A two-dimensionally stretchable and bendable microarray plasma reactor and a method for manufacturing the same

Abstract

The application discloses a two-dimensional stretchable and bendable microarray plasma reactor and a preparation method thereof. In the application, the semi-flexible problem that the existing flexible plasma source can only be bent but cannot be stretched, and the large-size and high-precision preparation process problem required for realizing full flexibility are solved. The application provides a flexible plasma source with a coplanar dielectric barrier discharge structure and adopting PDMS and liquid gallium-indium alloy as materials, and a preparation method of the flexible plasma source based on a stamping method. The elasticity of the PDMS and the fluidity of the liquid gallium-indium alloy ensure that the flexible plasma source can be stretched and bent for a long time and many times, and has certain deformation and circuit breaking self-recovery ability. In addition, the stamping method manufacturing technology adopted by the application can make the effective discharge area reach 25cm 2 , and the electrode structure precision reaches 10mm, which is 10 times higher than the electrode structure precision of the plasma source manufactured based on the flexible printed circuit technology at present, thereby ensuring the uniformity and stability of the discharge generated plasma.

Description

Technical Field

[0001] This invention relates to the field of plasma source design and manufacturing technology, and in particular to a two-dimensional stretchable and bendable micron array plasma reactor and its preparation method. Background Technology

[0002] Plasma contains a large number of excited-state atoms, high-energy electrons, and free radicals, exhibiting high chemical and biological reactivity, and is widely used in biomedicine, materials processing, and energy conversion. However, with the deep integration of plasma technology into various fields, how to process complex three-dimensional objects and irregular surfaces with high quality, efficiency, and uniformity has become a common focus and challenge for researchers in the field of plasma source development. Conventional plasma generation methods, including plasma jets, sliding arc discharges, and dielectric barrier discharges, are limited by the finite plasma contact area, narrow discharge space, and rigid dielectric materials, making it difficult to meet the processing needs of large-area irregular material surfaces. A novel flexible plasma reactor with high surface adaptability, while being lightweight, convenient, and stable, can effectively solve this problem.

[0003] PDMS (polydimethylsiloxane) possesses heat resistance, cold resistance, water resistance, and thermal conductivity. It is non-toxic, odorless, physiologically inert, and has good chemical stability. It exhibits good electrical insulation, weather resistance, and hydrophobicity, and possesses high shear strength, allowing for long-term use at temperatures ranging from -50℃ to 200℃. Gallium-indium alloy is a stable, safe, non-toxic, low-melting-point liquid metal with excellent electrical conductivity, as well as flexibility, fluidity, and malleability, making it an excellent flexible conductive material.

[0004] Current flexible plasma sources typically use PI or PET as substrates and are primarily fabricated using flexible printed circuit technology. They possess bending capabilities and generate plasma through surface dielectric barrier discharge. The plasma is generated on the surface of the flexible plasma source and diffuses outwards, ultimately acting on the object being treated. However, the barrier medium in existing flexible plasma sources is generally made of inelastic organic materials, and the electrodes are made of metal materials without tensile properties. This significantly limits their application scenarios; for example, when using plasma to treat wounds close to the skin surface, they cannot stretch with the bending of joints. When using flexible plasma sources to treat materials, large-area, uniform, and stable discharge is required. Existing flexible stretching devices cannot simultaneously meet the requirements of a large electrode coverage area and accurate electrode structure precision. Even small errors in electrode size and position will enhance the local electric field, leading to uneven discharge or even device breakdown. Summary of the Invention

[0005] The purpose of this invention is to provide a two-dimensional stretchable and bendable micron array plasma reactor and its preparation method. This application addresses the problem of existing flexible plasma sources being only bendable and not stretchable, as well as the large-size and high-precision preparation process required to achieve full flexibility.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a micron array plasma reactor that can be stretched and bent in two dimensions, comprising an elastic insulating substrate and interdigitated electrodes disposed within the elastic insulating substrate; The elastic insulating substrate includes a substrate with interdigitated microchannels and an encapsulation layer encapsulated on the substrate; Interdigitated electrodes are disposed within the interdigitated microchannels on the substrate; The encapsulation layer has two through holes for connecting the interdigitated electrodes to the outside; The interdigitated electrode includes a grounded portion of the discharge electrode and a high-voltage portion of the discharge electrode, which are arranged alternately within the interdigitated microchannel. The grounding portion and the high-voltage portion of the discharge electrode are respectively connected to different through holes via the head electrode and the neck electrode.

[0007] Preferably, the elastic insulating substrate is a PDMS elastic substrate.

[0008] Preferably, the interdigitated microchannels on the substrate are prefabricated by photolithography.

