106, and a lateral side 108 opposite medial side 106. Also, as shown for example in FIG. 1A, article of footwear 100 can comprise a forefoot portion 110, a midfoot portion 112, and a rearfoot portion 114. Portions 110, 112, and 114 are not intended to demarcate precise areas of article of footwear 100. Rather, portions 110, 112, and 114 are intended to represent general areas of article of footwear 100 that provide a frame of reference. Although portions 110, 112, and 114 apply generally to article of footwear 100, references to portions 110, 112, and 114 also can apply specifically to sole portion 120, upper portion 160, or individual components of sole portion 120 or upper portion 160.

Sole portion 120 can comprise a midsole 140. In such embodiments, midsole 140 forms part of sole portion 120. In some embodiments, as shown for example in FIG. 1D, midsole 140 can comprise a three-dimensional mesh 142 comprising a plurality of interconnected unit cells 144. Each interconnected unit cell 144 can comprise a plurality of unit cell struts 146 defining a three-dimensional structure and a plurality of nodes 148 at which one or more unit cell struts 146 are connected.

In some embodiments, a top surface of midsole 140 can comprise an insole skin 156. In some embodiments, insole skin 156 can comprise a network of beams 158 that intersect each other at intersection points 159, as illustrated in for example FIG. 1B. In some embodiments, intersection points 159 can be located at nodes 148 of unit cells 144 of midsole 140. In embodiments comprising skin 156, beams 158 can comprise a smooth contour that does not oscillate between adjacent intersection points 159 with struts 146 of unit cells 144. In such embodiments, beams 158 can extend continuously in a straight or curved line between intersection points 159. In some embodiments, beams 158 of skin 156 may not define a portion of a repeating unit cell 144 for midsole 140. Rather, beams 158 of skin 156 can be integrally formed on repeating unit cells 144 of midsole 140.

As used herein, the term three-dimensional mesh refers to a three-dimensional structure comprising a plurality of unit cells 144 arranged in a web-like structure or a lattice structure. The web-like or lattice structure of a three-dimensional mesh comprises interconnected structural members (for example struts 146 or ribbons) defining the plurality of unit cells 144. In embodiments comprising struts 146, the struts 146, and thus the unit cells 144, are connected at the nodes 148. For example, the struts 146 are connected at nodes 148 and define unit cells 144 arranged in a lattice configuration. In some embodiments, the plurality of interconnected unit cells 144 can be arranged in a regular or repeating lattice configuration. Exemplary lattice configurations include, but are not limited to basic cubic lattices, body-centered cubic lattices, face-centered cubic lattices, and modified lattices based on these lattice types. Exemplary lattice configurations include, but are not limited to the lattice structures described in U.S. patent application Ser. Nos. 17/069,623 and 18/313,135, which are hereby incorporated by reference in their entireties.

Unit cells 144 can have various dimensions and geometries. Further, unit cells 144 within a three-dimensional mesh can be the same or may differ. Thus, a three-dimensional mesh can include unit cells of different dimensions or geometries. The three-dimensional shape of a unit cell 144 can be defined by a plurality of interconnected struts 146 connected to one another at nodes 148. In such embodiments, each unit cell 144 can have a base geometry defined by the struts 146. As used herein, “base geometry” means the base three-dimensional shape, connection, and arrangement of the struts 146 defining a unit cell 144. The base geometry of a unit cell may be, but is not limited to, a dodecahedron (e.g., rhombic), a tetrahedron, an icosahedron, a cube, a cuboid, a prism, or a parallelepiped. Each node 148 can connect two or more struts 146.

In some embodiments, the interconnected unit cells 144 can comprise a solid representation of a repeating implicit surface of a lattice structure. In such embodiments, the unit cells can comprise a “base surface geometry” defined by the base three-dimensional shape of a body formed by one or more ribbons (walls) of material that define a solid representation of an implicit surface for a full unit cell. In some embodiments, the implicit surface can be a periodic implicit surface such that the base surface geometry of each unit cell contacts the base surface geometry of at least some adjacent unit cells to create a lattice. One example of a suitable periodic surface is a gyroid, but any type of suitable periodic surface can be used.

Herein, a solid representation of an implicit surface refers to a solid object following the shape of an implicit surface. Whereas an actual implicit surface has no thickness, a solid representation of an implicit surface has a thickness on one or both sides of the actual implicit surface in a three dimensional space. The thickness gives the solid representation volume, meaning the solid representation can be built as a physical object from physical material. The added thickness or thicknesses can be uniform, or at least approximately uniform notwithstanding fillets or local deformities, and thin in comparison to the overall size of the represented implicit surface. In some embodiments, the relative density of a unit cell of the solid representation can be from 5% to 30%, from 5% to 40%, from 10% to 25%, or from 15% to 20%. The term “relative density” as used herein refers to an amount of a unit cell occupied by solid material as a percentage of a total volume of the unit cell.

In some embodiments, the implicit surfaces can be created using a combination of random Fourier series functions, in which linear and or nonlinear coefficient as well as linear and nonlinear variables inside sinuous and cosine terms over the x, y and z space are iterated to generate the functions. The resulting unit cells can have different planes of symmetry, such as, in various examples, zero planes of symmetry, one plane of symmetry, or more than one plane of symmetry. The function can be derived in a way that satisfies the periodicity of the unit cell. Criteria for the selection of an applicable implicit surface within the design space domain can include any one or any combination of number of terms in the equation, number of connected components, the edge boundary length, surface area, and volume fraction.

