Dimpled feathers

Abstract

To provide an arrow feather that realizes high stability with a smaller blade area and can widen the tuning tolerance range. [Solution] The archery feather of the present invention is characterized by having a plurality of dimple structures on the surface of the feather. The dimple structures cause turbulence in the boundary layer on the surface of the feather, delaying separation and achieving high stability even with a small feather area.

Description

[Technical Field]

[0001] The present invention relates to feathers for archery arrows, and more particularly to feathers having a dimple structure on the surface thereof to improve flight performance. [Background technology]

[0002] Traditionally, feathers have been provided on archery arrows to ensure the arrow's flight stability. Natural feathers or synthetic resin feathers with smooth surfaces have been used.

[0003] The flight of an arrow requires that vibrations caused by the Archer's Paradox immediately after firing be quickly damped to ensure stable, straight flight. Resistance to external disturbances such as crosswinds is also an important factor.

[0004] Conventional blades have a smooth surface, which causes boundary layer separation early on, making them prone to stalling. This requires a larger blade area, which results in increased drag and a decrease in arrow speed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Jitsuzen Showa 50-040099 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was made in consideration of the above-mentioned problems with conventional arrow feathers, and aims to provide an arrow feather that uses a dimple structure to control the boundary layer, achieves high stability with a smaller blade area, and allows for a wider tuning tolerance range. [Means for solving the problem]

[0007] To solve the above problems, the archery feather of the present invention is characterized by having a plurality of dimple structures on the surface of the feather. The dimple structures turbulentize the boundary layer on the surface of the feather, delaying separation and achieving high stability even with a small feather area.

[0008] These and other aspects, features, and advantages of the present disclosure will become apparent from the following detailed written description of the preferred embodiments and aspects taken in conjunction with the following drawings, variations and modifications of which may be made without departing from the spirit and scope of the novel concepts of the present disclosure. Aspects of one embodiment of the present disclosure may be combined with or substituted for one or more aspects of another embodiment of the present disclosure, unless inconsistent. [Effects of the Invention]

[0009] According to the present invention, the dimple structure delays boundary layer separation, making it possible to realize a blade that is less prone to stall. This allows for stability equivalent to or greater than that of conventional blades with a smaller blade area, reducing overall drag and improving arrow speed. The shape, size, and arrangement pattern of the dimples are preferably optimized according to the arrow's flight speed, rotation speed, and usage environment. Furthermore, the dimple structure can be formed on only one side of the blade, or on both sides. In addition, vibration damping immediately after firing is quicker, widening the tuning tolerance range. Furthermore, the water film breaks off easily even in rainy weather, maintaining stable performance. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the overall structure of an archery feather according to an embodiment of the present invention, in which (1) shows the feather body, (2) shows the dimple recess, and (3) shows the dimple protrusion. [Figure 2]This is an enlarged view of the base of an archery feather according to an embodiment of the present invention, showing the dimple-free zone (smooth surface) that will be the area where the feather will be attached to the arrow shaft. Fig. 1 shows the structure of the entire feather, illustrating the arrangement of multiple dimple structures (concave portions 2 and convex portions 3) formed on the surface. Fig. 2 is an enlarged view of the base of the feather, showing the smooth adhesive surface (dimple-free zone 4) where dimples are intentionally not placed to ensure adhesive strength. The dimple-free zone (4) is set within 10% to 30% of the entire feather length from the base side, ensuring reliable adhesion to the arrow shaft.

[0011] The following disclosure provides many different embodiments and examples for implementing different features of the presented subject matter. To simplify the disclosure, specific examples of components and arrangements are disclosed below. Of course, these are merely examples and are not intended to be limiting. For example, a structure in which a first feature is covered by or in contact with a subsequently disclosed second feature may include embodiments in which the first and second features are formed in direct contact, as well as embodiments in which an additional feature is formed between the first and second features to prevent direct contact between the first and second features. Furthermore, the disclosure may repeat reference numbers and / or letters in various examples. Such repetition is for the purposes of brevity and clarity and does not, in itself, require a relationship between the various embodiments and / or configurations described. Furthermore, when a first element is described as being "coupled" or "coupled" to a second element, such a description includes embodiments in which the first and second elements are directly coupled or coupled to each other, as well as embodiments in which the first and second elements are indirectly coupled or coupled to each other via one or more intervening elements. As used herein, the phrase "at least one of" encompasses all exemplary variations. For example, the phrase "comprises at least one of A, B, or C" is equivalent to "consisting of A, B, and C and combinations thereof," and encompasses all possible variations of A, B, C, A+B, A+C, B+C, and A+B+C. In this disclosure, the use of a machine, an electronic operator, or a computer may include embodiments of a method, a recording medium, an apparatus, or a program. As used herein, the statement "A is B" can be replaced with "A includes B" unless there is a contradiction or unless otherwise stated in the specification.Terms in this disclosure, including terms set forth in the claims, may be interpreted in light of the descriptions set forth in the specification and, further, by what one or more citizens, past, present, or future, have so called, so designated, so understood, or so performed, or may so perform, unless otherwise indicated in this disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] In at least one embodiment, the feathers of the present invention have dimples with diameters ranging from 0.05 mm to 10 mm formed on the surface of a substrate with a thickness ranging from 0.005 mm to 0.1 mm. The dimple depth can be 5% to 50% of the diameter, but is not limited to this. The size of the feather can be set within a range from 35 mm to 180 mm and is selected appropriately depending on the competition rules and intended use. The substrate can be selected from any material usable for feathers, such as synthetic resin, natural feathers, thin metal plate, or composite material. The dimples can be arranged regularly or irregularly, and the density and size can be varied from the leading edge to the trailing edge of the feather. Manufacturing methods can include injection molding, press molding, etching, laser processing, and other methods appropriate for the material. Maintaining the strength of the material during dimple formation is particularly important for thin feathers. Optimizing processing conditions can achieve a dimple structure without impairing the mechanical properties of the feather.

[0013] In at least one embodiment, the dimples are formed as circular depressions, but other shapes, such as ovals, polygons, and stars, are also acceptable. Dimples of multiple different shapes can also be combined. The edges of the dimples can be sharp or curved, promoting or suppressing flow separation. The cross-sectional shape in the depth direction can be selected based on aerodynamic characteristics, such as hemispherical, conical, pyramidal, or compound curve. The spacing between dimples can range from 0.1 to 10 times the dimple diameter and may vary depending on the location on the blade. Even for extremely thin blades, such as 0.005 mm, dimples of the appropriate depth can be formed without penetrating the material by precision stamping or chemical etching. While this variety of shapes allows for optimization for various flight conditions, it is important to select the appropriate shape by balancing manufacturing cost and performance.

[0014] In at least one embodiment, larger dimples can be arranged on the leading edge of the blade and smaller dimples on the trailing edge. This allows for both turbulence generation at the leading edge and flow stabilization at the trailing edge. The dimple density can be gradually decreased from the leading edge to the trailing edge, or can be concentrated in a specific area. Spanwise flow control can also be achieved by varying the dimple pattern at the root and tip of the blade. Small 35mm blades allow for effective placement with a minimal number of dimples, while large 180mm blades allow for more precise flow control using a larger number of dimples. A blade with a thickness of 0.1mm allows for deeper dimples, increasing the flexibility of fluid control. While this arrangement can optimize the balance between arrow rotation and straightness, it is not limited to a specific placement pattern and can be flexibly modified depending on the conditions of use.

[0015] In at least one embodiment, a finer uneven structure can be formed inside the dimples. For example, it is possible to form microscopic protrusions with diameters of 0.001 mm to 0.1 mm on the bottom surface of the dimples, or to form concentric steps. Such hierarchical surface structures can realize multi-scale fluid control. The microstructures can be formed by methods such as nanoimprinting, etching, and laser texturing. For a blade with an intermediate thickness of approximately 0.05 mm, by appropriately setting the depth ratio between the primary dimples and the secondary microstructure, advanced fluid control can be achieved while maintaining structural strength. Furthermore, applying a hydrophilic or hydrophobic coating inside the dimples can further improve performance in rainy weather. These microstructures are not required and can be selectively adopted depending on the application. A wide range of designs, from simple dimple-only configurations to complex hierarchical structures, are possible depending on the requirements of the playing level and the usage environment.

[0016] In at least one embodiment, the blade material can be mixed with or coated with a conductive material to prevent static electricity buildup. Materials such as carbon nanotubes, metal powder, and conductive polymers can be used, with the surface resistivity preferably adjusted to a range of 10^6 to 10^12 Ω / □. This prevents dust from adhering during flight and maintains dimple performance. For ultra-thin blades with a thickness of 0.005 mm, the conductive layer must be minimized to achieve its effectiveness, and ultra-thin film formation using atomic layer deposition or sputtering is effective. On the other hand, for blades with a thickness of 0.1 mm, mixing in a conductive filler or thick film coating can also be used. The conductive layer can be applied before or after dimple formation, with the optimal process selected taking into account the flexibility and processability of the material. Anti-static functionality is not essential and can be selected depending on the usage environment, but it is particularly effective in dry environments and high-speed flight.

[0017] In at least one embodiment, a fractal geometric pattern can be used to arrange the dimples. For example, a hierarchical structure can be created in which similarly shaped small dimples are arranged around a large dimple, and even smaller dimples are arranged around that. The fractal dimension can be set in the range of 1.2 to 2.8, generating a flow field similar to the turbulent flow structure in nature. For small 35 mm blades, a simple fractal structure with two to three levels is practical, while for large 180 mm blades, complex patterns with five or more levels can be realized. Computer algorithms can be used to generate patterns, and various methods such as L-systems, IFS, and cellular automata can be applied. The minimum dimple size that can be formed is limited depending on the blade thickness. For a thickness of 0.005 mm, the minimum dimple is set to approximately 0.05 mm, and for a thickness of 0.1 mm, fine dimples of 0.01 mm can be formed. Such complex patterns are not required; they can be selected based on a balance between manufacturing cost and performance.

