Additively manufactured structures for supporting plant growth in BIO-diverse green construction

Abstract

The present disclosure contemplates an additively manufactured structure for supporting plant growth (e.g., a green wall for supporting diverse plant growth). It includes a wall defining an internal and external surface. The external surface has vessels formed at different locations, wherein each vessel has an opening leading to a storage volume. At least two different vessels have different storage volumes. At least a portion of the wall is additively manufactured and each of the plurality of vessels is configured to receive a growth medium and a portion of a plant. The structure may further include at least one irrigation conduit configured to receive water that is in fluid communication with at least a portion of one of the plurality of vessels. Computational methods for designing a pattern for additively manufacturing a structure for supporting plant growth are also provided.

Description

ADDITIVELY MANUFACTURED STRUCTURES FOR SUPPORTING PLANT GROWTH IN BIO DIVERSE GREEN CONSTRUCTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 538,194, filed on September 13, 2023. The entire disclosure of the above application is incorporated herein by reference.FIELD

[0002] The present disclosure relates to additively manufactured structures for supporting plant growth.BACKGROUND

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] Urban areas face a host of environmental crises brought on by anthropogenic climate change. The Urban Heat Island (UHI) effect, along with pollution and a lack of biodiversity in urban areas, pose serious threats to human health that will only worsen with the rapid urbanization expected in the coming decades. For example, a difference in atmospheric temperature can reach 12°C at night while surface temperatures are found to be 15 °C higher during the day in UHI regions as compared to other non-urban locations. This is believed to be caused by several factors, including high thermal absorption of exterior building materials, heat entrapment by urban canyons, heat generation from human activities, and a lack of green spaces. In this manner, UHI adversely affects urban communities through increased energy demand, thermal pollution of aquatic ecosystems, the formation of ground-level ozone and other air pollutants, as well as heat-related illness and mortality. For example, UHI is estimated to cause an additional 1.1 million heat-related deaths in the United States each year, while ambient air pollution is responsible for an additional 4.2 million deaths globally.

[0005] Green building envelopes that incorporate plants and vegetation on the exterior of buildings offer a solution to reduce the UHI effect and air pollutants while also improving building performance through passive cooling, wind buffering, and added insulation. Plants cooltheir surrounding environments through evapotranspiration and shading, reducing ambient temperatures during extreme heat events and improving building performance. Green envelope systems also filter harmful pollutants and contaminants from the air, absorb carbon, increase building longevity, and provide insulation and wind protection to further reduce energy consumption.

[0006] However, conventional green wall systems are often materially inefficient due to their lack of integration with functional building envelope layers, as well as being limited in the size and types of plants that can be integrated. For example, conventional green wall systems are typically designed as superimposed structures lacking integration with the many functional layers of the building envelope, making them materially inefficient and difficult to recycle. These systems often comprise mats (often non-recyclable felt) or modular and flat panels or planters with a uniform depth of growing substrate that limits plant size, variety, and support of biodiversity. Proper container size is critical to the survival and growth of cultivated plants; containers either too small or too large can harm plant health, leading plants to become rootbound or develop root rot. Additionally, root depth and morphology varies among plant species, necessitating a variety of pod sizes to foster plant diversity.

[0007] Thus, such conventional green wall systems suffer from various limitations, including typically only having standard vessel or pot sizes, typically relatively small in volume, and can only grow certain limited species of plants, especially those with shallow root systems. This results in only being able to grow limited plant types. However, it can be important to support the growth of diverse flora. For example, plant species with small leaves and high foliage density have been found to exhibit greater cooling effects. Woody plants have been found to store greater amounts of carbon, while leaf morphology has been found to affect the capture of airborne particulate matter. Further, conventional systems with vertical substrates are also economically unsustainable due to the high installation and maintenance costs of substrate and irrigation systems.

[0008] Thus, it would be desirable to have a wall system that promotes the growth of a self-watering, biodiverse plant ecology that passively cools buildings, filters pollutants from the air, and attracts diverse wildlife.SUMMARY

[0009] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0010] In certain aspects the present disclosure relates to an additively manufactured structure for supporting plant growth. The structure may comprise a wall defining an internal surface and an external surface that comprises a plurality of vessels formed at different locations. The plurality of vessels each comprises an opening that leads to a storage volume. The plurality of vessels further comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume, wherein at least a portion of the wall is additively manufactured and each of the plurality of vessels is configured to receive a growth medium and a portion of a plant. The additively manufactured structure may further comprise at least one irrigation conduit configured to receive water and in fluid communication with at least a portion of the plurality of vessels.

[0011] In one aspect, the wall further comprises an insulation layer defined by a plurality of sheets defining at least one gap therebetween. The at least one gap is configured to receive an insulating medium.

[0012] In one aspect, the at least one gap has an average width of less than or equal to about 25 mm.

[0013] In one aspect, the wall further comprises an irrigation layer comprising a porous material through which water is transported and that supplies water to the at least one irrigation conduit.

[0014] In one further aspect, the porous material is selected from the group consisting of: sand, silt, clay, and combinations thereof.

[0015] In one aspect, a region on the external surface above at least one of the respective vessels has a concave shape configured to direct water into the storage volume of the at least one respective vessel.

[0016] In one aspect, the storage volume is greater than or equal to about 500 cm3.

[0017] In one aspect, the wall is disposed on a planar substrate and defines a first end adjacent to the planar substrate and a second end opposite to the first end. A portion of the plurality of vessels has a maximum storage volume, which are disposed at the first end of the wall. A portion of the plurality of vessels has a minimum storage volume, which are disposed at the second end.

[0018] In one aspect, the wall comprises a thermoplastic polymer.

[0019] In one further aspect, the thermoplastic polymer comprises polyethylene terephthalate glycol (PETG).

[0020] In one aspect, the wall comprises a composite comprising a polymer and a reinforcement material.

[0021] In one further aspect, the reinforcement material is selected from the group consisting of: carbon fibers, wood particles, cellulose-based fibers, and combinations thereof.

[0022] In one aspect, the wall comprises a printable material selected from the group consisting of: concrete, clay, dirt, bio-materials, hempcrete, and combinations thereof.

[0023] In one aspect, the wall is disposed in a vertical orientation on a planar substrate and the plurality of vessels are vertically oriented along the external surface.

[0024] In one aspect, the wall is disposed in a vertical orientation on a planar substrate and the additively manufactured structure further comprises at least one slab that is parallel to the planar substrate and substantially horizontal to and in contact with the wall.

[0025] In one further aspect, the additively manufactured structure further comprises an irrigation channel along a region where the at least one slab is in contact with the wall. The irrigation channel may be in fluid communication with the irrigation conduit.

