CN116345168A - Electromagnetic super-surface device and preparation method thereof - Google Patents

Abstract

The electromagnetic super-surface device and the preparation method provided by the application comprise a super-surface structure unit array layer and an auxiliary layer, wherein a plurality of micro-fluid channels capable of allowing working liquid to flow are arranged on the super-surface structure unit array layer, any micro-fluid channel is provided with super-surface structure units in an arrayed mode, the auxiliary layer comprises an encapsulation layer, the encapsulation layer comprises an upper encapsulation layer and a lower encapsulation layer, and the super-surface structure unit array layer is arranged between the upper encapsulation layer and the lower encapsulation layer.

Description

Electromagnetic metasurface device and preparation method

technical field

The application belongs to the technical field of artificial electromagnetic materials, and in particular relates to an electromagnetic metasurface device and a preparation method.

Background technique

Electromagnetic metasurface, also known as artificial electromagnetic surface, is essentially equivalent to a two-dimensional artificial metamaterial with negligible longitudinal thickness. Thin surface for low loss and easy conformability. By rationally designing the morphology structure of metasurface units and their array arrangement, comprehensive regulation of electromagnetic waves can be achieved. Early metasurfaces mainly used the periodic arrangement of units with the same structure, such as frequency selective surfaces, electromagnetic band gaps, polarization grids, artificial magnetic conductors, etc.

Because the structure and function of the above-mentioned metasurface electromagnetic devices are relatively fixed, it is often difficult to meet the diverse control requirements for electromagnetic waves with only a single device. In recent years, reconfigurable electromagnetic metasurfaces have emerged as the times require. The classic reconfigurable methods mainly use tuning devices such as varactor diodes, PIN diodes, and microelectromechanical system switches, or mechanical stretching and rotation. In terms of material selection, Mostly solid metal and dielectric materials are used. The present invention seeks a new reconfigurable mechanism to improve the reconfigurable ability of the electromagnetic metasurface.

Contents of the invention

The invention provides a reconfigurable electromagnetic metasurface device based on liquid metal and microfluidic technology and a preparation method thereof.

The application adopts the following technical solutions:

One of the purposes of the present application is to provide an electromagnetic metasurface device, including a metasurface structural unit array layer and an auxiliary layer, and several microfluidic channels for working liquid flow are arranged on the metasurface structural unit array layer, Any one of the microfluidic channels is arranged with metasurface structural units, the auxiliary layer includes an encapsulation layer, and the encapsulation layer includes an upper encapsulation layer and a lower encapsulation layer, and the metasurface structural unit array layer is installed on the upper encapsulation layer layer and the lower encapsulation layer.

In some of these embodiments, several microfluidic channels have the same or different shapes.

In some of these embodiments, several microfluidic channels are independent and not connected to each other.

In some of the embodiments, the working liquid includes liquid metal, and the liquid metal is gallium indium tin alloy.

In some embodiments, the working fluid further includes a lubricating fluid that is mutually non-wetting with the liquid metal, and the lubricating fluid includes but is not limited to simethicone.

In some of these embodiments, the metasurface structure unit is a helical or linear or zigzag or open ring structure and various derivatives thereof.

In some of these embodiments, an isolation layer and a flow guide layer are sequentially arranged between the metasurface structure unit array layer and the lower encapsulation layer, the isolation layer is provided with a through hole structure, and the flow guide layer is provided with Has a microchannel structure.

In some of these embodiments, the upper encapsulation layer, the metasurface structural unit array layer, the isolation layer, the flow guide layer, and the lower encapsulation layer are bonded with pressure-face adhesive, and applied A certain pressure discharges the air bubbles in the non-channel area to ensure the bonding quality between the layers.

In some of these embodiments, through holes are also opened on the upper encapsulation layer.

