Surface micro-nano structure with wide-spectrum antibacterial property and manufacturing method thereof

Abstract

The application discloses a surface micro-nano structure with wide-spectrum antibacterial property and a manufacturing method thereof. The manufacturing method can preliminarily determine the parameters of the microscale structure and the nanoscale structure with better antibacterial performance according to the antibacterial mechanism model of the microscale structure and the nanoscale structure, respectively research the optimal antibacterial structure of the microscale structure and the nanoscale structure, and combine the optimal structures of the two scales to obtain a cross-scale micro-nano composite structure with the optimal theoretical antibacterial performance. The surface micro-nano structure has the microscale structure with the height range of 0.4-2 microns and the height-width ratio range of 0.02-0.20, and has the nanoscale structure with the width range of 500-1000 nanometers and the height-width ratio range of 0.01-1.00. On one hand, the surface micro-nano structure can reduce the number of bacteria adhesion and hinder the formation of bacterial biofilm, and on the other hand, the surface micro-nano structure can pierce the bacterial biofilm to kill the bacteria, thereby improving the antibacterial performance of the instrument and having wide-spectrum antibacterial property.

Description

Technical Field

[0001] This invention relates to the field of micro-nano technology, specifically to a surface micro-nano structure with broad-spectrum antibacterial properties and its manufacturing method. Background Technology

[0002] In the medical field, antibiotics are the most common measure for preventing and combating fatal bacterial infections during surgical transplantation. However, antibiotic resistance caused by overuse poses the greatest safety threat to healthcare worldwide. Currently, the main approach to addressing this threat is to fabricate antibacterial micro / nanostructures on the surface of medical devices for physical antibacterial action. Existing technologies include preparing antibacterial coatings or laser-modified surfaces to create antibacterial micro / nanostructures. However, the antibacterial properties of these surface micro / nanostructures are currently limited; those fabricated on a single device can only exert antibacterial activity against one type of bacteria, failing to achieve broad-spectrum antibacterial applications. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a surface micro / nano structure with broad-spectrum antibacterial properties, which can improve the antibacterial performance of medical devices and has broad-spectrum antibacterial properties.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a surface micro / nano structure with broad-spectrum antibacterial properties, comprising a micrometer-scale structure and a nanometer-scale structure; the height of the micrometer-scale structure ranges from 0.4 μm to 2 μm, and the aspect ratio ranges from 0.02 to 0.20; the width of the nanometer-scale structure ranges from 500 nm to 1000 nm, and the aspect ratio ranges from 0.01 to 1.00.

[0005] Compared to existing technologies, the surface micro / nano structures of the present invention have at least the following beneficial effects: Micrometer-scale structures within the aforementioned height and aspect ratio ranges can reduce the number of bacteria adhering to the surface. By reducing the contact area between bacteria and the material surface, they can hinder the formation of bacterial biofilms, thereby inhibiting bacterial growth and reproduction. Furthermore, these micrometer-scale structures exhibit good antibacterial properties against both *Escherichia coli* and *Staphylococcus aureus*, possessing broad-spectrum antibacterial activity. Meanwhile, nanometer-scale structures within the aforementioned width and aspect ratio ranges, with their tiny nanospike structures, can directly pierce bacterial biofilms to kill bacteria, thus achieving antibacterial effects. These nanometer-scale structures also exhibit good antibacterial properties against both *Escherichia coli* and *Staphylococcus aureus*, possessing broad-spectrum antibacterial activity. Therefore, the surface micro / nano structures of the present invention include both micrometer-scale and nanometer-scale structures. On the one hand, they can reduce the number of bacteria adhering to the surface and hinder the formation of bacterial biofilms; on the other hand, they can pierce bacterial biofilms to kill bacteria, thereby improving the antibacterial performance of the device and possessing broad-spectrum antibacterial activity.

[0006] The aforementioned surface micro / nano structure with broad-spectrum antibacterial properties has a height of 1 μm and an aspect ratio of 0.02.