[0018] In at least one embodiment, temperature-responsive materials can be used to change the depth and shape of the dimples. Shape memory alloys, shape memory polymers, bimetal structures, and other materials can be used to maintain optimal aerodynamic characteristics across a wide temperature range. The deformation temperature can be set between -20°C and 50°C, allowing for adjustments to suit the playing environment. For blades with a thickness of 0.005 mm, shape memory alloy foil can be used as the substrate, and the shape memory effect can be imparted by localized heat treatment of the dimple area. For blades with a thickness of 0.1 mm, a composite structure of shape memory polymer and regular polymer can achieve greater deformation. While active shape control is possible in conjunction with a temperature sensor, passive temperature response can also be sufficient. For larger blades, creating temperature-responsive regions in certain areas allows for localized shape changes while maintaining overall rigidity. Such variable structures are intended for advanced applications, while a fixed shape is sufficient for general use.

[0019] In at least one embodiment, the dimple surface can be coated with a photocatalytic material to impart self-cleaning properties. Photocatalysts such as titanium oxide, zinc oxide, and tungsten oxide can be used, and are activated by ultraviolet or visible light. This decomposes attached organic matter and maintains the dimple shape for a long period of time. The thickness of the photocatalyst layer is preferably in the range of 10 nm to 1 μm, allowing it to function while maintaining transparency. For ultra-thin blades with a thickness of 0.005 mm, low-temperature deposition is important to prevent deformation due to stress in the photocatalyst layer. For small 35 mm blades, full coating is easy, while for large 180 mm blades, selective coating of the dimple area can reduce material costs. Visible light response can also be improved by controlling the crystalline structure and particle size of the photocatalyst. Such high-performance coatings are not required; their adoption can be considered depending on the frequency of maintenance.

[0020] In at least one embodiment, biodegradable plastics can be used as the material for the blades. Materials such as polylactic acid, polycaprolactone, and starch-based plastics can be used, reducing the environmental impact. The biodegradation rate can be controlled using additives, allowing the blades to maintain sufficient strength during use and naturally decompose after disposal. When manufacturing ultra-thin sheets of 0.005 mm thick, it is important to maintain biodegradability while improving strength through stretching and orientation. For 0.1 mm thick blades, a multilayer structure can optimize the balance between mechanical properties and biodegradability. Dimple formation can be performed in the same way as with conventional plastics, and injection molding, heat pressing, and other methods can be used. Depending on the blade size, a single-layer structure can be selected for small blades (35 mm), while a composite structure containing reinforcing fibers can be selected for large blades (180 mm). Controlling the crystallinity and molecular weight distribution of the biodegradable material allows for precise design of the usage period and decomposition period. While environmental considerations are important, conventional materials may be acceptable if competitive performance is a priority.

[0021] In at least one embodiment, fluorescent or phosphorescent materials can be placed within the dimples to improve visibility. Quantum dots, rare-earth phosphors, organic fluorescent dyes, and other materials can be used, emitting light when excited by ultraviolet or visible light. This makes it easier to see the trajectory of an arrow at dusk or indoors. For a blade thickness of 0.005 mm, the fluorescent material layer must be minimized while still providing sufficient luminous intensity. High-efficiency quantum dots or organic electroluminescent materials are effective. For blades with a thickness of 0.1 mm, a thicker fluorescent layer can be formed, achieving a long afterglow. The luminescent material can be applied to the bottom of the dimples or mixed into the resin. A dotted luminous pattern is possible for small 35 mm blades, while a linear or planar luminous pattern is possible for large 180 mm blades. The luminous intensity and duration can be adjusted by selecting the material, and should be implemented within the scope of the competition rules. Improved visibility is an additional function, and it need only be implemented to the extent that it does not affect basic aerodynamic performance.

[0022] In at least one embodiment, piezoelectric elements can be incorporated into the blades to harvest power from vibrations during flight. Piezoelectric materials such as PVDF, PZT, and single-crystal materials can be laminated or embedded in the blades in thin film or fiber form. The generated power can be used to light LEDs, drive sensors, transmit data, and more. Ultra-thin blades with a thickness of 0.005 mm use ultra-thin organic piezoelectric materials to generate power while maintaining flexibility. More efficient ceramic piezoelectric materials can be used with 0.1 mm blades, and the laminated structure can improve output voltage. The piezoelectric elements are designed to avoid interference with the dimple pattern and are positioned to maximize the blade's bending deformation. Efficient energy harvesting is possible with a single element for small 35 mm blades and a multiple-element array for large 180 mm blades. The amount of power generated depends on the flight speed and the blade's vibration mode, but microwatts to milliwatts of power can be expected. Such energy harvesting capabilities are intended for advanced applications and are not necessary for general competition.

[0023] In at least one embodiment, the dimple arrangement can be asymmetrical depending on the arrow's rotation direction. Different patterns can be used for right-handed and left-handed spin to maximize rotation efficiency. The degree of asymmetry can be controlled by the difference in dimple density, size, and depth between the leading and trailing edges. For a blade thickness of 0.005 mm, a gradual density gradient is desirable to avoid stress concentration due to asymmetry. A thickness of 0.1 mm allows for more drastic changes, allowing for the placement of locally deep dimples. Furthermore, optimizing the dimple pattern in conjunction with the blade mounting angle (helical angle) can enable more efficient rotation generation. For small 35 mm blades, a clear asymmetry created by a few large dimples is effective, while for large 180 mm blades, a continuous asymmetry created by many small dimples is effective. It is also possible to incorporate a rotation direction discrimination mark into the dimple pattern itself. However, sufficient performance can be achieved with a symmetrical pattern, so a symmetrical arrangement is acceptable if ease of manufacturing is prioritized.

[0024] In at least one embodiment, surface modification can be performed simultaneously with dimple formation. Surface energy can be controlled by plasma treatment, corona treatment, UV treatment, and other methods to impart water-repellent or hydrophilic properties. The contact angle can be adjusted between 5 and 150 degrees depending on the treatment conditions. For ultra-thin materials with a blade thickness of 0.005 mm, low-temperature and low-power treatment is required to prevent deformation due to heat and stress during treatment. For blades with a thickness of 0.1 mm, more powerful treatment conditions can be applied, allowing for the formation of a deeper modified layer. Furthermore, the application of diamond-like carbon (DLC) coating or fluororesin coating can improve wear resistance and low friction. For small 35 mm blades, full-surface treatment is effective, while for large 180 mm blades, selective treatment using masking allows for control of functional areas. The depth of the surface modification can be controlled within a range of several nanometers to several micrometers, imparting desired properties while ensuring adhesion to the substrate. These surface treatments are not required; they can be selected based on the operating environment and durability requirements.

[0025] In at least one embodiment, strength and rigidity can be improved by adding carbon nanofibers or graphene to the blade material. The preferred amount is between 0.1% and 10% by weight, which improves mechanical properties while maintaining dispersibility. For blades with a thickness of 0.005 mm, controlling the orientation of the nanomaterial is particularly important. Orientation techniques using electric or magnetic fields can selectively improve in-plane strength. At a thickness of 0.1 mm, the formation of a three-dimensional network structure is also possible, achieving isotropic reinforcement. This ensures sufficient rigidity even for thinner blades and improves the retention of the dimple shape. For small blades (35 mm), localized reinforcement through high-concentration addition is effective, while for large blades (180 mm), overall reinforcement through low-concentration addition is effective. It is also important to optimize interfacial bonding with the matrix resin and improve stress transfer efficiency through surface modification with nanomaterials. However, since sufficient performance can be achieved with conventional reinforcement materials, the selection should be based on a balance between cost and performance.

[0026] In at least one embodiment, tiny vortex generators can be placed within the dimples. Small protrusions or fins with heights ranging from 0.01 mm to 0.5 mm can be placed within the dimples to generate more complex flow fields. The vortex generators can be shaped in various ways, including triangular, trapezoidal, and curved, and their angle relative to the flow direction can be adjusted. With a blade thickness of 0.005 mm, the vortex generator height is limited to 50% of the dimple depth, but effective vortex generation is still possible. With a blade thickness of 0.1 mm, taller vortex generators can be placed, resulting in the formation of powerful vortex structures. This allows for advanced flow control not possible with dimples alone. For small 35 mm blades, vortex generators can be placed only in the main dimples, while for large 180 mm blades, vortex generators of different shapes can be placed in all dimples. While fabrication is possible using microfabrication techniques, this is not a required configuration, as conventional dimples alone can provide sufficient effectiveness. It is desirable to optimize the density and orientation of the vortex generators through CFD analysis.

[0027] In at least one embodiment, the color and pattern of the blades can be designed in conjunction with the dimple pattern. The optical effects of the dimples can be utilized to achieve structural colors that change color depending on the viewing angle. When using a transparent or translucent material with a blade thickness of 0.005 mm, the refraction and interference of light through the dimples can produce a rainbow effect. A 0.1 mm thick blade, combined with a multilayer thin-film structure, can achieve even more vivid structural colors. The dimple arrangement can also be used to express letters and shapes. Simple logos and marks can be expressed on small 35 mm blades, while complex graphic patterns can be implemented on large 180 mm blades. More complex designs can be achieved by combining the design with painting or printing. Gradation effects and three-dimensional visual effects can also be created by locally varying the depth and diameter of the dimples. However, design is a secondary factor, and it is important to implement it within a range that does not impair aerodynamic performance.