[0009] Preferably, the encapsulation layer achieves seamless bonding with the substrate by spin-coating liquid PDMS and curing it.

[0010] Preferably, the interdigitated electrode is made of liquid gallium indium alloy.

[0011] This invention provides a method for preparing a two-dimensionally stretchable and bendable micron array plasma reactor, comprising the following steps: S1. First, interdigitated microchannels are generated on the surface of PDMS using photolithography, and these are used as the PDMS substrate for the reactor. S2. Subsequently, toluene was used to modify the PDMS substrate to generate a hydrophobic layer that could reduce the residual hydrophobic layer on the surface of the gallium indium alloy during the subsequent transfer process. S3. Use a flat PDMS as a transfer substrate and coat its surface with liquid gallium indium alloy 5. S4. Fix the substrate with the hydrophobic layer and microchannels on the electric displacement platform and move it vertically back and forth multiple times relative to the transfer substrate to fill the microchannels with liquid gallium indium alloy 5 and form interdigitated electrodes on the substrate. S5. After the transfer is completed, the device is packaged, and an encapsulation layer is formed on the interdigitated electrode and the substrate to complete the preparation process of the plasma reactor.

[0012] Preferably, in S2, the hydrophobic modification time of toluene on the PDMS substrate is 5-10 min.

[0013] Preferably, in S3, the spin coating speed for preparing a smooth PDMS transfer substrate is 500~1500 r / s, the curing temperature of the PDMS prepolymer and curing agent of the transfer substrate is 50~70℃, and the required time is 1h.

[0014] Preferably, the plasma reactor can come into direct contact with the human body to disinfect and sterilize skin wounds.

[0015] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention employs a coplanar dielectric barrier discharge flexible electrode structure in which high-voltage electrodes and grounding electrodes are arranged alternately on the same plane and located within an insulating medium. Compared to commonly used non-planar dielectric barrier discharge, the coplanar design of the high-voltage and grounding electrodes in this invention, while increasing manufacturing difficulty, significantly reduces structural thickness and enhances the bending and stretching capabilities of the flexible plasma source. Simultaneously, the non-exposed electrode design allows for stable operation over extended periods and greatly improves safety during discharge. When used for skin wound disinfection and sterilization, this invention can directly contact the human body.

[0016] This invention proposes a flexible plasma source with a coplanar dielectric barrier discharge structure, using PDMS and liquid gallium-indium alloy as materials, and its fabrication method based on a stamping technique. The elasticity of PDMS and the fluidity of liquid gallium-indium alloy ensure that the flexible plasma source can be stretched and bent repeatedly over a long period of time, exhibiting certain deformation and self-recovery capabilities. Furthermore, the stamping technique used in this invention allows for an effective discharge area of ​​up to 25 cm². 2 At the same time, its electrode structure precision reaches 10mm, which is 10 times higher than the structural precision of the electrodes of plasma sources currently manufactured based on flexible printed circuit technology, ensuring the uniformity and stability of the plasma generated by the discharge. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the plasma reactor of the present invention; Figure 2 This is an exploded view of the plasma reactor device structure of the present invention; Figure 3 This is a schematic diagram of the plasma reactor electrode of the present invention; Figure 4 This is a flowchart illustrating the preparation process of the plasma reactor of the present invention. Figure 5 This is a schematic diagram of a PDMS substrate with vortex-shaped micron-sized flow channels.

[0019] Explanation of reference numerals in the attached figures: 1. PDMS elastic substrate; 1-1. Encapsulation layer; 1-2. Substrate; 1-2-1. PDMS substrate; 1-2-2. Hydrophobic layer; 2. Interdigitated electrode; 2-1. Head electrode; 2-2. Neck electrode; 2-3. Grounding part of discharge electrode; 2-4. High voltage part of discharge electrode; 3. Through hole; 4. Transfer substrate. Detailed Implementation

[0020] This embodiment discloses a micron array plasma reactor that can be stretched and bent in two dimensions, including an elastic insulating substrate 1 and interdigitated electrodes 2 prefabricated in the elastic insulating substrate 1; The elastic insulating substrate 1 includes a substrate 1-2 with interdigitated microchannels and an encapsulation layer 1-1 encapsulated on the substrate 1-2; the elastic insulating substrate 1 is a PDMS elastic substrate; the interdigitated microchannels on the substrate 1-2 are pre-fabricated by photolithography; the encapsulation layer 1-1 achieves seamless bonding with the substrate 1-2 by spin-coating liquid PDMS and curing. like Figure 3 As shown, an interdigitated electrode 2 is formed in the interdigitated microchannel on the substrate 1-2 using a gallium-indium alloy; specifically, the interdigitated electrode 2 is made of liquid gallium-indium alloy. Two through holes 3 are pre-formed on the encapsulation layer 1-1 for connecting the interdigitated electrode 2 to the outside; The interdigitated electrode 2 includes a grounding portion 2-3 and a high-voltage portion 2-4 of the discharge electrode, which are arranged alternately within the interdigitated microchannel; wherein the grounding portion 2-3 and the high-voltage portion 2-4 of the discharge electrode are respectively connected to different through holes 3 through the head electrode 2-1 and the neck electrode 2-2.