[0007] The aforementioned surface micro / nano structure with broad-spectrum antibacterial properties has a width of 1 μm and an aspect ratio of 0.07.

[0008] The present invention also provides a method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties, comprising the following steps:

[0009] Step S100: Determine the range of structural parameters for the micron-scale and nano-scale structures based on the antibacterial mechanism models of the micron-scale and nano-scale structures.

[0010] In step S200, within the range of structural parameters for the micron-scale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Micron-scale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds. Within the range of structural parameters for the nanoscale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Nanoscale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds.

[0011] Step S300: Surface structure detection is performed on the multiple sets of molds obtained in step S200 to determine the micron-scale structure and nano-scale structure with optimal antibacterial performance, respectively.

[0012] Step S400: Combine the micron-scale structure and nano-scale structure with optimal antibacterial properties obtained in step S300 to obtain the structural parameters of the surface micro / nano structure with broad-spectrum antibacterial properties, and then process and manufacture it.

[0013] Compared to existing technologies, the manufacturing method of this invention has at least the following beneficial effects: Based on the antibacterial mechanism model of the surface micron-level structure, that is, when the aspect ratio of the linear micron-level structure is within a certain range, the micron-level structure can reduce the number of bacteria adhering to it. It can inhibit the formation of bacterial biofilms by reducing the contact area between bacteria and the material surface, thereby suppressing bacterial growth and reproduction. Therefore, this method preliminarily determines the parameter range of the micron-level structure based on the antibacterial mechanism model. Similarly, based on the antibacterial mechanism model of the nanoscale structure, that is, the tiny nanospike structures can directly pierce the bacterial biofilm to kill bacteria, thereby achieving the antibacterial purpose. Therefore, this method preliminarily determines the parameter range of the nanoscale structure based on the antibacterial mechanism model. After determining the structural parameter ranges for micron-scale and nano-scale structures, multiple sets of data are selected within the structural parameter range determined in step S100. Multiple sets of micron-scale and nano-scale structures are then fabricated on multiple sets of molds. The micron-scale and nano-scale structures are fabricated and studied separately to obtain the structural parameters of the micron-scale and nano-scale structures with optimal antibacterial properties. Finally, the fabrication is carried out based on the obtained structural parameters of the micro / nano-structures with optimal antibacterial properties. This method allows for the separate study of micron-scale and nano-scale structures, and then the optimal results of each can be combined to obtain a surface micro / nano-structure with extremely high antibacterial properties and broad-spectrum antibacterial activity.

[0014] In the manufacturing method described above, in step S200, a single-point diamond cutting method is used to process micron-scale and nano-scale structures on the surface of the mold.

[0015] The manufacturing method described above, wherein step S300 includes the following steps:

[0016] S310. Characterize the micron-scale and nano-scale structures, and measure the height and width of the micron-scale and nano-scale structures.

[0017] S320. Static water contact angle test is performed on micron-scale and nano-scale structures to measure the surface contact angle of the mold parallel to the cutting direction.

[0018] S330. Select experimental bacterial strains and test the antibacterial properties of micron-scale and nano-scale structures.

[0019] S340. Based on the antibacterial performance test results in S330, determine the micron-scale and nano-scale structures with optimal antibacterial properties.

[0020] In the manufacturing method described above, in step S200, the height parameter of the micron-scale structure is first selected, the width parameter of the nano-scale structure is selected, and then multiple sets of aspect ratio parameters are selected to obtain multiple sets of width parameters of the micron-scale structure and multiple sets of height parameters of the nano-scale structure.

