BACKGROUND

[1] This disclosure generally relates to shoe soles and to the making of shoe soles. Shoe soles are an interface between the feet and the shoes of a user and therefore have an influence on the user physical activity or physiological state and comfort. Numerous different standard shoe sole types and shapes are manufactured and made available to users so a user may pick a shoe sole type adapted to their feet, in particular taking into account their shoe size or foot width.

BRIEF DESCRIPTION OF THE DRAWINGS

[2] FIG. 1A-C illustrate a first example shoe sole.

[3] FIG. 2 illustrates a second example shoe sole.

[4] FIG. 3 illustrates a third example shoe sole.

[5] FIG. 4 illustrates a fourth example shoe sole.

[6] FIG. 5 illustrates a fifth example shoe sole.

[7] FIG. 6A illustrates a sixth example shoe sole.

[8] FIG. 6B illustrates a seventh example shoe sole.

[9] FIG. 7 illustrates an example computer system.

[10] FIG. 8 illustrates a first example method.

[11] FIG. 9 illustrates a second example method.

[12] FIG. 10 illustrates a third example method.

DETAILED DESCRIPTION

[13] While numerous types of shoe soles are available to a user, such shoe soles are designed and manufactured following standards which can vary from a manufacturer to another, or from a geographical area to another. It may therefore be difficult for a user to find a fitting shoe sole. Even if some fitting shoe sole is found by a user, such shoe sole still may not be specifically adapted to the feet of a user. Each user indeed may have a specific user foot configuration. Such specific user foot configuration involves, among other elements, a perspiration configuration, whereby some areas of a user foot may be more prone to perspiration than others, and whereby such areas may differ of change in function of a user activity. Perspiration should be understood as a secretion of a saline fluid by sweat glands.

[14] A human foot indeed comprises a high number of sweat glands. For example, a significant proportion of such perspiration, sometimes of the order of 30% of a user foot perspiration, is emanating from a plantar area of the foot, such plantar area being in contact with a shoe sole when the user is wearing shoes. The repartition of such sweat glands varies from person to person, and may also be different for a same person from a left foot to a right foot. Such variety in the repartition of sweat grands may also lead to a variation as to the amount or location of perspiration in function of a given activity practiced by a user, whereby such activity may lead to exercising specific parts in a certain manner of a foot which may be subjected to varying perspiration. Being in a position to take such variety of perspiration configurations for taking into account specific user situations and configurations forms the foundation of the present disclosure. A specific perspiration configuration should be understood for example as a mapping of locations and corresponding quantities of perspiration corresponding to a specific user foot.

[15] Shoe soles are initially conceived as standard items provided in a variety of standard sizes and shapes. The possibility to manufacture portions of some objects by additive manufacturing or three dimensional (3D) printing by selectively solidifying portions of successively formed layers of build material on a layer-by-layer basis however enables the customization of shoe soles to, for example, reduce discomfort due to perspiration.

[16] 3D printers generate 3D objects based on data in a 3D model of an object or objects to be generated, for example, using a CAD computer program product. 3D printers may generate 3D objects by selectively processing layers of build material. For example, a 3D printer may selectively treat portions of a layer of build material, e.g. a powder, corresponding to a layer of a 3D object to be generated, thereby leaving the portions of the layer un-treated in the areas where no 3D object is to be generated.

[17] Some examples of 3D printers may selectively treat portions of a layer of build material by, for example, ejecting a printing liquid in a pattern corresponding to a cross-section of the 3D object to be generated. Examples of printing liquids may include fusing agents, detailing agents, curable binder agents (e.g., thermally or ultra-violet curable agents) or any printing liquid suitable for the generation of the 3D object.

[18] Other 3D printers may selectively treat portions of the layer of build material by, for example, using a focused energy source (e.g., laser, solid state emitter) to the portions of the layer of build material to be solidified. Some of these printers, such as Selective Laser Sintering (SLS), may use a powdered build material. Some others of these printers, such as Stereolithography (SLA) 3D printers, may use a liquid build material. Some further example 3D printers are fused deposition modelling (FDM) printers in which filaments such as thermoplastic filaments are 3D printed onto each other.

[19] As mentioned above, some 3D printers use fusing agents to treat the portions of the layer of build material. Energy is then applied to the layer of build material and those portions, on which a fusing agent has been applied, absorb sufficient energy to heat up, melt, coalesce and solidify upon cooling.

[20] Other agent 3D printing systems use a thermally or ultra-violet (UV) curable binder agent which has to be heated to a predetermined temperature to cause components of the liquid binder agent to bind together particles of build material on which the binder agent is applied. Such a liquid binder agent may comprise, for example, latex particles.

[21] Suitable powder-based build materials for use in additive manufacturing include polymer powder, metal powder or ceramic powder. Examples of polymeric powder may include a polyamide, polyurethane, polypropylene, polyphthalamide or any suitable thermoplastic or elastomeric polymer build material. In some examples, non-powdered build materials may be used such as liquids, gels, pastes, and slurries. In some examples, the powder-based build materials comprise both of a polymer powder and a metal powder, for example to increase temperature conductivity. In some examples, the powder-based build materials comprise both of a polymer powder and a ceramic powder, for example to increase friction and avoid foot slippage.

