阅读说明：本技术 增材制造的产品中的晶格过渡结构 (Lattice transition structures in additively manufactured products ) 是由 H·卡巴里亚 A·库尔茨 于 2019-10-17 设计创作，主要内容包括：增材制造的晶格结构包括：(a)包括第一晶格单位晶胞的重复互连阵列的第一三维晶格；(b)包括第二晶格单位晶胞的重复互连阵列的第二三维晶格,其中,所述第二晶格单位晶胞不同于所述第一晶格单位晶胞；以及(c)第一过渡节段,其使所述第一三维晶格和所述第二三维晶格互连。第一过渡节段包括：(i)包括所述第一晶格单位晶胞的重复阵列的第一三维过渡晶格；和(ii)包括所述第二晶格单位晶胞的重复阵列的第二三维过渡晶格,其与所述第一三维过渡晶格交错且互连。(The lattice structure of the additive manufacturing includes: (a) a first three-dimensional lattice comprising a repeating interconnected array of first lattice unit cells; (b) a second three-dimensional lattice comprising a repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and (c) a first transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice. The first transition segment includes: (i) a first three-dimensional transition lattice comprising a repeating array of the first lattice unit cells; and (ii) a second three-dimensional transition lattice comprising a repeating array of the second lattice unit cells interleaved with and interconnected with the first three-dimensional transition lattice.)

1. An additively manufactured lattice structure (10) comprising:

(a) a first three-dimensional lattice (11) comprising a repeating interconnected array of first lattice unit cells;

(b) a second three-dimensional lattice (12) comprising a repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and

(c) a first transition segment (14) interconnecting the first three-dimensional lattice and the second three-dimensional lattice; the first transition segment includes:

(i) a first three-dimensional transition lattice comprising a repeating array of the first lattice unit cells; and

(ii) a second three-dimensional transition lattice comprising a repeating array of the second lattice unit cells interleaved and interconnected with the first three-dimensional transition lattice.

2. The lattice structure of claim 1, further comprising:

(d) a third three-dimensional lattice consisting of a repeating interconnected array of third lattice unit cells, wherein the third lattice unit cells are different from the second and optionally the first lattice unit cells; and

(e) a second transition segment interconnecting the second three-dimensional lattice and the third three-dimensional lattice; the second transition segment comprises:

(iii) a third three-dimensional transition lattice comprising a repeating array of the second lattice unit cells; and

(iv) a fourth three-dimensional transition lattice comprising a repeating array of the third cell unit cells interleaved and interconnected with the third three-dimensional transition lattice.

3. The lattice structure of any preceding claim, wherein:

the first transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice;

the first lattice unit cell of the first three-dimensional transition lattice shrinks in size gradually from the first portion to the second portion;

the second crystal unit cells of the second three-dimensional transition lattice expand in size stepwise from the first portion to the second portion;

the second transition segment, when present, has a third portion connected to the second three-dimensional lattice and a fourth portion, when present, connected to the third three-dimensional lattice;

the second crystal unit cells of the third three-dimensional transition lattice shrink in size gradually from the third portion to the fourth portion; and

the third cell unit cell of the fourth three-dimensional transition cell gradually expands in size from the first portion to the second portion.

4. The lattice structure of any preceding claim, produced by an additive manufacturing process (e.g., Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Stereolithography (SLA), three-dimensional printing (3DP), or Multiple Jet Modeling (MJM)).

5. The lattice structure of any preceding claim, wherein the first and second three-dimensional lattices are formed from the same material (e.g., a polymer, a metal, a ceramic, or a composite thereof).

6. The lattice structure of any preceding claim, wherein the lattice structure is rigid, flexible, or elastic.

7. The lattice structure of any preceding claim, wherein the first and second arrays of unit cells are independently selected tetrahedral meshes (e.g., a15, C15, or alpha space packing, etc.) or hexahedral mesh lattices.

8. A bracket, arm, link, damper, cushion or pad comprised of a lattice structure according to any preceding claim.

9. A wearable protective device comprising the brace, arm, link, shock absorber, cushion or pad of claim 8 (e.g., shin guard, knee pad, elbow pad, athletic undergarment, cycling shorts, backpack strap, backpack back, neck brace, chest guard, protective vest, protective jacket, slacking pants, suit, coverall, jumpsuits, and protective slacking pants, etc.).

10. A base or seat comprising a bracket, arm, link, shock absorber, bolster or pad according to claim 8.

11. An automotive or aerospace panel, bumper or component comprising a bracket, arm, link, shock absorber, cushion or pad according to claim 8.

12. A method of making an object according to any preceding claim, comprising:

(a) providing a digital model of the object; and then,

(b) producing the object from the digital model by an additive manufacturing process.