[0028] In at least one embodiment, temperature and acceleration sensors can be embedded in the blades to record flight data. MEMS sensors, thin-film sensors, and other sensors can be used, positioned so as not to interfere with the dimple structure. For blades with a thickness of 0.005 mm, ultra-thin sensors formed on flexible substrates can be used, allowing for mounting without impairing the blade's flexibility. For blades with a thickness of 0.1 mm, more multifunctional sensor chips can be embedded, measuring not only temperature and acceleration but also strain, pressure, and humidity. Recorded data can be transmitted to an external device via wireless communication or stored in the blade's built-in memory. For small 35 mm blades, a single sensor can measure representative points, while for large 180 mm blades, multiple sensors can measure distributions. Data sampling frequencies can be set between 1 Hz and 10 kHz depending on the application, enabling detailed analysis of flight characteristics. This can be used to optimize the dimple pattern. However, sensors are not required and may be limited to research and development applications.

[0029] In at least one embodiment, nanoimprinting technology can be used to manufacture dimples. This allows for the formation of dimples with high precision, including microstructures of less than 100 nm. Mold materials such as silicon, quartz, and nickel can be used, and thermal or UV nanoimprinting can be applied. For blades with a thickness of 0.005 mm, imprinting at low pressure and low temperature allows for the transfer of microstructures while minimizing deformation of the substrate. For blades with a thickness of 0.1 mm, processing at higher pressures is possible, allowing for the formation of deep dimples and complex hierarchical structures. Roll-to-roll processing can also be used for mass production. Small 35 mm blades can be molded entirely using a single master mold, while large 180 mm blades can be expanded to larger areas using a tiling technique. Applying diamond-like carbon or nitride-based coatings to improve mold durability is also effective. However, sufficient effects can be achieved even with dimples on the order of micrometers, so the appropriate manufacturing method can be selected based on manufacturing equipment and costs.

[0030] In at least one embodiment, the blade material contains a phase-change material, which utilizes the latent heat generated by temperature changes to improve temperature stability. Phase-change materials, such as paraffin, fatty acid, and salt hydrate, can be microencapsulated and dispersed in resin. The phase-change temperature can be selected from a range of -10°C to 40°C depending on the operating environment. For blades with a thickness of 0.005 mm, the microcapsule size must be controlled to 1 μm or less and uniformly dispersed throughout the thin film. For blades with a thickness of 0.1 mm, larger capsules (approximately 10 μm) can be used, increasing the latent heat capacity. This suppresses blade deformation due to sudden temperature changes and stabilizes the dimple shape. For small 35 mm blades, the phase-change material content is 5 to 10 wt %, and for large 180 mm blades, localized high-concentration regions can be created, achieving the desired effect while minimizing weight gain. The phase-change response speed can also be controlled by selecting the capsule wall material. However, standard materials are sufficient in normal use environments, and this functionality is only required under extreme temperature conditions.

[0031] In at least one embodiment, a magnetic fluid is sealed within the dimples, and the fluid's behavior is controlled by an external magnetic field. A magnetic fluid, such as ferrofluid, is sealed within the dimples, which are covered with a flexible film, and controlled by a permanent magnet or electromagnet. For a 0.005 mm thick blade, microfluidic technology is used to precisely seal a very small amount of magnetic fluid, creating a thin film seal. A 0.1 mm thick blade allows for a larger fluid volume and improved magnetic field response. This allows the effective depth and shape of the dimples to be adjusted to suit flight conditions. The magnetic fluid concentration can be adjusted from 1% to 20% by volume, and the viscosity can be selected from 1 to 1000 mPa·s. For a small 35 mm blade, magnetic fluid is sealed only in a few major dimples, while for a large 180 mm blade, zone control allows for partial shape change. The magnetic field strength can be controlled from 0.01 to 1 Tesla, and response times on the order of milliseconds are possible. Such active control systems are intended for advanced research applications, while fixed dimples are sufficient for general use.

[0032] In at least one embodiment, the blade surface can be endowed with antibacterial and antiviral properties. Hygiene is improved by applying a coating containing silver nanoparticles, copper ions, zinc ions, photocatalysts, etc. For blades with a thickness of 0.005 mm, effectiveness is ensured by minimizing the amount of antibacterial components carried while increasing the surface concentration. Specifically, silver nanoparticles are dispersed with a size of 1 to 10 nm at a surface density of 10^11 to 10^13 particles per cubic centimeter. For blades with a thickness of 0.1 mm, long-term effectiveness can be maintained by incorporating antibacterial components into the interior as well. Antibacterial activity can be evaluated in accordance with JIS Z 2801 and ISO 22196, achieving a bacterial reduction rate of over 99%. The coating is applied after dimple formation, resulting in a thin film that does not affect the shape. Dip coating is effective for small 35 mm blades, while spray coating or roll coating is effective for large 180 mm blades. Controlling the elution rate of the antibacterial components optimizes the balance between immediate effectiveness and durability. This function is particularly useful when shared by multiple people or in unsanitary storage environments, but is not essential for personal use.

[0033] In at least one embodiment, the dimple pattern can be used for personal identification or information recording. Each blade can be given a unique dimple arrangement pattern, allowing information to be embedded similarly to a QR code (registered trademark) or barcode. For a blade with a thickness of 0.005 mm, binary information based on the presence or absence of dimples can be recorded, achieving an information density of approximately 100 bits per cubic centimeter. For a blade with a thickness of 0.1 mm, dimple depth can also be used as information, allowing for multi-value recording to improve information density. Image recognition technology can be used to read data, allowing for management of owner information, manufacturing information, performance data, and other information. A basic identification number can be recorded on a small 35 mm blade, while a detailed manufacturing history and usage history can be recorded on a large 180 mm blade. Intentionally randomizing portions of the pattern can also provide an anti-counterfeiting function. Incorporating error correction codes can also enable a design that allows information to be restored even if the blade is partially damaged. However, this function is optional and must be implemented within a scope that does not affect basic aerodynamic performance.

[0034] In at least one embodiment, an acoustic metamaterial structure can be incorporated into the blade. The placement and depth of dimples can be acoustically designed to control flight noise. Absorbing or reflecting specific frequencies can reduce noise or generate specific tones. A blade thickness of 0.005 mm can achieve a sound-absorbing mechanism using membrane vibration, which is effective in the 1 kHz to 10 kHz frequency range. A 0.1 mm thickness also allows for dimple design using the Helmholtz resonator principle, enabling control in lower frequencies (100 Hz to 1 kHz). Small 35 mm blades can be designed specifically for a single resonant frequency, while large 180 mm blades can be designed with a composite structure that achieves broadband sound absorption. Periodic dimple placement can theoretically create an acoustic bandgap, completely blocking sound in a specific frequency range. Acoustic characteristics can be evaluated using impedance tubes or anechoic chambers, and noise reductions of more than 20 dB are possible. This technology could be used to reduce noise at practice ranges and for hunting arrows, but is not essential for competitive use.

[0035] In at least one embodiment, dimple formation can be achieved using 3D printing technology. Various 3D printing methods, including FDM, SLA, SLS, PolyJet, and Binder Jet, are applicable, enabling the production of dimples with complex internal structures. For ultra-thin blade structures with thicknesses of 0.005 mm, SLA and PolyJet methods enable high-precision fabrication with layer thicknesses of 10 μm or less. For thicknesses of 0.1 mm, FDM also achieves sufficient precision and offers a wide range of material options. Materials available include PLA, ABS, nylon, TPU, photocurable resin, and resin containing metal powder. For small 35 mm blades, one-piece fabrication eliminates the assembly process, while for large 180 mm blades, separate fabrication and subsequent joining can accommodate larger blades. Dimples incorporating hollow, lattice, and gyroid structures can also be fabricated while maintaining interlayer adhesion. Designs that take support material removal into account minimize post-processing. While it is suitable for small-lot production or customized products, traditional molding methods are more efficient for mass production.

[0036] In at least one embodiment, the blade material can contain pressure-sensitive or temperature-sensitive dyes. Using materials that change color with pressure allows visualization of pressure distribution during flight. For blades with a thickness of 0.005 mm, the dyes are nanoencapsulated and dispersed in a thin film, designed to clearly change color even with slight pressure changes. Specifically, leuco dyes or spiropyran dyes are used to achieve continuous color changes over a pressure range of 0.1 kPa to 10 kPa. For blades with a thickness of 0.1 mm, a multilayer structure can achieve color changes corresponding to multiple pressure ranges. This allows direct observation of the flow field around the dimples, which can be used for design optimization. Small 35 mm blades allow for understanding of overall pressure distribution, while large 180 mm blades allow for detailed pressure mapping. The dyes can be reversible or irreversible, depending on the application. By combining them with temperature-sensitive dyes, simultaneous measurement of pressure and temperature is also possible. This function is primarily used in research and development and is not necessary for standard competitive blades.

[0037] In at least one embodiment, a liquid crystal material can be placed within the dimples. The optical and effective surface properties of the dimples can be controlled by using liquid crystals whose orientation changes depending on the electric field or temperature. When the blade thickness is 0.005 mm, a polymer-dispersed liquid crystal (PDLC) is used to achieve an ultrathin cell structure. The effective roughness of the dimple surface can also be electrically controlled by changing the orientation of the liquid crystal. A thickness of 0.1 mm allows for more complex cell structures and multifunctional devices with multiple stacked liquid crystal layers. This allows for detecting changes in temperature or electric field during flight and intentionally changing visibility. While simple ON / OFF control is possible with small 35 mm blades, large 180 mm blades allow for the display of complex patterns by independently controlling each region. The driving voltage ranges from 1 V to 50 V, and the response time is on the order of milliseconds to microseconds. The operating temperature range can be set from -40°C to 100°C by selecting the liquid crystal material. This technology is intended for specialized applications; for general use, fixed materials are sufficient.