[0021] In the manufacturing method described above, the mold provided in step S200 is a copper sample.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the antibacterial principle of the micron-scale structure in Embodiment 7 of the present invention;

[0024] Figure 2 This is a schematic diagram of the micron structure design in Embodiment 7 of the present invention;

[0025] Figure 3 This is a schematic diagram of three planar molds with micron-scale structures made of copper obtained in Embodiment 7 of the present invention;

[0026] Figure 4 The three-dimensional morphology and measurement data of the mold surface in Embodiment 7 of the present invention are as follows (a: mold A1; b: mold A2; c: mold A3);

[0027] Figure 5 This is a comparative schematic diagram of colony counts using the plate count method in the antibacterial test of three sets of mold surfaces in Embodiment 7 of the present invention (a: Escherichia coli colonies; b: Staphylococcus aureus colonies);

[0028] Figure 6 This is a schematic diagram illustrating the antibacterial principle of the nanoscale structure in Embodiment 7 of the present invention;

[0029] Figure 7 This is a schematic diagram of the design of the nanoscale structure in Embodiment 7 of the present invention;

[0030] Figure 8 This is a schematic diagram illustrating the fabrication principle of the nanoscale structure in Embodiment 7 of the present invention;

[0031] Figure 9 These are schematic diagrams of two planar molds with nanoscale structures made of copper obtained in Embodiment 7 of the present invention (a: mold A4; b: mold A5);

[0032] Figure 10 The three-dimensional morphology and measurement data of two sets of mold surfaces in Embodiment 7 of the present invention are shown (a: mold A4; b: mold A5).

[0033] Figure 11 This is a comparative schematic diagram of colony counts using the plate count method during the antibacterial test of the mold surface in Embodiment 7 of the present invention (a: Escherichia coli colonies; b: Staphylococcus aureus colonies);

[0034] Figure 12 This is a schematic diagram of the micro-nano composite structure in Embodiment 7 of the present invention. Detailed Implementation

[0035] The embodiments of the present invention are described in detail below:

[0036] Example 1

[0037] Embodiment 1 of the present invention provides a surface micro / nano structure with broad-spectrum antibacterial properties, including a micrometer-scale structure and a nanometer-scale structure; the height of the micrometer-scale structure ranges from 0.4 μm to 2 μm, and the aspect ratio ranges from 0.02 to 0.20; the width of the nanometer-scale structure ranges from 500 nm to 1000 nm, and the aspect ratio ranges from 0.01 to 1.00.

[0038] Within the aforementioned height and aspect ratio ranges, micron-sized structures can reduce the number of bacteria adhering to the surface. By reducing the contact area between bacteria and the material surface, they inhibit the formation of bacterial biofilms, thereby suppressing bacterial growth and reproduction. These micron-sized structures exhibit good antibacterial properties against both *Escherichia coli* and *Staphylococcus aureus*, demonstrating broad-spectrum antibacterial activity. Since the antibacterial mechanism of micron-sized structures primarily relies on reducing the contact area between bacteria and the material surface, better antibacterial performance is often observed when the height of the micron-sized structure is half the size of the bacteria. Based on the sizes of various bacteria, especially *Staphylococcus aureus* and *Escherichia coli*, and considering processing limitations, the height range of micron-sized structures can ultimately be limited to 0.4 μm–2 μm. Within this height range, the antibacterial performance is superior when the aspect ratio is between 0.02 and 0.20.

[0039] Within the aforementioned width and aspect ratio ranges, the tiny nanospikes can directly pierce bacterial biofilms to kill bacteria, thus achieving antibacterial effects. These nanostructures also exhibit good antibacterial properties against both *Escherichia coli* and *Staphylococcus aureus*, demonstrating broad-spectrum antibacterial activity. Since the key to the antibacterial mechanism of nanostructures lies in the sharpness of the nanospikes, theoretically, sharper nanospikes result in better antibacterial effects. However, when machining nanostructures using single-point diamond cutting, if the structure width is too small, the tool feed will damage the machined structure. Therefore, considering all factors, a width range of 500nm to 1000nm for nanostructures, with an aspect ratio between 0.01 and 1.00, yields superior antibacterial performance.

[0040] The surface micro / nano structure of this embodiment includes the aforementioned micron-scale and nano-scale structures. On the one hand, it can reduce the number of bacteria adhering and hinder the formation of bacterial biofilms. On the other hand, it can puncture bacterial biofilms to kill bacteria, thereby improving the antibacterial performance of the device and having broad-spectrum antibacterial properties.

