A method for measuring acceleration based on structural color devices

Abstract

The invention provides an acceleration measurement method based on a structural color device, relates to the field of acceleration measurement, and solves the problems of noise suppression and flow field influence existing in the prior art when using MEMS acceleration sensors. The method comprises: using flexible materials to design and prepare a structural color device with a pressure-sensitive metasurface; for the pressure-sensitive metasurface, a centrifugal effect is generated by a rotation loading method, so that the pressure-sensitive metasurface is subjected to a centrifugal acceleration perpendicular to the plane where the pressure-sensitive metasurface is located, and calibration is performed; by changing the rotation loading parameters, the pressure-sensitive metasurface presents different color changes under different rotation loading parameters, which are recorded as an acceleration-color mapping table of the structural color device, and the vibration acceleration of a model / support rod is measured in real time through the color change of the pressure-sensitive metasurface of the structural color device; the invention effectively utilizes the pressure-sensitive mechanism and performs accurate calibration, so as to realize real-time and accurate measurement of acceleration in a high-speed flow field test.

Description

Technical Field

[0001] The invention relates to the field of acceleration measurement, and is applied to the quantitative measurement process of model / support vibration acceleration in a high-speed flow field, and specifically relates to an acceleration measurement method based on a structural color device. Background Art

[0002] With the rapid development of aerospace engineering, the development of high-speed aircraft has become the focus of global scientific research competition. In order to ensure the accuracy and safety of high-speed aircraft design, ground tests have become an indispensable part. In these tests, scaled models are usually placed in high-speed flow fields to simulate actual flight conditions. The model is connected to the test bench through support rods, and the stability of this connection point directly affects the accuracy and safety of the test.

[0003] During the test, the model and supporting rods will experience significant vibration under the impact of high-speed airflow. This vibration not only affects the accuracy of the test data, but also may cause the rods to break in extreme cases, thereby causing damage to the model or test device, posing a serious safety hazard. Therefore, accurate monitoring and control of the vibration state of the rods is crucial to ensure test safety and data reliability.

[0004] At present, the commonly used vibration detection method in ground tests is the piezoelectric structural accelerometer based on MEMS technology. This type of sensor consists of a sensitive element, a sensor base and a mass block. Its working principle depends on the force generated by the mass block under the action of external acceleration, and this force is proportional to the acceleration. However, traditional MEMS accelerometers have the following technical bottlenecks:

[0005] 1. Circuit complexity and noise issues: The circuit design of the MEMS structure is complex, which makes it difficult to suppress and eliminate the measurement noise caused by current drift, which poses a serious challenge to measurement accuracy.

[0006] 2. Sensitivity to electromagnetic interference: In a strong electric field environment, MEMS sensors are susceptible to electromagnetic interference, which affects the stability and reliability of the measurement system and limits their application in specific industrial scenarios.

[0007] 3. Size and installation issues: The sensor module is large in size, which not only increases the difficulty of installation, but also may interfere with the flow field, limiting its use in space-constrained or flow-field-sensitive environments.

[0008] In view of the above limitations, the applicability of existing MEMS-based acceleration sensors in high-speed flow field tests is limited. Therefore, it is urgent to develop new sensor technologies to overcome the defects of existing technologies, improve measurement accuracy and reliability, reduce sensor size, reduce interference with the flow field, and adapt to a wider range of application scenarios. Summary of the invention

[0009] Based on the current status of the background technology, the present invention aims to propose a new solution to the demand for acceleration measurement in high-speed flow field tests, thereby solving the problems of complex control circuits, difficult noise suppression, strong electromagnetic interference, large module size, unfavorable installation and flow field interference of existing model / strut acceleration sensors in high-speed flow fields. The present invention proposes an acceleration measurement method based on a structural color device, using flexible materials to develop a pressure-sensitive metasurface structural color device, and through the pressure-sensitive mechanism of the metasurface structural color, the color of the structural color device changes during the vibration of the model / strut, thereby realizing real-time acceleration measurement in high-speed flow field tests.