[0038] In at least one embodiment, the blade edge can be provided with minute serrations (saw-tooth structures). The serration height ranges from 0.1 mm to 2 mm and works in concert with the dimples to reduce noise. For blades with a thickness of 0.005 mm, fine serrations of approximately 50 μm can be formed with high precision using chemical etching or laser processing. The serration tip angle is designed to range from 15 to 90 degrees to control flow separation. A blade with a thickness of 0.1 mm allows for larger serrations, and a multi-stage structure can achieve noise reduction over a wide frequency range. A design mimicking the owl's wing can significantly reduce flight noise. Small 35 mm blades feature continuous serrations around the entire edge, while large 180 mm blades feature selective placement in specific areas to optimize the balance between aerodynamic performance and noise reduction. The serration pitch can be set between 0.5 mm and 5 mm and adjusted according to the dominant noise frequency. Serrations can be integrally formed during blade molding or formed by post-processing. This is effective in applications where quietness is required, but is not essential for competitions.

[0039] In at least one embodiment, superhydrophobic nanostructures can be formed on the dimple surface. A hierarchical structure mimicking the lotus leaf structure can achieve superhydrophobicity with a contact angle of over 150°. For blades with a thickness of 0.005 mm, nanostructures are formed directly on the substrate surface, minimizing the thickness increase due to additional layers. Specifically, nanopillars and nanowires with heights of 50 to 500 nm are formed using plasma etching or the sol-gel method. For blades with a thickness of 0.1 mm, a true hierarchical structure, in which nanostructures are formed on top of larger microstructures, can be achieved, resulting in more stable superhydrophobicity. Nanopillars, nanowires, nanoparticles, and other structures are formed within the dimples, and the surface is then further treated with a fluorine-based material. For small 35 mm blades, full-surface treatment achieves uniform water repellency, while for large 180 mm blades, gradient treatment can be used to create partial hydrophilic and hydrophobic regions. This allows water droplets to become perfectly spherical, allowing them to roll off even at a slight incline, demonstrating a self-cleaning effect. It is particularly effective for use in rainy weather, but because of the high manufacturing costs, it may be limited to high-end products or special uses.

[0040] In at least one embodiment, shape memory alloy wires can be embedded in the blade. The camber (warping) of the blade can be changed by temperature changes, allowing for adjustment of flight characteristics. For a blade thickness of 0.005 mm, ultrafine shape memory alloy wires with a diameter of 10 to 50 μm are used and combined with a substrate. The wire arrangement pattern can be designed according to the desired deformation mode, from a simple parallel arrangement to a radial or mesh-like arrangement. For a thickness of 0.1 mm, thicker wires (100 to 500 μm) can be used, achieving large deformation amounts and high response forces. The wires are arranged from the leading edge to the trailing edge of the blade and are actuated by electrical heating or ambient temperature. For small 35 mm blades, basic shape control is possible with one to three wires, while for large 180 mm blades, complex three-dimensional shapes can be achieved with ten or more wires. The transformation temperature can be set between 20°C and 80°C depending on the application, and the hysteresis width can also be controlled. This makes it possible to achieve different blade shapes for low and high speeds. Because the system, including the control circuit, is complicated, this technology is limited to research and special applications.

[0041] In at least one embodiment, biomimetic design can be employed for the dimple pattern. By mimicking biological surface structures such as shark skin, dolphin skin, butterfly scales, bird feathers, and insect wings, fluid control optimized through evolution can be achieved. Although faithful reproduction of the surface microstructure is difficult for a 0.005 mm thick blade, functionally important features can be extracted and implemented as a simplified pattern. For example, when forming a riblet structure mimicking shark skin within a dimple, it can be realized as microgrooves 10 to 50 μm high and spaced 20 to 100 μm apart. A 0.1 mm thickness allows for more faithful biomimetic reproduction, even replicating hierarchical structures at multiple scales. While a small 35 mm blade can mimic the features of a single organism, a large 180 mm blade can also be designed as a hybrid design combining the features of multiple organisms. SEM, AFM, and micro-CT are used to observe the organisms, and the resulting structure is applied to the size of an arrow feather based on scaling laws. Implementation at the optimal scale is achieved through similarity transformation that takes into account differences in Reynolds number. Since perfect imitation is difficult, it is possible to extract and implement only the functionally important features.

[0042] In at least one embodiment, aerogel can be used as the feather material. Aerogel, with its ultra-low density (0.001 to 0.5 g / cubic centimeter) yet sufficient strength, enables ultralightweight feathers. Although manufacturing a thin aerogel film is technically difficult for feathers with a thickness of 0.005 mm, it is possible to achieve this by using polymer aerogel or aerogel composite materials. Specifically, a polyimide aerogel or cellulose nanofiber aerogel is used as the base material, with the surface coated with a dense layer. For a thickness of 0.1 mm, a wider variety of aerogel materials can be used, including silica aerogel and carbon aerogel. Dimples can be formed simultaneously with the formation of the aerogel or by post-processing. For small 35 mm feathers, surface strengthening is essential to compensate for the brittleness of the aerogel. For large 180 mm feathers, aerogel is used in part and combined with structural components to ensure practical strength. The extremely light weight of the feathers facilitates adjustment of the arrow's center of gravity, which is advantageous for optimizing flight characteristics. However, due to the high manufacturing costs and the need for careful handling, it is limited to special applications.

[0043] In at least one embodiment, artificial intelligence optimization can be applied to dimple placement. Using AI techniques such as genetic algorithms, particle swarm optimization, deep learning, and reinforcement learning, optimal solutions are searched for from a vast number of patterns. For a blade thickness of 0.005 mm, optimization taking manufacturing constraints into account is important, and optimal solutions are searched for within the range of feasible dimple sizes and placements. Design variables can handle tens to thousands of variables, including dimple position, diameter, depth, and shape parameters. A 0.1 mm thickness allows for greater design freedom, enabling optimization including three-dimensional internal structures. Performance under various flight conditions can be evaluated and refined in conjunction with CFD simulation. For small 35 mm blades, optimization using simplified models is also effective to reduce calculation time. For large 180 mm blades, detailed simulation-based optimization is possible using parallel computing. Training data can include wind tunnel test results, actual shooting data, and data from professional players. While optimization requires computational resources, once an optimal pattern is obtained, it can be deployed for mass production.

[0044] In at least one embodiment, the blades can be made of electroactive polymers (EAP). EAPs change shape when a voltage is applied, allowing for control of the dimple depth and the overall shape of the blade. For blades with a thickness of 0.005 mm, a thin film of ionic EAP is used, enabling actuation at low voltages (1 to 5 V). Specifically, conductive polymers such as ionic polymer metal composites (IPMC) and polypyrrole are used. For blades with a thickness of 0.1 mm, dielectric elastomers and electronic EAPs such as PVDF can also be used, which enable greater deformation. Response speeds vary depending on the material, ranging from 0.1 to 10 seconds for ionic EAPs and 0.001 to 0.1 seconds for electronic EAPs. For small 35 mm blades, the entire blade can be operated as a single actuator, while for large 180 mm blades, complex shape changes can be achieved by dividing the blade into multiple segments and controlling them independently. The drive voltage ranges from 1 V to 1 kV, depending on the application. Autonomous shape control is also possible by incorporating a small battery and control circuit into the arrow. This technology is expected to be applied to smart arrows in the future, but is currently in the research stage.

[0045] In at least one embodiment, an ultrashort pulse laser can be used to form dimples. Femtosecond and picosecond lasers enable high-precision dimple processing without a heat-affected layer. For a blade thickness of 0.005 mm, precise control of the laser fluence allows for the formation of dimples of the desired depth without penetrating the substrate. Specifically, processing is performed under conditions of a pulse width of 100 fs to 10 ps, ​​a wavelength of 800 nm to 1064 nm, and a pulse energy of 1 nJ to 1 mJ. For a thickness of 0.1 mm, processing with higher pulse energies is possible, resulting in improved processing speed. Laser-induced periodic structures (LIPSS) can also be used to form nanoscale regular structures within the dimples. For a small 35 mm blade, high-speed processing using a galvanometer scanner allows for full surface processing in a few seconds. For a large 180 mm blade, productivity can be ensured through multi-beam processing and parallel processing. By adjusting processing parameters, surface properties can be controlled, from hydrophilic to superhydrophobic, and structural coloring can also be achieved. Laser processing is highly flexible, but from a productivity standpoint it is suitable for small-scale production and prototyping.

[0046] In at least one embodiment, quantum dots can be incorporated into the blades. CdSe, InP, graphene quantum dots, carbon quantum dots, etc. are used to absorb and emit light of specific wavelengths. For blades with a thickness of 0.005 mm, it is important to uniformly disperse the quantum dots in the polymer matrix and prevent aggregation within the thin film. The size of the quantum dots can be controlled within a range of 2 to 20 nm, and the emission wavelength can be adjusted within a range of 400 to 1500 nm. A 0.1 mm thickness allows for higher concentrations, and by arranging multiple types of quantum dots in layers, white light emission and wavelength conversion functions can be achieved. This can improve visibility by converting ultraviolet light to visible light, or detect near-infrared light for use with night vision devices. Small 35 mm blades emit light like a point source, while large 180 mm blades emit light from a surface, allowing for visualization of the flight trajectory. The core-shell structure of the quantum dots improves their stability, and encapsulation in silica or polymer ensures environmental resistance. The luminous efficiency can be achieved as an external quantum efficiency of 20 to 90%, and the optimum material can be selected depending on the application.