[0041] Example 2

[0042] Embodiment 2 of the present invention provides a surface micro / nanostructure with broad-spectrum antibacterial properties, comprising a micrometer-scale structure and a nanometer-scale structure. The difference between this and the surface micro / nanostructure in Embodiment 1 is that the height of the micrometer-scale structure is 1 μm, and the aspect ratio is 0.02, meaning the width of the micrometer-scale structure is 50 μm. Under these structural parameters, the micrometer-scale structure exhibits excellent antibacterial properties, showing superior antibacterial activity against both *Escherichia coli* and *Staphylococcus aureus*, thus possessing broad-spectrum antibacterial activity. Within the height range of the micrometer-scale structure determined in Embodiment 1, considering the limitations of actual processing conditions, a height of 1 μm can simultaneously balance processing methods and antibacterial performance. At this height, an aspect ratio of 0.02, i.e., a width of 50 μm for the micrometer-scale structure, results in optimal antibacterial performance.

[0043] Example 3

[0044] Embodiment 3 of the present invention provides a surface micro / nanostructure with broad-spectrum antibacterial properties, comprising micron-scale and nanoscale structures. The difference between this and the surface micro / nanostructure in Embodiment 1 is that the nanoscale structure has a width of 1 μm and an aspect ratio of 0.07, i.e., a height of 70 nm. This nanoscale structure with these structural parameters exhibits excellent antibacterial properties, showing superior antibacterial activity against both *Escherichia coli* and *Staphylococcus aureus*, thus possessing broad-spectrum antibacterial activity. Within the width range of the nanoscale structure determined in Embodiment 1, considering the limitations of actual processing conditions, a width of 1 μm can simultaneously balance processing conditions and antibacterial performance. Based on processing principles, the nanoscale structure with an aspect ratio of 0.07, i.e., a height of 70 nm, exhibits optimal antibacterial performance.

[0045] Example 4

[0046] Embodiment 4 of the present invention provides a surface micro / nanostructure with broad-spectrum antibacterial properties, comprising a micrometer-scale structure and a nanometer-scale structure. The difference between this and the surface micro / nanostructure in Embodiment 1 is that the height of the micrometer-scale structure is 1 μm, and the aspect ratio is 0.02 (i.e., the width of the micrometer-scale structure is 50 μm). The width of the nanometer-scale structure is 1 μm, and the aspect ratio is 0.07 (i.e., the height is 70 nm). This surface micro / nanostructure in Embodiment 4 combines the excellent antibacterial properties of both micrometer-scale and nanometer-scale structures, further enhancing the antibacterial performance of the surface micro / nanostructure. It also exhibits excellent antibacterial properties against both *Escherichia coli* and *Staphylococcus aureus*, demonstrating broad-spectrum antibacterial activity.

[0047] Example 5

[0048] Embodiment 5 of the present invention provides a method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties, comprising the following steps:

[0049] Step S100: Determine the range of structural parameters for the micron-scale and nano-scale structures based on the antibacterial mechanism models of the micron-scale and nano-scale structures.

[0050] In step S200, within the range of structural parameters for the micron-scale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Micron-scale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds. Within the range of structural parameters for the nanoscale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Nanoscale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds.

[0051] Step S300: Surface structure detection is performed on the multiple sets of molds obtained in step S200 to determine the micron-scale structure and nano-scale structure with optimal antibacterial performance, respectively.

[0052] Step S400: Combine the micron-scale structure and nano-scale structure with optimal antibacterial properties obtained in step S300 to obtain the structural parameters of the surface micro / nano structure with broad-spectrum antibacterial properties, and then process and manufacture it.