In some embodiments, article of footwear 100 can comprise an outer skin 200 that defines at least part of an outer contour 162 of upper portion 160, at least part of an outer contour 122 of sole portion 120, or both at least part of an outer contour 162 of upper portion 160 and at least part of an outer contour 122 of sole portion 120. In some embodiments, outer skin 200 can comprise a plurality of continuous beams 202 extending adjacent to each other and defining at least part of outer contour 162 of upper portion 160, at least part of outer contour 122 of sole portion 120, or both. Space 204 between adjacent continuous beams 202 can separate adjacent continuous beams 202 from each other along at least a portion of sole portion 120, upper portion 160, or both. Continuous beams 202 of outer skin 200 may not define a portion of a repeating unit cell (for example, a unit cell 144 as described herein).

In some embodiments, one or more continuous beams 202 of outer skin 200 can extend from upper portion 160 to sole portion 120. In some embodiments, one or more continuous beams 202 of outer skin 200 can extend from upper portion 160 to sole portion 120 and extend across a ground-facing surface 134 of sole portion 120. In such embodiments, the one or more continuous beams 202 can form a portion of a ground-facing structure 130 for sole portion 120.

Outer contour 122 of sole portion 120 is defined by the overall outermost surface profile of the sole portion 120. Outer contour 122 is illustrated in for example FIG. 1E. Grooves or recesses between beams 202 of outer skin 200 do not define the shape of outer contour 122. Rather, outer contour 122 is characterized by the overall outmost shape of sole portion 120 defined by outer skin 200. Similarly, outer contour 162 of upper portion 160 is defined by the overall outermost surface profile of the upper portion 160. Outer contour 162 is illustrated in for example FIG. 1E. Grooves or recesses between beams 202 of outer skin 200 do not define the shape of outer contour 162. Rather, outer contour 162 is characterized by the overall outmost shape of upper portion 160 defined by outer skin 200.

In some embodiments, continuous beams 202 of outer skin 200 can extend continuously at outer contour 122, with a plurality of beams 202 extending continuously along a portion of sole portion 120. In some embodiments, continuous beams 202 of outer skin 200 can extend continuously at outer contour 162, with a plurality of beams 202 extending continuously along a portion of upper portion 160. In some embodiments, continuous beams 202 of outer skin 200 can extend continuously at outer contour 122 and outer contour 162, with a plurality of beams 202 extending continuously along a portion of sole portion 120 and a portion of upper portion 160.

In some embodiments, one or more beams 202 can extend continuously along a distance of at least 5 centimeters. In some embodiments, one or more beams 202 can extend continuously along a distance of at least 10 centimeters. In some embodiments, one or more beams 202 can extend continuously along a distance of at least 15 centimeters. In some embodiments, one or more beams 202 can extend continuously in a straight line. In some embodiments, one or more beams 202 can extend continuously in a curved line. In some embodiments, one or more beams 202 can extend continuously and comprise a first portion 210 extending continuously in a straight or curved line before arriving at a turn 212 and a second portion 214 beginning at the turn 212 and extending continuously in a straight or curved line. In some embodiments, the turn 212 can have a turn angle ranging from greater than or equal to 10 degrees and less than or equal to 170 degrees. In some embodiments, the turn 212 can have a turn angle ranging from greater than or equal to 20 degrees and less than or equal to 160 degrees. FIG. 1H illustrates a continuous beam 202 comprising a first portion 210, a turn 212, and a second portion 214 according to some embodiments.

In some embodiments, outer contour 122 defined by continuous beams 202 can comprise a smooth contour that does not oscillate between adjacent connection points 276 with struts 272 of a core structure 270 as described herein. In such embodiments, continuous beams 202 can extend continuously in a straight or curved line between connection points 276. In some embodiments, the distance between adjacent connection points 276 on sole portion 120 can be at least 1 millimeter (mm). In some embodiments, the distance between adjacent connection points 276 can be at least 2 mm. In some embodiments, the distance between adjacent connection points 276 can be at least 5 mm.

In some embodiments, outer contour 162 defined by continuous beams 202 can comprise a smooth contour that does not oscillate between adjacent connection points 276 with struts 272 of a core structure 270 as described herein. In such embodiments, continuous beams 202 can extend continuously in a straight or curved line between connection points 276. In some embodiments, the distance between adjacent connection points 276 on upper portion 160 can be at least 1 mm. In some embodiments, the distance between adjacent connection points 276 can be at least 2 mm. In some embodiments, the distance between adjacent connection points 276 can be at least 5 mm.

In some embodiments, adjacent beams 202 of a plurality of continuous beams 202 can extend substantially parallel to each other at outer contour 122, outer contour 162, or both outer contour 122 and outer contour 162. As used herein, “substantially parallel” means that two or more beams 202 either: (i) extend along straight or curved lines that are exactly a parallel to each other for a specified length, or (ii) extend along straight or curved lines that extend+/−10 degrees relative to parallel of each other for a specified length. In some embodiments, the specified length can be at least can be at least 5 mm, at least 10 mm, or at least 15 mm.