[0047] In at least one embodiment, microcapsules of a phase-transition material can be placed within the dimples. The effective depth of the dimples can be varied by using a material that changes from solid to liquid depending on temperature. For a 0.005 mm blade, controlling the capsule diameter to 1 to 5 μm and arranging it in a single layer achieves functionality while maintaining a thin structure. Phase-transition materials include n-octadecane, n-hexadecane, and paraffin wax, with transition temperatures selected between 10 and 40°C. For a 0.1 mm blade, larger capsules (10 to 50 μm) can be arranged in multiple layers, allowing for greater volumetric change due to the phase transition. For example, a design can be made in which the solid fills and smooths the dimples at low temperatures, and then liquefies at high temperatures to form deeper dimples. For a small 35 mm blade, selective placement in 10 to 20 dimples overall can be achieved. For a large 180 mm blade, gradual placement according to temperature distribution can improve environmental adaptability. The shell material for the microcapsules is selected from melamine resin, polyurethane, silica, etc., taking into consideration the balance between mechanical strength and thermal conductivity. This technology makes it possible to realize blades that automatically adapt to the environment in which they are used, but the structure is complex, so it is intended for special applications.

[0048] In at least one embodiment, plasmonic nanostructures can be formed on the blade surface. Metal nanoparticles, such as gold, silver, aluminum, and copper, or metamaterial structures strongly absorb or reflect specific wavelengths of light. For blades with a thickness of 0.005 mm, metal nanostructures ranging in size from 10 to 200 nm can be precisely positioned using electron beam lithography or nanoimprinting. Plasmon resonance exhibits unique optical properties in the visible to near-infrared range, enabling the realization of structural color and negative refractive index. With a thickness of 0.1 mm, three-dimensional metamaterial structures can be formed, enabling more complex electromagnetic wave control. This allows for the control of detection characteristics in radar and lidar, or the creation of blades that are visible only from specific angles. A small 35 mm blade can be used for a single-function metasurface, while a large 180 mm blade can be used for a multifunctional device, with multiple functions implemented in each region.

[0049] In at least one embodiment, the dimples can be used as microfluidic channels. Adjacent dimples are connected by fine grooves to form a network for circulating fluid. When the blade thickness is 0.005 mm, microchannels with channel widths of 10 to 100 μm and depths of 1 to 4 μm are formed, enabling passive fluid transport using capillary action. Fluids can be used, including coolants, lubricants, and functional fluids (e.g., magnetic fluids, liquid crystals, and phase-change materials), enabling temperature control and dynamic modification of the blade's surface properties. A 0.1 mm thickness allows for the construction of more complex three-dimensional flow channels, and active pumping mechanisms can also be incorporated. While a small 35 mm blade provides basic fluid circulation using a single loop structure, a large 180 mm blade achieves efficient fluid distribution through a dendritic branching structure. Micropumps can be driven by piezoelectric, electroosmotic, or surface tension, and flow rates can be controlled in the range of 0.1 μL / min to 10 mL / min. By surface-treating the flow channel, hydrophilic / hydrophobic patterning can be performed, enabling selective fluid transport. This technology is highly advanced and is currently at the proof-of-concept level, but it shows potential for future application to high-performance electrodes.

[0050] In at least one embodiment, topological optimization can be applied to blades. The finite element method (FEM) and optimization algorithms are combined to find the optimal material distribution under given constraints. For a blade with a thickness of 0.005 mm, two-dimensional optimization optimizes the in-plane material distribution, achieving the lowest possible weight while maintaining the required rigidity. Specifically, by creating hollow regions or thin-walled sections within the blade while taking into account stress concentrations at the dimple locations, weight can be reduced by 30 to 50%. For a blade with a thickness of 0.1 mm, three-dimensional optimization is possible, allowing for the creation of complex truss and honeycomb structures within the blade. This allows for the design of the lightest possible blade structure while maintaining the required rigidity. For small 35 mm blades, optimization using a simplified model is feasible to reduce the computational load, while for large 180 mm blades, detailed optimization using a supercomputer is practical. Multi-objective optimization, which simultaneously optimizes aerodynamic and structural performance by treating the dimple placement as part of the structural optimization, is also possible. While the optimization results often result in complex shapes, these can be realized using advanced manufacturing technologies such as 3D printing. Because of the high computational cost, it is practical to use it for special applications that require high performance.

[0051] In at least one embodiment, a self-healing function can be imparted to the blade surface. A microencapsulated healing agent is dispersed throughout the material, and when a crack occurs, the healing agent is released to repair the damage. For a blade thickness of 0.005 mm, the capsule diameter is controlled to 0.5 to 3 μm, making it less than 60% of the blade thickness, thereby maintaining structural integrity. The healing agent is a fast-curing cyanoacrylate, epoxy, or acrylic resin formulated to cure within seconds to minutes. For a blade thickness of 0.1 mm, larger capsules (5 to 50 μm) can be used, increasing the healing agent capacity and enabling repair of larger damage. Shape-memory polymers can also be used to design blades that can restore their original shape upon heating. For small 35 mm blades, self-healing functionality can be selectively imparted around critical dimples, while for large 180 mm blades, a full self-healing system can be implemented to ensure long-term durability. The repair efficiency is 60 to 95% of the initial strength, and the design can be made to withstand multiple repairs. This allows the dimple shape to be maintained for a long period of time and improves the durability of the blade. The self-repair function is an effective added value, but the balance between cost and effectiveness must be considered.

[0052] In at least one embodiment, tiny piezoelectric actuators can be placed within the dimples. By independently vibrating each dimple, active boundary layer control becomes possible. For a blade thickness of 0.005 mm, thin-film piezoelectric elements (1 to 4 μm thick) are used, enabling operation with low drive voltages (1 to 10 V). The element materials used are PZT thin film, AlN, ZnO, etc., with constants selected in the range of 50 to 500 pm / V. For a blade thickness of 0.1 mm, bulk-type piezoelectric elements can also be used, achieving larger displacements (0.1 to 10 μm). The vibration frequency can be set in the range of 1 Hz to 100 kHz and is optimized depending on the flow velocity. For a small 35 mm blade, actuators can be placed in 5 to 10 major dimples, while for a large 180 mm blade, a distributed control system with more than 50 actuators can be constructed. The actuators are fabricated using MEMS technology and mounted on a flexible substrate to maintain the blade's flexibility. Power can be supplied by thin-film batteries built into the blades, energy harvesting, or wireless power transmission. Control algorithms can be implemented using feedforward control, adaptive control, machine learning-based control, and more. This technology enables ultimate fluid control, but is currently at the laboratory level.

[0053] In at least one embodiment, graphene oxide can be used as the blade material. By controlling the degree of reduction, electrical properties can be tuned, from conductive to insulating. For blades with a thickness of 0.005 mm, a graphene oxide thin film with several to several dozen layers can be formed by spin coating or dip coating. Localized conductivity can be controlled by selectively applying thermal reduction (200 to 1000°C), chemical reduction (hydrazine, ascorbic acid, etc.), or photoreduction (UV, laser). At a thickness of 0.1 mm, a freestanding graphene oxide paper can be formed, improving mechanical strength. Furthermore, functionality can be imparted by inserting various molecules between the graphene oxide layers. For example, improved flexibility can be achieved by inserting polymer chains, catalytic functions by inserting metal ions, and optical functions by inserting organic dyes. Uniform properties can be achieved for small 35 mm blades, while gradient structures with different functions in different regions can be realized for large 180 mm blades. The dimples can be formed by laser processing, plasma etching, and nanoimprinting, and the degree of reduction can be controlled at the same time. Graphene-based materials are promising for the future, but at present, the manufacturing cost is an issue, and their application to high-value-added applications is realistic.

[0054] In at least one embodiment, a quasicrystalline structure can be used for the dimple pattern. Quasiperiodic patterns with 5-fold, 8-fold, or 12-fold symmetry, for example, can achieve unique fluid dynamic characteristics. For blades with a thickness of 0.005 mm, dimple placement accuracy is crucial, so high-precision manufacturing techniques (e.g., electron beam lithography and nanoimprinting) are used. Quasicrystalline patterns are designed based on mathematical structures such as Penrose tiling, Ammann-Venker tiling, and Dan-Schechtman patterns. With a thickness of 0.1 mm, three-dimensional quasicrystalline structures can also be realized, enabling more complex fluid control. Quasicrystalline structures possess properties intermediate between periodic and aperiodic structures and are expected to have vibration damping effects over a wide frequency range. For small 35 mm blades, two-dimensional quasicrystalline structures with 100 to 500 dimples can be realized, while for large 180 mm blades, large-scale quasicrystalline patterns with thousands of dimples can be realized. A computer is used to generate the patterns, applying algorithms such as the projection method, de Bruin's method, and substitution rule method. A systematic investigation of the correlation between the symmetry of the quasicrystal and the aerodynamic characteristics of the blades allows for the establishment of optimal design guidelines. Fabrication is carried out using lithography and precision molds, but high manufacturing precision is required to maintain the long-range order characteristic of quasicrystals.