13. A method for generating a lattice structure (10), comprising:

generating a first three-dimensional lattice (11) comprising a first repeating interconnected array of first lattice unit cells;

generating a second three-dimensional lattice (12) comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and

generating a transition segment (14) interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises: a first three-dimensional transition lattice comprising a second repeating array of the first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of the second unit cell interleaved with and interconnected with the first three-dimensional transition lattice.

14. The method of claim 13, wherein:

the transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice;

the first lattice unit cell of the first three-dimensional transition lattice shrinks in size gradually from the first portion to the second portion; and

the second crystal unit cells of the second three-dimensional transition lattice expand in size stepwise from the first portion to the second portion.

15. The method of claim 13 or 14, wherein generating the transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice comprises placing the second unit cell in the second repeating array of second unit cells adjacent to a vertex and/or edge of the first unit cell in the second repeating array of first unit cells.

16. The method of any of claims 13 to 15, wherein the transition segment further comprises a third three-dimensional transition lattice comprising a repeating array of third lattice unit cells different from the first and second lattice unit cells.

17. A computer program product, comprising:

a tangible, non-transitory computer-readable storage medium comprising computer-readable program code embodied in the computer-readable storage medium, the computer-readable program code, when executed by at least one processor, causes the at least one processor to perform operations comprising:

generating a first three-dimensional lattice (11) comprising a first repeating interconnected array of first lattice unit cells;

generating a second three-dimensional lattice (12) comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and

generating a transition segment (14) interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises: a first three-dimensional transition lattice comprising a second repeating array of the first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of the second unit cell interleaved with and interconnected with the first three-dimensional transition lattice.

18. The computer program product of claim 17, wherein:

the transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice;

the first lattice unit cell of the first three-dimensional transition lattice shrinks in size gradually from the first portion to the second portion; and

the second crystal unit cells of the second three-dimensional transition lattice expand in size stepwise from the first portion to the second portion.

19. The computer program product of claim 17 or 18, wherein generating the transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice comprises placing the second unit cell in the second repeating array of second unit cells adjacent to a vertex and/or edge of the first unit cell in the second repeating array of first unit cells.

20. The computer program product of any of claims 17 to 19, wherein the transition segment further comprises a third three-dimensional transition lattice comprising a repeating array of third lattice unit cells different from the first and second lattice unit cells.

Technical Field

The present invention relates to lattice transition structures useful in bumpers, liners, cushions, bumpers and other lattice objects produced by additive manufacturing.

Background

One group of additive manufacturing techniques, sometimes referred to as "stereolithography," creates three-dimensional objects by sequential polymerization of photopolymerizable resins. Such techniques may be: a "bottom-up" technique, in which light is projected through a light transmissive window onto the bottom of a growing object into the resin); or "top-down" techniques, in which light is projected onto the resin on top of the growing object, and the resin is then dipped down into a pool of resin.

The recent introduction of more rapid stereolithography techniques, sometimes referred to as Continuous Liquid Interface Production (CLIP), has expanded the usefulness of stereolithography from prototyping to manufacturing. See Continuous liquid interface production of 3D objects (SCIENCE 347, 1349-; U.S. patent No. 9211678 to DeSimone et al; no. 9205601; and No. 9216546; see also the layer-free preparation with continuous liquid interface production by Janusziewicz et al (PNAS 113, 11703-11708) (10/18/2016).

The introduction of dual cure resins for additive manufacturing shortly after the introduction of CLIP has expanded the usefulness of stereolithography for manufacturing a wide variety of objects even further. See U.S. Pat. Nos. 9676963, 9453142, and 9598606 to Rolland et al; J. a re-thought by Poelma and J.Rolland utilized digital fabrication with polymers (SCIENCE 358, 1384) 1385 (12.15.2017).

There is great interest in developing lattice objects for products of additive manufacturing. However, the problem of how to interconnect a plurality of different lattice types in a smooth manner in a single object has not been solved so far.

Disclosure of Invention

Various embodiments described herein provide lattice structures including transition segments between two types of lattices and methods for automatically generating the transition segments.

According to some embodiments described herein, the lattice structure of the additive manufacturing comprises: (a) a first three-dimensional lattice comprising a repeating interconnected array of first lattice unit cells; (b) a second three-dimensional lattice comprising a repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and (c) a first transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice. The first transition segment includes: (i) a first three-dimensional transition lattice comprising a repeating array of the first lattice unit cells; and (ii) a second three-dimensional transition lattice comprising a repeating array of the second lattice unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

In some embodiments, the lattice structure further comprises: (d) a third three-dimensional lattice consisting of a repeating interconnected array of third lattice unit cells, wherein the third lattice unit cells are different from the second and optionally the first lattice unit cells; and (e) a second transition segment interconnecting the second three-dimensional lattice and the third three-dimensional lattice. The second transition segment includes: (iii) a third three-dimensional transition lattice comprising a repeating array of the second lattice unit cells; and (iv) a fourth three-dimensional transition lattice comprising a repeating array of the third cell unit cells interleaved with and interconnected with the third three-dimensional transition lattice.