[0026] In other aspects, the present disclosure relates to a method of designing a pattern for additively manufacturing a structure for supporting plant growth. Such a method may comprise discretizing a surface that will define an additively manufactured structure. A rough mesh of interconnected geometry may be generated from the discretized surface. The rough mesh may be subdivided. The method may also comprise modifying the mesh to account for additive manufacturing fabrication constraints to define a pattern for additive manufacturing. The pattern defines a wall having an external surface that comprises a plurality of vessels formed at different locations. The plurality of vessels each comprises an opening that leads to a storage volume, The plurality of vessels further comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume. Each of the plurality of vessels is configured to receive a growth medium and a portion of a plant.

[0027] In one aspect, the discretizing comprises using a Voronoi algorithm and the rough mesh comprises a plurality of Voronoi cells.

[0028] In one aspect, an upper portion of each of the plurality of Voronoi cells is articulated as a concave surface and the generating the rough mesh of interconnected geometry guides tangential merging of interior layers for stability during the additive manufacturing process.

[0029] In one aspect, the subdividing the rough mesh comprises using a Catmull-Clark algorithm.

[0030] In one aspect, after the modifying the mesh, the method further comprises slicing the surface, batching the surface, and developing a toolpath for an automated printer.

[0031] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0032] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0033] FIG. 1 shows an example of an exploded view of one variation of an additively manufactured structure in the form of a wall structure for supporting growth of a plurality of plants according to certain aspects of the present disclosure.

[0034] FIG. 2 shows a sectional side view of an additively manufactured structure in the form of a wall for supporting growth of a plurality of plants on an external surface in accordance with certain aspects of the present disclosure.

[0035] FIG. 3 shows a detailed view of an intersection region between a wall and a slab in FIG. 2.

[0036] FIG. 4 shows a Robotic Pellet Extrusion (RPE) device used for a 3D printing process that can produce building parts by heating and depositing polymer layer by layer in accordance with certain aspects of the present disclosure.

[0037] FIGS. 5A-5B. FIG. 5 A shows a minimum cantilever angle from horizontal required to avoid delamination between layers when 3D printing in accordance with certain aspects of the present disclosure. FIG. 5B shows an additively manufactured wall structure, angles shallower than 45° are highlighted in the structure.

[0038] FIGS. 6A-6H show a computational design process for forming an additively manufactured wall structure according to certain aspects of the present disclosure. FIG. 6A shows an input surface. FIG. 6B shows Voronoi discretization of the surface. FIG. 6C shows a rough mesh. FIG. 6D shows a subdivided rough mesh. FIG. 6E show fabrication adjustments to the surface. FIG. 6F shows slicing of the surface. FIG. 6G shows batching of the surface. FIG. 6H shows the development of toolpathing.

[0039] FIGS. 7A-7C show designing an additively manufactured wall structure for supporting a diversity of plants with varying root structures and sizes via a computational model based on the Voronoi diagram / discretization according to certain aspects of the present disclosure. In FIG. 7A, a plurality of Voronoi nodes are defined. FIG. 7B shows a plurality of Voronoi cells developed based on the Voronoi nodes in FIG. 7A. FIG. 7C is a magnified view of a single Voronoi cell shown in FIG. 7B.

[0040] FIGS. 8A-8B. FIG. 8 A shows an example of an additively manufactured wall structure being formed via automated three-dimensional (3D) printing according to certain aspects of the present disclosure. FIG. 8B shows an example of an additively manufactured wall structure having plants disposed in vessels or pods integrally formed therein in accordance with certain aspects of the present disclosure.

[0041] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0042] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific compositions, components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0043] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,”“an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising,” is to be understood as a non-restrictive term used to describe and claim various embodiments set forth herein, in certain aspects, the term may alternatively be understood to instead be a more limiting and restrictive term, such as “consisting of’ or “consisting essentially of.” Thus, for any given embodiment reciting compositions, materials, components, elements, features, integers, operations, and / or process steps, the present disclosure also specifically includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of “consisting of,” the alternative embodiment excludes any additional compositions, materials, components, elements, features, integers, operations, and / or process steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations, and / or process steps that materially affect the basic and novel characteristics are excluded from such an embodiment, but any compositions, materials, components, elements, features, integers, operations, and / or process steps that do not materially affect the basic and novel characteristics can be included in the embodiment.

[0044] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed, unless otherwise indicated.

[0045] When a component, element, or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other component, element, or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus“directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0046] Although the terms first, second, third, etc. may be used herein to describe various steps, elements, components, regions, layers and / or sections, these steps, elements, components, regions, layers and / or sections should not be limited by these terms, unless otherwise indicated. These terms may be only used to distinguish one step, element, component, region, layer or section from another step, element, component, region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first step, element, component, region, layer or section discussed below could be termed a second step, element, component, region, layer or section without departing from the teachings of the example embodiments.

[0047] Spatially or temporally relative terms, such as “before,” “after,” “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially or temporally relative terms may be intended to encompass different orientations of the device or system in use or operation in addition to the orientation depicted in the figures.

[0048] Throughout this disclosure, the numerical values represent approximate measures or limits to ranges to encompass minor deviations from the given values and embodiments having about the value mentioned as well as those having exactly the value mentioned. Other than in the working examples provided at the end of the detailed description, all numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. For example, “about” may comprise a variation of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in certain aspects, optionally less than or equal to 0.1%.

[0049] In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range, including endpoints and sub-ranges given for the ranges.

[0050] Unless otherwise indicated, compositional amounts are on a mass basis. Further, if an amount is expressed as a weight, it may be used interchangeably with mass, but should be understood to reflect a mass of a given component.

[0051] In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of material or information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

[0052] In this application, including the definitions below, the term “module” or the term “controller” may be replaced with the term “circuit,” for example, when used in the context of a computing device or module, etc. The term “module” and / or “controller” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0053] The module and / or controller may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module and / or controller of the present disclosure may be distributed among multiple modules and / or controllers that are connected via interface circuits. For example, multiple modules and / or controllers may allow load balancing. In a further example, a server (also known as remote, or cloud) module and / or controller may accomplish some functionality on behalf of a client module and / or controller.

[0054] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules and / or controllers. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules and / or controllers. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules and / or controllers. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules and / or controllers.

[0055] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Nonlimiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0056] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described herein as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0057] The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input / outputsystem (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0058] The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

[0059] None of the elements recited in the claims are intended to be a means-plus- function element within the meaning of 35 U.S.C. § 112(f) unless an element is expressly recited using the phrase “means for,” or in the case of a method claim using the phrases “operation for” or “step for.”