[0055] In at least one embodiment, optical fibers can be embedded in the blades. Plastic optical fibers (POF) or glass optical fibers are placed inside the blades and used as distributed sensors. For blades with a thickness of 0.005 mm, ultrafine optical fibers with diameters of 50 to 125 μm are used, and they are placed on the midplane of the blades to minimize bending loss. Sensing principles include Brillouin scattering, Rayleigh scattering, and Raman scattering, enabling measurement of strain and temperature distribution with a spatial resolution of 1 mm to 10 cm. With a thickness of 0.1 mm, multiple optical fibers can be placed at different depths, enabling three-dimensional condition measurement. Light can also be incident on the end of the fiber to illuminate the blades, and dynamic color changes can be achieved by combining it with RGB LEDs. Simple sensing is possible with a single fiber bent into a U-shape for small 35 mm blades, while area-wide sensing is possible with multiple fibers arranged in a grid pattern for large 180 mm blades. The placement of the optical fiber is designed so as not to interfere with the dimple pattern, and grooves for the optical fiber are provided at the bottom of the dimples as needed. Measurement data is analyzed using an optical spectrum analyzer or optical time-domain reflectometer (OTDR), enabling real-time condition monitoring. This technology is suitable for research applications requiring advanced measurement.

[0056] In at least one embodiment, catalytic functionality can be imparted to the dimple surface. Catalysts such as platinum, palladium, rhodium, titanium oxide, and cerium oxide are supported to decompose air pollutants during flight. For blades with a thickness of 0.005 mm, atomic layer deposition (ALD) can be used to precisely control the thickness of the catalyst layer to 1 to 10 nm, minimizing the load on the substrate. The catalyst is highly dispersed as nanoparticles (1 to 20 nm), increasing the specific surface area to 200 to 1,000 m2 / g. For blades with a thickness of 0.1 mm, a thicker catalyst layer (100 nm to 1 μm) can be formed, and the introduction of a mesoporous structure can achieve even higher activity. For example, the detoxification of NOx, VOCs, and PM2.5 can contribute to environmental purification. Small 35 mm blades can decompose specific substances using a single catalyst, while large 180 mm blades can simultaneously treat a wide range of pollutants using a combination of multiple catalysts. The dimple structure promotes turbulence and improves mass transfer, which is expected to increase catalytic reaction efficiency by 2 to 10 times compared to a smooth surface. To maintain catalytic activity, the introduction of a self-regenerating function or a sacrificial protective layer can also be considered. This function has a strong social contribution aspect, and although it does not directly contribute to normal racing performance, it is appealing to environmentally conscious users.

[0057] In at least one embodiment, a memory alloy mesh can be layered on the blade. A mesh-like shape memory alloy is placed on the blade surface, and the mesh's opening ratio can be changed by temperature changes. For a blade with a thickness of 0.005 mm, a mesh woven with ultrafine shape memory alloy wires with a wire diameter of 10 to 30 μm is used, with a total thickness of 0.01 mm or less. The mesh's opening ratio can be changed between 20% and 80% depending on the temperature, thereby controlling the effective size of the dimples and the degree of air permeability. A 0.1 mm thickness allows the use of a mesh with a thicker wire diameter (50 to 200 μm), achieving both mechanical strength and shape change. The mesh can also be actively controlled by electrical resistance heating, with a response time settable between 0.1 and 10 seconds. For small 35 mm blades, basic opening ratio control is achieved using a single-layer mesh, while for large 180 mm blades, multi-stage control can be achieved by operating multiple layers of mesh at different transformation temperatures. The lamination method is selected depending on the material and application, and includes adhesive bonding, welding, mechanical fixing, and integral molding. Mesh patterns vary, including square, hexagonal, and diamond shapes, and are optimized according to the fluid characteristics. This technology makes it possible to realize variable geometry blades, but the complexity of the structure limits it to special applications.

[0058] In at least one embodiment, a shear-thickening fluid can be encapsulated within the dimples. A non-Newtonian fluid with low viscosity at low shear rates and high viscosity at high shear rates is used. For a blade thickness of 0.005 mm, a microencapsulated shear-thickening fluid is used, with capsule diameters controlled to 1 to 4 μm and dispersed within the thin film. Fluid compositions include silica particles (particle size 50 to 500 nm) dispersed in polyethylene glycol or cornstarch suspensions. For a blade thickness of 0.1 mm, a structure in which the fluid is directly encapsulated within the dimples is also possible, allowing for greater viscosity changes. This allows for deeper dimples at low flight speeds and shallower dimples at high flight speeds. The viscosity can be varied from 10 mPa·s to 10,000 mPa·s, and the critical shear rate can be set to 10 to 1,000 depending on the application. For small 35mm blades, optimal adaptability can be achieved by selectively filling a few key dimples, while for large 180mm blades, optimal adaptability can be achieved by arranging fluid with graded critical shear rates according to the flight velocity distribution. A flexible membrane (silicone rubber, thermoplastic elastomer, etc.) is used for filling, with a structure that can follow pressure changes. To ensure the long-term stability of the fluid, the addition of antioxidants and dispersion stabilizers is also being considered. This technology is interesting as an adaptive aerodynamic device, but ensuring reliability remains a challenge for practical use.

[0059] In at least one embodiment, a metasurface can be fabricated on the blade surface. Sub-wavelength periodic structures can control the propagation of electromagnetic and acoustic waves. For blades with a thickness of 0.005 mm, metal or dielectric structures 50 to 500 nm in size are periodically arranged using electron beam lithography or nanoimprinting. Split-ring resonators, V-shaped antennas, nanorods, and other components are used as metasurface components to achieve unique properties such as negative refractive index, perfect absorption, and anomalous reflection. A thickness of 0.1 mm allows for the fabrication of multilayer metasurfaces, enabling broader bandwidth and multifunctionality. For example, specific frequencies can be absorbed for noise reduction, or electromagnetic waves can be scattered in specific directions. A single-function metasurface design can be implemented on a small 35 mm blade, while a multifunctional device can be realized by arranging metasurfaces with different functions in different regions on a large 180 mm blade. Acoustic metasurfaces can reduce transmittance to below -30 dB in the frequency range from 100 Hz to 10 kHz. Electromagnetic metasurfaces can be designed to suit various applications, from visible light to microwave regions. Electromagnetic field simulations (FDTD method, finite element method, etc.) are used for design, and the structure is optimized to achieve the desired characteristics. This technology is expected to be a next-generation functional material, but due to the high difficulty and cost of manufacturing, it is only realistic to apply it to special applications.

[0060] In at least one embodiment, the dimple pattern can be designed holographically. Applying the principles of computer-generated holograms, the dimple arrangement that generates a specific flow field is determined as an inverse problem. For a blade thickness of 0.005 mm, a phase hologram is formed by modulating the dimple depth, enabling precise control of the fluid flow direction. The design process involves setting the target pressure and velocity distributions, and then calculating the required dimple pattern using inverse Fourier transform and iterative optimization. For a blade thickness of 0.1 mm, a complex hologram incorporating amplitude modulation is possible, enabling more precise flow field control. This theoretically allows for ideal pressure and vorticity distributions and complete control of boundary layer separation. For small 35 mm blades, basic flow control using simple phase patterns is possible, while for large 180 mm blades, higher-order holograms that generate complex three-dimensional flow fields are possible. The design uses a combination of fast Fourier transform (FFT), iterative Fourier transform algorithm (IFTA), and genetic algorithms. The fabrication is carried out using electron beam lithography, direct laser writing, and ultra-precision machining, achieving a shape accuracy of λ / 10 or less. This method can theoretically achieve optimal performance, but requires advanced technology in both calculations and fabrication, and is therefore primarily used for research and development purposes.

[0061] In at least one embodiment, biocompatible materials can be used for the feathers. Medical-grade silicone, polyurethane, PTFE, PEEK, titanium alloy, and other materials are used to ensure safety when in contact with the skin. For feathers with a thickness of 0.005 mm, medical-grade ultra-thin film manufacturing technology is applied to achieve a material design that is non-cytotoxic, non-sensitizing, and non-irritating. Specifically, materials that pass biocompatibility tests (cytotoxicity, sensitization, irritation, systemic toxicity, etc.) in accordance with the ISO 10993 series are selected. For feathers with a thickness of 0.1 mm, a wider variety of medical-grade materials can be used, enabling material designs that take long-term contact into consideration. This contributes to improved safety during arrow retrieval and transportation, which is especially important for users with allergies or sensitive skin. Small 35 mm feathers are constructed entirely from a single biocompatible material, while large 180 mm feathers can be constructed using a hybrid structure, with only the contact area made of biocompatible material and the rest made of high-performance materials. In addition, applying an anti-allergic coating (hyaluronic acid, collagen, silk fibroin, etc.) can further improve safety. Surface roughness and wettability also affect skin irritation, so they must be appropriately controlled. While these properties are not essential, they are effective in considering a wide range of users.

[0062] In at least one embodiment, a microbubble generation mechanism can be incorporated within the dimple. Microbubbles are generated using ultrasonic transducers, electrolysis, chemical reactions, or cavitation and injected into the boundary layer. When the blade thickness is 0.005 mm, ultrasonic generation using a piezoelectric thin film (1 to 4 μm thick) generates microbubbles with diameters of 1 to 10 μm. The vibration frequency ranges from 20 kHz to 1 MHz, selected based on bubble generation efficiency and noise reduction. A 0.1 mm thickness allows for the placement of larger transducers and electrodes, enabling the generation of hydrogen and oxygen microbubbles by electrolysis. Microbubbles reduce frictional resistance by 20 to 80%, potentially extending flight distance. Effective drag reduction can be achieved by generating bubbles locally in one to three locations on a small 35 mm blade, while a continuous bubble curtain along the leading edge can be formed on a large 180 mm blade. The bubble size is controlled within a range of 1 μm to 100 μm and optimized according to the flow velocity. To improve the stability of the bubbles, it is possible to consider adding surfactants or applying nanobubble technology. This technology has been researched for ships and aircraft, but its application to arrows is highly novel, and the challenges for practical use will be securing an energy source for bubble generation and making the system smaller and lighter. By combining it with a power generation element, it will also be possible to create a self-contained system.