In embodiments comprising a plurality of continuous beams 202 that extend substantially parallel to each other at outer contour 122, outer contour 162, or both, the plurality of beams 202 can define a lenticular structure at outer contour 122, outer contour 162, or both.

Adjacent continuous beams 202 extending at outer contour 122, outer contour 162, or both, can be spaced apart from each other by a spacing distance 206, as illustrated in for example FIG. 1H. In some embodiments, spacing distance 206 can range from greater than or equal to 0.1 mm to less than or equal to 10 mm.

In some embodiments, the spacing distance 206 between two adjacent beams 202 can be constant along a specified length, for example at least 5 mm, at least 10 mm, or at least 15 mm. In such embodiments, the two adjacent beams 202 can extend along straight or curved lines that are exactly a parallel to each other for the specified length.

In some embodiments, the spacing distance 206 between two adjacent beams 202 can vary along outer skin 200. In such embodiments, the two adjacent beams 202 can extend along straight or curved lines that are not exactly parallel to each other for a specified length. In some embodiments, outer skin 200 can comprise one or more portions 208 where the spacing distance 206 between two or more adjacent beams 202 is zero. In such embodiments, the two or more adjacent beams 202 can merge together at outer contour 122, outer contour 162, or both. In some embodiments, two or more adjacent beams 202 can be spaced apart as the beams 202 approach a portion 208, merge in the portion 208, and then diverge in a spaced apart relationship after portion 208. In some embodiments, a portion 208 can comprise three or more, four or more, or five or more adjacent beams 202 that merge together.

In some embodiments, article of footwear 100 can comprise an inner skin 240 defining at least part of an inner contour 164 of upper portion 160. In some embodiments, inner skin 240 can comprise beams 242 defining at least part of inner contour 164 of upper portion 160. In some embodiments, beams 242 can be the same as continuous beams 202. In such embodiments, beams 242 can comprise any feature of beams 202 as described herein. In some embodiments, inner skin 240 can comprise a network of beams 242 defining at least part of inner contour 164 of upper portion 160. In such embodiments, the network of beams 242 can comprise beams 242 that intersect each other at intersection points 244, as illustrated in for example FIG. 1G. Space 246 between adjacent beams 242 can separate adjacent beams 242 from each other along at least a portion of upper portion 160.

In embodiments comprising skin 240, beams 242 can comprise a smooth contour that does not oscillate between adjacent connection points 278 with struts 272 of a core structure 270 as described herein. In such embodiments, beams 242 can extend continuously in a straight or curved line between connection points 278. Beams 242 of inner skin 240 may not define a portion of a repeating unit cell (for example, a unit cell 144 as described herein).

In some embodiments, an interior surface 250 of inner skin 240 can comprise a low friction surface and/or a low friction texture. In such embodiments, interior surface 250 can comprise a coefficient of friction ranging from greater than or equal to 0.1 to less than or equal to 0.7. In some embodiments, the coefficient of friction can range from greater than or equal to 0.1 to less than or equal to 0.4.

In some embodiments, interior surface 250 of inner skin 240 can comprise a release agent. In such embodiments, the release agent can facilitate insertion and/or removal of a wearer's foot from article of footwear 100. Exemplary release agents include, but are not limited to, polydimethylsiloxane (PDMS), petroleum, a wax, silicone, and magnesium stearate.

In some embodiments, as illustrated in FIG. 1H, space 204 between adjacent beams 202 of outer skin 200 and space 246 between adjacent beams 242 of inner skin 240 can form through openings 166 in upper portion 160. In some embodiments, a core structure 270 as described herein may not occupy any volume within through openings 166. Through openings 166 can serve to provide ventilation for upper portion 160.

Inner contour 164 of upper portion 160 is defined by the overall innermost surface profile of the upper portion 160. Inner contour 164 is illustrated in for example FIG. 1E. Grooves or recesses between beams 242 of inner skin 240 do not define the shape of inner contour 164. Rather, inner contour 164 is characterized by the overall innermost shape of upper portion 160 defined by inner skin 240.

In some embodiments, as illustrated in for example FIG. 1E, inner contour 164 of upper portion 160 can comprise an undulating contour that varies relative to outer contour 122 defined by outer skin 200. In such embodiments, the undulating inner contour 164 can comprise a first region 170 spaced apart from outer skin 200 by a first distance 172 and a second region 174 spaced apart from outer skin 200 by a second distance 176 less than the first distance 172. In such embodiments, a length 275 of the struts 272 of a core structure 270 connecting outer skin 200 to inner skin 240 in the first region 170 can be greater than a length 275 of struts 272 connecting outer skin 200 to inner skin 240 in second region 174.

In some embodiments, first distance 172 and second distance 176 can range from greater than or equal to 0.2 mm to less than or equal to 30 mm, including subranges. For example, distance 172 and distance 176 can range from greater than or equal to 0.2 mm to less than or equal to 26 mm, from greater than or equal to 0.2 mm to less than or equal to 22 mm, from greater than or equal to 0.2 mm to less than or equal to 18 mm, from greater than or equal to 0.4 mm to less than or equal to 30 mm, from greater than or equal to 1 mm to less than or equal to 30 mm, or from greater than or equal to 2 mm to less than or equal to 30 mm. In some embodiments, distance 172 and distance 176 can range from greater than or equal to 0.4 mm to less than or equal to 26 mm.