In some embodiments, the first transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice, the first lattice unit cell of the first three-dimensional transition lattice shrinks in size gradually from the first portion to the second portion, the second crystal unit cells of the second three-dimensional transition lattice expand in size stepwise from the first portion to the second portion, the second transition segment, when present, has a third portion connected to the second three-dimensional lattice and a fourth portion, when present, connected to the third three-dimensional lattice, the second crystal unit cells of the third three-dimensional transition lattice shrink in size gradually from the third portion to the fourth portion, and, the third lattice unit cell of the fourth three-dimensional transition lattice is gradually expanded in size from the first portion to the second portion.

In some embodiments, the lattice structure is produced by an additive manufacturing process (e.g., Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Stereolithography (SLA), three-dimensional printing (3DP), or Multiple Jet Modeling (MJM)).

In some embodiments, the first and second three-dimensional lattices are formed of the same material (e.g., a polymer, a metal, a ceramic, or a composite thereof).

In some embodiments, the lattice structure is rigid, flexible, or elastic.

In some embodiments, the first lattice array and the second lattice array are independently selected tetrahedral lattices (e.g., a15, C15, or alpha space packing, etc.) or hexahedral lattice lattices.

According to some embodiments described herein, the bracket, arm, link, shock absorber, cushion, or pad comprises the lattice structure of the embodiments described herein.

According to some embodiments described herein, a wearable protective device includes a brace, arm, link, shock absorber, cushion or pad (e.g., shin guard, knee pad, elbow pad, athletic undergarment, cycling shorts, backpack strap, backpack back, neck brace, chest guard, protective vest, protective jacket, slacks, suits, overalls, jumpsuits, and protective slacks, etc.) of the embodiments described herein.

According to some embodiments described herein, the base or seat comprises the bracket, arm, link, shock absorber, cushion or pad of embodiments described herein.

According to some embodiments described herein, an automotive or aerospace panel, bumper or component comprises a bracket, arm, link, shock absorber, cushion or pad of embodiments described herein.

According to some embodiments described herein, a method of making an object of embodiments described herein comprises: (a) providing a digital model of the object; and then (b) producing the object from the digital model by an additive manufacturing process.

According to some embodiments described herein, a method for generating a lattice structure comprises: generating a first three-dimensional lattice comprising a first repeating interconnected array of first lattice unit cells; generating a second three-dimensional lattice comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and generating a transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises: a first three-dimensional transition lattice comprising a second repeating array of first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of second unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

In some embodiments, the transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice, the first cell unit cells of the first three-dimensional transition lattice shrinking in size gradually from the first portion to the second portion, and the second cell unit cells of the second three-dimensional transition lattice expanding in size gradually from the first portion to the second portion.

In some embodiments, generating the transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice includes placing a second unit cell in the second repeating array of second unit cells adjacent to a vertex and/or edge of a first unit cell in the second repeating array of first unit cells.

In some embodiments, the transition segment further comprises a third three-dimensional transition lattice comprising a repeating array of third lattice unit cells different from the first and second lattice unit cells.

According to some embodiments described herein, a computer program product comprises a tangible, non-transitory computer-readable storage medium including computer-readable program code embodied in the computer-readable storage medium, the computer-readable program code, when executed by at least one processor, causes the at least one processor to perform operations comprising: generating a first three-dimensional lattice comprising a first repeating interconnected array of first lattice unit cells; generating a second three-dimensional lattice comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and generating a transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises: a first three-dimensional transition lattice comprising a second repeating array of first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of second unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

The foregoing objects and aspects and other objects and aspects of the present invention are explained in more detail in the drawings herein and the specification set forth below. The disclosures of all U.S. patent references cited herein are hereby incorporated by reference.

Drawings

Fig. 1 schematically illustrates one embodiment of the lattice structure of the present invention.

Fig. 2 schematically illustrates an example of a tetrahedral lattice unit cell transitioning to its double through a series of five intermediate lattice unit cells as may be incorporated into the transition sections of the composite lattice structure of the present invention.

Fig. 3 and 4 are perspective views of an exemplary servo arm prototype prior to lattice filling by the process of the present invention.

Fig. 5 and 6 are perspective views of the exemplary servo arm of fig. 3 and 4 partially converted to a lattice filler during the course of the present invention.

Fig. 7 and 8 are perspective views of the exemplary servo arm of fig. 3 and 4 fully converted to a lattice filler by the process of the present invention.

Figure 9 schematically illustrates one embodiment of an apparatus that may be used to implement the method of the present invention.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the drawings, the thickness of some lines, layers, members, elements or features may be exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or groups or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups or combinations thereof.

As used herein, the term "and/or" includes any and all possible combinations or includes one or more of the associated listed items, except where no combination is present when interpreted in an alternative form ("or").