[0010] The present invention adopts the following technical solutions to achieve the purpose:

[0011] A method for measuring acceleration based on a structural color device, the method comprising the following steps:

[0012] S1. Design and prepare structural color devices with pressure-sensitive metasurfaces using flexible materials;

[0013] S2. For the pressure-sensitive metasurface of the structural color device, a centrifugal effect is produced by a rotation loading method, so that the pressure-sensitive metasurface is subjected to a centrifugal acceleration perpendicular to the plane on which it is located, and calibration is performed;

[0014] S3. During the calibration process, the rotation loading parameters are changed, and the pressure-sensitive metasurface presents different color changes under different rotation loading parameters; the centrifugal acceleration value reflected by the rotation loading parameter and the corresponding pressure-sensitive metasurface color are recorded to form an acceleration-color mapping table of the structural color device;

[0015] S4. After obtaining the acceleration-color mapping table, the calibration process of the structural color device is completed; the structural color device is placed in the model / support vibration acceleration measurement system, and according to the acceleration-color mapping table, the vibration acceleration of the model / support is measured in real time during the flow field test through the color change of the pressure-sensitive metasurface of the structural color device.

[0016] Furthermore, in step S2, the rotational loading method is completed using a rotating loading table, which has a horizontal rotating surface, and a circle of circular side walls is vertically formed on the rotating surface. The circular side walls are open above, and the center of the circular side walls corresponds to the rotation center of the rotating surface; during calibration, the structural color device is set on the circular side wall, and a light source is used to emit uniform white light to cover and continuously illuminate the pressure-sensitive metasurface of the rotating structural color device; at the same time, a CCD camera is used to capture and record the color of the pressure-sensitive metasurface of the structural color device in real time.

[0017] Furthermore, in step S1, when designing the structural color device, the device surface plasma resonance frequency and intensity are changed according to the centrifugal force to achieve device structural color control, thereby designing the composition structure of the structural color device based on the principle of acceleration measurement through the change of the device structural color;

[0018] The structural color device's composition structure, from bottom to top, includes: bottom metal, middle medium, and upper metal; among them, the bottom metal is the reflective layer, the middle medium is the waveguide layer, the middle medium uses PDMS flexible material, and the upper metal is the grating metal layer; the surface corresponding to the grating metal layer is the pressure-sensitive metasurface of the structural color device.

[0019] Specifically, in the calibration performed in step S2, the reflective layer of the structural color device is closely attached to the inner side or the outer side of the circular side wall to fix the structural color device on the circular side wall.

[0020] Preferably, when the reflective layer of the structural color device is in close contact with the inner side of the circular side wall, the entire circular side wall is made of transparent optical glass material, or an observation window is opened on the circular side wall at a position opposite to the setting position of the structural color device, and the observation window is filled with transparent optical glass material.

[0021] Preferably, when the reflective layer of the structural color device is in close contact with the outer side of the circular side wall, the entire circular side wall is made of an opaque material of a preset standard background color.

[0022] Preferably, during calibration, the shooting direction of the CCD camera is horizontal, the shooting height is the same as the height of the structural color device, and the shooting light path or its extension line passes above the rotation center of the rotating surface of the rotating loading platform, so that at the moment of shooting, the shooting light path of the CCD camera is perpendicular to the plane where the pressure-sensitive metasurface of the structural color device is located.

[0023] Furthermore, in step S4, the calibrated structural color device is pasted and fixed on the surface of the model / support rod, and a light source is used to emit uniform white light to continuously illuminate the pressure-sensitive metasurface of the structural color device. At the same time, a CCD camera is used to record the color of the pressure-sensitive metasurface of the structural color device in real time; the model / support rod is placed in a flow field test environment. During the test, when the model / support rod vibrates, the acceleration change caused by the vibration causes the color of the pressure-sensitive metasurface of the structural color device to change, which is recorded in real time by the CCD camera and processed as the vibration acceleration measurement result of the model / support rod.