[0060] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0061] In various aspects, the present disclosure contemplates additively manufactured structures for supporting plant growth, including a diverse group of distinct plant species. By way of example, the present disclosure provides a structure that includes may be a wall or a facade (referred to herein generically as a “wall”), which in certain variations, may be vertically oriented with respect to a planar substrate on which it is disposed or anchored, such as the ground, a floor, or other surface. The wall defines an internal surface and an external surface. The external surface may be exposed to air, light, and in certain aspects, an external environment that may include weather, wildlife, and the like. The external surface comprises a plurality of vessels formed at different locations along the external surface. Each vessel has at least one opening and defines a storage volume that is configured to receive a growth medium, such as soil. Each vessel is configured to hold and support a plant having a root system. In this manner, each vessel may be considered to be an integrated pot in the wall structure. The external surface may have a variety of contours or shapes, including defining the openings to each of theplurality of vessels. The plurality of vessels may have a variety of distinct shapes and sizes. For example, the plurality of vessels comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume. In this manner, a variety of different sized vessels may be formed within the exterior / external surface and may receive a variety of distinct plant species with differing leaf and / or root sizes. At least a portion of the wall is additively manufactured. The wall may be load-bearing.

[0062] The additively manufactured structure may further be self-watering and thus has at least one irrigation channel or conduit configured to receive and transport water. The irrigation conduit may be formed between the internal surface and the external surface and is in fluid communication with at least a portion of the storage volume containing the growth medium (and roots of a plant) to provide water thereto. In certain aspects, there may be one or more openings or diffusion membranes between each vessel and the irrigation conduit or channel to facilitate flow of water into the vessel. As will be described further below, the irrigation conduit may be in fluid communication with an irrigation layer formed of a porous material disposed between the external and internal surfaces of the wall that further transports water from a source of water, for example, via capillary action.

[0063] In certain aspects, the additively manufactured structure for supporting plant growth may be incorporated into a building or other structure, for example, as an envelope around an exterior of a building or structure. In this manner, the internal surface may be disposed adjacent to an interior region of a structure or building or may define an internal surface. Moreover, such a pot-like, integrative envelope system can only be materialized through additive manufacturing or 3D printing as provided by the present disclosure. Such a system combines the many functions of conventional building systems including structure, insulation, air and vapor barriers, and exterior cladding with components that support the cultivation of plant life.

[0064] Thus, in various aspects, the present disclosure provides methods of forming wall structures by using additively manufactured or three dimensionally printed (3D) printed lightweight materials. The methods provided by certain aspects of the present disclosure thus can be used to construct wall structures. In certain aspects, the methods may further involve additively manufacturing or 3D printing a wall structure, as described further herein, that may be formed of a polymer / plastic, a cementitious-based material like concrete, clay, hempcrete, earthbased, dirt, bio-material, or any printable material. In certain variations, the printable materialmay be a so-called “hempcrete,” that comprises particles derived from the hemp plant mixed with a cementitious or pozzolanic binder material, such as a calcium oxide (lime)-binder and water. The printable material may be a composite material that includes a binder and a reinforcement phase. For example, the binder may be a polymer and the reinforcement phase may be a reinforcing particle or fiber, such as carbon fibers or wood-based or cellulose- containing fibers. In certain variations, the wall structure may be formed of a transparent or semi-transparent material that permits light to pass through.

[0065] Additive manufacturing (AM) also commonly referred to as three-dimensional (3D) printing, is a process by which material is applied in an additive, layer-by-layer formation technique. In certain aspects, an additive manufacturing process may include any of the following processes, fused filament fabrication (FFF) printing, and fused granulate fabrication (FGF) printing, robotic extrusion based 3D printing, resin printing, fused deposition modeling (FDM), stereolithography (SLA), selective laser sintering (SLS), binder jetting (BJ), and the like. In these processes, a polymeric or plastic precursor or other printable material may be treated, for example, heated to flow and melt. By way of non-limiting example, laser sintering is a process involving the construction of a three-dimensional article by selectively projecting a laser beam having the desired energy onto a layer of particles of the polymer material to be sintered.

[0066] In certain aspects, large-scale 3D printing through fused filament fabrication (FFF) and / or and fused granulate fabrication (FGF) printing is capable of changing the conceptualization, design, and building of envelope and other systems by allowing for the integration of functions within a building envelope system. FFF and FGF are additive manufacturing (AM) processes in which material is heated and extruded through a nozzle to form objects layer by layer. FFF uses filaments or fibers, while FGF uses granular material as feedstock. These fabrication methods allow for the fast manufacturing of complex components. In certain aspects, the present disclosure contemplates 3D printing by using Robotic Pellet Extrusion (RPE) for creating large-scale geometrically-complex parts. In certain aspects, the additively manufactured structure is produced through a single additive manufacturing / 3DP process utilizing a single material for easy recyclability.

[0067] The 3D printing process can be paired with modeling or image data and / or parameters received from a customized model of the additively manufactured structure to be formed via the present technology. Various known polymer materials that can be 3D printed ona scale of 1 cm or greater can be used to form the additively manufactured formwork. The polymer may be a thermoplastic in certain variations. By way of non-limiting example, suitable polymers for 3D printing include polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS), ABS resin, polyesters like, polylactic acid (PLA), composites that include a polymer and a reinforcement material, such as particles or fibers, such as a woodplastic composite, and the like. In certain variations, the polymer comprises polyethylene terephthalate glycol (PETG). Polyethylene terephthalate glycol (PETG) may be used as the 3D printing feedstock, which is an affordable material that can produce durable and hard-wearing components. Other materials may include cementitious-based materials like concrete, earthbased materials, like clay, dirt, bio-materials, like hemp, or any printable material compatible with additive manufacturing. The material may be a composite that includes a polymer, either a thermoplastic or thermoset, having a reinforcing phase distributed therein, such as carbon fiberthermoplastic or wood-thermoplastic composites. In other variations, the printable material may be “hempcrete,” as discussed above.

[0068] Thermoplastic polymers are lightweight and versatile, as well as often being suitable barriers to water and air, which enable high-performance envelope solutions with energy saving benefits when printed. Material research of thermoplastics, especially bio-based plastics, is a rapidly expanding field that promises to greatly reduce the carbon footprint of the construction industry. In certain aspects, while not limiting, the present disclosure contemplates additive manufacturing / 3D printing with thermoplastics to produce the systems that include green walls that support plant growth. In one variation, the formwork may be FFF 3D printing or FGF 3D printing with an ABS-like resin or standard resin. In another variation, the formwork may be printed by robotic pellet extrusion with polymers such as PLA, PETG, and ABS pellets.