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and claims and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being "on," "attached to," "connected to," coupled with, "contacting," etc. another element, it can be directly on, attached to, connected to, coupled with, and/or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, "directly on," "directly attached" to, "directly connected" to, "directly coupled" with, or "directly contacting" another element, there are no intervening elements present. One skilled in the art will also appreciate that references to a structure or feature that is disposed "adjacent" another feature can have portions that overlap or underlie the adjacent feature.

Spatially relative terms (such as "under", "below", "lower", "over", "upper", and the like) may be used herein for ease of description to describe one element or feature's relationship to another element or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upward," "downward," "vertical," "horizontal," and the like are used herein for illustrative purposes only, unless specifically indicated otherwise.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer and/or section from another element, component, region, layer and/or section. Thus, a first element, component, region, layer or section discussed herein could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

Additive manufacturing methods, apparatus, and resins.

Techniques for additive manufacturing are known. Suitable techniques include, but are not limited to, techniques such as: selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Stereolithography (SLA), material jetting including three-dimensional printing (3DP), and Multiple Jet Modeling (MJM) (including multiple jet fused MJM such as available from Hewlett Packard), among others. See, e.g., additive manufacturing methods and modeling approaches of h. Bikas et al: (Additive manufacturing methods and modeling approaches: a critical review) (int. J. adv. Manual. technol. 83, 389-.

Resins for additive manufacturing of polymeric articles are known and described in the following: such as U.S. patent nos. 9211678 to DeSimone et al; no. 9205601; and No. 9216546. Dual cure resins for additive manufacturing are known and described in: for example, U.S. patent nos. 9676963 to Rolland et al; no. 9598606; and No. 9453142. Non-limiting examples of dual cure resins include, but are not limited to, resins used to produce: objects composed of polymers such as polyurethanes, polyureas and their copolymers; an object composed of an epoxy resin; an object composed of cyanate ester; objects composed of silicone, and the like.

Stereolithography, including bottom-up and top-down techniques, is known and described in the following: for example, U.S. patent No. 5236637 to Hull, U.S. patent nos. 5391072 and 5529473 to Lawton, U.S. patent No. 7438846 to John, U.S. patent No. 7892474 to Shkolnik, U.S. patent No. 8110135 to El-Siblani, U.S. patent application publication No. 2013/0292862 to Joyce, and U.S. patent application publication No. 2013/0295212 to Chen et al. The disclosures of these patents and applications are incorporated herein by reference in their entirety.

In some embodiments, the object is formed by Continuous Liquid Interface Production (CLIP). CLIP is known and described in: for example, PCT application No. PCT/US2014/015486 (U.S. Pat. No. 9211678); PCT/US2014/015506 (U.S. Pat. No. 9205601), PCT/US2014/015497 (U.S. Pat. No. 9216546) and Continuous liquid interface production of 3D Objects (3D Objects) by J. Tumbleston, D. Shirvanyants, N. Ermoshkin et al (Science 347, 1349-. See also the layer-free preparation by Janusziewcz et al with continuous liquid interface production (Proc. Natl. Acad. Sci. USA 113, 11703-. In some embodiments, CLIP employs bottom-up three-dimensional preparation features as described above, but also while performing the irradiation and/or the advancing step, simultaneously maintains a stable or durable liquid interface between the growing object and the build surface or window, such as by: (i) continuously maintaining a dead zone of polymerizable liquid in contact with the build surface, and (ii) continuously maintaining a gradient of polymerization zone (such as an active surface) between and in contact with each of the dead zone and the solid polymer, the gradient of polymerization zone comprising the first component in partially cured form. In some embodiments of the CLIP, the optically transparent member comprises a semi-permeable member (e.g., fluoropolymer), and the continuously maintaining dead zone is implemented by: the polymerization inhibitor is supplied through the optically transparent member, thereby creating a gradient of inhibitor in the dead zone and optionally in at least part of the gradient of the polymerization zone. Other approaches for implementing CLIPs that can be used in the present invention and that obviate the need for semi-permeable "windows" or window structures include the use of liquid interfaces comprising immiscible liquids (see WO2015/164234 published by l. Robeson et al at 29/10/2015), the generation of oxygen as an inhibitor by electrolysis (see WO2016/133759 published by i. Craven et al at 25/8/2016), and the incorporation of magnetically localizable particles to which a photosensitizer is attached into a polymerizable liquid (see WO2016/145182 published by j. Rolland at 15/9/2016).