[22] 3D printers are used to generate 3D objects or 3D parts that may be used individually or may be included within objects manufactured in a different manner. Using 3D printing compared to traditional manufacturing methods enable the manufacturing of more complex structures that lead to the generation of objects with enhanced capabilities.

[23] Referring now to the drawings, Figures 1A and IB are schematic diagrams showing an example of a shoe sole 100.

[24] A shoe sole should in this disclosure be understood as an object configured to support a human foot. In some examples a shoe sole may be configured to be a part separated from a shoe which may be inserted into or removed from a shoe. In other examples, a shoe sole may be an integral part of a shoe. In some examples, a shoe sole is associated with a shoe such as a tennis shoe or a leather shoe which covers a foot from the sole up to the ankle. In some examples, a shoe sole is associated with a shoe such as a boot which covers a foot and an ankle up to a knee area or up to an area between an ankle and a knee. In some examples, a shoe sole is associated with a shoe such as a sandal which protects a foot from directly being in contact with the ground while at least part of an upper surface of the foot remains directly exposed to the external environment. It should be understood that different activities may be associated with different perspiration patterns, such that different shoe soles according to this disclosure may be adapted to different shoes, for example when such shoes, correspond to a specific activity inducting a specific perspiration pattern. This may be illustrated by the fact that a boot is likely to be associated to an increased perspiration compared to a sandal. It should also be understood that a shoe sole according to this disclosure may in some examples be associated with shoes made of different materials, such materials comprising one or more of leather, woven textile, unwoven textile or thermoplastic materials. Different shoe materials may be associated with different perspiration patterns, in which case shoe soles according to this disclosure may be associated with different shoe materials. In some examples, for a same specific user foot, a textile tennis shoe may correspond to a first example shoe sole, and a leather mountain climbing shoe to a different second example shoe sole.

[25] A shoe sole according to this disclosure may comprise different elements. Such elements may for example comprise an insole. An insole should be understood as a part of the shoe sole configured to run underneath and support the bottom of a foot, corresponding to a footbed or inner sole. Some insoles may be purchased separately from a shoe. Example shoe soles may comprise an insole and a midsole, the midsole being an element of a shoe sole located between an insole and an outsole, the outsole being a part of a shoe configured to be in direct contact with the floor. While an insole may provide comfort, a midsole may provide mechanical characteristics to a shoe sole. Example mechanical characteristics of a midsole may include one or more of a midsole stiffness and energy loss. In some cases, the midsole stiffness is measured in N/mm and represents deformation corresponding to a load, for example a 1000N load. In some examples, a midsole stiffness is a stiffness of more than lOON/mm and of less than 400N/mm. In some cases, the midsole energy loss is measured as a % of energy loss over energy input by a user foot during an activity. In some examples, a midsole energy loss is of more than 25% and of less than 90%. In some examples, the shoe sole according to this disclosure is an insole.

[26] Figure 1A illustrates a top view of shoe sole 100, such shoe sole 100 comprising a portion 110 which has been 3D printed. In this example, shoe sole 100 further comprises a further portion 120 corresponding to a portion of the sole on which toes are to lye thereon when the shoe sole is in use, whereby such portion 120 may be a standard part, for example made out of leather. A standard part should be understood as an off the shelf part which is not customized to a specific user but is manufactured in multiple like units, for example manufactured as more than 1000 like units. Portions 120 and 110 may be joined along a transition area such as line 121, for example by glue. Using such combination of 3D printed portions and standard parts may permit reducing costs and/or obtaining additional advantages. Some of these advantages may include the usage of leather in some specific areas to benefit from the natural flexibility and breathability of leather; while the other areas may benefit from the advantages provided by 3D printing. It should be understood that while the shoe sole 100 comprises a 3D printed portion 110 and a standard part 120 which may not have been 3D printed, other example shoe sole may comprise other or additional portions which may or may not be 3D printed, and other example shoe soles may be integrally formed of a single 3D printed portion.

[27] Top view of Figure 1 A illustrates a surface of portion 110 which is configured to be in direct contact with a specific user foot (the reverse portion of the shoe sole, not visible here, being turned towards the floor when the shoe sole is used). It should be understood that direct contact with a user foot may be a direct contact with the skin of a user foot, or with a garment worn by the user foot such as a sock. In some example, a direct contact with a specific user foot is such that the specific user foot and the surface are separated at most by a flexible textile layer, in some examples at most by a single textile layer. It should be understood that different foot garment may have different impact or influence on a user perspiration. Shoe soles according to this disclosure may be associated with specific garment, for example when specific garment are themselves associated with a specific activity such as, for example, a sport activity.

[28] Figure IB illustrates a section view of the shoe sole 100 along the plane V indicated on Figure 1A. As illustrated on Figures 1A and IB, the surface of portion 110 comprises a 3D printed texture gradient.