In some embodiments, the second distance 176 can be at least 4 mm less than the first distance 172. As another example, in some embodiments, second distance 176 can be at least 10 mm less than the first distance 172.

Distances 172 and 176 can be varied to provide a targeted amount of cushioning and/or fit to different regions of upper portion 160. In addition, distances 172 and 176 can be varied based on the contour of a wearer's foot.

In some embodiments, as shown for example in FIG. 1D, inner skin 240 can be disposed around a lateral side 152 of midsole 140. In some embodiments, inner skin 240 can be disposed around a medial side 150 of midsole 140. In some embodiments, inner skin 240 can be disposed around lateral side 152 and medial side 150 of midsole 140. In such embodiments, inner skin 240 can connect midsole 140 to struts 272 of a core structure 270 around all or a portion of lateral side 152 and/or all or a portion of medial side 150 of midsole 140. In some embodiments, inner skin 240 can directly connect midsole 140 to struts 272 of core structure 270 around all or a portion of lateral side 152 and/or all or a portion of medial side 150 of midsole 140. In some embodiments, inner skin 240 can directly connect nodes 148 of unit cells 144 to struts 272 of core structure 270 around all or a portion of lateral side 152 and/or all or a portion of medial side 150 of midsole 140.

In some embodiments, as illustrated in for example FIG. 1G, a plurality of the nodes 148 of midsole 140 can be located at an interior perimeter boundary 154 of midsole 140. In some embodiments, each of the plurality of nodes 148 at interior perimeter boundary 154 can comprise a plurality of beams 242 of inner skin 240 directly connected to the node 148. In some embodiments, intersection points 159 of insole skin 156 can be located at nodes 148 of midsole 140 at interior perimeter boundary 154.

As illustrated in for example FIGS. 1D and 1E, article of footwear 100 can comprise a core structure 270 that connects outer skin 200 to inner skin 240. Core structure 270 can comprise struts 272 that connect beams 202 of outer skin 200 to beams 242 of inner skin 240. In some embodiments, core structure 270 can comprise struts 272 that directly connect a beam 202 of outer skin 200 to a beam 242 of inner skin 240. In such embodiments, a first end of a strut 272 can connect to a beam 202 at a connection point 276 and a second end of the strut 272 can connect to a beam 242 at a connection point 278. In some embodiments, upper portion 160 can include one or more regions with core structure 270 and one or more regions without core structure 270. In regions without core structure 270, beams 202 of outer skin 200 can be directly connected to beams 242 of inner skin 240.

In some embodiments, struts 272 of core structure 270 can be linear struts that directly connect a beam 202 of outer skin 200 to a beam 242 of inner skin 240. In such embodiments, the linear struts can extend directly from a beam 202 of outer skin 200 to a beam 242 of inner skin 240 with changing direction at a node or turn. In some embodiments, struts 272 of core structure 270 can define unit cells (for example, unit cells 144) that connect beams 202 of outer skin 200 to beams 242 of inner skin 240. In such embodiments, the unit cells can comprise a plurality of struts (e.g., struts 146) that form a connection between a beam 202 of outer skin 200 and a beam 242 of inner skin 240.

In some embodiments, core structure 270 can be disposed around a lateral side 152 of midsole 140. In some embodiments, core structure 270 can be disposed around a medial side 150 of midsole 140. In some embodiments, core structure 270 can be disposed around lateral side 152 and medial side 150 of midsole 140. In such embodiments, core structure 270 can connect midsole 140 to outer skin 200 around all or a portion of lateral side 152 and/or all or a portion of medial side 150 of midsole 140. In such embodiments, struts 272 of core structure 270 can connect beams 202 of outer skin 200 to unit cells 144 of midsole 140. In some embodiments, core structure 270 can comprise struts 272 that directly connect a beam 202 of outer skin 200 to a node 148 or strut 146 of a unit cell 144. In some embodiments, struts 272 of core structure 270 can be linear struts that directly connect a beam 202 of outer skin 200 to a node 148 or strut 146 of a unit cell 144. In such embodiments, the linear struts can extend directly from a beam 202 of outer skin 200 to a node 148 or strut 146 of a unit cell 144 with changing direction at a node or turn.

In some embodiments, a thickness 274 of core structure 270 can vary across different regions of upper portion 160. In such embodiments, as illustrated in FIG. 1D, thickness 274 is defined as the distance between outer skin 200 and inner skin 240. In embodiments comprising a core structure 270 with linear struts 272, thickness 274 can be the length 275 of the linear struts 272 directly connecting a beam 202 of outer skin 200 to a beam 242 of inner skin 240.

In some embodiments, thickness 274 can range from greater than or equal to 0.2 mm to less than or equal to 30 mm, including subranges. For example, thickness 274 can range from greater than or equal to 0.2 mm to less than or equal to 26 mm, from greater than or equal to 0.2 mm to less than or equal to 22 mm, from greater than or equal to 0.2 mm to less than or equal to 18 mm, from greater than or equal to 0.4 mm to less than or equal to 30 mm, from greater than or equal to 1 mm to less than or equal to 30 mm, or from greater than or equal to 2 mm to less than or equal to 30 mm. In some embodiments, thickness 274 can range from greater than or equal to 0.4 mm to less than or equal to 26 mm.