Other examples of methods and apparatus for implementing particular embodiments of the CLIP include, but are not limited to: B. U.S. patent application publication No. US2018/0243976 to beller (published on 2018, 8-month 30-day); U.S. patent application publication No. US2018/0126630 to m, Panzer and j, Tumbleston (published on 5/10/2018); K. U.S. patent application publication No. US2018/0290374 to Willis and b. Adzima (10 months and 11 days 2018); a Continuous liquid interface production system with a viscous pump (Continuous liquid interface production system with viscidity pump) by Batchelder et al (U.S. patent application publication No. US2017/0129169(2017, 5/11)); three-dimensional manufacturing systems for rapid production of objects by Sun and Lichkus (Three-dimensional marking systems for rapid manufacturing objects) (U.S. patent application publication No. US2016/0288376 (10/6/2016)); 3d print adhesion reduction process during the curing process (U.S. patent application publication No. US2015/0360419 (12/17 2015)); intelligent 3d printing by optimization of 3d printing parameters by Lin et al (Intelligent 3d printing through optimization of 3d print parameters) (U.S. patent application publication No. US2015/0331402 (11/19/2015)); and Castanon's Stereolithography System (Stereolithography System) (U.S. patent application publication No. US2017/0129167(2017, 5/11).

After the object is formed, the object is typically cleaned, and, in some embodiments, the object is then further cured, preferably by baking (however, further curing may occur in some embodiments simultaneously with the first curing, or may be by a different mechanism such as contact with water, as described in U.S. patent No. 9453142 to Rolland et al).

Embodiments described herein provide methods and lattice structures derived therefrom that provide for a transition from a first lattice type to a second lattice type.

Fig. 1 schematically illustrates one embodiment of a lattice structure 10 of the present invention. As illustrated in fig. 1, the lattice structure 10 may be composed of a first lattice 11 of a first type and a second lattice 12 of a second type. The first cell 11 may include a repeating interconnected array of first cell unit cells. The second cell 12 may comprise a repeating interconnected array of second cell unit cells. In some embodiments, the first cell unit cell of the first cell 11 and the second cell unit cell of the second cell 12 may be different from each other. Although illustrated in two dimensions in fig. 1, it will be understood that the first crystal lattice 11 and the second crystal lattice 12 may be formed in three dimensions. In some embodiments, the first lattice 11 and the second lattice 12 may be defined by a grid of a plurality of polyhedrons. In some embodiments, first lattice 11 and/or second lattice 12 may be comprised of struts arranged along the centroids, edges, and/or vertices of the polyhedrons of the mesh.

In some embodiments, the first lattice 11 and the second lattice 12 may be segments of the lattice structure 10 (e.g., working cells). For example, in international patent application PCT/US2018/056842 to Kabaria et al (claiming priority to U.S. provisional patent application No. 62/579346 to Kabaria et al and U.S. provisional patent application No. 62/719316 to Kabaria et al), the contents of each of which are incorporated herein by reference, a method for forming a lattice structure consisting of a plurality of working cells of different lattice types is described. In some embodiments, lattice structure 10 may be a lattice formed, for example, using an additive manufacturing process. In some embodiments, the lattice structure 10 may be represented by a data representation of the lattice to be fabricated. Thus, lattice structures described herein may refer to both data representations of physical lattice structures as well as lattices constructed from such data representations.

As illustrated in fig. 1, the lattice structure 10 may further include a transition segment 14 connecting the first lattice 11 to the second lattice 12. The transition segment 14 may include a plurality of different unit cells, including a first unit cell, a second unit cell, and/or other unit cells. In some embodiments, the transition segment 14 may include a repeating array of first unit cell interleaved and/or interconnected with a repeating array of second unit cell. In some embodiments, the dimensions of the respective first unit cells of the repeating array of first unit cells may gradually shrink in size within the transition section 14 as the distance from the first cell 11 increases. Similarly, the dimensions of the respective second crystal unit cells of the repeating array of second crystal unit cells may progressively shrink in size within the transition section 14 as the distance from the second crystal 12 increases. In some embodiments, the transition segment 14 may have a first portion connected to the first crystal lattice 11 and a second portion connected to the second crystal lattice 12. The first cell of the transition segment 14 may gradually shrink in size from the first portion to the second portion, and the second cell of the transition segment 14 may gradually increase in size from the first portion to the second portion. The transition segment 14 may allow for a transition (e.g., a gradual transition and/or a less abrupt transition) from a first cell of the first cell 11 to a second cell of the second cell 12 within the lattice structure 10.

In some embodiments, the transition section 14 is formed by arranging one type of unit cell (e.g., a first unit cell) at the vertices and/or edges of another type of unit cell (e.g., a second unit cell). For example, within the transition segment 14, the second lattice unit cells may be arranged at the vertices and/or edges of the first one of the first lattice unit cells, and further arranged such that the size of the second lattice unit cells successively decreases as the arrangement proceeds from the second portion to the first portion of the transition segment 14. In some embodiments, the size of the second cell unit cell may be reduced until the second cell unit cell is no longer present adjacent to the first cell unit cell (e.g., at the first portion of the transition section 14 and the first cell 11 boundary). Similarly, within the transition segment 14, a first unit cell may be arranged at a vertex and/or edge of a second unit cell in a second unit cell, and further arranged such that the size of the first unit cell decreases successively as the arrangement proceeds from the first portion to the second portion of the transition segment 14. In some embodiments, the size of the first unit cell may decrease until the first unit cell no longer exists adjacent to the second unit cell (e.g., at the boundary of the second portion of the transition section 14 and the second cell 12). In some embodiments, the increase in size of the first unit cell from the first portion to the second portion and/or the increase in size of the second unit cell from the second portion to the first portion may progress with expanding foam within the transition section 14.