[29] A texture should be understood as a surface characteristic, in this case a surface characteristic of the surface of the portion which has been 3D printed, such as portion 110 for example, configured to be in direct contact with a specific user foot. In some examples, the texture comprises one or more motifs having a given size, shape, density, arrangement or proportion. In other examples, the texture may not comprise any motif. As a result of such motifs, a texture may be described as rough, smooth, soft, hard, coarse or fine for example. In this disclosure, the surface comprises a 3D printed texture gradient, a gradient signifying in this disclosure that the texture of the surface of the portion which has been 3D printed varies in at least one of its characteristics over the surface. In the example represented on Figures 1A and IB, the texture comprises round or bubble like motifs, whereby some motifs such as motif 111 have a diameter larger than some motifs such as motif 112, and whereby some motifs such as motif 111 have a depth larger than some motifs such as motif 112. In this example, the round or bubble like motifs are recesses in the surface 110. In this example, the texture gradient comprises variation between first surface areas such as surface area 131 which are smooth and in which motifs are absent, and other surface areas such as surface area 132 which does comprise some motifs. In this example, the gradient comprises more than two levels, whereby surface area 132 comprises subsurface areas 133 and 134 each have a specific texture. A texture gradient comprising more than two level should be understood as a texture gradient such that more than two surface areas comprise respective textures having different characteristics. Example different texture levels differ by one or more of a surface of contact with a foot of a user, a depth of a gap separating motifs, a motif size of shape, a texture hardness or softness, or a texture smoothness or roughness. Different surface areas permitting to compare different textures of a same 3D printed portion may for example each cover an area of at least 1cm ² , and have respective geometrical centres separated by at least 2cm. In some examples, a first texture in a first surface area has a first characteristic dimension and a second texture in a second surface area has a second characteristic dimension, an example texture gradient being obtained between the first and the second surface areas whereby the first characteristic dimension and the second characteristic dimension differ by more than 5%, 10%, 30% or 50%. Such characteristic dimension may for example be one of a size, a depth, a height, a surface, a cross section, a roughness, a softness, a flexibility, a resilience or a grain dimension.

[30] The 3D printed portion of the shoe sole comprises in some examples a plurality of shoe sole layers of a predetermined thickness. The thickness of a shoe sole layer may be in a direction generally parallel to the surface configured to be in direct contact with the foot, thereby leading to a reduced 3D printing manufacturing time. In some examples, the thickness of a shoe sole layer may be in a direction generally perpendicular to the surface configured to be in direct contact with the foot, thereby leading to an improved control on the shoe sole thickness. In some examples the thickness of a shoe sole layer may range from about 50 microns to about 1 centimetre, for example, about 50 microns, 100 microns, 500 microns, 1 millimetre, 5 millimetres, 0.7 centimetre and 1 centimetre. In other examples, a layer of the plurality of layers may be thicker than about 2 centimetres. As mentioned above, the plurality of layers that constitutes the portion may be 3D printed in a layer-wise manner using any of the 3D printing technologies disclosed above. The thickness of each build material layer may range from about 50 to about 120 microns, for example, about 50, 70, 80, 90, 100, or 120 microns. In some examples, different ones of the plurality of layers may have different thicknesses. Therefore, a single shoe sole layer may be manufactured using a plurality of build material layers.

[31] The 3D printed portion of the shoe sole may comprise any number of shoe sole layers, for example, 2, 3, 4, 5, 6, 10 or 30 layers.

[32] The surface configured to be in direct contact with the specific user foot may comprise a set of solidified portions and a set of voids arranged in a 3D pattern such that the set of solidified portions are raised to form the texture gradient providing functionalities which may include, in addition to perspiration control, ergonomic comfort, performance enhancement, aesthetic designs, mechanic interaction, and the like. The texture gradient may be arranged, for example, to include a circular motif or pattern, a geometric motif or pattern or any other motif pattern or lack thereof suitable to enable a desired functionality to the 3D printed portion of the shoe sole. In some examples, the texture gradient may be designed in such a way that the set of solidified portions has a constant cross-section. However, in other examples, the texture gradient may be designed in such a way that the set of solidified portions has a variable cross-section, for example, in a direction generally perpendicular to the surface.

[33] While in Figure IB motifs such as motif 111 or motif 112 appear as debossed, or “sunk in” the surface configured to be in direct contact with a specific user foot, meaning that the additive manufacturing or 3D printing defines such motifs as voids surrounded by 3D printing material, such motifs may in some other examples appear as embossed as illustrated in Figure 1C, whereby in Figure 1C such motifs would be 3D printed to “stick out” of the surface configured to be in direct contact with a specific user foot. In other examples not illustrated here, the gradient may comprise a combination of motifs appearing as embossed and of motifs appearing as debossed compared to the surface configured to be in direct contact with a specific user foot.

[34] In examples shoe soles comprising void spaces, such void spaces may be encapsulated within the shoe sole, therefore being fully surrounded by other parts of the shoe sole. The voids may be filled with a substance which varies depending on the 3D printing technology used. In the examples in which the portion of the shoe sole is generated with an FDM 3D printer, the substance in encapsulated voids may be a gas in which the 3D printer build chamber is subject to, for example, atmospheric air or nitrogen. In examples in which the portion of the shoe sole 100 is generated with an SLA 3D printer, the substance of the encapsulated voids may be a nonsolidified liquid build material. In the examples in which the portion of the shoe sole is generated with a fusing agent 3D printer or a SLS 3D printer, the substance of the encapsulated voids may be a non-solidified powdered build material.

