, the eddy current or the inductance, the change is output by a post-processing circuit, finally, a one-to-one correspondence relationship is established between the displacement and an electric signal, and the magnitude of the measured displacement is obtained by acquiring the electric signal. Various sensors designed based on the above force or displacement measurement methods usually have the sensing element and the conversion element in contact, which greatly limits the design, preparation and the like of the sensing element and the conversion element, and because the two elements need to be in contact with each other, noise and interference cannot be avoided from propagating between the two elements, which affects the measurement accuracy of the sensor. In some occasions with limited measuring space, the problems of difficult installation, inconvenient use, high environmental requirement, high price of measuring equipment or improper volume and the like are caused, and great inconvenience is caused to the measurement of force or displacement.

The negative Poisson ratio structure is a hot spot in the research field of emerging technologies due to the unique auxetic property. The porosity of the negative poisson's ratio structure changes accordingly after it is displaced in the vertical (or horizontal) direction.

Disclosure of Invention

The invention aims to solve the technical problem of providing a measuring method and a system based on a negative Poisson ratio structure, aiming at the defects in the prior art, the measuring method and the system are composed of a light source, the negative Poisson ratio structure and a photocell, can be regarded as the negative Poisson ratio structure of a sensor substrate, and can be regarded as the absence of contact between the photocells between conversion elements, thereby effectively reducing interference and noise, improving the measuring precision and simultaneously reducing the design difficulty.

The invention adopts the following technical scheme:

a measurement method based on a negative Poisson ratio structure comprises the following steps:

the method comprises the steps that a light source, a negative Poisson ratio structure and a photocell are sequentially arranged in parallel, the negative Poisson ratio structure is used as a substrate to be in contact with a measured object, after the measured object exerts force on the negative Poisson ratio structure, the negative Poisson ratio structure generates elastic deformation, light emitted by the light source irradiates the photocell through the elastically deformed negative Poisson ratio structure, electric signals of the photocell are collected through data collection equipment, and the size of a measured object is obtained through the relation between the electric signals and the measured object.

Specifically, the relationship between the electrical signal output by the photocell and the measured d is as follows:

d＝aU+b

wherein a and b are constants, and U is the electrical signal output by the photocell.

Further, the relationship between the electrical signal output by the photocell and the incoming light amount received by the photocell from the light source is as follows:

U＝kQ_v

wherein k is a proportionality coefficient, U is an electrical signal output by the photocell, and Q_vThe light entering amount of the photocell.

Specifically, the light inlet quantity of the light source entering the photocell through the negative Poisson ratio structure is changed due to the change of the porosity of the negative Poisson ratio structure, and the light inlet quantity Q of the photocell_vComprises the following steps:

Q_v＝Q_v0P

wherein Q is_v0P is the amount of light entering when the photovoltaic cell is not shaded, and P is the porosity.

Specifically, the porosity P of the negative poisson's ratio structure changes after the negative poisson's ratio structure deforms, so that the light incident amount of the light source reaching the photocell through the negative poisson's ratio structure changes, and the porosity P is as follows:

P＝(s-s_c)/s

wherein s is the area of the photocell exposed to light when the photocell is not shielded, s_cThe area of the photovoltaic cell exposed to light is shielded by the negative Poisson ratio structure.

Specifically, the light source includes a planar or non-planar light source, a visible light source, or infrared.

Specifically, the negative poisson's ratio structure is a cellular porous structure, when the x direction is stretched, the y direction expands laterally within the elastic range, and when the x direction is compressed, the y direction contracts.

Further, the negative poisson's ratio structure has a poisson ratio of-1 to-8.

The invention also provides a measuring system based on the negative Poisson ratio structure, which comprises the negative Poisson ratio structure, wherein the negative Poisson ratio structure is contacted with an object to be measured, the negative Poisson ratio structure is arranged between a light source and a photocell, and the photocell is electrically connected with data acquisition equipment.

Compared with the prior art, the invention has at least the following beneficial effects:

the invention relates to a measuring method based on a negative Poisson ratio structure, which is characterized in that based on the unique mechanical property of the negative Poisson ratio structure, the one-to-one correspondence relationship is established between the measured electrical signal and the electrical signal output by a photocell by utilizing the property that the electrical signal output by the photocell is in direct proportion to the illuminated area of the electrical signal, so that the measured measurement is converted into the measurement of the electrical signal output by the solar cell. In the measuring method, the substrate and the conversion element are not in physical contact, so that interference and noise are reduced; the choice and design of the conversion element is no longer limited by the size of the substrate; the measuring method is simple, high in precision and low in cost.

Further, there is a linear relationship between the electrical signal output by the photocell and the measurand: d ═ aU + b; when the constants a and b are obtained by calibration, the measured quantity d can be conveniently obtained from the measured electrical signal U.

Furthermore, the electric signal output by the photocell is in direct proportion to the light incoming quantity of the light source received by the photocell, and the direct proportion relation is a linear relation, so that the linearity of the measuring method and the system can be improved, and measuring errors are reduced.