[0069] In the case of 3D printing from a printable material comprising hemp, such as hempcrete, this can serve to capture carbon dioxide and thus enhance carbon sequestration potential in building construction where building elements are formed with hempcrete. Further, by integrating diverse greenery the carbon sequestration of the structure is further enhanced. Hempcrete, a carbon-negative composite material, absorbs carbon through biogenic storage and carbonation, while plants store carbon in biomass and soil through photosynthesis. Thus, for additively manufactured structures made from printable materials, like hempcrete, a relatively waste-free construction process is contemplated, where the hempcrete structure formed is biodegradable and fully recyclable, contributing to a circular building economy.

[0070] Polymers can be manufactured into a wall structure using an additive manufacturing process, like those described above. The additively manufactured wall structure may be an assembly of multiple distinct components or segments, such that the methods may involve assembling the components or segments to define a wall assembly or system. Where necessary, adhesives, mechanical connectors, interlocks or the like may be used to secure adjacent components or segments to one another. Thus, a wall, which in certain variations may define an envelope system of a building or other structure, can promote the growth of a selfwatering, biodiverse plant ecology that passively cools buildings or structures, filters pollutants from the air, and attracts diverse wildlife. In various aspects, the present disclosure contemplates the design of the geometry of the vessels to be pot- like with different volumes for different plants with different root system requirements and the integrated vertical substrates. One nonlimiting advantage of the present disclosure is that a wall may be designed to support growth of a variety of different plants, including those with deep root systems, like trees, bushes, or crops, as well as other plants with intermediate or shallow root systems. As noted above, such a wall structure can be 3D printed with many materials, such as clay, concrete, hempcrete, and plastic. As will be appreciated, in certain variations, the wall structure may be formed, at least in part, from an additively manufactured plastic that is lightweight, as well as providing an effective barrier to water and air, for example.

[0071] In various aspects, the present disclosure contemplates development of an integrative green building envelope (IGBE) system. In certain aspects, a computational design method can be used for the seamless integration of diverse plant species into a building envelope system to passively cool buildings and urban environments. Further, the present disclosure provides tool pathing methods and control systems that improve the speed and efficiency of Robotic Pellet Extrusion (RPE) 3D printing for construction. In various aspects, the additively manufactured structure may combine the many functions of conventional building systems, including providing structure, voids for insulation, air and vapor barriers, and exterior cladding with additional features to incorporate greenery / live plants. In certain variations, an additively manufactured structure may be an envelope system that may comprise one or more of the following features: a) an exterior shell having a plurality of vessels (e.g., plant pods) that vary in size, b) a self-watering feature, such as an irrigation layer or capillary irrigation layer (CIL) containing sand or another porous medium, c) conduits or channels that connect each plant podto the CIL, and d) multiple, separate interior air layers between the external surface and the internal surface that provide thermal insulation.

[0072] FIG. 1 shows an example of an exploded view of one variation of an additively manufactured structure in the form of a wall structure 20 formed from multiple layers for supporting growth of a plurality of plants 22. The wall 20 defines an internal surface 24 and an external surface 26. The external surface 26 may form an external layer 28 comprises a plurality of vessels 30 formed at different locations. As will be appreciated by those of skill in the art, each respective layer of the wall 20 may itself comprise a plurality of layers or sheets. As shown in FIG. 1, the external surface 26 of the external layer 28 may define a contoured or non- planar / non-flat surface having peaks and valleys that help define the plurality of vessels 30. Further, the external surface 26 may have one or more regions that form an angle other than 90° (e.g., other than perpendicular) with respect to a surface or substrate 29 and thus define one or more distinct angled regions. The ability to design the external surface 26 at angles other than 90° can permit plants to inhabit the vessels in an upright orientation as they would inhabit the earth’s ground, which differs from conventional green wall systems that orient plants perpendicular to the wall surface. This feature further allows for more diverse plant habitation and higher plant life expectancy. Each of the plurality of vessels 30 comprises an opening 32 that leads to a storage volume 34. In various aspects, the plurality of vessels 30 have a variety of distinct storage volumes. By way of non-limiting example, the plurality of vessels 30 may comprise at least a first vessel 36 having a first storage volume and a second vessel 38 having a second storage volume distinct from the first storage volume. In certain aspects, the vessels may each respectively have a minimum storage volume of greater than or equal to about 500 cm3, optionally greater than or equal to about 1,000 cm3, optionally greater than or equal to about 5,000 cm3, optionally greater than or equal to about 10,000 cm3, optionally greater than or equal to about 15,000 cm3, optionally greater than or equal to about 20,000 cm3, and optionally greater than or equal to about 25,000 cm3, by way of non-limiting example. The storage volume of the vessels may have a vertical orientation, meaning that where the wall is disposed on an underlying substrate, the wall may have a substantially vertical orientation to the substrate, and the vessel may likewise have an orientation that is orthogonal (90°) to or within about ± 45° from 90° (e.g., from 45° to 135°) with respect to the underlying substrate, optionally within about ± 25° from 90° (e.g., from 65° to 115°), optionally within about ± 15° from 90° (e.g., from75° to 105°), and in certain variations, optionally within about ± 10° from 90° (e.g., from 80° to 110°) with respect to the underlying substrate.

[0073] The wall structure is formed at least in part and optionally predominantly or fully by additive manufacturing, but may also comprise components that are formed via non-additive manufacturing techniques. As noted above, each of the plurality of vessels 30 is configured to receive a growth medium 39, such as soil or dirt, in which the roots of each plant 22 may be disposed.

[0074] An intermediate irrigation layer 40 is disposed within the wall 20 between the interior surface 24 and the exterior surface 26. The intermediate irrigation layer 40 may provide self-watering capabilities e.g., to the plants 22) to the plurality of vessels 30 in the wall 20. The intermediate irrigation layer 40 may have a complementary shape to the contours of the external layer 28, including defining a lower portion 34B of the storage volume 34 for each of the plurality of vessels 30. The intermediate irrigation layer 40 may comprise an internal region 44 that may be filled with or formed from a porous material. By way of example, the porous material may be packed sand, a porous or felted material, like a porous fabric, or the like. In other aspects, the additive manufacturing process may be used to form a porous material of a polymer or other printable material that has a plurality of interconnected pores and further permits water to wick.

[0075] In certain aspects, experiments were conducted to demonstrate the irrigation layer filled with sand holds and transports water. In certain variations, the intermediate irrigation layer 40 may be formed from sheets of a hydrophobic plastic (such as PETG, which does not wick water). When a test cylinder formed of PETG was filled with sand, water wicked all the way to the top of the cylinder, and the sand was fully saturated with water. Capillary rise depends on the porosity of the infill material. For example, water has the potential to rise in sand to greater than or equal to about 1 foot to less than or equal to about 8 feet via capillary forces and wicking, to rise in silt to greater than or equal to about 12 feet to less than or equal to about 16 feet, and to rise in clay to greater than or equal to about 12 feet foot to less than or equal to about 20 feet, by way of example. Any of these materials may be suitable porous materials for filling one or more gaps defined within the intermediate irrigation layer 40 depending on the height through which the water will travel.

