CN116774425A - Adjustable super-surface light beam deflection device, application method and preparation method thereof - Google Patents
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Abstract
The application belongs to the field of optical elements, and discloses an adjustable super-surface light beam deflection device, an application method and a preparation method thereof, wherein the adjustable super-surface light beam deflection device comprises the following steps: a supersurface comprising an electret layer and upper and lower electrodes located above and below the electret layer; and applying voltage to the upper electrode and the lower electrode to cause microscopic deformation of an air gap structure of the electret layer, so as to regulate and control the geometric structure of the super-structured surface, further cause the phase change of the optical field and realize the control of the voltage and the optical phase. The technical scheme of the application can realize accurate control of voltage to optical phase, and realize wide-angle, multi-angle and continuous multi-angle beam deflection.
Description
Technical Field
The application belongs to the field of optical elements, and particularly relates to an adjustable super-surface light beam deflection device, an application method and a preparation method thereof.
Background
Tunable super-structured surfaces are the leading edge and hot spot of current optical research, and more remarkable research results are obtained at present.
In the existing beam deflection technology based on the adjustable super-structured surface, three common technical schemes are as follows: 1. modulating based on field effect; 2. tuning based on the wavefront of the phase change material; 3. an adjustable super-structured surface based on liquid crystal modulation.
In the technical scheme based on field effect modulation, the limited phase modulation range limits the angle range of beam deflection, the beam deflection is mainly switched by the angle, and the technical scheme causes the problem of low diffraction efficiency under the condition that most devices work near absorption resonance.
Based on wave front tuning of phase change materials, multi-angle deflection switching is difficult to realize, once the physical size of a device is determined, the deflection angle is also determined, light beam deflection is realized by high-order diffraction, the efficiency is low, long-distance detection is limited to a certain extent, and the modulation means needs to additionally use heavy optical elements for thermal braking so as to change the physical state of the materials, so that miniaturization and integration application are difficult to realize in the future. As the size of the ultra-surface aperture increases, the mitigation of thermal non-uniformity becomes a key challenge, and the migration of elements due to thermal cycling can lead to defects at the edges of the device, and non-uniformity of crystallization can lead to spectral shifts, thereby limiting the device's cycle life and reliability.
In the technical scheme of the adjustable super-structured surface based on liquid crystal modulation, the non-uniformity of liquid crystal molecule arrangement, the susceptibility to disturbance and other factors can reduce the modulation efficiency of polarized light, induce instability problems, and prevent the further application and the practical application of the device due to the environment/temperature sensitivity of the liquid crystal molecules.
Therefore, the existing beam deflection technology based on the adjustable super-structured surface cannot efficiently realize large-angle continuous scanning.
Disclosure of Invention
The application aims to provide an adjustable super-surface light beam deflection device, an application method and a preparation method thereof, so as to solve the problems in the prior art.
In order to achieve the above object, the present application provides a piezoelectric electret adjustable super-surface beam deflection device, comprising:
a supersurface comprising an electret layer and upper and lower electrodes on the electret layer;
the electret layer is internally provided with an air gap structure which is a solid geometry structure.
Optionally, the solid geometry structure comprises one or more of a cylinder, a cuboid, and a cube.
Optionally, the upper electrode is a silver nanowire transparent electrode, and the lower electrode is a transparent conductive metal oxide layer.
A method of using a piezoelectric electret adjustable super-surface beam deflection device, comprising:
by applying voltage to the upper electrode and the lower electrode, the air gap structure of the electret layer is subjected to microscopic deformation, so that the geometric structure of the super-structure surface is regulated and controlled, the phase change of the optical field is further caused, and the control of the voltage and the optical phase is realized.
Optionally, the process of micro-deforming the air gap structure of the electret layer includes:
and (3) carrying out gas gap breakdown on the gas layer of the electret layer by applying voltage to the upper electrode and the lower electrode to generate positive and negative charges, and enabling the positive and negative charges to enter the electret layer and store the positive and negative charges through a corona polarization method and a contact polarization method.