[0024] In summary, due to the adoption of this technical solution, the beneficial effects of the present invention are as follows:

[0025] The pressure-sensitive metasurface structural color device developed by the present invention uses flexible materials. Its unique physical properties enable the device to respond to changes in external acceleration and directly reflect the acceleration level through color changes, thereby achieving real-time monitoring of model / support vibration. This innovative mechanism avoids the circuit complexity and noise problems in traditional acceleration sensors and provides a more direct and accurate measurement method.

[0026] Since the super-surface structural color device is used, the surface pasting method ensures the relative accuracy of the shape of the object being measured. Therefore, the measurement method of the present invention has minimal interference with the flow field and will not have a negative impact on the normal progress of the high-speed flow field test, thus ensuring the purity and reliability of the test results. The non-electronic nature of the structural color device makes it naturally resistant to environmental electromagnetic interference, and it can maintain stable performance even in a strong electric field environment, significantly improving the stability of the applied system.

[0027] The measuring device used in the measuring method of the present invention has a simple structure and is easy to install and maintain. Compared with the traditional MEMS acceleration sensor, the measuring and maintenance costs of the present invention are greatly reduced, providing an economical and efficient solution for high-frequency, large-scale, high-speed flow field tests. After detailed theoretical calculations and simulations, it has been shown that the effect of the structural color changing with acceleration in the present invention is significant, and it has use value and potential advantages in high-speed flow field tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The schematic diagram briefly describes the overall process of the acceleration measurement method of the present invention;

[0029] Figure 2 It is a schematic diagram of the calibration process of the rotation loading method in the present invention;

[0030] Figure 3 It is a schematic diagram of the principle of using the structural color device to measure acceleration in the present invention;

[0031] Figure 4 Schematic diagram of a typical composition structure of the structural color device of the present invention;

[0032] Figure 5 It is a schematic diagram of the preparation process flow of the structural color device of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A method for measuring acceleration based on structural color devices. Figure 1 The overall process of the method is briefly described in FIG. 1 , which can be viewed simultaneously; the steps of the method are summarized as follows:

[0037] S1. Design and prepare structural color devices with pressure-sensitive metasurfaces using flexible materials;

[0038] S2. For the pressure-sensitive metasurface of the structural color device, a centrifugal effect is produced by a rotation loading method, so that the pressure-sensitive metasurface is subjected to a centrifugal acceleration perpendicular to the plane on which it is located, and calibration is performed;

[0039] S3. During the calibration process, the rotation loading parameters are changed, and the pressure-sensitive metasurface presents different color changes under different rotation loading parameters; the centrifugal acceleration value reflected by the rotation loading parameter and the corresponding pressure-sensitive metasurface color are recorded to form an acceleration-color mapping table of the structural color device;

[0040] S4. After obtaining the acceleration-color mapping table, the calibration process of the structural color device is completed; the structural color device is placed in the model / support vibration acceleration measurement system, and according to the acceleration-color mapping table, the vibration acceleration of the model / support is measured in real time during the flow field test through the color change of the pressure-sensitive metasurface of the structural color device.

[0041] The structural color device mentioned in step S1 refers to the color produced by the physical effects of interference, diffraction, scattering, etc. of light by the nano- or micro-scale structure inside the material, which is different from the color of traditional pigments. These structures can be periodic photonic crystals, metal nanoparticle arrays, or other types of micro-nano structures.

[0042] In step S2, the pressure-sensitive metasurface is subjected to centrifugal acceleration perpendicular to its plane. Since the micro-nano structure of the metasurface is very sensitive to mechanical stress, when subjected to external force, its internal structure will undergo slight deformation, resulting in changes in structural color. This change can be captured by a spectrometer or a high-resolution camera.

[0043] In the calibration process of step S3, the rotation loading parameters (such as rotation speed) are changed, and the color changes of the structural color device under different centrifugal accelerations are recorded, so as to establish an acceleration-color mapping table. The mapping table is obtained by recording experimental data, and can reflect the color response of the structural color device under different acceleration conditions, and is used for calibration comparison of actual measurements.

[0044] Finally, step S4 puts the structural color device into practical application. When the model or the support rod vibrates, the structural color device will change color according to the acceleration it is subjected to. By real-time monitoring of the color change, the magnitude of the acceleration can be inferred using the acceleration-color mapping table.