[0076] The lower portion 34B of the storage volume 34 may have an opening or conduit(not shown in FIG. 1 but described further below in FIGS. 2 and 3) that provides fluidcommunication with the internal region 44. Thus, the internal region 44 may itself be in fluid communication with at least one source of water to enable transport and wicking of water therethrough to each of the lower storage volume 34B / storage volume 34 for the respective storage vessels 30. In this manner, the internal region 44 may be understood to define or further include at least one irrigation conduit or channel in fluid communication with at least a portion of one of the plurality of vessels 30 that is configured to receive and transport water between the internal surface 24 and the external surface 26.

[0077] Adjacent to the intermediate irrigation layer 40 in the wall 20 may be an optional insulation layer 50 that includes sandwiched sheets or layers of material that provide thermal insulation. For example, the insulation layer 50 may have at least two layers 52 (e.g., sheets of polymer) that define a void or gap 54 therebetween. The gap 54 may receive an insulating medium, such as air. In certain variations, the insulation layer 50 may comprise a plurality of layers or sheets 52 each defining respective gaps 54 therebetween, wherein the gaps 54 are configured to receive air. Other insulating gases, such as argon or noble gases, such as krypton and / or xenon could also be disposed in the gap 54 to further increase insulating value. Additionally, other insulating materials may be disposed within the gap 54, such as insulating foams or other insulating material known in the art. For example, the insulation layer 50 may comprise greater than 2 layers or sheets 52 to greater than 30 layers or sheets 52. The close proximity of the layers creates air pockets, and air is a heat insulator. More layers, which creates more air pockets, results in a higher thermal resistance. For instance, according to the 2015 IECC, residential buildings in Climate Zones 3, 4, and 5 require a minimum insulation value of R-20 for building envelope systems. To achieve an R-20 insulation value, approximately 30 layers of PETG would be used. In one variation, four layers are sandwiched at an approximate 25 mm spacing. Using these guidelines and fabrication setup, a building envelope with 4 sandwiched layers or sheets at an approximate 25 mm spacing between respective layers was created.

[0078] In certain variations, the gaps 54 have an average width of less than or equal to about 25 mm, where having as thin of a gap as possible is advantageous. In certain variations, the gaps 54 may have an average width of greater than or equal to about 10 mm to less than or equal to about 25 mm and optionally of greater than or equal to about 10 mm to less than or equal to about 15 mm. The insulating layer 50 may be disposed adjacent to an exterior surface ofa building where the wall structure 20 defines a building envelope and thus may provide insulating properties to the building.

[0079] In certain aspects, such an additively manufactured multilayer wall may define a building envelope with an exterior layer comprising vertically oriented plant vessels / pods that can vary in size and shape to accommodate a diversity of root sizes, therefore expanding the plant sizes and species that can grow. In certain aspects, vessels having the greatest size and storage volume are located near the bottom of the wall and those of the smallest size and storage volume are located near the top of the wall. A gradient of different vessel sizes may thus be formed along the height of the wall. In this manner, such a design can give clearance to various plants for vertical growth as well as providing sufficient access to sunlight and ambient conditions, like precipitation. These vessels (along the exterior layer) are connected to at least one layer that contains a growing substrate as a medium for growth. These connections are enabled by channels connecting vertical plant vessels to the substrates layer. In an alternative version, there may be multiple layers of the growing substrates that are interconnected to one another. Meaning that there may be more than one sublayer. Further, an irrigation system may be integrated to either the first sublayer or the other layers for distribution of water. This can enable self- watering capability and in certain aspects, may eliminate the need for drip watering / irrigation systems that can be costly to maintain and prone to failure. In other variations, the interior layers also entail multiple, separate air layers for thermal insulation. In certain variations, multiple layers of air gaps may be incorporated into the wall structure to provide additional thermal insulation.

[0080] In certain variations, an additively manufactured structure may be a wall that forms an envelope system for a building or structure that may comprise one or more of the following features: a) an exterior shell having a plurality of vessels (e.g., plant pods) that vary in size, b) a self-watering feature, such as an irrigation layer or capillary irrigation layer (CIL) containing sand or another porous medium, c) conduits or channels configured to receive and transport water to connect each plant vessel / pod to the CIL, and d) multiple, separate interior air layers between the external surface and the internal surface that provide thermal insulation.

[0081] FIG. 2 shows a side view of an additively manufactured structure 60 in the form of a wall for supporting growth of a plurality of plants 62 on an external surface 64. The additively manufactured structure 60 also defines an internal surface 66. The additively manufactured structure 60 includes a wall 70 with a generally vertical orientation to the groundor surface beneath and a plurality of horizontal slabs 72 cantilevered from the wall 70 that are parallel to the ground or surface. As will be appreciated by those of skill in the art, the slabs 72 may be formed of non- additively manufacturing processes, such as casting, and may form floors within a building.

[0082] FIG. 3 shows a detailed view of an intersection region between the wall 70 and slab 72 in FIG. 2. The external surface 64 defined by the wall 70 is contoured and defines at least one vessel 80. The vessel 80 comprises an opening 82 that is connected to a storage volume 84. The storage volume 84 of the vessel is configured to receive a growth medium 86, such as soil or dirt, in which the roots 88 of each plant 62 may be disposed. The storage volume 84 is connected to a conduit or channel 90 configured to transport water, including from a capillary irrigation layer 92 disposed behind the external surface 64. As best seen in FIG. 3, the water channel 90 may be formed along each floor of the building, just above where the slab 72 connects with the wall 30, thus providing a source of water in the channel 90 along the perimeter of the wall 60 to supply water at a lower end / base of the capillary irrigation layer 92 in that segment. This water channel 90 can provide the plants 62 with water that has been collected from rainwater in the external environment or may be automatically supplied from a source of water, such as the building’s water supply system. As described in the context of FIG. 1, the capillary irrigation layer 92 may comprise a porous material to help transport water via wicking or capillary action up through the vertical height of the wall 60 (or up the vertical height in a given segment of the wall 60). The interior layers, including the capillary irrigation layer 92, may include one or more openings or voids 94 that permit air, light, and optionally water, to pass through. Such voids 94 may permit light and ventilation to permeate into the capillary irrigation layer 92 at each vessel / plant pod. While in summer these voids 94 would be shaded by foliage, winter sun could passively heat buildings in temperate climate zones if perennial plants are used.