In some embodiments, in a first region 170 of upper portion 160, core structure 270 can comprise a first thickness 274 and, in a second region 174 of upper portion 160, core structure 270 can comprise a second thickness 274 less than the first thickness 274. For example, in some embodiments, the second thickness 274 can be at least 4 mm less than the first thickness 274. As another example, in some embodiments, the second thickness 274 can be at least 10 mm less than the first thickness 274.

Thickness 274 of core structure 270 can be varied to provide targeted amount of cushioning and/or fit to different regions of upper portion 160. In addition, thickness 274 of core structure 270 can be varied based on the contour of a wearer's foot.

As discussed herein, sole portion 120 and upper portion 160 can be additively manufactured (3D printed) as a single piece. Further, various components of footwear 100 can be additively manufactured (3D printed) as a single piece. Any two or more components of footwear 100 can be 3D printed as a single piece. For example, in embodiments comprising outer skin 200, inner skin 240, core structure 270, and midsole 140, each of sole portion 120, upper portion 160, outer skin 200, inner skin 240, core structure 270, and midsole 140 can be 3D printed as a single piece. As another example, in embodiments comprising outer skin 200, inner skin 240, and core structure 270, each of sole portion 120, upper portion 160, outer skin 200, inner skin 240, and core structure 270 can be 3D printed as a single piece. As another example, outer skin 200, inner skin 240, and core structure 270 can be 3D printed as a single piece.

In some embodiments, sole portion 120 and upper portion 160 can be formed of the same material. Further, various components of footwear 100 can be formed of the same material. Any two or more components of footwear 100 can formed of the same material. For example, in embodiments comprising outer skin 200, inner skin 240, core structure 270, and midsole 140, each of sole portion 120, upper portion 160, outer skin 200, inner skin 240, core structure 270, and midsole 140 can formed of the same material. As another example, in embodiments comprising outer skin 200, inner skin 240, and core structure 270, each of sole portion 120, upper portion 160, outer skin 200, inner skin 240, and core structure 270 can be formed of the same material. As another example, outer skin 200, inner skin 240, and core structure 270 can be formed of the same material.

Exemplary materials for sole portion 120 and upper portion 160, and any other component of footwear 100 include, but at not limited to, a foam, a rubber, ethyl vinyl acetate (EVA), a thermoplastic elastomer, a polyurethane, a thermoplastic polyurethane (TPU), an elastomeric polyurethane, an expanded thermoplastic polyurethane (eTPU), an expanded elastomeric polyurethane, a polyether block amide (PEBA), an expanded polyether block amide (ePEBA), a thermoplastic rubber (TPR), and a polyolefin, for example polyethylene (PE), polystyrene (PS), or polypropylene (PP), polyamides (nylon), or a combination of any of these materials, or a foam comprising one or more of these materials. Additional materials for use in forming sole portion 120 and upper portion 160 include carbon and carbon allotropes, such as graphene, carbon nanotubes, and carbon fibers, fiber reinforced polymers, biological materials such as Mycelium, and metals, such as aluminum, steel, or titanium, among others and combinations thereof.

An articles of footwear described herein (for example, article of footwear 100), and any component of footwear described herein (for example, sole portion 120 or upper portion 160), can be formed by additive manufacturing (e.g., three-dimensional (3D) printing). Exemplary additive manufacturing techniques include for example, selective laser sintering, selective laser melting, selective heat sintering, stereo lithography, fused deposition modeling, or 3-D printing in general. Various additive manufacturing techniques related to articles of footwear are described for example in US 2009/0126225, WO 2010/126708, US 2014/0300676, US 2014/0300675, US 2014/0299009, US 2014/0026773, US 2014/0029030, WO 2014/008331, WO 2014/015037, US 2014/0020191, EP 2564719, EP 2424398, and US 2012/0117825. In some embodiments, the additive manufacturing process can include a continuous liquid interface production process. For example, the additive manufacturing process can include a continuous liquid interface production process as described in U.S. Pat. No. 9,453,142, issued on Sep. 27, 2016, which is hereby incorporated in its entirety by reference thereto. In some embodiments, 3-D printing an article of footwear, or component thereof, can comprise 3-D printing the article or component in an intermediate green state, shaping the article or component in the green state, and curing the green state in its final shape. In some embodiments, 3-D printing an article of footwear, or component thereof, can comprise 3-D printing the article or component in an intermediate green state, expanding the intermediate green state, shaping the article or component in the green state, and curing the green state in its final shape.

Techniques for producing an intermediate green state object from resins by additive manufacturing are known. Suitable techniques include bottom-up and top-down additive manufacturing, generally known as stereolithography. Such methods are known and described in, for example, U.S. Pat. No. 5,236,637 to Hull, U.S. Pat. Nos. 5,391,072 and 5,529,473 to Lawton, U.S. Pat. No. 7,438,846 to John, U.S. Pat. No. 7,892,474 to Shkolnik, U.S. Pat. No. 8,110,135 to El-Siblani, U.S. Patent Application Publication No. 2013/0292862 to Joyce, and US Patent Application Publication No. 2013/0295212 to Chen et al. The disclosures of these patents and applications are incorporated by reference herein in their entirety.