Although fig. 1 illustrates two lattice types (first lattice 11 and second lattice 12), it will be understood that more than just two additional lattices may be incorporated. For example, the third lattice may be connected to the first lattice 11 and/or the second lattice 12 via additional transition segments. The additional lattice may include additional transition segments between the additional lattice and the lattice to which the additional lattice is connected. The additional transition segment may include unit cells from two crystal lattices between which the additional transition segment is located in a manner as described herein with respect to the first crystal lattice 11, the second crystal lattice 12, and the transition segment 14.

Fig. 2 is a non-limiting illustration of a wide variety of different lattice unit cell types that can be defined by tetrahedral mesh unit cells, ranging from original unit cell (in which the pillars are aligned with the edges and connected at the corners, and the pillars along the edges are common to adjacent unit cells) to corresponding doublets (in which the centroids of adjacent unit cells are connected to each other by the pillars). Fig. 2 illustrates the recorded transition morphology of the polyhedral expansion. In fig. 2, lines terminating as points on each of the four faces of a tetrahedron represent struts projecting into and connecting with the centroids of adjacent tetrahedrons. In all the embodiments shown, the bold lines represent the legs of the unit cell; struts along the edges are common to adjacent cells; and the pillars terminating on the faces of the tetrahedron are interconnected with corresponding pillars of an adjacent unit cell. The composite lattice structure of the present invention can be assembled from two or more individual lattices by producing an intermediate structure in which the unit cells are progressively transformed from one cell type to another through a series of intermediate unit cell types, such as those illustrated in fig. 2.

Fig. 3-8 illustrate servo arms that can be produced according to the invention. A prototype of the servo arm (fig. 3 and 4) is shown progressing through an intermediate body (e.g. in a software program) (fig. 5 and 6) to a final form of a lattice-filled servo arm (fig. 7 and 8) that can be produced by additive manufacturing. The final form may be generated, for example, in the form of a data file that may include a representation of the final lattice structure.

Referring to fig. 3 and 4, a prototype 8 of the servo arm may be generated. In some embodiments, the prototype 8 may be a data representation of a three-dimensional object. In some embodiments, the geometry of the data representation may comprise a multi-surface file (e.g., an. iges file) or a Boundary Representation (BREP) file (e.g., an. stl,. obj,. ply,. 3mf,. amf, or. mesh file). In some embodiments, the data representation may include a boundary shape of the three-dimensional object, such as, for example, an outer surface. In some embodiments, the data representation may include a summary and/or data description of the object in three dimensions suitable for fabrication via an additive manufacturing process.

Referring to fig. 5 and 6, the interior portion of the prototype representation may be replaced with an initial lattice structure 10'. The initial lattice structure 10' may include a representation of a first lattice 11 including a first unit cell and a second lattice 12 including a second unit cell and a transition segment 14 between the first lattice 11 and the second lattice 12. The first lattice 11 and/or the second lattice 12 may be selected based on desired properties of the model of the prototype at a particular physical location (e.g., stability, flexibility, etc.). The transition segment 14 may be automatically generated based on the first and second unit cell. In other words, the formulation of the transition section 14 may be based on a repeating array of first unit cell interleaved and/or interconnected with a repeating array of second unit cell. In some embodiments, the dimensions of the first and/or second lattice unit cells may be adjusted to create the transition segment 14. In some embodiments, the creation of the transition segment 14 may include interconnecting a first unit cell (whose size decreases in a direction away from the first cell 11) with a second unit cell (whose size decreases in a direction away from the second cell 12). Within the transition segment 14, there may be a first portion closest to the first crystal lattice 11 and a second portion closest to the second crystal lattice 12. Automatically generating the transition segment 14 may include: arranging a plurality of first unit cells having a size decreasing from a first portion to a second portion within a data model; arranging a plurality of second lattice unit cells having a size decreasing from the second portion to the first portion within the data model; and interconnecting the plurality of first unit cell and the plurality of second unit cell. In some embodiments, additional unit cells of different types (e.g., different from the first and/or second unit cells) may be interspersed between the first and second unit cells within the transition section 14 in order to improve and/or maintain stability of the transition section 14.