[35] It should also be understood that while the insole is illustrated in a manner such that the surface configured to be in direct contact with a specific user foot appears flat, in some examples such surface configured to be in direct contact with a specific user foot may have a profile matching a shape of a foot of a user, for example by having a raised surface matching the arch of a foot of a user, compared to other portions of the foot of the user.

[36] In some examples, a texture gradient comprises two different textures. In other examples, a texture gradient comprises more than two different textures. In some examples, a texture gradient comprises textures varying in a single characteristic, such as presence or absence or a given motif, or variation in size, shape, density, arrangement or proportion of a given motif. In some examples, a texture gradient comprises textures varying in more than one characteristic, such as varying in both depth and diameter as illustrated in the example of shoe sole 100.

[37] Example motifs forming a texture comprise motifs forming a depletion in the surface, the depletion having for example a round, oval, elliptical, triangle, rectangular, curvilinear or polygonal perimeter. Using different shapes permits to take into account, in addition to perspiration control, a comfort element to avoid angular areas, for example by using smooth or curved profiles, particularly in areas of the foot which may be particularly sensitive. Using different shapes permits to take into account a comfort element, in addition to perspiration control, to thereby avoid slippage of a foot into a shoe, for example by using angular profiles preventing or reducing such foot slippage, for example through motifs having an elongated shape in an axis generally perpendicular to a longitudinal axis of the foot. Using different shapes permits to take into account, in addition to perspiration control, a rigidity element to ease torsion of the shoe sole along a torsion axis, for example through motifs having an elongated shape in an axis generally aligned with such a torsion axis. Such example different textures may be combined in different or in the same areas of the surface in order to obtain a plurality of benefits.

[38] Figure 2 illustrates an example shoe sole 200 which is integrally 3D printed. The texture gradient of the shoe sole 200 comprises a first texture in an area 231 comprising aligned motifs, each motif having for example a same elongated shape and depth; and a smooth and motif-less second texture in the remaining surface area of shoe sole 200.

[39] In some example shoe soles, the 3D printed texture gradient may comprise one or both of a depth variation and a variation in contact surface (see, e.g., Figures 1A-B and Figure 2). An example depth variation comprises smooth areas with zero depth such as area 131 of Figure 1A or the area surrounding area 231 of Figure 2, or areas comprising a motif such as motif 111 with a depth DI and motif 112 with a depth D2, whereby, in this example, D2 differs from DI. Example depth variation over the shoe sole may range between 0 and 1 mm. Example depth variation over the 3D printed portion of the shoe sole may be of more than 0.2 mm or more than 0.5 mm. In some examples, depth variation over the3D printed portion of the shoe sole may comprise one or more through holes in the 3D printed portion of the shoe sole, thereby permitting increasing ventilation. In some examples, the shoe sole is an insole having a thickness of about 0.8mm. [40] Example variation in contact surface comprises smooth areas with 100% contact surface such as area 131 of Figure 1A or the area surrounding area 231 of Figure 2, or areas comprising one or more motifs such as motifs 111 or 112 which, by introducing a gap in contact surface, locally reduce the contact surface between the specific user foot and the surface configured to be in direct contact with a specific user foot below 100%. Example variation in contact surface over the shoe sole may reduce contact surface such that less than 97% or less than 95% of the surface of the 3D printed portion would be in direct contact with a specific user foot. In order to maintain sufficient foot support, example variation in contact surface over the shoe sole may reduce contact surface such that more than 90%, 70% or 50% of the surface of the 3D printed portion would be in direct contact with a specific user foot.

[41] In some examples such as example shoe sole 100, the shoe sole has a thickness Tl. In this example, shoe sole 100 is an insole, and the thickness is of about 3 mm. The thickness may be defined as a thickness of the shoe sole in a direction generally normal to the surface configured to be in contact with the specific user foot. In some examples, the thickness is comprised between 0.5 and 5 mm or between 0.5 and 1 mm. In other examples, the shoe sole may comprise, in addition to an insole, a midsole and, in some cases, an outsole, in which cases the thickness may be of more than 4 mm, more than 7 mm, or more than 1 cm. It should be understood that such different shoe sole elements being the insole, midsole or outsole may be structurally separated, or may be structurally integral. The portion comprising the surface configured to be in direct contact with a specific user foot is comprised in the insole.

[42] Figure 3 illustrates an example shoe sole 300. Shoe sole 300 is represented here in section a view similar to the view of Figure 1A. Shoe sole 300 comprises an insole portion 310 and a midsole portion 320, whereby the surface pertains to the insole 310, and whereby the midsole comprises a 3D printed structure gradient.