[0053] This manufacturing method is based on the antibacterial mechanism model of surface micron-level structures. Specifically, when the aspect ratio of the linear micron-level structure is within a certain range, this structure can reduce the number of bacteria adhering to the surface. By reducing the contact area between bacteria and the material surface, it can hinder the formation of bacterial biofilms, thereby inhibiting bacterial growth and reproduction. Therefore, this method preliminarily determines the parameter range of micron-level structures based on this antibacterial mechanism model. Similarly, based on the antibacterial mechanism model of nanoscale structures, where tiny nanospike structures can directly pierce bacterial biofilms to kill bacteria, thus achieving antibacterial effects, this method preliminarily determines the parameter range of nanoscale structures based on this antibacterial mechanism model. After determining the structural parameter ranges for micron-scale and nano-scale structures, multiple sets of data are selected within the structural parameter range determined in step S100. Multiple sets of micron-scale and nano-scale structures are then fabricated on multiple sets of molds. The micron-scale and nano-scale structures are fabricated and studied separately to obtain the structural parameters of the micron-scale and nano-scale structures with optimal antibacterial properties. Finally, the fabrication is carried out based on the obtained structural parameters of the micro / nano-structures with optimal antibacterial properties. This method allows for the separate study of micron-scale and nano-scale structures, and then the optimal results of each can be combined to obtain a surface micro / nano-structure with extremely high antibacterial properties and broad-spectrum antibacterial activity.

[0054] Example 6

[0055] Embodiment 6 of the present invention provides a method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties, comprising the following steps:

[0056] Step S100: Determine the range of structural parameters for the micron-scale and nano-scale structures based on the antibacterial mechanism models of the micron-scale and nano-scale structures.

[0057] In step S200, within the structural parameter range of the micron-level structure determined in step S100, the height parameter of the micron-level structure is selected, and then multiple sets of aspect ratio parameters of the micron-level structure are selected to obtain multiple sets of width parameters of the micron-level structure. A corresponding number of molds are provided; the molds can be copper samples. After polishing the molds, a suitable diamond tool is selected, and a single-point diamond cutting method is used to process the micron-level structure on the surface of the mold, obtaining multiple sets of molds with micron-level structures. Similarly, within the structural parameter range of the nano-level structure determined in step S100, the width parameter of the nano-level structure is selected, and then multiple sets of aspect ratio parameters of the nano-level structure are selected to obtain multiple sets of height parameters of the nano-level structure. A corresponding number of molds are provided; the molds can be copper samples. After polishing the molds, a suitable diamond tool is selected, and a single-point diamond cutting method is used to process the nano-level structure on the surface of the mold, obtaining multiple sets of molds with nano-level structures.

[0058] S310. Characterize micron-scale and nano-scale structures, and measure the height and width of micron-scale and nano-scale structures. White light interferometer or atomic force microscope can be used to characterize and measure micron-scale and nano-scale structures.

[0059] S320. Static water contact angle test is performed on micron-scale and nano-scale structures. The surface contact angle of the mold parallel to the cutting direction is measured. When the surface contact angle is greater than 90°, it can be proved that the processed mold surface is hydrophobic.

[0060] S330. Escherichia coli and Staphylococcus aureus were selected as experimental strains to test the antibacterial properties of micron-scale and nano-scale structures.

[0061] S340. Based on the antibacterial performance test results in S330, determine the micron-scale and nano-scale structures with optimal antibacterial properties.

[0062] Step S400: Combine the micron-scale structure and nano-scale structure with optimal antibacterial properties obtained in step S300 to obtain the structural parameters of the surface micro / nano structure with broad-spectrum antibacterial properties, and then process and manufacture it.