[0045] The above method and process can be successfully implemented in combination with the development of related technologies. Modern micro-nano processing technology can accurately control the microstructure of materials, thereby preparing structural color devices with the required optical and mechanical properties. In addition, the progress of high-speed imaging technology and spectral analysis makes it possible to capture and analyze structural color changes in real time.

[0046] In this embodiment, the pressure sensitivity of the structural color device comes from the geometric deformation of its micro-nanostructure. When the structure is subjected to external forces (such as forces caused by acceleration), the spacing between the microstructures changes, which directly affects the propagation path of the light waves therein, and then affects the interference and diffraction patterns, which ultimately manifests as a change in color. By accurately controlling and measuring this color change, acceleration can be measured indirectly and contactlessly, which is suitable for application scenarios that require real-time, high-precision acceleration measurement, and is particularly suitable for use in models / struts for high-speed flow field tests.

[0047] Example 2

[0048] Based on Example 1, this example introduces in detail the calibration process and related technical details involved in steps S2 and S3 of the method.

[0049] like Figure 2 As shown, the rotational loading method is completed using a rotational loading platform. The rotational loading platform has a horizontal rotating surface, on which a circle of circular side walls is vertically formed, with an opening above the circular side walls, and the center of the circular side walls corresponds to the rotation center of the rotating surface. During calibration, the structural color device is set on the circular side wall, and a light source is used to emit uniform white light to cover and continuously illuminate the pressure-sensitive metasurface of the rotating structural color device. At the same time, a CCD camera is used to capture and record the color of the pressure-sensitive metasurface of the structural color device in real time.

[0050] It is necessary to introduce the structural design of the structural color device in step S1 here. The structural color of the device is controlled by changing the resonance frequency and intensity of the plasma on the device surface through the action of centrifugal force, so as to measure the acceleration through the change of the structural color of the device. The composition structure of the structural color device is designed. The composition structure of the structural color device includes, from bottom to top: bottom metal, middle medium, and upper metal. Among them, the bottom metal is a reflective layer, the middle medium is a waveguide layer, the middle medium is made of PDMS flexible material, and the upper metal is a grating metal layer. The surface corresponding to the grating metal layer is the pressure-sensitive metasurface of the structural color device.

[0051] Based on the above device structure, in the calibration performed in step S2, the reflective layer of the structural color device is closely attached to the inner side or outer side of the circular side wall to achieve the fixation of the structural color device on the circular side wall.

[0052] For the two methods of being close to the inside or outside, the details are as follows: when the reflective layer of the structural color device is close to the inner side of the circular side wall, the entire circular side wall is made of transparent optical glass material, or an observation window is opened at a position opposite to the setting position of the structural color device on the circular side wall, and the observation window is filled with transparent optical glass material; when the reflective layer of the structural color device is close to the outer side of the circular side wall, the entire circular side wall is made of opaque material with a preset standard background color.

[0053] In this embodiment, whether the inner or outer fixing method is used in the calibration, the structural color device can respond to the centrifugal force through the change of the resonance frequency and intensity of its grating metal layer to achieve the measurement of the corresponding acceleration. The choice of which method mainly depends on the specific requirements of the application scenario, such as internal observation during calibration, physical protection of the device, and convenience of installation and maintenance.

[0054] As a preferred method, during calibration, the shooting direction of the CCD camera is horizontal, the shooting height is the same as the height of the structural color device, and the shooting light path or its extension line passes above the rotation center of the rotating surface of the rotating loading platform, so that at the moment of shooting, the shooting light path of the CCD camera is perpendicular to the plane where the pressure-sensitive metasurface of the structural color device is located.

[0055] The vertical incident angle formed by the CCD camera in the above manner ensures that the angle between the light and the metasurface is 90 degrees, which helps to reduce color changes caused by angle dependence and ensures the accuracy of the calibration measurement results. During calibration, the geometric relationship between the camera and the device is guaranteed to remain unchanged during each shot, reducing measurement errors caused by different viewing angles and improving the comparability and reliability of the data. Using uniform white light to continuously illuminate the rotating structural color device can ensure that the properties and intensity of the light source remain consistent throughout the observation process. This is crucial for quantifying the relationship between pressure and color change, as any changes in lighting conditions may affect the perception and measurement of color.