Optionally, constructing an equivalent circuit of the super surface based on the electret layer, and performing calculation and analysis on the equivalent circuit through a Gaussian theorem to obtain corresponding relation data of the voltage and microscopic deformation of the air gap structure;
the calculation formula for obtaining the corresponding relation data comprises the following steps:
obtaining the electric field magnitude of the electret layer and the air layer in the electret layer through the Gaussian theorem:
-ε 0 ε r E 1i -ε 0 E 2i-1 ＝σ i-1
ε 0 ε r E 1i +ε 0 E 2i ＝σ i
wherein E1i and E2i respectively represent the electric field magnitude and sigma in the electret layer and the air layer i Representing the charge density, ε, at the electret-air interface r Indicating the relative permittivity, epsilon, of the electret layer 0 Represents the vacuum dielectric constant;
obtaining the potential difference V on the two electrodes and the thicknesses d1i and d2i of the electret layer and the air gap structure according to the kirchhoff second law:
-ε 0 ε r E 1i ＝-σ
wherein σ is the charge density on the upper electrode and the lower electrode;
acquiring electric field strength E in the electret layer according to an air gap breakdown theory and a Gaussian theorem 1i And charge density on the electret layer:
wherein d is the thickness of the air gap, V bre To correspond to the breakdown voltage of the air gap E 2i ＝V bre /d is the maximum electric field allowed in the gas layer, d air The total thickness of the electret layer is d e ；
Layered theoretical model based on piezoelectric electretsPiezoelectric coefficient d of electret layer 33 The method comprises the following steps:
wherein Y is Young's modulus in the thickness direction, d e ＝∑ i d 1i ，d air ＝∑ i d 2i Indicating the total thickness of the electret layer and the air layer, respectively;
the inverse piezoelectric coefficient of the electret is:
acquiring the corresponding relation data according to the inverse piezoelectric effect:
wherein s is 3 、d 33 The strain and the electric field in the thickness direction of the piezoelectric electret film are expressed, Δl represents the deformation amount of the device, and L represents the total length in the thickness direction of the film.
Optionally, the process of implementing control of the optical phase of the voltage includes:
and acquiring change relation data between the microscopic deformation quantity and the optical field phase, and carrying out combination analysis on the change relation data and the corresponding relation data to obtain influence relation data of voltage on the optical field phase, so as to realize control of the voltage on the optical phase.
In order to achieve the above object, the present application provides a method for manufacturing a piezoelectric electret adjustable super-surface beam deflection device, including:
a first silicon substrate is obtained, a buffer layer is paved on the first silicon substrate, transparent silver nanowires are obtained and are plated above the buffer layer in order, a polydimethylsiloxane layer is generated above the transparent silver nanowires through a spin coating method and a defoaming treatment method, and upper electrode manufacturing is completed;
obtaining a second silicon substrate, cleaning the second silicon substrate, photoetching the cleaned second silicon substrate by a photoresist homogenizer, spin-coating photoresist on the substrate in the photoetching process, baking the photoresist by a hot plate to fix the photoresist, performing selective exposure and development by an electron beam exposure photoetching machine, removing the photoresist layer after the selective exposure and development is finished, and cleaning by deionized water to finish the preparation of the ultra-structured surface imprinting master;
taking a conductive metal oxide as a lower electrode, spin-coating a polydimethylsiloxane solution above the lower electrode through a spin-coating method, demolding the super-structured surface imprinting master plate through spin-coating a demolding agent, pressing the super-structured surface imprinting master plate on the polydimethylsiloxane solution after demolding is finished to imprint, stripping the super-structured surface imprinting master plate after imprinting is finished to obtain a polydimethylsiloxane solution layer, processing the polydimethylsiloxane solution layer through plasma, and bonding the upper electrode on the surface of the polydimethylsiloxane solution layer after processing is finished to finish electret layer preparation;
and stripping the first silicon substrate by a solution soaking method to finish the preparation of the piezoelectric electret adjustable super-surface beam deflection device.