[0021] This embodiment discloses a method for preparing a two-dimensionally stretchable and bendable micron array plasma reactor, specifically including the following steps: S1. First, interdigitated microchannels are generated on the surface of PDMS using photolithography, and these are used as the PDMS substrate for the reactor 1-2-1. S2. Subsequently, toluene is used to modify the PDMS substrate 1-2-1 to generate a hydrophobic layer 1-2-2 that can reduce the residual hydrophobic layer on the surface of the gallium indium alloy during the subsequent transfer process. In S2, the hydrophobic modification time of toluene on the PDMS substrate 1-2-1 is 5~10 min. The ratio of PDMS prepolymer to curing agent in the PDMS substrate 1-2-1 should preferably be 10:1. S3. A flat PDMS is used as a transfer substrate 4, and liquid gallium indium alloy 5 is coated on its surface; wherein the ratio of PDMS prepolymer to curing agent in the transfer substrate 4 is preferably 15:1; in S3, the spin coating speed for preparing the flat PDMS transfer substrate 4 is preferably 500~1500 r / s, the curing temperature of PDMS prepolymer and curing agent in the transfer substrate 4 is 50~70℃, and the required time is 1h; S4. Fix the substrate 1-2 with hydrophobic layer and microchannels on the electric displacement platform and move it vertically back and forth multiple times relative to the transfer substrate to fill the microchannels with liquid gallium indium alloy 5 and form interdigitated electrodes 2 on the substrate 1-2. S5. After the stamping method transfer is completed, the device is packaged, and an encapsulation layer 1-1 is formed on the interdigitated electrode 2 and the substrate 1-2, thus completing the preparation process of the plasma reactor.

[0022] The process of the stamping method in this application is as follows: as described in steps S3 and S4, a liquid gallium indium alloy is coated on the substrate surface, analogous to "ink pad". The gallium indium alloy is transferred into the microchannel by contact pressing method, analogous to "stamping process". The stamping method is a vivid description of this type of transfer method in the field of micro-nano manufacturing.

[0023] The working principle of this embodiment: With one end of the plasma reactor grounded and the other end connected to a high voltage, there are interlaced potential differences on the electrodes arranged in an interdigitated pattern inside the elastic PDMS, which discharge on the surface of the reactor and generate plasma.

[0024] The plasma reactor described in this embodiment can come into direct contact with the human body to disinfect and sterilize skin wounds.

[0025] exist Figure 1 and Figure 2 In this structure, the interdigitated electrode 2, made of liquid gallium indium alloy, is located inside the elastic insulating dielectric PDMS1. The elastic dielectric PDMS1 consists of an upper package 1-1 and a substrate 1-2 with interdigitated microchannels. The upper package 1-1 achieves seamless bonding with the substrate 1-2 by spin-coating liquid PDMS and curing it. The interdigitated microchannels of the substrate 1-2 are pre-fabricated using photolithography. Figure 3 In this design, the interdigitated electrode consists of a head electrode 2-1, a neck electrode 2-2, a grounding portion 2-3 of the discharge electrode, and a high-voltage portion 2-4 of the discharge electrode. A wire for grounding or connecting to high voltage is connected to the corresponding head electrode through a through-hole 3 on the upper package 1-1, while the head electrode conducts the potential to each discharge electrode through the neck electrode. The interdigitated electrode structure allows the grounding portion 2-3 and the high-voltage portion 2-4 of the discharge electrode to be alternately arranged inside the PDMS after voltage is applied.

[0026] like Figure 4This paper demonstrates the fabrication process of a two-dimensionally stretchable and bendable plasma reactor based on elastic PDMS. Interdigitated microchannels were formed on the PDMS surface using photolithography, serving as the reactor substrate 1-2-1. Subsequently, toluene was used to modify the PDMS substrate 1-2-1, generating a hydrophobic layer 1-2-2 that reduces residual gallium-indium alloy on the surface during subsequent transfer processes. A flat PDMS substrate 4 was used as the transfer substrate, and liquid gallium-indium alloy 5 was coated onto its surface. The PDMS electrode substrate 1-2, with its hydrophobic layer and microchannels, was fixed on an electric displacement platform and reciprocated vertically relative to the transfer substrate several times, allowing the liquid gallium-indium alloy to fill the microchannels, forming interdigitated electrodes 2. The device, after transfer using the stamping method, was encapsulated to form a PDMS encapsulation layer 1-1, thus completing the fabrication of this plasma reactor.