[0056] Then, in step S3, by changing the rotational angular velocity of the rotating loading stage , to obtain different centrifugal accelerations ; When the rotating loading platform rotates, the centrifugal force on the structural color device for:

[0057]

[0058] In the formula, is the quality of the structural color device, is the distance from the structural color device to the rotation center of the rotating surface of the rotating loading platform, is the angular velocity of rotation; according to Newton's formula, the centrifugal acceleration is obtained The expression is:

[0059]

[0060] Based on centrifugal force and centrifugal acceleration The expression for centrifugal acceleration is With the angular velocity , the distance from the structural color device to the rotation center of the rotating surface of the rotating loading platform The relationship is:

[0061]

[0062] The color of the pressure-sensitive metasurface of the structural color device is denoted as , then the color With the angular velocity The mapping relationship can be recorded as: , indicating that due to different rotation angular speeds Generate different centrifugal forces Corresponding to different colors , which can reflect different centrifugal accelerations The corresponding color , as the acceleration-color mapping table of the structural color device.

[0063] This embodiment also introduces the application of step S4 accordingly. Figure 3 The schematic diagram of the structural color device in the process of measuring the vibration acceleration of the support rod is shown, which can be viewed simultaneously. In step S4, the calibrated structural color device is pasted and fixed to the surface of the model / support rod, and a light source is used to emit uniform white light to continuously illuminate the pressure-sensitive metasurface of the structural color device. At the same time, a CCD camera is used to record the color of the pressure-sensitive metasurface of the structural color device in real time; the model / support rod is placed in a flow field test environment. During the test, when the model / support rod vibrates, the acceleration change caused by the vibration causes the color change of the pressure-sensitive metasurface of the structural color device to be recorded in real time by the CCD camera.

[0064] This embodiment recommends that the resolution of the CCD camera is 2K×2K, the grayscale level of the output image is 4096, and the shortest cross-frame delay is about 200ns. After the shooting and recording is completed, the color change data captured by the CCD camera is processed, and the vibration acceleration of the model or support rod at a specific moment is calculated based on the acceleration-color mapping table as the vibration acceleration measurement result of the model / support rod.

[0065] Example 3

[0066] Based on the above embodiment, this embodiment describes in detail the design and preparation of the structural color device in step S1. Figure 4 The composition structure of the structural color device includes, from bottom to top: bottom metal, middle medium, and upper metal; among them, the bottom metal is the reflective layer, the middle medium is the waveguide layer, the middle medium uses PDMS flexible material, and the upper metal is the grating metal layer; the surface corresponding to the grating metal layer is the pressure-sensitive metasurface of the structural color device.

[0067] According to the composition structure of the structural color device, the structural color is generated as follows:

[0068] The incident light is coupled through the sub-wavelength grating metal layer and the SPP mode on the surface of the PDMS flexible material, that is, the wave vector matching described by the following formula:

[0069]

[0070] In the formula, and Together they represent the projection of the surface SPP and the incident light wave vector in the horizontal plane, which can be described as follows:

[0071]

[0072]

[0073] and Respectively represent and The grating reciprocal lattice basis vector in the direction is described as follows:

[0074]

[0075]

[0076] and Respectively represent and Unit vector of direction; and Indicates different diffraction orders;

[0077] The wave vector matching formula is simplified to obtain the following formula:

[0078]

[0079] In this formula, is the wavelength of incident light; and are the dielectric constants of the middle dielectric layer and the bottom metal as they vary with wavelength; and They represent the upper metal grating and Dimensions in direction; is the incident angle; thus the wave vector matching process is completed;

[0080] After the wave vector is matched, the surface SPP wave at the interface between the bottom metal and the intermediate medium will be excited by the irradiation of the incident light. The distribution of the light field is constrained according to the wavelength of the surface SPP wave in the intermediate medium and the Fabry-Perot resonance wavelength of the intermediate medium cavity. Finally, the structural color of the device is generated by designing the super-surface grating structure of the grating metal layer and the Fabry-Perot medium cavity structure of the PDMS flexible material.