[43] A 3D printed structure gradient should be understood as comprising a variation in structure. In this description, while the wording texture and area refer to a surface aspect, the wording structure and a zone refer to a volume aspect. A variation in structure leading to a structure gradient may be obtained by using a different material composition in different zones of the midsole when 3D printing the midsole. A variation in structure leading to a structure gradient may be obtained by including more or less voids in different zones of the midsole when 3D printing the midsole. In this example, the insole part 310 is similar to the shoe sole 100 represented in Figure 1A-B and the midsole comprises micro structures 32N. The micro structures may in this example comprise an additive or agent leading to increasing rigidity compared to the surrounding material.

[44] In this example illustrated in Figure 3, the 3D printed texture gradient is coordinated with the 3D printed structure gradient. What should be understood by coordinated is that the 3D printed structure gradient introduces a structural change in the mass or volume of the midsole which is generally aligned or synchronized with the texture gradient on the surface of the insole. Such coordination takes place between texture, on the surface, and structure, in a volume underlying the surface.

[45] In this specific example of Figure 3, the texture gradient permits gaining comfort by reducing contact surface at the insole surface through, for example, motif 311. The corresponding cluster- like 3D printed structure is generally aligned, or coordinated, below the corresponding motif 311 in order to increase rigidity of the underlying midsole in an area in which the insole would be less rigid, due to the motif 311. It should be understood that such coordination of a 3D printed structure may not exactly correspond to a 3D printed texture. The coordination between the 3D printed structure in the midsole and the 3D printed texture of the insole permits in some cases compensating, using the 3D printed structure, effects introduced by the 3d printed texture. In some example, the 3D printed texture increases comfort while having a mechanical impact compensated by the 3D printed structure.

[46] Figure 4 illustrates an example shoe sole 400. Shoe sole 400 is represented here in section a view similar to the view of Figure 1A or of Figure 3. Shoe sole 400 comprises an insole portion 410 and a midsole portion 420, whereby the surface pertains to the insole 410, and whereby the midsole comprises a 3D printed structure gradient. In this example, the insole part 310 is similar to the shoe sole 100 represented in Figure 1A-B and the midsole comprises structures 42N. The structures 42N are in this example void spaces to reduce rigidity of the midsole compared to the surrounding material. In this example, the 3D printed texture gradient is coordinated with the 3D printed structure gradient. The 3D printed structure gradient introduces a structural change in the mass or volume of the midsole which is generally aligned or synchronized with the texture gradient on the surface of the insole. In this specific example, while the texture gradient permits gaining comfort by reducing contact surface at the insole surface through, for example, motif

411, a corresponding lack of void space 3D printed is generally aligned, or coordinated, below the corresponding motif 411 in order to increase rigidity of the midsole in an area in which the insole would be less rigid, due to the motif 411. It should be understood that such coordination of a 3D printed structure may not exactly correspond to a 3D printed texture, as illustrated here.

[47] In some examples, the portion according to this disclosure is configured for a specific activity. Specific activities should be understood as physical activities comprising for example sport, leisure, relaxation or displacement activities. Different activities may lead to different perspiration profiles or to different mechanical requirements. While classical ballet dancing may for example be associated with a high rigidity of a shoe sole in the toe area compared to a plantar area, cycling may for example be associated with a high rigidity in the areas pushing pedals compared to other areas. Such differentiation in activities can advantageously be taken into account in shoe soles according to this disclosure.

[48] In an example, a given user may, for a specific activity such as cycling, benefit from the shoe sole 200 of Figure 2 while benefitting from a shoe sole such as shoe sole 500 illustrated in Figure 5 for a different activity such as skiing, whereby this given user may have a skiing style benefiting from a texture gradient whereby direct contact surface be reduced in an area 531.

[49] In some examples, a shoe sole according to this disclosure is configured to be interchangeable. This may for example be the case when a shoe sole is an insole separate from a midsole, the midsole being integral to a shoe. This may also be the case when a shoe sole is a combination of a midsole and of an insole separate from an outsole integral to a shoe. In some examples, a kit may comprise a plurality of different shoe soles according to this disclosure, each of such shoe soles corresponding to the same specific user foot. Such a kit may for example comprise interchangeable insoles such that the specific user may pick the appropriate shoe sole for an appropriate shoe, activity of ambient temperature.

[50] In Figure 6A, an example shoe sole 600 according to this disclosure is illustrated whereby the 3D printed texture gradient comprises a first texture type corresponding to a first section 631 of the surface and a second texture type corresponding to a second section 632 of the surface, the first texture type being configured to evacuate more perspiration than the second texture type. Another example shoe sole 601 is represented in Figure 6B, whereby the shoe sole comprises two different 3D printed portions separated by a separation line 621, such configuration providing additional customisation flexibility to a user of the shoe sole. [51] In some examples the 3D printed portion constitutes the entirety of the shoe sole. In other examples, the 3D printed portion is a subset of the shoe sole which is later assembled or attached to other subsets corresponding to the rest of the shoe sole. The other subsets 150 may, or may not, be 3D printed.

[52] Figure 7 illustrates is a block diagram showing a computer system 700 example comprising a processor 701, a storage 702 coupled to the processor 701, and an instruction set.