[0063] Example 7

[0064] Embodiment 7 of the present invention provides a more specific method for manufacturing surface micro / nano structures. This method, within the structural parameter range determined in Embodiment 1, first determines the height of the micrometer-level structure based on actual processing conditions, then sets three different aspect ratios to verify the width of the micrometer-level structure with optimal antibacterial performance. Similarly, it first determines the width of the nanometer-level structure, then sets two different aspect ratios to verify the height of the nanometer-level structure with optimal antibacterial performance. Finally, the micrometer-level structure and nanometer-level structure with optimal antibacterial performance are combined to obtain the surface micro / nano structure with optimal antibacterial performance that can be processed. Specifically, it includes the following steps:

[0065] Step 1: Design of Micrometer-Scale Structures

[0066] Depend on Figure 1 and Figure 2 It is known that when the structural parameters of the surface micron-scale structure are reasonable, the number of bacteria adhering to the instrument surface is small, and the contact area between bacteria and the material surface is small, thus hindering the formation of bacterial biofilms. However, on material surfaces with unreasonable micron-scale structural parameters, especially polished surfaces, the number of bacteria adhering is large, and the contact area between bacteria and the material surface is large, resulting in poor antibacterial performance. Therefore, in this step, the aspect ratio of the surface micron-scale structure is used as an important parameter to design the micron-scale structure of the mold surface for broad-spectrum antibacterial applications. First, the height of the micron-scale structure is selected as 1 μm, and three sets of micron-scale structures with different aspect ratios are set, with aspect ratios of 0.02, 0.05, and 0.20, which are equivalent to widths of 50 μm, 20 μm, and 5 μm, respectively.

[0067] Step Two: Manufacturing of a Micrometer-Scale Planar Mold

[0068] Three copper samples with dimensions of 38mm x 18mm x 8mm (length x width x height) were provided as molds. After polishing, diamond tools with a clearance angle of 20°, a rake angle of 0°, and a tool tip radius of 0.48mm were selected. A workpiece servo motion mechanism was used to vibrate along the depth of cut at a frequency of 200Hz, and a three-axis platform was used to cut the copper samples, resulting in micron-level structures with aspect ratios of 0.02, 0.05, and 0.20. The cutting speeds of the three-axis platform were 4mm / s, 10mm / s, and 1mm / s, respectively, yielding copper planar molds A1 (theoretical aspect ratio 0.02), A2 (theoretical aspect ratio 0.05), and A3 (theoretical aspect ratio 0.20). (Refer to...) Figure 3 , Figure 3 The image shows schematic diagrams of the three planar molds with micron-scale structures made of copper obtained in this step. Figure 3 The middle molds a, b, and c correspond to the three sets of molds A1, A2, and A3, respectively.

[0069] Step 3: Characterization and Measurement of Micrometer-Scale Structures

[0070] The surface structures of molds A1 and A2 were characterized and measured using a white-light interferometer. Under a 20x microscope, the micron-scale structure of mold A1 was characterized, and its height and width were measured. Under a 50x microscope, the micron-scale structure of mold A2 was characterized, and its height and width were measured. The micron-scale structure of mold A3 was characterized and measured using an atomic force microscope. (Reference) Figure 4 , Figure 4 Figures a, b, and c correspond to three sets of molds A1, A2, and A3, respectively. They represent the surface three-dimensional morphology and measurement data of the three sets of molds A1, A2, and A3 obtained in this step. In fact, three planar molds made of copper with aspect ratios of 0.02, 0.05, and 0.15 were obtained.

[0071] Step 4: Wettability testing of micron-scale structures

[0072] The droplet volume was set to 3 μL, and the droplet rate to 3 μL / s. A static water contact angle test was performed using an OCA contact angle meter to measure the contact angle of the mold surface parallel to the cutting direction. The measured contact angles of mold surfaces A1, A2, and A3 were 95.22°, 102.81°, and 98.25°, respectively. All three mold surface contact angles are greater than 90°, demonstrating that the three mold surfaces obtained in this embodiment are hydrophobic.