Referring to fig. 7 and 8, once the formulation of the initial lattice structure 10' is complete, the final lattice structure 10 may be generated. The formulation of the final lattice structure 10 may include: forming pillars along the segments of the initial lattice structure 10'; and removing an inner portion of the grid representation. The final lattice structure 10 may be represented by a data model (e.g., a. igs,. stl,. obj,. ply,. wrl,. x3d,. 3mf,. amf,. fbx, or. mesh file) suitable for three-dimensional modeling and/or printing via an additive manufacturing process.

It will be appreciated that during the generation of the initial lattice structure 10' and/or the final lattice structure 10, portions of the lattice structure at and/or near the edges of the lattice structure may be smoothed to create a planar surface and/or a smooth surface. The smoothing may remove, for example, portions of the lattice structure that would otherwise extend outside the boundaries of the representation of the three-dimensional object. Smoothing may be accomplished according to known techniques as understood by those skilled in the art. In some embodiments, an outer surface (e.g., skin) having a particular thickness may be placed over some or all of the lattice structure to provide the outer surface.

An apparatus for practicing the invention is schematically illustrated in fig. 9. Such an apparatus comprises: a user interface 3 for inputting instructions (such as selecting an object to be produced and selecting a feature to be added to the object); a controller 4; and a stereolithography apparatus 5 such as described above. An optional scrubber (not shown) can be included in the system if desired, or a separate scrubber can be utilized. Similarly, for dual cure resins, an oven (not shown) can be included in the system, however a separate oven operated can also be utilized.

Connections between components of the system can be made through any suitable configuration, including wired connections and/or wireless connections. The components may also communicate over one or more networks, including any conventional, public and/or private, real and/or virtual, wired, and/or wireless networks, including the internet.

The controller 4 may be of any suitable type, such as a general purpose computer. Typically, the controller will include at least one processor 4a, volatile (or "working") memory 4b (such as random access memory) and at least one non-volatile or persistent memory 4c (such as a hard disk drive or flash drive). The controller 4 may be implemented using hardware, software implemented using hardware, firmware, a tangible computer readable storage medium having instructions stored thereon, and/or combinations thereof, and may be implemented in one or more computer systems or other processing systems. The controller 4 may also utilize a virtual instance of a computer. As such, the apparatus and methods described herein may be embodied in any combination of hardware and software, which may all generally be referred to herein as a "circuit," module, "" component, "and/or" system. Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable media having computer-readable program code embodied in the media.

Any combination of one or more computer-readable media may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a suitable optical fiber with a relay, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the preceding. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. The computer readable signal medium may be any computer readable medium that: is not a computer readable storage medium and is capable of communicating, propagating or transporting a program for use by or in connection with an instruction execution system, apparatus or device. Program code embodied on a computer readable signal medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

The at least one processor 4a of the controller 4 may be configured to execute computer program code, which may be written in any combination of one or more programming languages, including: object-oriented programming languages (such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, and so forth), conventional procedural programming languages (such as the "C" programming language, Visual Basic, Fortran 2003, COBOL 2002, PHP, ABAP), dynamic programming languages (such as Python, PERL, Ruby, and Groovy), or other programming languages.

The at least one processor 4a may be or may include one or more programmable general or special purpose microprocessors, Digital Signal Processors (DSPs), programmable controllers, Application Specific Integrated Circuits (ASICs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), Trusted Platform Modules (TPMs), or a combination of such or similar devices, which may be collocated or distributed across one or more data networks.

The connections between the internal components of the controller 4 are only partially shown, and the connections between the internal and external components of the controller 4 are not shown for clarity, but are provided by additional components known in the art (such as buses, input/output boards, communication adapters, network adapters, etc.). Thus, the connections between the internal components of the controller 4 may include, for example, a system bus, a Peripheral Component Interconnect (PCI) bus or PCI-Express bus, a HyperTransport or Industry Standard Architecture (ISA) bus, a Small Computer System Interface (SCSI) bus, a Universal Serial Bus (USB), an IIC (I2C) bus, an Advanced Technology Attachment (ATA) bus, a serial ATA (sata) bus, and/or an Institute of Electrical and Electronics Engineers (IEEE) standard 1394 bus (also known as a "firewire").

The user interface 3 may be of any suitable type. The user interface 3 may comprise a display and/or one or more user input devices. The display may be accessible by the at least one processor 4a via connections between system components. The display may provide a graphical user interface for receiving input, displaying intermediate operations/data, and/or deriving output of the methods described herein. The display may include, but is not limited to, a monitor, a touch screen device, and the like, including combinations thereof. Input devices may include, but are not limited to, a mouse, a keyboard, a camera, and the like, including combinations thereof. The input means may be accessible by the at least one processor 4a via connections between system components. The user interface 3 may interface with and/or operate through computer readable software code instructions residing in volatile memory 4b that are executed by the processor 4 a.