[0027] Application Example 1 Specifically, the waveform of the excitation power supply driving the present invention is preferably a unipolar square wave nanosecond pulse. When the distance between the interdigital electrodes is 0.1 mm, the pulse amplitude is preferably 2~4 kV, the repetition frequency is 1~2 kHz, the rising and falling edges are 50~500 ns, and the pulse width is 5~20 ms.

[0028] The main function of the micron array flow channel structure design of the flexible plasma reactor in this embodiment is to arrange the high-voltage electrode and the ground electrode at equal intervals and staggered inside the PDMS, ensuring that the plasma can be generated uniformly and stably. Therefore, the structure can take various forms. In addition to the interdigitated structure design, it can also be a vortex, concentric circle, or other equally spaced staggered flow channel structure design, wherein the PDMS substrate 6 with the vortex flow channel is as follows: Figure 5 As shown. Furthermore, depending on actual needs, the finished shape of the flexible plasma reactor of this invention can be... Figure 1 The circle and Figure 5 Besides the square shape, it can also be designed into various shapes using molds to adapt to the bonding requirements of different surface treatments.

[0029] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A micron array plasma reactor capable of two-dimensional stretching and bending, characterized in that: Includes an elastic insulating substrate (1) and interdigitated electrodes (2) disposed within the elastic insulating substrate (1); The elastic insulating substrate (1) includes a substrate (1-2) with interdigitated microchannels and an encapsulation layer (1-1) encapsulated on the substrate (1-2). Interdigitated electrodes (2) are disposed in the interdigitated microchannels on the substrate (1-2); Two through holes (3) are provided on the encapsulation layer (1-1) for connecting the interdigitated electrode (2) to the outside; The interdigitated electrode (2) includes a grounded portion (2-3) of the discharge electrode and a high-voltage portion (2-4) of the discharge electrode, which are arranged alternately in the interdigitated microchannel. The grounding part (2-3) and the high-voltage part (2-4) of the discharge electrode are respectively connected to different through holes (3) through the head electrode (2-1) and the neck electrode (2-2); The elastic insulating substrate (1) is a PDMS elastic substrate; the encapsulation layer (1-1) is seamlessly bonded to the substrate (1-2) by spin-coating liquid PDMS and curing; the interdigitated electrode (2) is made of liquid gallium indium alloy.

2. The two-dimensionally stretchable and bendable micron array plasma reactor according to claim 1, characterized in that: The interdigitated microchannels on the substrate (1-2) are prefabricated by photolithography.

3. The method for preparing the two-dimensionally stretchable and bendable micron array plasma reactor according to any one of claims 1-2, characterized in that: Includes the following steps: S1. First, interdigitated microchannels are generated on the surface of PDMS using photolithography, and these are used as the PDMS substrate for the reactor (1-2-1). S2. Subsequently, toluene was used to modify the PDMS substrate (1-2-1) to generate a hydrophobic layer (1-2-2), which can reduce the residual gallium indium alloy on the surface during the subsequent transfer process. S3. Use a flat PDMS as a transfer substrate (4) and coat its surface with liquid gallium indium alloy (5). S4. Fix the substrate (1-2) with hydrophobic layer and microchannels on the electric displacement platform and move it vertically back and forth multiple times relative to the transfer substrate. This allows the liquid gallium indium alloy (5) to fill the microchannels and form interdigitated electrodes (2) on the substrate (1-2), which is the pattern transfer method of stamping. S5. After the transfer is completed, the device is packaged, and a packaging layer (1-1) is formed on the interdigitated electrode (2) and the substrate (1-2) to complete the preparation process of the plasma reactor.

4. The method for preparing the two-dimensionally stretchable and bendable micron array plasma reactor according to claim 3, characterized in that: In S2, the hydrophobic modification time of toluene on the PDMS substrate (1-2-1) is 5~10 min.

5. The method for preparing the two-dimensionally stretchable and bendable micron array plasma reactor according to claim 3, characterized in that: In S3, the spin coating speed for preparing a smooth PDMS transfer substrate (4) should be 500~1500r / s, and the curing temperature of the PDMS prepolymer and curing agent of the transfer substrate (4) should be 50~70℃, with a curing time of 1h.

6. The application of the two-dimensionally stretchable and bendable micron array plasma reactor according to claim 1, characterized in that: The plasma reactor can come into direct contact with the human body to disinfect and sterilize skin wounds.

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