The second purpose of the present application is to provide a method for preparing an electromagnetic metasurface device, comprising the following steps:

Carry out pretreatment to substrate, described substrate comprises plexiglass plate or polyimide film;

Micro-machining technology is used to process the metasurface structural unit array layer on the surface of the substrate, and several microfluidic channels for the flow of working liquid are arranged on the metasurface structural unit array layer, and any one of the microfluidic channels is Arranged with metasurface structural units;

The metasurface structure unit array layer is installed between the upper encapsulation layer and the lower encapsulation layer, and the upper encapsulation layer and the lower encapsulation layer are both processed from the base material.

In some of these embodiments, the following steps are also included:

Passing simethicone oil into any one of the microfluidic channels for surface pretreatment;

Seal the liquid metal with sodium hydroxide solution in an oxygen-free environment to remove the oxide layer on the surface of the liquid metal;

The electronic syringe pump is used to sequentially circulate quantitatively to form a working liquid in the microfluidic channel that combines liquid metal and sodium hydroxide solution in stages;

The microfluidic channel filled with working liquid is installed in the corresponding holes of the upper encapsulation layer and sealed well.

The application adopts the above-mentioned technical solution to have the following effects:

The electromagnetic metasurface device and preparation method provided by the application include a metasurface structural unit array layer and an auxiliary layer, and a plurality of microfluidic channels for working liquid flow are arranged on the metasurface structural unit array layer, and any one of the microfluidic channels The metasurface structure unit is arranged on the fluid channel, the auxiliary layer includes an encapsulation layer, the encapsulation layer includes an upper encapsulation layer and a lower encapsulation layer, and the metasurface structure unit array layer is installed on the upper encapsulation layer and the lower encapsulation layer Among them, in the electromagnetic metasurface device and preparation method provided by this application, the liquid metal has many characteristics such as high conductivity, good fluidity, and controllable deformation. Applying liquid metal materials in the design of reconfigurable metasurface electromagnetic devices, combined with microfluidic technology, through the rational design of the microfluidic channel structure of the microfluidic chip, the shape and size of liquid metal can be changed as needed, and ultra-wideband, The multi-state performance can be reconfigured to ensure that the device meets different functional requirements in real time under complex application scenarios; secondly, liquid metal does not have the nonlinear characteristics of control components, and it has high power capacity, which can meet the power requirements of more electronic systems ; In addition, using flexible materials such as polydimethylsiloxane and polyimide film to design liquid metal microfluidic channels can design conformable electromagnetic devices.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present application or in the description of the prior art. Obviously, the accompanying drawings described below are only of the present application For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without creative effort.

Fig. 1 is the schematic diagram of layered structure of the electromagnetic metasurface device of embodiment 1 of the present invention;

2 is a schematic diagram of various working states of the electromagnetic metasurface device of Embodiment 1 of the present invention;

3 is a schematic diagram of the layered structure of the electromagnetic metasurface device of Embodiment 2 of the present invention;

4 is a schematic cross-sectional structure diagram of an electromagnetic metasurface device according to Embodiment 2 of the present invention;

5 is a schematic diagram of various working states of the electromagnetic metasurface device according to Embodiment 2 of the present invention;

Fig. 6 is a schematic diagram of the preparation process of the electromagnetic metasurface device provided by Embodiments 1 and 2 of the present invention.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, and are intended to explain the present application, and should not be construed as limiting the present application.

In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings , is only for the convenience of describing the present application and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

Example 1

Please refer to FIG. 1 , which is a schematic structural diagram of an electromagnetic metasurface device provided by an embodiment of the present application, including: a metasurface structural unit array layer 2 and an auxiliary layer 10 . The specific implementation solutions of each layer are described in detail below.

Several microfluidic channels for the flow of working liquid are arranged on the metasurface structure unit array layer 1, and a metasurface structure unit 5 is arranged on any one of the microfluidic channels.

Specifically, several microfluidic channels have the same or different shapes.

Further, the several microfluidic channels are independent from each other and not communicated with each other.