[0083] As shown, the wall 60 further includes an optional insulation layer 100 that defines the internal surface 66. For example, the insulation layer 100 may have at least two layers 102 (e.g., sheets of polymer) that define one or more voids or gaps 104 therebetween. The gap 104 may receive an insulating medium, such as air. Other insulating gases, such as argon or noble gases, such as krypton and / or xenon could also be disposed in the gap 104 to further increase insulating value. Additionally, other insulating materials may be disposed within the gap 104, such as insulating foams or other insulating material known in the art. The closeproximity of the sheets / layers 102 creates air pockets. As shown, the layers / sheets of polymer 102 may have intermittent contact or fused points along a length of the wall to create isolated pockets of air and that may also further stabilize the structure. As noted above, the openings or voids 94 may permit air flow into the insulation layer 100. In certain variations, the gaps 104 may have an average width of greater than or equal to about 10 mm to less than or equal to about 15 mm. The insulating layer 100 may form an internal surface 66 of a building as shown or may be disposed on and thus may form an envelope around the existing building structure. The wall structure 60 thus may define a building envelope and provide insulating properties to the building. Notably, this is a design advantage, because conventional systems are installed separately from the main building envelope, resulting in excessive material waste, labor, and high maintenance. Whereas the present technology may form an integrated all-in-one multilayer envelope system using large scale 3D printing.

[0084] Such an exterior cladding is thus designed in certain aspects for plants to inhabit the vessels / pods in an upright orientation as they would naturally grow and inhabit the ground. The vessel size / volume is parametrically adjustable based on the dimensions of a mature plant and its type of root system. In this manner, each computationally generated vessel / pod may be unique in form and size / volume. By incorporating the ability to support and grow plants of differing types and sizes, the additively manufactured structure provides a diverse and varied green envelope. This variation may be achieved through computational design, as described further herein. Each computationally generated vessel / pod may be unique in its form (e.g., shape) and storage volume, and this myriad variation fosters a great diversity of different plant species. In this variation, the vessels are largest in scale / volume at a base of the envelope near the ground or surface / slab and decrease in size as the facade height increases (higher in vertical elevation). This design feature ensures clearance to plants for vertical growth. Further, the wall itself may have a surface that defines an angle with respect to a vertical or orthogonal position to the ground / surface, which can further ensure vertical clearance for the plants as they grow.

[0085] The plant vessels / pods may be connected by interior channels to the capillary irrigation layer (CIL), which optionally contains a substrate or other porous material to transport water upwards through capillary action. These channels act as a pathway for water for uptake into the plant roots. In one variation, sand was chosen as the porous material for a capillary substrate given its relatively large particle size. At each building floor / slab, a perimeter water channel or conduit can supply water at the base of the CIL. As discussed above, this waterchannel can provide plants with water that has been collected from rainwater or may be supplied from the building’s water system. The irrigation (CIL) layer may transport rainwater downwards from saturated plant pods to the water channel by gravity during a rain event. Voids for light and ventilation may perforate the irrigation (CIL) layer at each plant vessel / pod.

[0086] Achieving holistic integration of various additively manufactured structures, such as building envelope functions, results in geometric complexity that can only be produced through additive manufacturing / 3D printing. In certain variations, the present disclosure provides a computational model based on Voronoi logic developed to partition the exterior layer of the wall structure / envelope optimally based on the plant sizes and to create the channels that connect each plant vessel to the capillary irrigation layer (CIL).

[0087] Further, production of complex topologies via robotic extrusion additive manufacturing entails toolpath strategies that account for sharp overhangs, minimizing or eliminating support material, and optimizing the route between discontinuous polylines in a single layer as well as between each layer. The toolpath is defined by contour curves that outline the designed form. A complex geometry with interior porosity and voids as in certain variations of the present disclosure entails outlines of the form in the exterior and interior of the designed part. Therefore, contouring the overall mesh geometry to generate 3D printing data results in sets of open and closed polylines (with connected start and endpoints) per layer. These polylines are the source for the toolpath generation process and they contain all of the information needed to generate tool paths.

[0088] Through prototyping, the toolpath strategies, fabrication settings, computational model and the geometry of the components are adjusted and refined. The developed additively manufactured structures / envelope system, computational and fabrication methods in this disclosure are generalizable and scalable.

[0089] In certain variations, as will be described further below, a computational design algorithm allows for modification of the additively manufactured structures / envelope design adaptable to various designs and environments. Generally, the methods may include designing a pattern for additively manufacturing a structure for supporting plant growth. The method may comprise discretizing a surface that will define the additively manufactured structure. Next, a rough mesh of interconnected geometry is formed from the discretized surface. The rough mesh may be further subdivided. Then, the mesh may be further modified to account for additive manufacturing fabrication constraints to define a pattern for additive manufacturing. The patterndefines a wall having an external surface that comprises a plurality of vessels formed at different locations, like those described above. The plurality of vessels each comprises an opening that leads to a storage volume. The plurality of vessels further comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume. Each of the plurality of vessels is configured to receive a growth medium and a portion of a plant.

[0090] In certain aspects, the discretizing comprises using a Voronoi algorithm and the rough mesh comprises a plurality of Voronoi cells. Additional information about the Voronoi algorithm may be found in the attached Appendix A, the relevant portions of which are incorporated herein by reference. In other aspects, the upper portions of the plurality of Voronoi cells are articulated as concave surfaces. Further, the generating the rough mesh of interconnected geometry may also guide tangential merging of interior air layers (for example, creating joints between gaps in sheets in the insulation layer) to add stability during the additive manufacturing process. The subdividing of the rough mesh may comprise using a Catmull-Clark algorithm. Additional information about the Catmull-Clark algorithm may be found in the attached Appendix B, the relevant portions of which are incorporated herein by reference. After modifying the mesh, the methods may also further comprise slicing the surface, batching the surface, and developing a toolpath for 3D printing. Notably, subdividing a surface, for example by slicing and batching, can create a curved surface or what appears to be a smoother surface. Repeated subdivisions of surfaces result in a less jagged appearance.

[0091] In certain variations, the computational design stages may include: 1) inputting any freeform surface, 2) discretizing the freeform surface via a pattern, such as with a Voronoi algorithm, 3) generating a rough mesh of interconnected geometry, for example, from the Voronoi cells, 4) subdividing the rough mesh with the Catmull-Clark algorithm, and 5) modifying the mesh for fabrication constraints. In this manner, such an additively manufactured structure / envelope system is specifically tailored to additive manufacturing / 3D printing.

[0092] Such a computational design may be conducted on a special purpose computing device with one or more memory circuits and the pattern may be executed from code programmed into the memory circuits / computing device. The computing device may thus operate one or more controllers or modules for an automated additive manufacturing printing device, such as a robotic pellet extrusion (RPE) printing device, as understood by those of skill in the art and described further herein.