The application has the technical effects that:
the piezoelectric electret adjustable super-surface light beam deflection device provided by the application can deform a device by utilizing the inverse piezoelectric effect of the device, namely by applying voltage to two ends of the device, when an air gap is extruded to generate microscopic deformation, namely the geometric structure of the super-structure surface is regulated and controlled, the fluctuation of an optical field is caused, so that the accurate control of voltage on the optical phase is realized, the multiple purposes of the adjustable super-structure surface are realized, and the light beam deflection with large angle, multiple angles and continuous multiple angles is realized; the device adopts a flexible device, the manufacturing process cost is low, the device is insensitive to environment and temperature, and the device has good stability.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a piezoelectric electret adjustable super-surface beam deflection device for realizing beam deflection in an embodiment of the application;
FIG. 2 is a schematic diagram of a piezoelectric electret equivalent circuit in an embodiment of the application;
FIG. 3 is a flow chart of the fabrication of a piezoelectric electret adjustable super-surface beam deflector device in an embodiment of the application;
FIG. 4 is a diagram showing the relationship between microscopic deformation and optical field phase in an embodiment of the present application;
FIG. 5 is a schematic diagram showing the beam deflection effect according to an embodiment of the present application;
FIG. 6 is a schematic diagram showing the beam deflection effect at different angles according to an embodiment of the present application;
FIG. 7 is a diagram showing the relationship between the normalized light intensity and the deflection angle for realizing the deflection of the dual beam at different angles under different phase gradients in the embodiment of the present application.
Detailed Description
Various exemplary embodiments of the application will now be described in detail, which should not be considered as limiting the application, but rather as more detailed descriptions of certain aspects, features and embodiments of the application.
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.
Example 1
As shown in fig. 1-7, in this embodiment, an adjustable super-surface beam deflection device, an application method and a preparation method thereof are provided, including:
a supersurface comprising an electret layer and upper and lower electrodes on the electret layer;
the electret layer is internally provided with an air gap structure which is a solid geometry structure.
The solid geometry structure may include one or more of a cylinder, a cuboid, and a cube.
The upper electrode may be a silver nanowire transparent electrode, and the lower electrode may be a transparent conductive metal oxide layer.
The method comprises the steps of obtaining a first silicon substrate, paving a buffer layer on the first silicon substrate, obtaining transparent silver nanowires, orderly plating the transparent silver nanowires above the buffer layer, and generating a polydimethylsiloxane layer above the transparent silver nanowires by a spin-coating method and a defoaming treatment method to finish upper electrode manufacturing;
obtaining a second silicon substrate, cleaning the second silicon substrate, photoetching the cleaned second silicon substrate by a photoresist homogenizer, spin-coating photoresist on the substrate in the photoetching process, baking the photoresist by a hot plate to fix the photoresist, performing selective exposure and development by an electron beam exposure photoetching machine, removing the photoresist layer after the selective exposure and development is finished, and cleaning by deionized water to finish the preparation of the ultra-structured surface imprinting master;
taking a conductive metal oxide as a lower electrode, spin-coating a polydimethylsiloxane solution above the lower electrode through a spin-coating method, demolding the super-structured surface imprinting master plate through spin-coating a demolding agent, pressing the super-structured surface imprinting master plate on the polydimethylsiloxane solution after demolding is finished to imprint, stripping the super-structured surface imprinting master plate after imprinting is finished to obtain a polydimethylsiloxane solution layer, processing the polydimethylsiloxane solution layer through plasma, and bonding the upper electrode on the surface of the polydimethylsiloxane solution layer after processing is finished to finish electret layer preparation;
and stripping the first silicon substrate by a solution soaking method to finish the preparation of the piezoelectric electret adjustable super-surface beam deflection device.