It can be understood that the microfluidic channel can be controlled independently or jointly controlled by multiple channels, that is, in an external control device such as a high-precision electronic syringe pump and its supporting pipelines, the high-precision electronic syringe pump can precisely control the microfluidic channel. The flow rate and velocity of the working liquid in the channel.

Specifically, the metasurface structure unit 5 is a helical or linear or zigzag or open ring structure and various derivatives thereof.

It can be understood that the metasurface structure unit 5 of the microfluidic channel determines the size, shape and arrangement of the metal microstructure. According to the subwavelength electromagnetic theory, different subwavelength metal microstructures have corresponding resonant operating frequencies and impedance matching characteristics. Physical parameters such as the amplitude, polarization, and phase of electromagnetic waves can be effectively controlled. The metasurface structure unit 5 can be configured in a spiral shape, a broken line shape, a split ring structure shape and various derivatives or combinations thereof to meet different functional requirements for electromagnetic wave regulation. Specifically, the working liquid includes liquid metal, a segmented mixture of liquid metal and other liquids, simethicone lubricating liquid and other liquid substances necessary to ensure the normal operation of the device, and the liquid metal is gallium indium tin alloy.

It can be understood that liquid metal combines the excellent properties of solid metal and fluid medium materials, and has conductivity and fluidity at the same time. Gallium indium tin alloy is suitable for the preparation of various electromagnetic devices. The main reasons are as follows. First, it has low viscosity and good fluidity, which is easy to inject into microchannels; second, it has good electrical conductivity, and its conductivity is much higher than that of other conductive liquids; third, Its performance is stable and not volatile; fourth, it has no biological toxicity, which ensures the safety and reliability of the device.

Further, the microfluidic channel is also pre-filled with a lubricating liquid that is mutually non-wetting with the liquid metal, and the lubricating liquid includes but is not limited to simethicone oil.

The encapsulation layer 10 includes an upper encapsulation layer 1 and a lower encapsulation layer 3 , and the metasurface structure cell array layer is installed between the upper encapsulation layer 1 and the lower encapsulation layer 3 .

Further, through holes 4 are opened on the upper packaging layer 1 .

It can be understood that under the action of the through hole 4, the upper encapsulation layer 1, the metasurface structure unit array layer and the lower encapsulation layer 3 are bonded with pressure-face adhesive, and a certain pressure is applied to discharge the non-channel area. Air bubbles to ensure the quality of fit between layers. The electromagnetic metasurface device provided in the above-mentioned Example 1 of the present application adopts liquid metal microfluidic technology, and controls the flow rate and flow direction of the working liquid in each microfluidic channel through a high-precision electronic syringe pump, which can precisely control the flow of the working liquid in the microfluidic channel. The position and shape of the electromagnetic metasurface device, so as to realize the continuous real-time reconfiguration of the working state and performance of the electromagnetic metasurface device. Several working states of the device are shown in Figure 2. In the microfluidic channel, the black part is liquid metal, and the white part is sodium hydroxide. solution.

In this embodiment, polyimide films are used as materials to process electromagnetic metasurface devices, which can be attached to various surfaces to meet various conformal application requirements.

Example 2

Please refer to FIG. 3 and FIG. 4 , which are schematic structural diagrams of the electromagnetic metasurface device provided by Embodiment 2 of the present application. The difference from Embodiment 1 is that the auxiliary layer further includes an isolation layer 3 and a flow guide layer 4 disposed between the metasurface structure unit array layer 2 and the lower encapsulation layer 5, and the isolation layer 4 A through-hole structure 5 is opened, and a micro-channel structure 9 is opened in the guide layer 4 .

Further, the upper encapsulation layer 1, the metasurface structure unit array layer 2, the isolation layer 3, the flow guide layer 4 and the lower encapsulation layer 5 are glued together with pressure-surface adhesive, and Apply a certain pressure to expel the air bubbles in the non-channel area to ensure the bonding quality between the layers.