[53] In some implementations, the system 700 may be or may form part of a computing unit within a 3D printing system or facility, which may permit obtaining a shoe sole as per any of the examples hereby described. In some implementations, the system 700 is a processor-based system and may include a processor 701 coupled to a machine-readable medium or storage 702. The processor 701 may include a single-core processor, a multi-core processor, an applicationspecific integrated circuit (ASIC), a field programmable gate array (FPGA), and/or any other hardware device suitable for retrieval and execution of instructions from the machine-readable medium 702 (e.g., instructions 703-705) to perform functions related to various examples. Additionally, or alternatively, the processor 701 may include electronic circuitry for performing the functionality described herein, including the functionality of instructions 703-705.

[54] The storage 702 may be any medium suitable for storing executable instructions, such as a random-access memory (RAM), electrically erasable programmable read-only memory (EEPROM), flash memory, hard disk drives, optical disks, and the like. In some example implementations, the storage is a machine-readable medium which may be a tangible, non- transitory medium, where the term “non-transitory” does not encompass transitory propagating signals. The storage 702 may be disposed within the processor-based system 700, as shown in Figure 7, in which case the executable instructions may be deemed “installed” on the system 700. Alternatively, the storage 702 may be a portable (e.g., external) storage medium, for example, that allows system 700 to remotely execute the instructions or download the instructions from the storage medium. In this case, the executable instructions may be portion of an “installation package”. As described further herein below, the storage 702 may be encoded with a set of executable instructions 703-705.

[55] Instructions 703, when executed by the processor 701, cause the processor 701 to receive footprint data associated with a specific foot profile, the foot profile comprising a parameter variation. In some examples, the format of the data may include a Computer Aided Product (CAD) file. Footprint data associated with a specific foot profile should be understood as digital data providing a digital representation of a footprint. A footprint may be a planar footprint, the corresponding data being for example generated by a planar, or 2D, scanner, or may be a 3D footprint, the corresponding data being for example generated by a 3D scanner. The footprint data is associated with a specific foot profile, whereby such footprint data is related to a specific foot of a specific user. A footprint is expected to differ from user to user. For a given user, a right foot footprint would thereby be expected to differ, or differ, from a mirror image of a left foot print just as a right foot is expected to differ from a mirror image of a corresponding left foot.

[56] As per instruction 703, the foot profile comprises a parameter variation. The parameter should be understood as a parameter directly or indirectly related to perspiration, such parameter taking specific data values at specific points or locations of the respective footprint. Example parameters comprise temperature, humidity, salinity, pressure or distance from a given plane. Temperature at a specific location of a foot may indeed provide an indication of perspiration, whereby a higher temperature at a given location may be associated with a higher risk of perspiration at this location. Pressure at a specific location of a foot may indeed provide an indication of perspiration, whereby a higher pressure at a given location may be associated with a higher risk of perspiration at this location. Humidity at a specific location of a foot may indeed provide an indication of perspiration, whereby a higher humidity at a given location may be associated with a higher risk of perspiration at this location. Salinity at a specific location of a foot may indeed provide an indication of perspiration, whereby a higher salinity at a given location may be associated with a higher risk of perspiration at this location. Distance at a specific location of a foot from a given plane, in particular a plane substantially aligned to a surface configured to be in direct contact with a specific user foot, the distance being normal to such plane substantially aligned to a surface configured to be in direct contact with a specific user foot, may indeed provide an indication of perspiration, whereby a higher distance dimension at a given location may be associated with a lower risk of perspiration at this location. Such parameter may be measured by respective parameter sensors or scanners, whether planar or in 3D. The variation of such parameter thereby provides an indication as to an expected variation of perspiration at given locations of the footprint.

[57] It should be understood that the footprint may be specific to a given activity or environmental conditions. An example footprint may correspond to a foot being at rest. An example footprint may correspond to a foot being exercising an activity. An example footprint may correspond to a foot exposed to environmental hot and humid conditions. An example footprint may correspond to a foot exposed to environmental hot and dry conditions. In some examples, the footprint data is generated by combining footprint data collected over a period of time, for example by averaging such data over such period of time.

[58] Instructions 704, when executed by the processor 701, cause the processor 701 to receive shoe sole data corresponding to a portion of a shoe sole which is to be manufactured by a 3D printer. In some examples, such shoe sole data is associated with a standard size of a foot corresponding to the specific foot profile. Such shoe sole data may be received from a shoe sole data depository, the shoe sole data depository comprising shoe sole data classified in different classification categories. Classification categories may for example correspond to different standard foot sizes, different shoe types, different activities, different shoe manufacturing materials or to a combination of these. Shoe sole data may be generated or obtained from historical footprint data, from a same single user or from a plurality of users. Such shoe sole data may include a Computer Aided Product (CAD) file. In some examples, such shoe sole data represents a shoe sole or shoe sole portion comprising a surface configured to be in direct contact with a specific user foot, whereby the surface comprises a homogeneous 3D printed texture.