(1) Device model:
the embodiment is intended to propose a tunable super-structured surface based on piezoelectric electrets for dynamic beam deflection, the designed device structure is shown in fig. 1, and the optical device mainly comprises upper and lower transparent electrode layers and an intermediate piezoelectric electret substrate. The upper surface electrode adopts a silver nanowire (AgNanowires, agNWs) transparent electrode, and the lower surface electrode adopts a transparent conductive metal oxide layer, such as indium tin oxide and aluminum zinc oxide glass, or a flexible transparent electrode. The upper and lower electrodes of the device may be any other conductive electrode material, such as opaque metal electrodes of Al, cu, ag, etc. The middle piezoelectric electret substrate is internally composed of an air gap with an ultra-structured surface, and the air gap structure can be in various morphological structures such as a cylinder, a cuboid, a cube and the like. The material of the piezoelectric electret substrate may be Polydimethylsiloxane (PDMS), silicone gel (Ecoflex) or other high-flexibility and stretchable materials.
(2) Basic conceptual explanation of piezoelectric electrets:
the piezoelectric electret is a flexible porous electret material with strong piezoelectric effect, and is a novel artificial microstructure flexible electromechanical coupling material. The piezoelectricity is derived from the orientation arrangement of bipolar space charges on a matrix and the special micropore structure of the material, and the typical piezoelectric coefficient d33 in the study can reach 3000-6000 pC/N.
After the piezoelectric electrets are polarized, electric dipoles are arranged in an oriented mode to form electric domains. When mechanical pressure/stress is applied to the piezoelectric electret film, the thickness of the film is reduced, the deformation of the material forces the electric dipole to deflect, the electric dipole moment is changed accordingly, and accordingly electric domain change is generated, the electric dipole/electric domain change breaks the potential balance inside the material, meanwhile, potential difference is generated on the upper electrode and the lower electrode, and the piezoelectric electret shows a piezoelectric-like effect. In contrast to the piezoelectric effect, when a certain voltage is applied to both sides of the piezoelectric electret film, the electric dipole is forced to deflect by an external electric field, so that internal stress of the material is generated, and further the thickness/volume of the material is changed, and the piezoelectric electret exhibits a piezoelectric-like effect, which is called an inverse piezoelectric effect. The embodiment utilizes the inverse piezoelectric effect of the device, namely, the device can be deformed by applying voltage to two ends of the device, when the air gap is extruded to generate microscopic deformation, namely, the geometric structure of the super-structured surface is regulated, the variation of an optical field is caused (the wave front/phase of an incident light field is changed), so that the accurate control of the voltage on the optical phase is realized, and the multiple purposes of the tunable super-structured surface are realized.
(3) Polarization principle of piezoelectric electret:
the piezoelectric properties of a piezoelectric electret are created by an electric-like dipole within the material, and the formation of the electric-like dipole results from the different number charges stored by the electret material after polarization. In the polarization process, when a high voltage is applied to two sides of the piezoelectric electret, a strong electric field is formed in the gas layer in the material, when the electric field (voltage) rises to a certain value, gas gap breakdown occurs, so that positive and negative charges are generated, the positive and negative charges move in opposite directions under the action of an external electric field, and finally, the positive and negative charges are captured and stored at an electret-gas interface. Corona polarization and contact polarization may be used to inject charge into the electret material for storage.
The gas gap breakdown phenomenon is described by Paschen's law (Paschen' slaw) and thomson theory (thomson theory), the gas gap breakdown voltage V bre The method comprises the following steps:
where p and d represent the gas pressure and air gap thickness, respectively, M, N is an experimental parameter, γ is the secondary ionization coefficient, and represents the process coefficient of electron emission generated when ions strike the cathode. The principle of air gap breakdown determines the breakdown voltage at a certain air gap height in theory, so as to determine the initial charge quantity of the polarized device.
(4) Basic working principle of piezoelectric electret:
the piezoelectric electret device of this embodiment is equivalent to a parallel plate capacitor structure as shown in fig. 2. In the equivalent circuit model, the electret structure is composed of a fixed capacitor (electret layer C1 i) and an equivalent variable capacitor (air gap layer C2 j) which are alternately connected in series (i=1, 2, … n+1;j =1, 2, … n; wherein n represents the number of air layers), and the ith gas layer (variable capacitor) is arranged above and below the ith gas layerThe surface charge densities are sigma respectively i And-sigma i The induced charge densities of the upper electrode and the lower electrode are-sigma and sigma respectively, and the external resistor load is R.