[0073] Step 5: Antibacterial performance test of micron-scale structure

[0074] Escherichia coli and Staphylococcus aureus were selected as experimental strains to test the antibacterial properties of the three micron-scale structural surfaces in this embodiment. The experimental method used was the national standard film application method (national standard number GB / T31402-2015). PE film without antibacterial properties was used as a blank control group A0. Figure 5 The diagram shows a comparison of colony counts using the plate count method during the antibacterial performance test of the mold surface in this step. In the diagram, 'a' represents *E. coli* colonies, and 'b' represents *S. aureus* colonies. The test results are as follows: Mold A1 showed an antibacterial rate of 99.20% against *E. coli* and 99.96% against *S. aureus*; Mold A2 showed an antibacterial rate of 99.89% against *E. coli* and 99.95% against *S. aureus*; Mold A3 showed an antibacterial rate of 99.10% against *E. coli* and 99.30% against *S. aureus*. This demonstrates that the mold in this embodiment exhibits good antibacterial performance against both bacteria, thus demonstrating its broad-spectrum antibacterial activity. The optimal micron-sized structure for antibacterial performance was determined to be: a structure height of 1 μm, a structure width of 50 μm, and an aspect ratio of 0.02.

[0075] Step Six: Design of Nanoscale Structures

[0076] Depend on Figure 6 It is known that tiny nanoscale spike structures can directly pierce bacterial biofilms, killing bacteria to achieve antibacterial effects. The aspect ratio of the nanoscale structure can be maximized within the range allowed by the processing method. Therefore, the width D of the nanoscale structure is determined to be 1000 nm, and two sets of aspect ratio parameters, 0.75 and 0.50, are selected, corresponding to heights H of 750 nm and 500 nm, respectively. Figure 7 A schematic diagram of the nanoscale structure designed for this step.

[0077] Step 7: Manufacturing of Nanoscale Planar Molds

[0078] Two copper samples with dimensions of 20mm x 20mm x 8mm (length x width x height) were provided and polished. A diamond tool with a clearance angle of 20°, a rake angle of 0°, and a tool tip radius of 0.48mm was selected and elliptical vibration was performed at a frequency of 40kHz. The copper samples were then cut using a three-axis platform at a cutting speed of 40mm / s. The elliptical circumference in the cutting direction was set to 2μm and the elliptical circumference in the depth of cut direction was set to 6μm during the elliptical vibration of the tool. A nanoscale copper planar mold A4 with a theoretical aspect ratio of 0.75 was machined. The elliptical circumference in the cutting direction was set to 3μm and the elliptical circumference in the depth of cut direction was set to 6μm during the elliptical vibration of the tool. A nanoscale copper planar mold A5 with a theoretical aspect ratio of 0.50 was machined. Figure 8 The diagram shown illustrates the principle of nanostructure fabrication. Figure 9 This is a schematic diagram of two planar molds with nanoscale structures made of copper obtained in this embodiment.

[0079] Step 8: Characterization and Measurement of Nanoscale Structures

[0080] The nanostructures on the surfaces of molds A4 and A5 were characterized and measured using atomic force microscopy, such as... Figure 10 As shown, Figure 10 Figures a and b show the surface three-dimensional morphology and measurement data of molds A4 and A5 in this embodiment, respectively. Two planar molds with nanoscale structure made of copper were actually obtained with aspect ratios of 0.14 and 0.07, respectively.

[0081] Step Nine: Wetting Test of Nanoscale Structures

[0082] The droplet volume was set to 3 μL and the droplet rate to 3 μL / s. A static water contact angle test was performed using an OCA contact angle meter. The contact angle of the mold surface parallel to the cutting direction was measured. The contact angle of mold surface A4 was 110.19° and the contact angle of mold surface A5 was 102.34°. The contact angles of both mold surfaces were greater than 90°, which proved that the two mold surfaces obtained in this case are hydrophobic.