In this embodiment, metasurface structural units 7 are arranged on the microfluidic channel, and the shape of the structural units is a helical structure. The difference from Embodiment 1 is that due to the particularity of the shape of the resonant unit in this embodiment, connecting each The microfluidic channel of the structural unit is not on the same layer as the structural unit. Figure 4 shows the schematic cross-sectional structure of this embodiment to illustrate the flow of the working liquid between the layers of the device. In this embodiment, the material of each layer is a plexiglass plate with a thickness of 0.5mm.

It can be understood that the working liquid in each microfluidic channel is driven by applying pressure through a high-precision electronic syringe pump to achieve different working states, and various structures can be realized in this embodiment by changing the mixing ratio of liquid metal and sodium hydroxide solution in the pipeline The units are controlled independently of each other. Figure 5 lists 6 different working states. The black part in Figure 5 represents liquid metal, the gray part represents the base material, and the white part is sodium hydroxide solution.

Example 3

Please refer to FIG. 6, which is a flow chart of the steps of a method for preparing an electromagnetic metasurface device provided in Example 3 of the present application, including the following steps:

Step S110: performing pretreatment on the base material, the base material comprising a plexiglass plate or a polyimide film.

Specifically, the materials to be processed are cut and pre-treated with glue. The conformal material is polyimide film with a thickness of 0.05 mm, and the conventional material is a plexiglass plate with a thickness of 0.5 mm. Cut the above material into a suitable size and spread it out and fix it on a horizontal ceramic workbench. Apply glue to the surface to be processed evenly. The thickness of the glue on the surface is 0.2 mm, and apply a certain pressure to eliminate air bubbles to ensure the degree of fit.

Step S120: Using micromachining technology to process the metasurface structural unit array layer on the surface of the substrate, the metasurface structural unit array layer is provided with several microfluidic channels for the flow of the working liquid, and any one of the microfluidic channels The metasurface structural units are arranged on the fluid channel.

Specifically, when using a carbon dioxide laser engraving machine to process the microstructure of the metasurface structure unit array layer and the auxiliary layer, it is necessary to adjust the processing speed and processing power, strictly control the warping deformation of the material during processing, and ensure the processing quality.

Step S130: Installing the metasurface structure cell array layer between the upper encapsulation layer and the lower encapsulation layer, both of which are processed from the base material.

It can be understood that after completing the bonding and assembly of each layer, it should be noted that a certain external force should be applied to eliminate the air bubbles between the layers when bonding each layer. If the air bubbles are not eliminated layer by layer during the assembly process, it will be difficult to remove the air bubbles when the assembly is completed. , affecting the normal operation of the device.

Further, the preparation method of the electromagnetic metasurface device also includes the following steps:

Step S140: injecting simethicone oil into any one of the microfluidic channels for surface pretreatment.

Introduce simethicone oil into the above-mentioned multiple microfluidic channels for surface pretreatment, the purpose of which is to form a hydrophobic oil film on the inner wall of the microfluidic channels, improve the quality of the processed surface, facilitate the smooth flow of liquid metal in the channels, and reduce Remnants of the inner wall during remodeling.

Step S150: Seal the liquid metal with sodium hydroxide solution in an oxygen-free environment to remove the surface oxide layer of the liquid metal;

Step S160: Using an electronic syringe pump to sequentially circulate and quantitatively extract, form a working liquid in the microfluidic channel that combines liquid metal and sodium hydroxide solution in stages;

It can be understood that through the electronic syringe pump, the method of sequentially circulating quantitative extraction is used to form a working liquid composed of liquid metal and sodium hydroxide solution in the pipeline in a certain proportion. The working liquid can be stored in the pipeline, reducing the cost of the chip design. Complexity, and the diversification of reconfigurable states can be achieved by adjusting the ratio between the components of the working fluid.

Step S170: installing the microfluidic channel filled with the working liquid in the corresponding holes of the upper encapsulation layer to achieve a sealed installation.