The upper and lower surfaces of the ith electret are made into Gaussian surfaces, and the Gaussian theorem is used for obtaining:
-ε 0 ε r E 1i -ε 0 E 2i-1 ＝σ i-1
ε 0 ε r E 1i +ε 0 E 2i ＝σ i
wherein E1i and E2i respectively represent the electric field magnitude and sigma in the electret layer and the air layer i Representing the charge density, ε, at the electret-air interface r Indicating the relative permittivity, epsilon, of the electret material 0 Indicating the vacuum dielectric constant. From the gaussian theorem:
-ε 0 ε r E 1i ＝-σ
where σ represents the charge density on the electrode, and the output voltage expression of the device is according to kirchhoff's second law:
where V is the potential difference across the two electrodes, d1i, d2i represent the thickness of the electret layer and air layer, respectively.
According to the air gap breakdown theory, the thickness of the air gap is set to d, and the breakdown voltage of the corresponding air gap is V bre The maximum allowable electric field in the gas layer is E 2i ＝V bre And/d. Let the total thickness of the air gap be d air The total thickness of the electret layer is d e . It is assumed that the air layer is uniformly deformed and that the charge density carried by each electret layer is equal. In a stable state, v=0, the electric field strength in the electret layer can be obtained as:
according to the gaussian theorem, the charge density on the electret layer can be expressed as:
the charge density is attenuated, and the attenuation is 1/3 when the charge density is stabilized;
according to the layered theoretical model of the piezoelectric electret, the piezoelectric coefficient d of the piezoelectric electret can be calculated 33 Expressed as:
wherein Y is Young's modulus in the thickness direction, d e ＝∑ i d 1i ，d air ＝∑ i d 2i Indicating the total thickness of the electret layer and air layer, respectively. The inverse piezoelectric coefficient of the piezoelectric electret is:
by the inverse piezoelectric effect:
wherein s is 3 、d 33 The strain and the electric field in the thickness direction (z-axis) of the piezoelectric electret film are expressed, Δl represents the deformation amount (displacement amplitude value) of the device, and L represents the total length in the thickness direction (z-axis) of the film.
According to the above formula and deduction result, under the action of external voltage, the gap of air gap will deform due to the inverse piezoelectric effect of the device, and the deformation of the device and the piezoelectric coefficient d of piezoelectric electret 33 Closely related.
(5) Simulation result/effect display:
obtaining the corresponding relation between deformation (displacement) and voltage: as shown in fig. 4, under the action of 0-1000 v,1hz frequency voltage, the change relation of the air gap displacement of the super surface with time,
acquiring the change relation of the phase and the transmittance along with the deformation: as shown in fig. 5, when the air gap height changes, i.e., the device is deformed, a change in the optical field phase will be caused;
taking an example of realizing a beam deflector by using an ultra-structure piezoelectric electret, the beam deflector realizes the deflection effect display of a specific deflection angle;
principle of beam deflection: using the snell generalized refraction law:
wherein n is t And n i Refractive index of outgoing medium and incident medium respectively, θ i And theta t Respectively, the incident angle and the exit angle of the light beam, lambda is the wavelength of the incident light,is a spatial phase gradient. When incident light theta i When=0°, the exit angle can be obtained according to the formula, i.e. the beam deflection angle. When different voltage gradients are applied to the electret unit, an adjustable phase gradient dphi can be obtained, so that the switching of different deflection angles of the light beam is realized.
And (3) showing a beam deflection effect: FIG. 6 (a) shows a graph of the relative phase versus relative position for a subsurface air gap height with implementation of + -38.1 DEG, and FIG. 6 (b) shows a graph of far field normalized light intensity for a spot with implementation of + -38.1 DEG deflection angle;
the beam deflector realizes deflection effect display of different angles: FIG. 7 shows the relationship between normalized intensity and deflection angle for different angles of dual beam deflection achieved with different phase gradients.