[0063] In at least one embodiment, a manufacturing method is employed in which a sheet material is supplied in a rolled form, and after punching using a punching die, the dimple structure is formed by a combination of thermoforming and vacuum suction. The raw material for the blades is a plastic sheet, metal foil, composite sheet, or other material with a thickness ranging from 0.005 mm to 0.1 mm. The blade shape is punched out at high speed from a continuous rolled sheet. The punching process uses a progressive die or compound die, achieving a production rate of 100 to 1,000 blades per minute. The punched blade material is heated in a heating station to near the material's glass transition temperature (e.g., 70 to 80°C for PET and 140 to 150°C for polycarbonate). The heating time is set to 0.5 to 2 seconds for small 35 mm blades and 2 to 10 seconds for large 180 mm blades, ensuring uniform temperature distribution. The heated blade material is placed on a mold engraved with a dimple pattern and formed using a pressure difference of atmospheric pressure (approximately 0.1 MPa) through vacuum suction. The vacuum level can be adjusted between -80 kPa and -99 kPa and is optimized according to the type and thickness of the material. For extremely thin materials (0.005 mm thick), pressure is controlled by applying a vacuum in stages and partially masking the material to prevent breakage due to excessive suction. The mold temperature is set 10 to 30°C lower than the molding temperature to promote shape fixation after molding. This manufacturing method is suitable for mass production and minimizes material waste, making it cost-effective.

[0064] In at least one embodiment, a manufacturing method can be employed in which an ultra-thin injection mold is used to integrally mold dimpled arrow feathers. An ultra-precision mold is manufactured to accommodate feather thicknesses of 0.005 mm to 0.1 mm, and a high-fluidity resin is used to achieve thin-wall molding. The mold cavity thickness is designed taking into account the product thickness and the resin shrinkage rate (0.2 to 2%), and the dimples are formed using electrical discharge machining, laser processing, or ultra-precision cutting. The injection molding machine is selected with a clamping force ranging from 50 to 500 tons, with low-pressure molding applied to small 35 mm feathers and high-speed, high-pressure molding applied to large 180 mm feathers. A high-fluidity resin material, such as liquid crystal polymer (LCP), polyphenylene sulfide (PPS), or cyclic olefin copolymer (COC), is used, with a melt flow rate (MFR) ranging from 30 to 300 g / 10 min. For ultra-thin molding of 0.005 mm thickness, the mold temperature is raised to near the melting point of the resin (for example, 280 to 320°C for LCP) to minimize flow resistance during filling. The injection speed is set at a high speed of 500 to 2000 mm / s to prevent the resin from solidifying in the thin-walled areas. The holding pressure is set at 30 to 80% of the injection pressure, and the holding time is short, at 0.1 to 2 seconds, to prevent warping due to overfilling. The use of gas-assisted molding and an insulated runner system makes it possible to further thin the wall and improve quality. This manufacturing method achieves high reproducibility of the dimple shape and dimensional accuracy (within ±0.01 mm), making it suitable for mass production.

[0065] In at least one embodiment, a manufacturing method is employed in which dimples are continuously transferred onto a sheet material using an embossing roll bearing a dimple pattern, followed by punching into a blade shape using a die. A plastic sheet, metal foil, or composite sheet with a blade thickness ranging from 0.005 mm to 0.1 mm is used as the raw material. The sheet is first passed between an embossing roll engraved with a dimple pattern and a smooth backup roll. The embossing roll has a diameter ranging from 100 mm to 500 mm, and a dimple pattern with a diameter of 0.05 mm to 10 mm is formed on its surface by photoetching, laser engraving, or precision machining. The pressure between the rolls can be adjusted between 0.5 MPa and 50 MPa and is optimized depending on the type and thickness of the material. For ultra-thin materials with a thickness of 0.005 mm, a multi-stage roll forming process is used, gradually increasing the dimple depth with each stage to prevent breakage or stretching due to excessive pressure. The roll temperature can be controlled between room temperature and 200°C, and for thermoplastic materials, it is set near the softening temperature to improve dimple transferability. The roll speed can be adjusted between 1m / min and 100m / min, and is set taking into consideration the balance between production volume and quality. After the dimples have been transferred, the sheet is punched into the shape of a blade using a progressive die or rotary die. For small 35mm blades, continuous punching using a high-speed rotary die is efficient, while for large 180mm blades, punching using a precision press is efficient. This manufacturing method has the advantage that by separating the dimple formation and punching, each process can be easily optimized, and a variety of dimple designs can be accommodated by changing the roll pattern.

[0066] In at least one embodiment, injection molding can be used to produce a structure with a smooth, dimple-free area at the base of the feather. In precision injection molding for feathers with thicknesses of 0.005 mm to 0.1 mm, a 5 mm to 20 mm area at the base of the feather is designated as a dimple-free zone during mold design. This smooth area maximizes the bonding area with the arrow shaft, ensuring sufficient adhesive strength to withstand aerodynamic loads during high-speed flight, reaching speeds of up to 240 kilometers per hour. Injection molding employs a hot runner system to precisely control the resin temperature between 220°C and 350°C. Injection pressure is set between 50 MPa and 200 MPa to ensure reliable filling of thin-walled sections. For ultra-thin molding of 0.005 mm, a vacuum (below -90 kPa) inside the mold prevents air entrapment and ensures complete transfer of the dimple pattern. The smooth area at the base is finished to a surface roughness of Ra 0.05 μm or less to improve wettability with adhesives. For small 35mm blades, a smooth region of 5 to 8mm is provided at the base, while for large 180mm blades, a smooth region of 10 to 20mm is provided, ensuring appropriate adhesive strength according to the blade size. To avoid stress concentration, a smooth transition with a curvature radius of 0.5mm or more is provided at the boundary between the dimpled part and the smooth part of the mold. This manufacturing method significantly reduces the risk of peeling during high-speed flight.

[0067] In at least one embodiment, a special surface treatment can be applied to the dimple-free zone of the blade root to improve adhesive strength. After injection molding, plasma treatment, corona treatment, or UV / ozone treatment can be selectively applied to the smooth area of ​​the blade root to increase the surface energy from 40 mN / m to 80 mN / m. This dramatically improves adhesion with epoxy, cyanoacrylate, or urethane adhesives. Plasma treatment conditions include an output power of 50 W to 500 W and a treatment time of 5 to 60 seconds, achieving optimal surface modification while preventing material degradation. For ultra-thin blades with a thickness of 0.005 mm, pulsed plasma or low-temperature plasma is used to prevent thermal deformation during treatment. Furthermore, forming microtextures (fine grooves 0.1 μm to 1 μm deep) in the blade root can improve adhesive strength through a mechanical interlocking effect. The lift generated per blade during flight at 240 km / h can reach a maximum of 50 N, and this structure can achieve a peel strength of over 100 N. One advantage of injection molding is that it allows for thickness variations, increasing the thickness of the base part locally from 0.1mm to 0.3mm, which further improves the rigidity and strength of the bonded joint. The molding cycle time ranges from 15 to 60 seconds, achieving both mass productivity and quality.

[0068] In at least one embodiment, the injection molding mold can be designed so that no dimples are placed in the bonding area of ​​the feathers. In the mold cavity design, the area from 10% to 30% of the base of the feather (3.5 to 10.5 mm for 35 mm feathers, and 18 to 54 mm for 180 mm feathers) is intentionally designed as a smooth surface, and no dimples are applied to this area. This ensures that the surface of the part that is bonded to the arrow shaft is completely smooth, maximizing the contact area with the adhesive. Resin flow analysis during injection molding optimizes the gate position to ensure smooth resin flow from the dimpled area to the smooth area. Specifically, pinpoint gates are placed at the center or multiple points of the base of the feather, and weld lines are controlled to form in the dimpled area. The mold temperature is differentiated between 80°C and 150°C in the smooth area and 60°C and 130°C in the dimpled area, thereby particularly improving the surface quality of the smooth area. The smooth parts of the molded product have a mirror finish (Ra 0.02 μm or less), which allows the adhesive to wet and spread evenly. The peeling moment caused by air resistance when flying at 240 kilometers per hour is greatest at the tip of the wing, but the strong adhesion provided by the smooth part at the base prevents the formation of peeling points.

[0069] In at least one embodiment, the design of the dimple-free zone can be optimized from an aerodynamic perspective. The base of the feather is an area near the arrow shaft where the boundary layer is not fully developed. Therefore, even if dimples are provided in this area, the aerodynamic effect is limited. Therefore, a smooth design that prioritizes adhesive performance is rational. In the injection molding mold, a transition zone of 0.5 to 2 mm is provided at the boundary between the dimpled area and the smooth area to prevent stress concentration and flow separation due to steps. The cross-sectional shape of the transition area is designed using a cubic spline curve or elliptical arc to achieve a smooth shape change. For ultra-thin feathers with a thickness of 0.005 mm, locally increasing the thickness of the smooth area by 0.01 to 0.05 mm improves handling and strength during bonding. For 0.1 mm thick feathers, providing a fine undercut structure (0.01 to 0.1 mm deep) in the smooth area promotes mechanical interlocking of the adhesive. During the injection molding dwelling process, high dwell pressure (50MPa to 150MPa) is applied to the smooth area to increase surface density. Cooling time is ensured for the smooth area, at 5 to 20 seconds, minimizing warping and shrinkage. This design improves adhesive strength by 200% to 300% compared to conventional full-dimple structures, ensuring reliable fixation even under extreme flight conditions.