According to some embodiments described herein, the lattice structure of the additive manufacturing comprises: (a) a first three-dimensional lattice comprising a repeating interconnected array of first lattice unit cells; (b) a second three-dimensional lattice comprising a repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and (c) a first transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice. The first transition segment includes: (i) a first three-dimensional transition lattice comprising a repeating array of the first lattice unit cells; and (ii) a second three-dimensional transition lattice comprising a repeating array of the second lattice unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

In some embodiments, the lattice structure further comprises: (d) a third three-dimensional lattice consisting of a repeating interconnected array of third lattice unit cells, wherein the third lattice unit cells are different from the second and optionally the first lattice unit cells; and (e) a second transition segment interconnecting the second three-dimensional lattice and the third three-dimensional lattice. The second transition segment includes: (iii) a third three-dimensional transition lattice comprising a repeating array of the second lattice unit cells; and (iv) a fourth three-dimensional transition lattice comprising a repeating array of the third cell unit cells interleaved with and interconnected with the third three-dimensional transition lattice.

In some embodiments, the first transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice, the first lattice unit cell of the first three-dimensional transition lattice shrinks in size gradually from the first portion to the second portion, the second crystal unit cells of the second three-dimensional transition lattice expand in size stepwise from the first portion to the second portion, the second transition segment, when present, has a third portion connected to the second three-dimensional lattice and a fourth portion, when present, connected to the third three-dimensional lattice, the second crystal unit cells of the third three-dimensional transition lattice shrink in size gradually from the third portion to the fourth portion, and, the third lattice unit cell of the fourth three-dimensional transition lattice is gradually expanded in size from the first portion to the second portion.

In some embodiments, the lattice structure is produced by an additive manufacturing process (e.g., Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Stereolithography (SLA), three-dimensional printing (3DP), or Multiple Jet Modeling (MJM)).

In some embodiments, the first and second three-dimensional lattices are formed of the same material (e.g., a polymer, a metal, a ceramic, or a composite thereof).

In some embodiments, the lattice structure is rigid, flexible, or elastic.

In some embodiments, the first lattice array and the second lattice array are independently selected tetrahedral lattices (e.g., a15, C15, or alpha space packing, etc.) or hexahedral lattice lattices.

According to some embodiments described herein, the bracket, arm, link, shock absorber, cushion, or pad comprises the lattice structure of the embodiments described herein.

According to some embodiments described herein, a wearable protective device includes a brace, arm, link, shock absorber, cushion or pad (e.g., shin guard, knee pad, elbow pad, athletic undergarment, cycling shorts, backpack strap, backpack back, neck brace, chest guard, protective vest, protective jacket, slacks, suits, overalls, jumpsuits, and protective slacks, etc.) of the embodiments described herein.

According to some embodiments described herein, the base or seat comprises the bracket, arm, link, shock absorber, cushion or pad of embodiments described herein.

According to some embodiments described herein, an automotive or aerospace panel, bumper or component comprises a bracket, arm, link, shock absorber, cushion or pad of embodiments described herein.

According to some embodiments described herein, a method of making an object of embodiments described herein comprises: (a) providing a digital model of the object; and then (b) producing the object from the digital model by an additive manufacturing process.

According to some embodiments described herein, a method for generating a lattice structure comprises: generating a first three-dimensional lattice comprising a first repeating interconnected array of first lattice unit cells; generating a second three-dimensional lattice comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and generating a transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises; a first three-dimensional transition lattice comprising a second repeating array of first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of second unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

In some embodiments, the transition segment has a first portion connected to the first three-dimensional lattice and a second portion connected to the second three-dimensional lattice, the first cell unit cells of the first three-dimensional transition lattice shrinking in size gradually from the first portion to the second portion, and the second cell unit cells of the second three-dimensional transition lattice expanding in size gradually from the first portion to the second portion.

In some embodiments, generating the transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice includes placing a second unit cell in the second repeating array of second unit cells adjacent to a vertex and/or edge of a first unit cell in the second repeating array of first unit cells.

In some embodiments, the transition segment further comprises a third three-dimensional transition lattice comprising a repeating array of third lattice unit cells different from the first and second lattice unit cells.

According to some embodiments described herein, a computer program product comprises a tangible, non-transitory computer-readable storage medium including computer-readable program code embodied in the computer-readable storage medium, the computer-readable program code, when executed by at least one processor, causes the at least one processor to perform operations comprising: generating a first three-dimensional lattice comprising a first repeating interconnected array of first lattice unit cells; generating a second three-dimensional lattice comprising a first repeating interconnected array of second lattice unit cells, wherein the second lattice unit cells are different from the first lattice unit cells; and generating a transition segment interconnecting the first three-dimensional lattice and the second three-dimensional lattice, wherein the transition segment comprises: a first three-dimensional transition lattice comprising a second repeating array of first lattice unit cells; and a second three-dimensional transition lattice comprising a second repeating array of second unit cells interleaved with and interconnected with the first three-dimensional transition lattice.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.