Further, the quantity Q of light entering the photocell_vThe method has a direct proportion relation with the porosity of the negative Poisson ratio structure, and the direct proportion relation is a linear relation, so that the linearity of the measuring method and the system can be improved, and the measuring error is reduced.

Furthermore, one part of light emitted by the light source is shielded by the entity of the negative Poisson ratio structure, the other part of light irradiates the photocell through the pore of the negative Poisson ratio structure, and the change of the porosity can change the light entering amount of the light source irradiating the photocell. Thereby establishing the relation between the measured quantity and the quantity of incoming light.

Furthermore, the light source property is not limited, and the selection range is wide. The planar light source or the non-planar light source, the visible light source or the infrared non-visible light source and the like can be selected according to different application environments. The arrangement enlarges the application range of the measuring method and the system.

Furthermore, the negative Poisson ratio structure realizes the movement of the equipment through elastic deformation, and has no kinematic pair, thereby having no clearance leakage and no abrasion, and being convenient for installation and maintenance.

Furthermore, the negative Poisson ratio structure is flexible to select, and the negative Poisson ratio structure formed by cellular structure topology with honeycomb property can be applied to the measuring method and the measuring system. The arrangement enlarges the application range of the measuring method and the system.

A measuring system based on a negative Poisson ratio structure comprises the negative Poisson ratio structure, a light source, a photocell and data acquisition equipment. The negative Poisson ratio structure is contacted with the object to be measured, the negative Poisson ratio structure is arranged between the light source and the photocell, and the photocell is electrically connected with the data acquisition equipment. The arrangement can separate the substrate and the conversion element, reduce the mutual limitation and influence of the substrate and the conversion element in the design process, and also reduce the transmission of errors and noises. This arrangement also enables flexible selection of light sources and negative poisson's ratio structures.

In conclusion, the invention has the characteristics of flexible structure, low design difficulty, small noise and interference transmission, high precision and the like.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic view of the measurement principle of the present invention;

FIG. 2 is a sample illustration of a negative Poisson's ratio structure of the present invention as a substrate, wherein (a) is before deformation and (b) is after deformation;

FIG. 3 is a comparison chart of the present invention, wherein (a) is an experimental comparison of a negative Poisson ratio structure with a normal structure, and (b) is a repetitive experiment performed on the negative Poisson ratio structure;

FIG. 4 is a sample view of another negative Poisson's ratio structure of the present invention as a substrate, wherein (a) is before deformation and (b) is after deformation.

Wherein: 1. a light source; 2. a negative poisson's ratio structure; 3. a photovoltaic cell; 4. and (3) data acquisition equipment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, 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.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

The invention provides a measuring method based on a negative Poisson ratio structure, which is characterized in that based on the mechanical characteristic that the negative Poisson ratio structure can shrink (or expand) in the vertical direction when the negative Poisson ratio structure is axially compressed (or stretched), the negative Poisson ratio structure is arranged between a light source and a photocell according to the property that the output current of the photocell is in direct proportion to the illuminated area (light inlet quantity), the light source illuminates the photocell through the negative Poisson ratio structure, the photocell generates a certain electric signal after being illuminated, and the magnitude of the electric signal can be acquired and analyzed through an acquisition system. The negative Poisson ratio structure is contacted with a measured object, and the measured object generates force on the negative Poisson ratio structure, so that the negative Poisson ratio structure is deformed, the porosity of the negative Poisson ratio structure is changed, at the moment, the irradiation area of the light source irradiating the photocell through the negative Poisson ratio structure is changed, and finally, the output electric signal of the photocell is changed. The measuring scheme establishes the corresponding relation between the measured quantity and the electric signal output by the photocell. The measured magnitude is obtained by the variation of the electrical signal output by the photocell.

Referring to fig. 1, the present invention provides a measurement method based on a negative poisson's ratio structure, which includes the following steps:

s1, arranging the light source 1, the negative Poisson ratio structure 2 and the photocell 3 in parallel in sequence, and connecting the output of the photocell 3 with the data acquisition equipment 4;

the light source 1, the negative Poisson ratio structure 2 and the photocell 3 are arranged in a non-contact mode, and the negative Poisson ratio structure 2 is located between the light source 1 and the photocell 3.

S2, the negative Poisson ratio structure 2 is used as a substrate to be contacted with a measured object, when the measured object exerts force on the negative Poisson ratio structure 2, the negative Poisson ratio structure 2 generates elastic deformation, the photocell 3 is used as a conversion element to convert the received light input quantity into an electric signal to be output, and the size of the electric signal output by the photocell 3 is proportional to the light input quantity received by the photocell 3 from the light source 1; the amount of light entering the photovoltaic cell 3 from the light source 1 through the negative poisson's ratio structure 2 will vary due to the change in the porosity of the negative poisson's ratio structure 2. The porosity of the negative poisson's ratio structure 2 changes when the negative poisson's ratio structure 2 is measured to change. The electrical signal output by the photocell 3 can therefore reflect the magnitude of the measurement being taken.