(6) The preparation process of the device comprises the following steps: the choice of materials can vary, taking the case of a transmissive device where the upper electrode is a silver nanowire transparent electrode, the electret substrate is PDMS, and the lower electrode is a conductive metal oxide (ITO) as examples.
The main process flow of the tunable super-structured surface device based on the piezoelectric electret proposed in the embodiment is shown in fig. 3.
Transparent silver nanowire electrode: first, silver nanowires are orderly arranged on a silicon substrate plated with a buffer layer. And then, processing to remove the polymer on the surface of the silver nanowire, and simultaneously realizing self-welding of the silver nanowire node so as to improve the electrical performance. Next, a Polydimethylsiloxane (PDMS) solution was coated over the silver nanowires, subjected to a defoaming treatment (hereinafter, the same treatment as the PDMS solution), and left standing for a certain period of time, and then placed in a vacuum oven for curing, to prepare a flexible transparent electrode.
Super-structured surface imprinting master: the silicon substrate is first cleaned. Next, an electron beam resist was spin-coated on the silicon substrate sheet using a spin coater, and then the silicon substrate was moved to a hot plate to perform "pre-bake" to volatilize the solution in the photoresist and maintain the exposure characteristics stable. The selective exposure is carried out by an electron beam exposure photoetching machine, and after development, post baking, namely film hardening treatment is carried out on a heating plate with the temperature slightly higher than 100 ℃ so that the photoresist is adhered with the substrate more tightly. And then, the silicon layer is etched by optimizing the etching process so as to realize the nano-pillars with smooth surfaces and high aspect ratios. And finally, removing the photoresist layer, and repeatedly cleaning with deionized water to prepare the super-structured surface imprinting master.
Pattern embossing and bonding: first, a PDMS solution was spin-coated on a custom metal oxide transparent electrode glass substrate. The surface of the super-structured surface imprinting master plate prepared in the earlier stage is required to be treated before imprinting, and the free energy of the master plate surface is reduced by spin coating of a nano imprinting mold release agent, so that the subsequent master plate stripping process is facilitated. Subsequently, the master is pressed on the PDMS solution, and after the PDMS solution is completely solidified, the nanoimprint process is completed and the master is peeled off. The surface of the PDMS layer was treated with plasma to enhance bonding strength before bonding to the transparent electrode of the silver nanowires. And finally, stripping the silicon substrate from the buffer layer by using a solution soaking method to finish the preparation of the super-structure piezoelectric electret device.
The present application is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present application are intended to be included in the scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims (8)
1. A piezoelectric electret adjustable subsurface beam deflection device, comprising:
a supersurface comprising an electret layer and upper and lower electrodes on the electret layer;
the electret layer is internally provided with an air gap structure which is a solid geometry structure.
2. A piezoelectric electret tunable ultra-surface beam deflection apparatus as defined in claim 1, wherein,
the solid geometry structure comprises one or more of a cylinder, a cuboid and a cube.
3. A piezoelectric electret tunable ultra-surface beam deflection apparatus as defined in claim 1, wherein,
the upper electrode adopts a silver nanowire transparent electrode, and the lower electrode adopts a transparent conductive metal oxide layer.
4. A method of using a piezoelectric electret adjustable super-surface beam deflection device, comprising:
by applying voltage to the upper electrode and the lower electrode, the air gap structure of the electret layer is subjected to microscopic deformation, so that the geometric structure of the super-structure surface is regulated and controlled, the phase change of the optical field is further caused, and the control of the voltage and the optical phase is realized.
5. The method of claim 4, wherein,
the process for generating microscopic deformation of the air gap structure of the electret layer comprises the following steps:
and (3) carrying out gas gap breakdown on the gas layer of the electret layer by applying voltage to the upper electrode and the lower electrode to generate positive and negative charges, and enabling the positive and negative charges to enter the electret layer and store the positive and negative charges through a corona polarization method and a contact polarization method.