In the preparation method of the electromagnetic metasurface device provided by the present application, the liquid metal has many characteristics such as high conductivity, good fluidity, and controllable deformation. Applying liquid metal materials in the design of reconfigurable metasurface electromagnetic devices, combined with microfluidic technology, through the rational design of the microfluidic channel structure of the microfluidic chip, the shape and size of liquid metal can be changed as needed, and ultra-wideband, The multi-state performance can be reconfigured to ensure that the device meets different functional requirements in real time in complex application scenarios; secondly, liquid metal has high power capacity and can meet the power requirements of more electronic systems; in addition, the use of polydimethylsiloxane By designing liquid metal microfluidic channels with flexible materials such as alkanes and polyimide films, conformal electromagnetic devices can be designed.

The above are only examples of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may occur in this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims (11)

1. An electromagnetic metasurface device, is characterized in that, comprises supersurface structural unit array layer and auxiliary layer, on described metasurface structural unit array layer, is provided with several microfluidic passages that can flow for working liquid, any one described The microfluidic channels are arranged with metasurface structural units, the working liquid includes liquid metal, the auxiliary layer includes an encapsulation layer, and the encapsulation layer includes an upper encapsulation layer and a lower encapsulation layer, and the metasurface structural unit array layer is installed on between the upper encapsulation layer and the lower encapsulation layer. 2. The electromagnetic metasurface device according to claim 1, wherein the shapes of several microfluidic channels are the same or different. 3 . The electromagnetic metasurface device according to claim 2 , wherein several microfluidic channels are independent of each other and not communicated with each other. 4 . 4. The electromagnetic metasurface device according to claim 1, wherein the liquid metal is gallium indium tin alloy. 5 . The electromagnetic metasurface device according to claim 4 , wherein the working fluid further includes a lubricating fluid that is non-wetting with the liquid metal, and the lubricating fluid includes but is not limited to dimethyl silicone oil. 6 . The electromagnetic metasurface device according to claim 1 , wherein the metasurface structure unit is a helical or linear or zigzag or open ring structure and various derivatives thereof. 7 . 7. The electromagnetic metasurface device according to claim 1, wherein the auxiliary layer also includes an isolation layer and a flow guide layer arranged between the metasurface structural unit array layer and the lower encapsulation layer, The isolation layer is provided with a through-hole structure, and the guide layer is provided with a micro-channel structure. 8. The electromagnetic metasurface device according to claim 7, characterized in that, the upper encapsulation layer, the metasurface structural unit array layer, the isolation layer, the flow guide layer and the lower encapsulation layer The gaps are bonded with pressure adhesive, and a certain pressure is applied to discharge the air bubbles in the non-channel area to ensure the bonding quality between the layers. 9 . The electromagnetic metasurface device according to claim 1 , wherein a through hole is opened on the upper encapsulation layer. 10 . 10. A method for preparing an electromagnetic metasurface device according to claim 1, comprising the steps of: Carry out pretreatment to substrate, described substrate comprises plexiglass plate or polyimide film; Micro-machining technology is used to process the metasurface structural unit array layer on the surface of the substrate, and several microfluidic channels for the flow of working liquid are arranged on the metasurface structural unit array layer, and any one of the microfluidic channels is Arranged with metasurface structural units; The metasurface structure unit array layer is installed between the upper encapsulation layer and the lower encapsulation layer, and the upper encapsulation layer and the lower encapsulation layer are both processed from the base material. 11. The preparation method of electromagnetic metasurface device according to claim 10, is characterized in that, also comprises the following steps: Passing simethicone oil into any one of the microfluidic channels for surface pretreatment; Seal the liquid metal with sodium hydroxide solution in an oxygen-free environment to remove the oxide layer on the surface of the liquid metal; The electronic syringe pump is used to sequentially circulate quantitatively to form a working liquid in the microfluidic channel that combines liquid metal and sodium hydroxide solution in stages; The microfluidic channel filled with working liquid is installed in the corresponding holes of the upper packaging layer to realize sealed installation.

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