[59] Instructions 705, when executed by the processor 701, cause the processor 701 to combine the received shoe sole data and the received footprint data to include a texture variation on a surface of the shoe sole configured to be in direct contact with a specific user foot, the texture variation corresponding to the parameter variation. The combination of the received shoe sole data and of the received footprint data modifies, in some example, a homogeneous 3D printed texture of a surface of the shoe sole data configured to be in direct contact with a specific user foot from being homogeneous to comprising a texture variation corresponding to the parameter variation, doing so prior to printing the actual shoe sole portion. In some examples where the parameter is a temperature, a variation corresponding to an increase of 0.1 degrees Celsius in footprint temperature at a first point may correspond compared to a reference point may correspond to a texture variation leading to a decrease of 1 % of contact surface at the corresponding first point compared to the corresponding reference point in order to facilitate perspiration control. In some examples where the parameter is a temperature, a variation corresponding to an increase of 0.2 degrees Celsius in footprint temperature at a first point may correspond compared to a reference point may correspond to a texture variation leading to a decrease of 5% of contact surface at the corresponding first point compared to the corresponding reference point in order to facilitate perspiration control. In some examples where the parameter is a pressure, a variation corresponding to an increase of 5000 Pascal at a first point may correspond compared to a reference point may correspond to a texture variation leading to a decrease of 1 % of contact surface at the corresponding first point compared to the corresponding reference point in order to facilitate perspiration control. In some examples where the parameter is a pressure, a variation corresponding to an increase of 10000 Pascal at a first point may correspond compared to a reference point may correspond to a texture variation leading to a decrease of 5% of contact surface at the corresponding first point compared to the corresponding reference point in order to facilitate perspiration control. In some example whereby both temperature and pressure are parameters, both parameters may contribute to the texture variation, in the same or different proportions.

[60] The correspondence between the texture variation and the parameter variation should be understood as the existence of a correlation between the texture variation and the parameter variation between different areas or locations of the surface of the shoe sole configured to be in direct contact with a specific user foot. In some examples, if the parameter comprises a first temperature data point of a user foot at a first location of the footprint, and a second temperature data point of the user foot at a second location of the foot print, whereby the first temperature is lower than the second temperature, the correspondence may be achieved by printing, at a point of the surface of the shoe sole configured to be in direct contact with a specific user foot corresponding to the first location, a first 3D printed texture offering a higher surface of contact with a user foot than a second 3D printed texture printed at a point of the surface of the shoe sole configured to be in direct contact with a specific user foot corresponding to the second location. In some examples, if the parameter comprises a first pressure data point of a user foot at a first location of the footprint, and a second pressure data point of the user foot at a second location of the foot print, whereby the first pressure is lower than the second pressure, the correspondence may be achieved by printing, at a point of the surface of the shoe sole configured to be in direct contact with a specific user foot corresponding to the first location, a smooth first 3D printed texture, a second 3D printed texture being printed at a point of the surface of the shoe sole configured to be in direct contact with a specific user foot corresponding to the second location, whereby the second 3D printed texture comprises moisture absorbing microchannel permitting evacuation of perspiration. In some examples, the correspondence between texture variation and parameter variation comprises using one or more threshold values, whereby a first texture is used when the parameter is below the threshold, and a second texture is used when the parameter is above a threshold. In some examples, a plurality of threshold is used, for example n thresholds, where n is a natural number taking a value of 2 or more, whereby the n thresholds define n+1 categories, each category corresponding to a respective parameter range and to a respective texture. In some examples, different textures types are stored as digital data in the storage coupled to the processor, permitting obtaining the texture variation.

[61] In some examples, the received footprint data comprises more than 5000 data points corresponding to a specific pair of feet. Using such a number of data points permits reflecting the complexity and variety of sweat gland locations. In some examples, such data points are resulting from a measurement at a specific point in time. In some examples, such data points are resulting from a plurality of measurement at different points in time during a time range. In some examples, such data points are resulting from a plurality of measurement at different points in time at a specific frequency, for example at a frequency of more than 1Hz. In some examples, such data points are resulting from a plurality of measurement at different points in time at a specific frequency, for example at a frequency of more than 10Hz. In some examples, such data points are resulting from a plurality of measurement at different points in time at a specific frequency, for example at a frequency of more than 100Hz. In some examples, such data points are resulting from a plurality of measurement at different points in time at a specific frequency, for example at a frequency of more than 400Hz. In some examples, the received footprint data comprises more than 6500 data points corresponding to a specific pair of feet. In some examples, the received footprint data comprises more than 8000 data points corresponding to a specific pair of feet. The received footprint data may result from a 2D or from a 3D scan. The received footprint data may result from a measurement taken when the user is practicing an activity, or when a user is at standstill. Received footprint data resulting from a measurement taken when the user is practicing an activity permits customising the resulting shoe sole or shoe soles in accordance with such activity. In some examples, footprint data is captured or measured homogeneously across the footprint. In some examples, footprint data is captured or measured heterogeneously across the footprint, whereby a first footprint area may be subjected to a higher sampling than a second footprint area, the first footprint area comprising one or more of a heel or a great toe joint, the second footprint are comprising one or more of a toe area or a plantar arch area. [62] Figure 8 illustrates an example computer implemented method 800 of manufacturing a shoe sole. Method 800 may for example be implemented by system 700 of Figure 7. Method 800 may lead to manufacturing a shoe sole or shoe soles as per any of the examples hereby described.