In some embodiments, the additive manufacturing step can be carried out by one of the family of methods sometimes referred to as continuous liquid interface production (CLIP). CLIP is known and described in, for example, U.S. Pat. Nos. 9,211,678; 9,205,601; 9,216,546; and others; in J. Tumbleston et al., Continuous liquid interface production of 3D Objects, Science 347, 1349-1352 (2015); and in R. Janusziewcz et al., Layerless fabrication with continuous liquid interface production, Proc. Natl. Acad. Sci. USA 113, 11703-11708 (Oct. 18, 2016). Other examples of methods and apparatus for carrying out particular embodiments of CLIP include, but are not limited to: Batchelder et al., US Patent Application Pub. No. US 2017/0129169 (May 11, 2017); Sun and Lichkus, US Patent Application Pub. No. US 2016/0288376 (Oct. 6, 2016); Willis et al., US Patent Application Pub. No. US 2015/0360419 (Dec. 17, 2015); Lin et al., US Patent Application Pub. No. US 2015/0331402 (Nov. 19, 2015); D. Castanon, US Patent Application Pub. No. US 2017/0129167 (May 11, 2017). B. Feller, US Pat App. Pub. No. US 2018/0243976 (published Aug. 30, 2018); M. Panzer and J. Tumbleston, US Pat App Pub. No. US 2018/0126630 (published May 10, 2018); K. Willis and B. Adzima, US Pat App Pub. No. US 2018/0290374 (Oct. 11, 2018) L. Robeson et al., PCT Patent Pub. No. WO 2015/164234 (see also U.S. Pat. Nos. 10,259,171 and 10,434,706); and C. Mirkin et al., PCT Patent Pub. No. WO 2017/210298 (see also US Pat. App. US 2019/0160733). The disclosures of these patents and applications are incorporated by reference herein in their entirety.

While stereolithography techniques such as CLIP can be preferred, it will be appreciated that other additive manufacturing techniques, such as jet printing (see, e.g., U.S. Pat. No. 6,259,962 to Gothait and US Patent App. Ser. No. US 2020/0156308 to Ramos et al.) can also be used.

In some embodiments, upper portion 160 can comprises a collar 180 defining an opening 182 configured to receive a wearer's foot. In some embodiments, collar 180 can comprise a rim 184 defining opening 182. In some embodiments, one or more continuous beams 202 of outer skin 200 can extend from collar 180 (for example, from rim 184 of collar). In some embodiments, one or more continuous beams 202 of outer skin 200 can extend from collar 180 to sole portion 120. In some embodiments, one or more continuous beams 202 of outer skin 200 can extend from collar 180 to a ground-facing surface 134 of sole portion 120.

In some embodiments, as illustrated in for example FIG. 1G, a plurality of continuous beams 202 of outer skin 200 can intersect rim 184 at an angle 215 of less than 45 degrees. In some embodiments, a plurality of continuous beams 202 of outer skin 200 can intersect rim 184 at an angle 215 of less than 30 degrees.

In some embodiments, the plurality of continuous beams 202 that intersect rim 184 at an angle 215 of less than 45 degrees can each comprise a first portion 210 that approaches the rim 184 at an angle 211 ranging from greater than or equal to 45 degrees and less than or equal to 90 degrees, a turn 212, and a second portion 214 extending from the turn 212 and intersecting the rim 184 at an angle of less than 45 degrees. In some embodiments, the plurality of continuous beams 202 that intersect rim 184 at an angle 215 of less than 30 degrees can each comprise a first portion 210 that approaches the rim 184 at an angle 211 ranging from greater than or equal to 30 degrees and less than or equal to 90 degrees, a turn 212, and a second portion 214 extending from the turn 212 and intersecting the rim 184 at an angle of less than 30 degrees.

In some embodiments, by intersecting rim 184 at an angle of less than 45 degrees, or at an angle of less than 30 degrees, undesirably high stress concentrations at connection points between beams 202 and rim 184 during use can be limited or avoided.

In some embodiments, as shown for example in FIG. 12, collar 180 can comprise a pull tab 190 extending into opening 182. In such embodiments, pull tab 190 can form all or a portion of a tongue for article of footwear 100. In some embodiments, pull tab 190 can be integrally formed with (for example, integrally 3D printed with) upper portion 160. In some embodiments, pull tab 190 can be integrally formed with (for example, integrally 3D printed with) inner skin 240 of upper portion 160. In some embodiments, pull tab 190 can extend from rim 184 of collar 180.

In some embodiments, as shown for example in FIG. 13, collar 180 can comprise a notch 192 extending forward from opening 182 towards forefoot end 102 of article of footwear. In such embodiments, notch 192 can form all or a portion of a throat for article of footwear 100. In some embodiments, rim 184 of collar 180 can extend around notch 192.

In some embodiments, as shown for example in FIG. 13, collar 180 can comprise a perimeter beam 186 spaced apart from and extending around all or a portion of rim 184. In such embodiments, perimeter beam 186 can be can be integrally formed with (for example, integrally 3D printed with) upper portion 160. In some embodiments, perimeter beam 186 can be integrally formed with (for example, integrally 3D printed with) outer skin 200 of upper portion 160. Perimeter beam 186 can intersect a plurality of continuous beams 202 of outer skin 200 around all or a portion of a perimeter of rim 184. In some embodiments, perimeter beam 186 can intersect a plurality of continuous beams 202 of outer skin 200 at turns 212 around all or a portion of a perimeter of rim 184. In some embodiments, perimeter beam 186 can extend around at least the portion of rim 184 around notch 192.