The electrical signal output by the photocell is related to the measured d as follows:

d＝aU+b

wherein a and b are constants, and U is the electric signal output by the photocell and is in proportion to the incident light quantity received by the photocell.

The proportion of the electric signal output by the photocell to the incoming light quantity received by the photocell from the light source is as follows:

U＝kQ_v

wherein k is a proportionality coefficient, U is an electrical signal output by the photocell, and Q_vThe light entering amount of the photocell.

S3, the negative Poisson ratio structure 2 is used as a substrate to be contacted with a measured object, when the measured object exerts force on the negative Poisson ratio structure 2, the negative Poisson ratio structure 2 generates elastic deformation, the photocell 3 is used as a conversion element to convert the received light input quantity into an electric signal to be output, and the size of the electric signal output by the photocell 3 is proportional to the light input quantity received by the photocell 3 from the light source 1. The amount of light entering the photovoltaic cell 3 from the light source 1 through the negative poisson's ratio structure 2 will vary due to the change in the porosity of the negative poisson's ratio structure 2. The porosity of the negative poisson's ratio structure 2 changes as a result of a change in the force experienced by the negative poisson's ratio structure 2. The electrical signal output by the photocell 3 can therefore reflect the magnitude of the measurement being taken.

The light inlet quantity of the light source entering the photocell through the negative Poisson ratio structure is changed due to the change of the porosity of the negative Poisson ratio structure, and the light inlet quantity Q of the photocell_vComprises the following steps:

Q_v＝Q_v0P

wherein Q is_v0P is the amount of light entering when the photovoltaic cell is not shaded, and P is the porosity.

The porosity P of the negative Poisson ratio structure is changed after the negative Poisson ratio structure is deformed, so that the light incoming quantity of the light source reaching the photocell through the negative Poisson ratio structure is changed, and the porosity P is as follows:

P＝(s-s_c)/s

wherein s is the area of the photocell exposed to light when the photocell is not shielded, s_cThe area of the photovoltaic cell exposed to light is shielded by the negative Poisson ratio structure.

The invention relates to a measuring system based on a negative Poisson ratio structure, which comprises a light source 1, a negative Poisson ratio structure 2, a photocell 3 and a data acquisition device 4, wherein the negative Poisson ratio structure 2 is arranged between the light source 1 and the photocell 3, the negative Poisson ratio structure 2 is contacted with a measured object and converts the measured size into an electric signal, and the data acquisition device 4 is connected with the photocell 3 and is used for acquiring the electric signal and converting the electric signal into a corresponding measured quantity.

The light source 1 has wide selectable range, and a plane or non-plane light source, a visible light source or an infrared or other non-visible light source can be used in the measuring method, so that the light source 1 can be selected according to different application scenes.

The basic cellular structure of the negative Poisson ratio structure 2 is not limited in kind, and the negative Poisson ratio structure formed by the cellular structure topology with negative Poisson ratio characteristics and porosity can be used in the system.

Preferably, the negative poisson's ratio structure is formed by a hexagon with two inwards concave sides through topology, when the x direction is stretched, the y direction expands transversely in an elastic range, and when the x direction is compressed, the y direction contracts conversely; the negative poisson's ratio structure has a poisson ratio of-1 to-8.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 2, a sample of a negative poisson's ratio structure for a substrate according to the present invention is shown, which changes the porosity after deformation in the vertical direction.

After the object to be measured exerts force on the negative Poisson ratio structure 2, the negative Poisson ratio structure 2 generates elastic deformation after being stressed, so that the porosity is changed, the area irradiated by the light source of the photocell 3 is changed, finally, the electric signal output by the photocell 3 is changed, the relation between the measured size and the electric signal output by the photocell 3 is established, and the measured size is obtained by collecting the electric signal output by the photocell 3.

Referring to fig. 4, the example of the negative poisson's ratio structure for a substrate according to the present invention can generate lateral contraction when a force is applied in a vertical direction, so as to change the porosity. In the invention, the negative Poisson ratio structure 2 generates elastic deformation after being stressed so as to change the porosity, which can cause the change of the area of the photocell 3 irradiated by the light source and finally cause the change of the electric signal input by the photocell 3. Therefore, the relationship between the force borne by the negative Poisson ratio structure 2 and the electric signal input by the photocell 3 is established, and the force borne by the negative Poisson ratio structure 2, namely the force of the measured object (point), can be obtained by collecting the electric signal output by the photocell 3.

Referring to fig. 3, fig. 3(a) is an experimental comparison of a negative poisson's ratio structure and a conventional structure. It is evident from the figure that the use of a negative poisson's ratio structure in the present measurement system has a higher sensitivity and linearity.

Fig. 3(b) is a repetitive experiment with a negative poisson's ratio structure, and it can be seen that the use of a negative poisson's ratio structure in the present measurement system has good reproducibility and stability.

In conclusion, the measuring method and system based on the negative poisson ratio structure have the advantages that the selectable structure is flexible and various, and the overall design is simple and convenient; the components are mutually independent, and are not physically connected, so that the transmission of interference and noise can be effectively reduced, and the measurement precision is higher.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.