[0070] In at least one embodiment, an asymmetric structure can be adopted in the blade root bonding area, where convex dimples are removed from the shaft side (inner surface) and concave dimples are formed only on the outer surface. This design makes the bonding surface completely smooth, ensuring 100% contact area with the adhesive, while maintaining aerodynamic performance through the concave dimples on the outer surface. In the design of the injection molding mold, the root portion 5 to 20 mm of the movable mold (forming the inner surface of the blade) is mirror-finished (Ra 0.02 μm or less), and a concave dimple pattern is arranged on the fixed mold (forming the outer surface of the blade). The depth of the concave dimples is limited to 20% to 40% of the blade thickness, with a depth of 0.001 mm to 0.002 mm for 0.005 mm thick blades and 0.02 mm to 0.04 mm for 0.1 mm thick blades. This achieves boundary layer control while maintaining structural strength. When flying at 240 kilometers per hour, the concave dimples on the outer surface promote turbulent flow transition, while the smooth surface on the inner surface maintains laminar flow, minimizing drag across the entire blade. This asymmetric structure is applied over a range of 5 to 8 mm at the root for small 35 mm blades, and 15 to 30 mm for large 180 mm blades, ensuring the optimal bonding area for each blade size. By considering the resin filling balance during molding and optimizing the gate position and holding pressure profile, warpage can be kept to less than 0.1 mm even when dimples are formed on only one side.

[0071] In at least one embodiment, a special mold cooling system can be used to manufacture single-sided concave dimple structures. The fixed mold, which contains the concave dimples, is equipped with fine cooling channels (0.5 mm to 2 mm in diameter) corresponding to each dimple position, enabling localized temperature control. The movable mold, which forms the smooth surface, employs spiral or lattice-shaped cooling circuits to maintain uniform temperature distribution (within ±2°C). This temperature control enables uniform shrinkage and minimal warpage, even for complex single-sided shapes. For ultra-thin molding with blades as thin as 0.005 mm, titanium nitride (TiN) or diamond-like carbon (DLC) coatings are applied to the mold surface to improve mold release and transferability of the smooth surface. The concave dimples in the adhesive area are tapered, gradually becoming shallower in the depth direction, creating a smooth transition from the dimple edge to the smooth area. This structure further enhances adhesive strength through an anchor effect, even if the adhesive penetrates into the dimples. Actual measurements have confirmed that the single-sided concave dimple structure improves adhesive strength by 150% to 250% compared to conventional double-sided dimple structures, while minimizing the loss of aerodynamic performance by 5%. The injection molding cycle time is 20 to 45 seconds, and stable quality can be maintained even in mass production.

[0072] The feathers attached to archery arrows have multiple dimple structures on their surface. This dimple structure improves the aerodynamic performance of the feather and ensures stability during flight. The dimple structure is formed with a diameter ranging from 0.05 mm to 2 mm. Specifically, feathers with a dimple diameter of 0.1 mm are manufactured to reduce air resistance. The dimple depth ranges from 5% to 100% of the diameter. For example, a dimple with a diameter of 0.5 mm has a depth ranging from 0.025 mm to 0.5 mm. This controls the boundary layer on the feather surface and delays separation. Feather thickness ranges from 0.005mm to 0.1mm. For example, a 0.05mm thick feather is both lightweight and rigid, and allows for easy dimple formation. This thickness range is suitable for the high-speed flight of archery arrows and promotes vibration damping. Feathers are manufactured by injection molding, which precisely forms the dimple structure and can reproduce even minute dimples as small as 0.05mm. In injection molding, resin is injected into a mold, and the dimple shape is transferred to the feather surface. This ensures uniform dimple diameter and depth and improves mass production. For example, a 0.08mm thick feather with a 1mm diameter, 0.3mm deep dimple structure is manufactured using injection molding. This feather is then attached to an archery arrow to improve flight stability. The dimple structure is evenly distributed from the leading edge to the trailing edge of the feather to optimize airflow. Injection molding can also produce extremely thin feathers as thin as 0.005mm, achieving a microstructure with dimples 0.05mm diameter and 0.005mm deep. This reduces feather drag and improves arrow velocity. The archery fletching of this embodiment has a dimple structure that improves aerodynamic characteristics, and consistent quality is ensured through high-precision manufacturing using injection molding. The dimple diameter and depth can be adjusted within a range of thickness from 0.005 mm to 0.1 mm, making it possible to accommodate a variety of flight conditions.

[0073] Dimple-free zone design In at least one embodiment, the injection molding mold is designed to have a smooth structure in which no dimple concave portions (Fig. 2) or convex portions (Fig. 3) are placed in the adhesive portion of the blade body (Fig. 1) or the dimple-free zone (Fig. 4). Design details 10% to 30% of the blade base end (e.g., 3.5mm to 10.5mm for a 35mm blade, and 18mm to 54mm for an 180mm blade) is designed as a smooth surface, the dimple-free zone (Fig. 4). This smooth surface maximizes the contact area with the adhesive and improves adhesive strength. Mold design and molding conditions Gate position is optimized based on resin flow analysis (e.g., a pinpoint gate is placed in the center of the blade base). The mold temperature is set to 80°C to 150°C for the smooth portion (Fig. 4), and 60°C to 130°C for the dimple portion (Fig. 23), improving the surface quality of the smooth portion to a mirror finish of Ra 0.02μm or less Detailed specifications of adhesive surface design and manufacturing method: Within the adhesive surface range of 1mm to 5mm, there are no convex structures on the seal adhesive surface, maintaining a completely smooth surface, dramatically improving adhesion during bonding. A technical feature of this adhesive surface design is the realization of an ultra-mirror finish with a surface roughness of Ra 0.01μm or less, which enables adhesion with the adhesive at a molecular level. Technology for controlling adhesive surface width The adhesive surface width was set to a range of 1mm to 5mm based on the following technical grounds. If it is less than 1mm, the adhesive surface area is insufficient, reducing the strength of the attachment to the arrow shaft. On the other hand, if it exceeds 5mm, the ratio of the adhesive area to the effective area of ​​the blade becomes too large, adversely affecting aerodynamic performance. Experiments have confirmed that an adhesive surface width of 1.5mm to 3.5mm, the optimal range, can ensure an adhesive strength of 15N or more and a peel moment resistance of 0.8N·m or more. Manufacturing process for smooth adhesive surfaces Smoothing adhesive surfaces during injection molding is achieved by a dedicated temperature control system. The mold area corresponding to the adhesive surface is locally heated to 120 to 180°C to maximize the fluidity of the resin. At the same time, the cooling rate is controlled to 0.5°C per second or less to prevent the formation of minute irregularities on the surface due to shrinkage. This manufacturing method improves the surface roughness of the adhesive surface by 70% compared to conventional methods, making it possible to stably manufacture products in the range of Ra 0.008 to 0.015 μm. Quantitative evaluation of adhesive performance: The smooth adhesive surface ensures uniform distribution of adhesive and complete elimination of air bubbles. Specifically, the adhesive layer thickness can be maintained uniformly within the range of 0.005 mm to 0.02 mm, reducing the air bubble content to 0.1% or less. As a result, stress concentration points at the adhesive interface are reduced by 85%, improving durability against fatigue failure. In tensile tests, adhesive strength was improved by an average of 23.7% compared to conventional uneven surface bonding, and a 31.2% improvement in shear strength was confirmed. Ensuring long-term durability and reliability In temperature cycle tests (-40°C to +80°C, 1,000 cycles), the adhesive strength of blades with smooth adhesive surfaces decreased by less than 5%, a significant improvement over the conventional 15% decrease. Furthermore, no peeling was observed at the adhesive interface in high-speed rotation tests (10,000 rpm, 100 continuous hours), demonstrating reliability for long-term use. Effect: Suppresses the peeling moment caused by air resistance when flying at 240 km / h. The smooth base (Figure 4) improves adhesive strength and prevents the formation of peeling points. Furthermore, the smooth adhesive surface of 1 to 5 mm maximizes the stress dispersion effect at the adhesive interface, dramatically improving resistance to vibrations and impacts during flight.

[0074] The components of the present invention are not limited to those described in the above embodiments, and can be combined, modified, substituted, or deleted in any manner within the scope of the technical concept of the present invention. The components described in each embodiment can be combined as appropriate as long as there is no technical contradiction, and the combination patterns are virtually infinite. Furthermore, each means, step, and functional unit of the present invention can be implemented independently or in any combination, and the effects obtained by such selective combinations are diverse. Furthermore, each parameter, threshold, and setting value can be changed as appropriate depending on the application and environment, and the range of possible changes and combinations are virtually limitless. The technical scope of the present invention is not limited to the individual embodiments described above, but also encompasses any combination, modification, or application of the components of each embodiment. The possibilities for such combinations are theoretically infinite, and those skilled in the art will be able to easily conceive of various modifications based on the technical concept of the present invention.

Claims

1. 1. An archery feather attached to an archery arrow, the feather having a plurality of dimple structures on the surface thereof, and a fine uneven structure within the dimple structures.

2. 2. The archery fletching according to claim 1, wherein the dimple structure has a diameter ranging from 0.05 mm to 2 mm and a depth ranging from 5% to 100% of the diameter.

3. 3. The archery fletching according to claim 1, wherein the thickness of the feathers is in the range of 0.005 mm to 0.1 mm.

Images