[0083] Step 10: Antibacterial performance test of nanoscale structure

[0084] Escherichia coli and Staphylococcus aureus were selected as experimental strains to test the antibacterial properties of the two nanoscale structural surfaces in this embodiment. The experimental method adopted was the national standard film application method (national standard number GB / T31402-2015). PE film without antibacterial properties was used as a blank control group A0. Figure 11 The diagram shows a comparison of colony counts using the plate count method in the antibacterial test of the mold surface in this case. In the diagram, 'a' represents *E. coli* colonies, and 'b' represents *S. aureus* colonies. The antibacterial rate of mold A4 against *E. coli* was 89.22%, and against *S. aureus* was 91.40%; the antibacterial rate of mold A5 against *E. coli* was 98.34%, and against *S. aureus* was 99.29%. This demonstrates that the mold in this embodiment exhibits good antibacterial properties against both bacteria, thus illustrating its broad-spectrum antibacterial activity. The optimal nanostructure for antibacterial performance was determined to have a width of 1000 nm, a height of 71.31 nm, and an aspect ratio of 0.07.

[0085] Step 11: Composite to obtain surface micro / nano structures with broad-spectrum antibacterial properties

[0086] From steps one to ten, micron-scale and nano-scale structures with optimal antibacterial properties can be obtained. Combining these two structures yields a composite micro / nano structure with theoretically optimal antibacterial properties. The micron-scale structure parameters are: height 1 μm, width 50 μm; the nano-scale structure parameters are: height 70 nm, width 1000 nm. Figure 12 The diagram shown is a schematic of the composite micro / nano structure in this embodiment.

[0087] It is important to note that "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If a description mentions "first" or "second," it is only for the purpose of distinguishing technical features and should not be interpreted as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0088] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties, characterized in that, Includes the following steps: Step S100: Based on the antibacterial mechanism models of micron-scale and nano-scale structures, determine the structural parameter ranges of the micron-scale and nano-scale structures. The surface micro / nano structures with broad-spectrum antibacterial properties include micron-scale and nano-scale structures. The height range of the micron-scale structure is 0.4μm-2μm, and the aspect ratio range is 0.02-0.

20. The width range of the nano-scale structure is 500nm-1000nm, and the aspect ratio range is 0.01-1.

00. In step S200, within the range of structural parameters for the micron-scale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Micron-scale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds. Within the range of structural parameters for the nanoscale structure determined in step S100, multiple sets of structural parameters are selected, and a corresponding number of molds are provided. Nanoscale structures with multiple sets of selected structural parameters are then fabricated on the surfaces of the multiple sets of molds. Step S300: Surface structure detection is performed on the multiple sets of molds obtained in step S200 to determine the micron-scale structure and nano-scale structure with optimal antibacterial performance, respectively. Step S400: Combine the micron-scale structure and nano-scale structure with optimal antibacterial properties obtained in step S300 to obtain the structural parameters of the surface micro / nano structure with broad-spectrum antibacterial properties, and then process and manufacture it.

2. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1, characterized in that, The micron-scale structure has a height of 1 μm and an aspect ratio of 0.

02.

3. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1 or 2, characterized in that, The nanoscale structure has a width of 1 μm and an aspect ratio of 0.

07.

4. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1, characterized in that, In step S200, a single-point diamond cutting method is used to process micron-scale and nano-scale structures on the surface of the mold.

5. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1, characterized in that, Step S300 includes the following steps: S310. Characterize the micron-scale and nano-scale structures, and measure the height and width of the micron-scale and nano-scale structures. S320. Static water contact angle test is performed on micron-scale and nano-scale structures to measure the surface contact angle of the mold parallel to the cutting direction. S330. Select experimental bacterial strains and test the antibacterial properties of micron-scale and nano-scale structures. S340. Based on the antibacterial performance test results in S330, determine the micron-scale and nano-scale structures with optimal antibacterial properties.

6. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1, characterized in that, In step S200, the height parameter of the micron-scale structure is first selected, the width parameter of the nano-scale structure is selected, and then multiple sets of aspect ratio parameters are selected to obtain multiple sets of width parameters of the micron-scale structure and multiple sets of height parameters of the nano-scale structure.

7. The method for manufacturing a surface micro / nano structure with broad-spectrum antibacterial properties according to claim 1, characterized in that, In step S200, the mold provided is a copper sample.

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