In some embodiments, as shown for example in FIG. 14, collar 180 can comprise pull tab 190 and notch 192. In such embodiments, pull tab 190 can be disposed within notch 192.

In some embodiments, one or more continuous beams 202 of outer skin 200 can comprise an extended portion 220 comprising an increased height 221 extending from outer contour 122 of sole portion 120, outer counter 162 of the upper portion 160, or both. In some embodiments, extended portion 220 of a continuous beam 202 can define a tab 222 on upper portion 160. FIG. 1B illustrates a tab 222 on upper portion 160 according to some embodiments. In some embodiments, extended portion 220 of a continuous beam 202 can define a tab 222 on sole portion 120.

As shown for example, in FIG. 1A, in some embodiments, outer skin 200 can comprise a region 230 with one or more images 232. Image(s) 232 can comprise, but are not limited to a manufacture's logo, a trademark, a technology name, numerical images, non-numerical images, user customized images, and other graphical images.

Exemplary graphical image types for image(s) 232 can comprise a basic geometrical shape, an animal character shape, a sports object shape, or a symbol. Exemplary basic geometrical shapes for image(s) 232 comprise a triangle, a quadrilateral, a polygon (e.g., a pentagon, a hexagon, a heptagon, etc.), a circle, an ellipse, a crescent, and a pill-shape. Exemplary animal character shapes for image(s) 232 comprise a bear, a bison, a cat, a dog (for example, a husky), a tiger, a lion, a horse, an elephant, a giraffe, a monkey, a gorilla, a bird, a ram, a turtle, a snake, a spider, a fish, or a shark. Exemplary sports object shapes for the images comprise a soccer ball, a baseball, a softball, a basketball, a tennis ball, a volleyball, a frisbee, a football, a golf club, a lacrosse stick, a hockey stick, a hockey skate, a baseball cap, a baseball bat, a skateboard, and a surf board. Exemplary symbols for image(s) 232 comprise a dollar sign, a Greek letter, a peace sign, a ying-yang, a zodiac sign, a heart, a spade, and a musical note.

In some embodiments, region 230 can comprise one or more films 234 that fill in space 204 between one or more groups of adjacent continuous beams 202. In such embodiments, film(s) 234 can define all or a portion of an image 232 on upper portion 160, sole portion 120, or both. In some embodiments, film(s) 234 can comprise a thickness less than the thickness of beams 202 to create cavities 236 between adjacent beams 202. Together, beams 202 and film(s) 234 can define one or more images 232 on outer skin 200, and therefore on footwear 100. In some embodiments, film(s) 234 can be integrally 3D printed with the group of adjacent continuous beams 202 within region 230.

In some embodiments, region 230 can comprise one or more films 234 that fill in space 246 between one or more groups of adjacent beams 242 of inner skin 240. In such embodiments, film(s) 234 can define all or a portion of an image 232 on upper portion 160, sole portion 120, or both. Together, beams 242 and film(s) 234 can define one or more images 232 on inner skin 240, and therefore on footwear 100. In some embodiments, film(s) 234 can be integrally 3D printed with the group of adjacent beams 242 within region 230.

In some embodiments, as illustrated in for example FIG. 2, region 230 can comprise one or more images 232 defined by an image contour 226 extending from outer contour 122, outer contour 162, or both. In such embodiments, one or more groups 224 of adjacent beams 202 of outer skin 200 can comprise beams 202 that each have an extended portion 220 with an increased height 221 and define an image contour 226 extending from outer contour 122, outer contour 162, or both.

In some embodiments, sole portion 120 can comprise a ground-facing surface 134 comprising a ground-facing structure 130. In some embodiments, ground-facing structure 130 can comprise an outsole. In some embodiments, the outsole can be a separate component attached to ground-facing surface 134 (for example, via adhesive bonding or heat bonding). In some embodiments, the outsole can be integrally 3D printed with ground-facing surface 134. In some embodiments, ground-facing structure 130 can be formed in whole or in part by beams 202 of outer skin 200 that extend from a lateral or medial side of sole portion 120 to ground-facing surface 134 of sole portion 120. In some embodiments, ground-facing structure 130 can be formed in whole or in part by beams 202 of outer skin 200 that extend from upper portion 160 to ground-facing surface 134 of sole portion 120.

In some embodiments, as shown for example in FIG. 1F, ground-facing structure 130 can comprise one or more outsole portions 132 integrally 3D printed with sole portion 120. In some embodiments, a ground-facing structure 130 can comprise one or more outsole portions 132 integrally 3D printed with continuous beams 202 of outer skin 200 that extend across ground-facing surface 134 of sole portion 120.

In some embodiments, as illustrated in for example FIG. 3, ground-facing structure 130 of sole portion 120 can comprise a ground-facing structure 300 comprising one or more cavities 302 with an outsole material 304 filled within the one or more cavities 302. In such embodiments, the one or more cavities 302 can be integrally 3D printed with sole portion 120. In some embodiments, the one or more cavities 302 can be integrally 3D printed with continuous beams 202 of outer skin 200 that extend across ground-facing surface 134 of sole portion 120.