[0081] After the above design process, the preparation of structural color devices can be referred to Figure 5 , as shown below:

[0082] The preparation process is carried out using standard ultra-clean room semiconductor micro-nano processing technology, wherein the material of the underlying metal is Ti or Au; the preparation steps are:

[0083] S11, preparing a metal reflective layer made of Ti or Au on a Si substrate by electron beam sputtering;

[0084] S12, mixing the basic components of the PDMS flexible material and the curing agent in a ratio of 10 to 1 to obtain a PDMS prepolymer, uniformly dropping the PDMS prepolymer onto the metal reflective layer, uniformly spin-coating the metal reflective layer using a coating machine, and then heating and curing the metal reflective layer on a thermostatic table at 80° C.;

[0085] S13, using electron beam lithography to prepare a super surface pattern mask on the PDMS film obtained after curing, and then using plasma etching, electron beam sputtering and metal stripping in sequence to prepare a super surface metal pattern on the PDMS film to form a grating metal layer;

[0086] S14. Use slicing technology to complete the preparation of the entire nanomaterial structural color device.

[0087] In summary, the method proposed in the present invention not only solves many problems of traditional acceleration sensors in high-speed flow field tests, but also provides a novel, efficient and low-cost measurement solution, which greatly improves the safety of the test and the accuracy of the data. It is expected to become an important auxiliary tool for the development of high-speed aircraft in the field of aerospace engineering.

Claims

1. A method for measuring acceleration based on a structural color device, characterized in that: The method comprises the following steps: S1. Design and prepare structural color devices with pressure-sensitive metasurfaces using flexible materials; S2. For the pressure-sensitive metasurface of the structural color device, a centrifugal effect is produced by a rotation loading method, so that the pressure-sensitive metasurface is subjected to a centrifugal acceleration perpendicular to the plane on which it is located, and calibration is performed; S3. During the calibration process, the rotation loading parameters are changed, and the pressure-sensitive metasurface presents different color changes under different rotation loading parameters; the centrifugal acceleration value reflected by the rotation loading parameter and the corresponding pressure-sensitive metasurface color are recorded to form an acceleration-color mapping table of the structural color device; S4. After obtaining the acceleration-color mapping table, the calibration process of the structural color device is completed; the structural color device is placed in the model / support vibration acceleration measurement system, and according to the acceleration-color mapping table, the vibration acceleration of the model / support is measured in real time during the flow field test through the color change of the pressure-sensitive metasurface of the structural color device; In step S2, the rotational loading method is completed using a rotational loading table, which has a horizontal rotating surface, and a circle of circular side walls is vertically formed on the rotating surface. The circular side walls are open above, and the center of the circular side walls corresponds to the rotation center of the rotating surface; during calibration, the structural color device is set on the circular side wall, and a light source is used to emit uniform white light to cover and continuously illuminate the pressure-sensitive metasurface of the rotating structural color device; at the same time, a CCD camera is used to capture and record the color of the pressure-sensitive metasurface of the structural color device in real time.

2. The acceleration measurement method based on a structural color device according to claim 1, characterized in that: In step S1, when designing a structural color device, the device surface plasma resonance frequency and intensity are changed according to the centrifugal force to achieve device structural color control, thereby designing the composition structure of the structural color device based on the principle of acceleration measurement through the change of the device structural color; The structural color device's composition structure, from bottom to top, includes: bottom metal, middle medium, and upper metal; among them, the bottom metal is the reflective layer, the middle medium is the waveguide layer, the middle medium uses PDMS flexible material, and the upper metal is the grating metal layer; the surface corresponding to the grating metal layer is the pressure-sensitive metasurface of the structural color device.

3. The acceleration measurement method based on a structural color device according to claim 2, characterized in that: In the calibration performed in step S2 , the reflective layer of the structural color device is closely attached to the inner side or the outer side of the circular side wall, so that the structural color device is fixed on the circular side wall.