[0093] Examples

[0094] A construction scale Robotic Pellet Extrusion (RPE) device 110 is shown in FIG. 4 and is used for a 3D printing process that can produce building parts by heating and depositing polymer layer by layer, using a pellet extruder conveyed by an industrial robotic arm. The RPE device 110 includes a translatable 3D printing device 112 that includes a robotic arm 114 (such as a KR120 available from Kuka AG) disposed on a conveyor track 120. A hopper 122 associated with the 3D printing device 112 receives feedstock for 3D printing, such as polymer pellets. The hopper 122 is connected to a feedstock delivery hose 124 that delivers the feedstock for 3D printing to a 3D printer head 126 disposed on the robotic arm 114. The 3D printer head 126 includes a pellet extruder 128 and a digitally controlled cooling component 130. While not shown, the system may include other cooling components, such as fans and the like. The 3D printer head 126 may deposit printed material onto a substrate, such as a heated bed 132, adjacent to the conveyor track 120. A controller or control station 134 may be connected to a computing device 136 used to program and control the 3D printer 112. In this manner, an additively manufactured structure 140 may be formed by extruding, melting, printing, and cooling the feedstock on the heated bed 132.

[0095] In this example, fabrication set up includes the industrial robotic arm 114 with payload of 120 Kg and a 2.5 m maximum reach, accommodated with an inhouse built pellet extruder 128, automatic pellet feeding system 122, 124, digitally controlled cooling systems 130, and a heated bed 132 having dimensions of about 1236 mm x 762 mm.

[0096] As will be appreciated by those of skill in the art, the RPE process comes with certain challenges and limitations including: a) limited cantilevers without the use of support material, b) horizontal printing without support material, c) adhesion between the first printed layer and the heated bed, d) layer adhesion and print stability as the height of the print increases, and e) unintended material deposition during traversal of the extruder. In this example, these challenges were addressed respectively through computational modeling and fabrication setups that: a) integrate parameters to limit cantilever angles; b) provide cooling and air flow at moments of unsupported horizontal printing; c) generate a dense raft beneath the first printed layer and increase extrusion rates when printing the first few layers to facilitate adhesion; d) tangentially merging internal layers to add stability; and e) optimizing traversal path while refining traversal settings. At shallow cantilevers and moments of unsupported horizontalprinting, manual techniques were also employed to ensure the success of the print, such as manual reduction of print speed and addition of external support.

[0097] In this example, the generation of toolpaths for FFF processes utilizes polyline geometries. Through planar slicing of a 3D geometry, each slice, or layer, contains many 2D open and closed polyline geometries. In this example, toolpaths are generated at 1 mm increments. The term “islands” refers to collections of closed polylines in one layer. The complex topology of the additively manufactured structure / building envelope entails continuous internal cavities and passages for functional integration, which produce islands through planar slicing. Islands each entail starting and stopping the print with lead in and lead out motion parameters that affect fabrication time. To reduce the number of islands and shorten fabrication time with toolpath continuity, alternating edges of the interior air layers were enclosed prior to slicing.

[0098] As islands increase in size in successive layers, they merge with each other. At the moment of merging, each island toolpath must intersect tangentially. This is considered a lamination layer. A perfect tangent in the lamination layer provides water tightness and stability of the 3D printed part. A successful build-up of the printed part is determined by the cantilevering angle of islands in successive layers, as well as the amount of cooling delivered by the fan. Minimal unsupported distance between islands and high cooling decreases the chance of drooping in the lamination layer. Through prototyping, as shown in FIG. 5A, it was found that a minimum cantilever angle of 45° from horizontal was required to avoid delamination between layers. This data was integrated in the computational model to guide the geometric design of the enclosure system, as shown in FIG. 5B, where shallower angles than 45° are highlighted in the structure.

[0099] Full adhesion of the printed structure geometry 140 to the heated bed 132 in FIG. 4 during the fabrication process helps ensure success of the printing process. As the height of the printed structure increases, the vibration of the robotic arm 114 increases, which can lead to shaking of the printed structure 140. Proper bed adhesion and the design of tangentially merging inner air layers ensure the stability of the printed structure as it grows in height. The temperature of the heated bed 132 and surface area of the first several print layers contribute to the print adhesion. To prevent detachment of the printed part from the heated bed 132 throughout the printing process, in this example, a temperature of the heated bed was set to 105°C and a zig-zag patterned raft with 4 mm thickness was introduced at the base of the prototype geometry.

[0100] A computation design / computational methodology for forming the additively manufactured wall structure may involve the generation of design geometry and fabrication data, as discussed herein in the context of FIGS. 6A-6H. As discussed above, in certain variations, computational design stages for forming a multilayer wall 150 are shown in order and may include: 1) inputting a given freeform surface 152 for the wall 150 as shown in FIG. 6A, where arrows show a width dimension, for example, 1,000 mm and a height dimension, for example, about 2,100 mm, 2) discretizing the surface 152 via a Voronoi algorithm to generate Voronoi cells 154 as shown in FIG. 6B, 3) generating a rough mesh 156 of interconnected geometry from Voronoi cells 154 as shown in FIG. 6C, 4) subdividing the rough mesh 156, for example, with the Catmull-Clark algorithm to form a subdivided mesh 156A as shown in FIG. 6D, 5) modifying the subdivided mesh 156A for fabrication constraints including: a) a raft 158 for bed adhesion and b) layer or side enclosure 160 for toolpath continuity as shown in FIG. 6E, 6) slicing the subdivided mesh 156A to generate contours 162 as shown in FIG. 6F, 7) batching the contours 162 as shown in FIG. 6G, and 8) generating toolpaths 164 with printing parameters per batch as shown in FIG. 6H.

[0101] To incorporate a diversity of plants with varying root structures and sizes, a computational model based on the Voronoi diagram / discretization is developed as shown in FIGS. 7A-7C. In FIG. 7A, a plurality of nodes 166 are defined on a surface 168 of a wall structure model 170. This model 170 allows parametric partitioning of any given exterior surface into regions close to each of a given set of plants. As shown in FIGS. 7B-7C, for each proposed plant, a corresponding region 172 or Voronoi cell is defined on the surface 168, so that a plurality of Voronoi cells 172 is defined. The bottom portions of these cells 172 form the vessels (e.g., plant pods) and their connection to the irrigation layer (e.g., capillary irrigation layer, not shown) behind the external surface and layer, resulting in one continuous mesh. As best seen in FIG. 7C, an upper or top portion 174 of the Voronoi cells 172 are articulated as concave surfaces that are designed to direct precipitation (e.g., water) to a storage volume 174 in which the roots of plants will be disposed, as shown by the arrows. Voronoi partitioning also guides the tangential merging of interior air layers for stability during printing.