6. The method of claim 5, wherein,
constructing an equivalent circuit of the super surface based on the electret layer, and performing calculation and analysis on the equivalent circuit through a Gaussian theorem to obtain corresponding relation data of the voltage and microscopic deformation of the air gap structure;
the calculation formula for obtaining the corresponding relation data comprises the following steps:
obtaining the electric field magnitude of the electret layer and the air layer in the electret layer through the Gaussian theorem:
-ε 0 ε r E 1i -ε 0 E 2i-1 ＝σ i-1
ε 0 ε r E 1i +ε 0 E 2i ＝σ i
wherein E1i and E2i respectively represent the electric field magnitude and sigma in the electret layer and the air layer i Representing the charge density, ε, at the electret-air interface r Indicating the relative permittivity, epsilon, of the electret layer 0 Represents the vacuum dielectric constant;
obtaining the potential difference V on the two electrodes and the thicknesses d1i and d2i of the electret layer and the air gap structure according to the kirchhoff second law:
-ε 0 ε r E 1i ＝-σ
wherein σ is the charge density on the upper electrode and the lower electrode;
acquiring electric field strength E in the electret layer according to an air gap breakdown theory and a Gaussian theorem 1i And charge density on the electret layer:
wherein d is the thickness of the air gap, V bre To correspond to the breakdown voltage of the air gap E 2i ＝V bre /d is the maximum electric field allowed in the gas layer, d air The total thickness of the electret layer is d e ；
According to a layered theoretical model of the piezoelectric electret, the piezoelectric coefficient d of the electret layer 33 The method comprises the following steps:
wherein Y is Young's modulus in the thickness direction, d e ＝∑ i d 1i ，d air ＝∑ i d 2i Indicating the total thickness of the electret layer and the air layer, respectively;
the inverse piezoelectric coefficient of the electret is:
acquiring the corresponding relation data according to the inverse piezoelectric effect:
wherein s is 3 、d 33 The strain and the electric field in the thickness direction of the piezoelectric electret film are expressed, Δl represents the deformation amount of the device, and L represents the total length in the thickness direction of the film.
7. The application method according to claim 6, wherein,
the process for realizing the control of the voltage to the optical phase comprises the following steps:
and acquiring change relation data between the microscopic deformation quantity and the optical field phase, and carrying out combination analysis on the change relation data and the corresponding relation data to obtain influence relation data of voltage on the optical field phase, so as to realize control of the voltage on the optical phase.
8. A method for manufacturing a piezoelectric electret adjustable super-surface beam deflection device, which is characterized by comprising the following steps:
a first silicon substrate is obtained, a buffer layer is paved on the first silicon substrate, transparent silver nanowires are obtained and are plated above the buffer layer in order, a polydimethylsiloxane layer is generated above the transparent silver nanowires through a spin coating method and a defoaming treatment method, and upper electrode manufacturing is completed;
obtaining a second silicon substrate, cleaning the second silicon substrate, photoetching the cleaned second silicon substrate by a photoresist homogenizer, spin-coating photoresist on the substrate in the photoetching process, baking the photoresist by a hot plate to fix the photoresist, performing selective exposure and development by an electron beam exposure photoetching machine, removing the photoresist layer after the selective exposure and development is finished, and cleaning by deionized water to finish the preparation of the ultra-structured surface imprinting master;
taking a conductive metal oxide as a lower electrode, spin-coating a polydimethylsiloxane solution above the lower electrode through a spin-coating method, demolding the super-structured surface imprinting master plate through spin-coating a demolding agent, pressing the super-structured surface imprinting master plate on the polydimethylsiloxane solution after demolding is finished to imprint, stripping the super-structured surface imprinting master plate after imprinting is finished to obtain a polydimethylsiloxane solution layer, processing the polydimethylsiloxane solution layer through plasma, and bonding the upper electrode on the surface of the polydimethylsiloxane solution layer after processing is finished to finish electret layer preparation;
and stripping the first silicon substrate by a solution soaking method to finish the preparation of the piezoelectric electret adjustable super-surface beam deflection device.
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