In some embodiments, as illustrated in for example FIG. 4, ground-facing structure 130 of sole portion 120 can comprise a ground-facing structure 400 comprising one or more regions 402 where space 204 between a plurality of beams 202 of outer skin 200 is filled with a film 404 that forms cavities 406 between adjacent beams 202 extending across ground-facing surface 134 of sole portion 120. In such embodiments, the cavities 406 can be filled with an outsole material 408. In some embodiments, film(s) 404 can comprise a thickness less than the thickness of beams 202 to create cavities 406 between adjacent beams 202.

Exemplary outsole materials for ground-facing structure 300 and ground-facing structure include 400 include, but are not limited to, a rubber, ethyl vinyl acetate (EVA), a thermoplastic elastomer, a polyurethane, a thermoplastic polyurethane (TPU), a thermoplastic rubber (TPR), and a polyolefin, for example polyethylene (PE), polystyrene (PS), polypropylene (PP), a polyether block amide (PEBA), an expanded polyether block amide (ePEBA) an elastomeric polyurethane (EPU), an expanded elastomeric polyurethane (cEPU), polyamides (nylon), a combination of any of these materials, or a foam comprising one or more of these materials. Additional exemplary materials include carbon and carbon allotropes, such as graphene, carbon nanotubes, and carbon fibers, fiber reinforced polymers, biological materials such as Mycelium, and metals, such as aluminum, steel, or titanium.

In some embodiments, as shown for example in FIG. 5, article of footwear 100 can comprise a sock bootie 500. In such embodiments, sock bootie 500 can comprise an inner surface 504 defining a space for receiving a wearer's foot and an outer surface 502 opposite the inner surface 504. In some embodiments, sock bootie 500 can be directly or indirectly coupled to inner skin 240, midsole 140, or both. In embodiments comprising insole skin 156, sock bootie 500 can be directly or indirectly coupled to insole skin 156.

In some embodiments, outer surface 502 of sock bootie 500 can be mechanically coupled to inner skin 240 by, for example, an adhesive or stitching. Additionally or alternatively, outer surface 502 of sock bootie 500 and inner skin 240 can be frictionally coupled together. In such embodiments, interior surface 250 of inner skin 240 can comprise a texture configured to engage with a corresponding texture on outer surface 502 of sock bootie 500.

In some embodiments, as shown for example in FIG. 6, upper portion 160 of footwear 100 can comprise a plurality lace structures 600 formed in the upper portion 160. In some embodiments, lace structures 600 can be integrally 3D printed with upper portion 160.

In some embodiments, each of the lace structures 600 can comprise an opening 602 extending through outer skin 200, core structure 270, and inner skin 240 of upper portion 160. Openings 602 can define an aperture for receiving a shoe lace. In some embodiments, openings 602 can comprise a rim 604 defining an aperture for receiving a shoe lace. In such embodiments, rim 604 can comprise any of the same characteristics described herein for rim 184 of collar 180. For example, continuous beams 202 can intersect rim 604 at an angle of less than 45 degrees, or less than 30 degrees as described herein for continuous beams 202 and rim 184.

In some embodiments, as shown for example in FIG. 7, sole portion 120 can comprise one or more reinforcement structures 700. In some embodiments, the reinforcement structure(s) can be disposed within one or more voids 702 formed in sole portion 120. In some embodiments, the one or more voids 702 can be formed in midsole 140. In some embodiments, the one or more voids 702 can be integrally 3D printed with sole portion 120. In some embodiments, one or more voids 702 can be a tube formed in sole portion 120.

In some embodiments, upper portion 160 can comprise one or more reinforcement structures 700. In such embodiments, the reinforcement structure(s) 700 can be disposed within one or more voids 702 formed in upper portion 160. For example, in some embodiments, the one or more voids 702 can be formed in core structure 270 of upper portion 160. In some embodiments, the one or more voids 702 can be integrally 3D printed with upper portion 160.

In some embodiments, reinforcement structure(s) 700 can comprise a shank or torsion bar. In such embodiments, the shank or torsion bar can be made of a nylon polymer or a fiber composite material.

FIG. 8 illustrates an article of footwear 800 in the form a slide sandal according to some embodiments. Article of footwear 800 can comprise sole portion 120 and upper portion 160 in the form of a strap for a slide sandal. As illustrated in FIG. 8, article of footwear 800 can comprise outer skin 200 and inner skin 240. Article of footwear 800 can also comprise any other feature described herein for article of footwear 100, including a core structure 270, an image region 230, and a collar 180.

FIG. 9 illustrates a method of making article of footwear 100 according to some embodiments. Unless stated otherwise, the steps of method 900 need not be performed in the order set forth herein. Additionally, unless specified otherwise, the steps need not be performed sequentially. The steps can be performed in a different order or simultaneously.

First, in step 902, method 900 can comprise printing a green 3D-printed article (for example, article 1010 illustrated in FIG. 10) for article of footwear 100. The green 3D-printed article can comprise any feature of footwear 100 as described herein, as well as any combination of two or more features of footwear 100 as described herein. For example, the green 3D-printed article can comprise a sole portion corresponding to sole portion