[63] Example method 800 comprises, in block 801, receiving footprint data representing a foot profile from a specific user foot, the foot profile comprising a parameter gradient. In some examples, the parameter gradient is a perspiration parameter, whereby the perspiration parameter comprises one or more of a temperature, a pressure or a distance dimension. In some examples, the parameter gradient comprises at least two parameters selected from a temperature, a pressure or a distance dimension, thereby permitting enriching the information comprised in the foot profile. The receiving may take place through a networking unit which may be comprised in a computer system such as computer system 700.

[64] Example method 800 comprises, in block 802, receiving shoe sole data representing a portion of the shoe sole which is to be manufactured by a 3D printer. One should note that while such shoe sole data may be specific to a standard foot size, such data may be reused between different users having a same foot size. One should note that the processing of 3D data may consume significant computing and memory resources. It is thereby particularly beneficial to reuse such shoe sole data, while limiting user specific data processing to the footprint data such as received in block 801.

[65] Example method 800 further comprises, in block 803, modifying the received shoe sole data to include a texture gradient on a surface of the shoe sole, the surface being configured to be in direct contact with the specific user foot, the texture gradient corresponding to the parameter gradient. The modification may take place by adding data to the received shoe sole data, by removing data from the received shoe sole data, or by replacing data from the received shoe sole data. Such modification leads to customizing the shoe sole to the specific user foot while enabling the reusing of shoe sole data which may not be user specific. In some examples however, the shoe sole data may also be user specific, particularly if or when the user has specificities which should be reflected beyond the surface of the shoe sole configured to be in direct contact with a specific user foot.

[66] Figure 9 illustrates another example method 900. Example method 900 comprises block 801-803 as described in the context of example method 800. Example method 900 further comprises block 904 of designing the texture gradient at least partially in function of one or more defined characteristic axis. A characteristic axis should be understood as a characteristic geometrical direction of the footprint. In some examples, a characteristic axis is input by a designer, such characteristic axis input information being received by a computer system running the method. In some examples, the characteristic axis is defined by the computer system running the method in function of one or more of an activity or footprint data. A characteristic axis may be associated with one or more foot properties. Such foot properties may comprise a mechanical property such as rigidity, flexibility or torsion. A characteristic axis may be related to one or more activities in view of which the shoe sole may be customised according to this disclosure. As explained above, different activities may imply different properties. Different shoe soles may thereby be used for example by a same user for activities as different as cycling, escalating, sailing, dancing, running, walking or long distance running. Characteristics axis may also be related to specific user physiological conditions. In the example of the shoe sole 200, the area 231 provides a specific reduced contact surface with a user foot while defining a characteristic axis along a direction parallel to long sides of the various rectangular motifs having mechanical consequences beyond and in addition to the impact obtained on perspiration.

[67] In some examples, the at least one of the one or more characteristic axis follows a direction away from the surface. A direction away from the surface should be understood as a direction making an angle with the surface configured to be in direct contact with a specific user foot. In some examples, this angle is of more than 5 degrees. In some examples, the characteristic axis following a direction away from the surface is associated with both a 3D printed texture gradient of an insole portion as per this description and a 3D printed structure of a midsole portion. In the example 300, the characteristic axis 322 thereby is perpendicular to the configured to be in direct contact with a specific user foot. In some examples, the one or more characteristic axis is or are aligned with one or more directions of a force exerted by a foot on the sole during an activity. In some examples, the shoe sole is designed for running, whereby a first force direction and first characteristic axis is substantially perpendicular to the surface configured to be in direct contact with a specific user foot, such first force corresponding to the force exerted by the foot landing on the floor, and whereby a second force direction and second characteristic axis is at an angle of between 30 and 60 degrees with the surface configured to be in direct contact with a specific user foot, corresponding to the propulsion force exerted by the foot while running. It should be understood that such angles may be adapted to the specific user concerned. Such configurations combine advantages as to perspiration control obtained by a customised texture on the surface configured to be in direct contact with a specific user foot, and customized mechanical characteristics extending into the volume of the shoe sole.

[68] Figure 10 illustrates another example method 1000. Example method 1000 comprises block 801-803 as described in the context of example method 800. While not illustrated, in some cases example method 1000 may further comprise block 904 of method 900. Example method 1000 comprises block 1005 of iterating the method for a second foot of the same specific user. This permits customizing the shoe soles for both user feet, which may have different characteristics.

[69] The above examples may be implemented by hardware, or software in combination with hardware. For example, the various methods described herein may be implemented by a physical processor (the term processor is to be implemented broadly to include CPU, SoC, processing module, ASIC, logic module, or programmable gate array, etc.). The methods may all be performed by a single processor or split between several processors. The methods are implemented as machine-readable instructions executable by at least one processor, hardware logic circuitry of the at least one processor, or a combination thereof.