4. The acceleration measurement method based on a structural color device according to claim 3, characterized in that: When the reflective layer of the structural color device is in close contact with the inner side of the circular side wall, the entire circular side wall is made of transparent optical glass material, or an observation window is opened at a position on the circular side wall opposite to the setting position of the structural color device, and the observation window is filled with transparent optical glass material.

5. The acceleration measurement method based on a structural color device according to claim 3, characterized in that: When the reflective layer of the structural color device is in close contact with the outer side of the circular side wall, the entire circular side wall is made of an opaque material with a preset standard background color.

6. The acceleration measurement method based on a structural color device according to claim 4 or 5, characterized in that: During calibration, the shooting direction of the CCD camera is horizontal, the shooting height is the same as the height of the structural color device, and the shooting light path or its extension line passes above the rotation center of the rotating surface of the rotating loading table, so that at the moment of shooting, the shooting light path of the CCD camera is perpendicular to the plane where the pressure-sensitive metasurface of the structural color device is located.

7. The acceleration measurement method based on a structural color device according to claim 1, characterized in that: In step S3, by changing the rotational angular velocity of the rotating loading platform , to obtain different centrifugal accelerations ; When the rotating loading platform rotates, the centrifugal force on the structural color device for: In the formula, is the quality of the structural color device, is the distance from the structural color device to the rotation center of the rotating surface of the rotating loading platform, is the angular velocity of rotation; according to Newton's formula, the centrifugal acceleration is obtained The expression is: Based on centrifugal force and centrifugal acceleration The expression for centrifugal acceleration is With the angular velocity , the distance from the structural color device to the rotation center of the rotating surface of the rotating loading platform The relationship is: The color of the pressure-sensitive metasurface of the structural color device is denoted as , then the color With the angular velocity The mapping relationship can be recorded as: , indicating that due to different rotation angular speeds Generate different centrifugal forces Corresponding to different colors , which can reflect different centrifugal accelerations The corresponding color , as the acceleration-color mapping table of the structural color device.

8. The acceleration measurement method based on a structural color device according to claim 7, characterized in that: In step S4, the calibrated structural color device is pasted and fixed on the surface of the model / support rod, and a light source is used to emit uniform white light to continuously illuminate the pressure-sensitive metasurface of the structural color device. At the same time, a CCD camera is used to record the color of the pressure-sensitive metasurface of the structural color device in real time; the model / support rod is placed in a flow field test environment. During the test, when the model / support rod vibrates, the acceleration change caused by the vibration causes the color of the pressure-sensitive metasurface of the structural color device to change, which is recorded in real time by the CCD camera and processed as the vibration acceleration measurement result of the model / support rod.

9. The acceleration measurement method based on a structural color device according to claim 2, characterized in that: According to the composition structure of the structural color device, the structural color is generated as follows: The incident light is coupled through the sub-wavelength grating metal layer and the SPP mode on the surface of the PDMS flexible material, that is, the wave vector matching described by the following formula: In the formula, and Together they represent the projection of the surface SPP and the incident light wave vector in the horizontal plane, which can be described as follows: and Respectively represent and The grating reciprocal lattice basis vector in the direction is described as follows: and Respectively represent and Unit vector of direction; and Indicates different diffraction orders; The wave vector matching formula is simplified to obtain the following formula: In this formula, is the wavelength of incident light; and are the dielectric constants of the middle dielectric layer and the bottom metal as they vary with wavelength; and They represent the upper metal grating and Dimensions in direction; is the incident angle; thus the wave vector matching process is completed; After the wave vector is matched, the surface SPP wave at the interface between the bottom metal and the intermediate medium will be excited by the irradiation of the incident light. The distribution of the light field is constrained according to the wavelength of the surface SPP wave in the intermediate medium and the Fabry-Perot resonance wavelength of the intermediate medium cavity. Finally, the structural color of the device is generated by designing the super-surface grating structure of the grating metal layer and the Fabry-Perot medium cavity structure of the PDMS flexible material.

Images