[0102] To integrate thermal performance, the developed computational model generates interior layers that can be controlled parametrically that can define an insulation layer. The overall thickness of the envelope, spacing between layers, and tangential merging of layers can be computationally adjusted in response to design and fabrication considerations such as thermalresistance, daylighting, material efficiency, and print speed. The reduction in spacing between layers as they merge allows for variation in translucency and patterning across the facade. This merging between layers also provides structural stability during the fabrication process so that a full height additively manufactured structure can be produced without the need for infill support, reducing the overall weight of the 3D printed part, material used, and printing time.

[0103] In one variation, the computational design of the envelope was refined multiple times in response to a number of fabrication constraints after prototyping. For example, the geometries of vessel rims (e.g., plant pod rims) were angled downward at a sufficiently steep angle to allow for successive layer deposition based on the observed minimum cantilever angle. Vessel and channel geometries were steepened and elongated as well. Interior voids were shaped and rescaled to limit the unsupported distance at unsupported moments.

[0104] In certain aspects, tool path generation is developed as an automated process. The complex and interconnected geometry of the additively manufactured wall structure entails islands that require turning on and off the extruder as well as the unique naming of separate toolpaths on each layer. An algorithm was developed to automatically name these islands based on K-Nearest Neighbor (KNN) to optimize the travel path of the robot, and therefore minimize the time needed to fabricate a piece via additive manufacturing.

[0105] Besides toolpath generation, print settings for material deposition were developed and refined through prototyping. These print settings include: lead-in and lead-out path and parameters, material extrusion rate, robotic toolhead velocity, traversal velocity, extruder activation and deactivation locations, and cooling activation and deactivation locations, reflected in Table 1. Lead in and lead out settings were refined to minimize excess material deposition at the end of toolpaths and during traversal, while also balancing the reduction in speed necessary for such quality control measures. The introduction of helical lead ins / outs resulted in neat and watertight seams with high resolution. Print speed, extrusion rate, and cooling settings were refined as well.Table 1. RPE full-scale prototype fabrication settings.

[0106] A series of wall prototypes at multiple scales were printed to investigate the relation between the geometric properties of the additively manufactured wall structure envelope design and the fabrication settings, constraints, and criteria, as shown in FIGS. 8 A and 8B. FIG. 8A shows a multilayered wall structure having a contoured surface with a plurality of vessels to receive plants being formed via 3D printing with a Robotic Pellet Extrusion (RPE). FIG. 8B shows a formed additively manufactured wall structure where the plurality of vessels have a growth medium and plant disposed therein. Based on the prototypes formed across these scales, strategies for computational design and fabrication methods were refined. Table 2. Fabrication results.

[0107] The resulting 1:1 scale prototype (1018 mm x 678 mm x 1022 mm) showcases the advantages of FFF 3D printing thermoplastic for integrative and green building envelopes. The 3D printed building envelope prototype entails a highly complex topology with an array of unique plant vessels / pods that form interconnected channels and multiple interior layers. Theprototype weighs 58.9 kg and was 3D printed over the course of 64 hours, as shown in Table 2. The prototype plant vessels / pods were filled with plants of various species and sizes to demonstrate the utility and design of the green building envelope system. The planted envelope attracted pollinators. Moreover, layers of translucent polymer shaded by plants and growing substrate allow diffuse light to permeate the envelope prototype.

[0108] The size of vessels / plant pods can vary in several domains. In this example, the largest vessel / pod (174 mm x 181 mm x 488 mm) measured a volume of 7,845 cm3and the smallest vessel (70 mm x 67 mm x 29 5mm) measured a volume of 710 cm3. The computational design algorithm developed by certain aspects of the present disclosure is versatile and can generate and customize an additively manufactured wall structure / envelope system with different vessel or pod sizes. The user will need to input a freeform surface and identify the largest and smallest pod sizes needed and the algorithm will automatically generate the number of vessels with those dimensions on any given freeform surface.

[0109] Portions of the envelope shallower than the 45-degree angle minimum managed to print effectively, though minor delamination and drooping occurred at these moments. Human robot collaboration to support the cantilevered areas was the cheapest and most time efficient method to ensure the success of shallow cantilevers without 3D printing any support. It is contemplated that shallow cantilever limitations could be resolved through geometric adjustments in the computational model.

[0110] Design and development of a robust raft helped ensure the stability of the prototype throughout the 3D printing process. The 4-layer thick raft effectively secured the print to the heated bed throughout the entire printing time. The interconnected geometry and merging layers also provided adequate stability and support for a successful print. No additional support was required. The toolpath was refined to allow excess extrusion material to collect outside the printed geometry rather than along the toolpath. Consequently, manual care during the fabrication process was no longer required.

[0111] The limits of both the angle and the height were pushed while prototyping. These experiments established rulesets for the design geometries, which were incorporated into the computational design and the toolpath as well.

[0112] The present disclosure contemplates use of Robotic Pellet Extrusion of a thermoplastic polymer, which is a viable and promising method for the 3D printing of additively manufactured structures for use in integrative green building envelopes that can remediate UHIeffects and atmospheric pollution in urban areas while supporting an increase in biodiversity, thereby contributing to the development of resilient urban ecologies. The fabrication and computational methods developed through the present teachings resulted in the successful 3D print of a geometrically-complex full-scale prototype with multiple layers that can be applied and adapted to many different architectural typologies and locations.

[0113] It is further contemplated that fabrication systems can be optimized to allow for the high speed production of thinner plastic layers, provide performance testing for passive cooling, thermal resistance values, daylighting metrics, and longevity, performance testing of the capillary irrigation layer and optimization of a self-watering irrigation system, studying specific plant species and their unique requirements to be integrated for passive cooling benefits, incorporating circular materials, like circular thermoplastic and bioplastic building envelopes, and bioplastic 3D printing and its performance in the context of building envelope fabrication.

[0114] Thus, the present disclosure contemplates large-scale 3D printing with robotic pellet extrusion to produce a novel integrative green building envelope system. The envelope system fosters the growth of a self-watering, diverse plant ecology to passively cool buildings, filter contaminants from polluted air, and attract diverse forms of wildlife. The fabrication and computational methods provided in the present disclosure provide successful 3D printing of a geometrically-complex full-scale additively manufactured structure with multiple layers that can be adapted and applied to many different architectural typologies and locations.

[0115] In this manner, the structures and methods provided by the present disclosure provide the capability to improve building performance and human health by developing a green building envelope system that provides: passive cooling, shade, insulation, air filtration, stormwater management, and support of urban biodiversity. Further, the present technology can promote environmental justice by ensuring equitable access to affordable green buildings and healthy living spaces. For example, such additively manufactured walls can be used for vertical farms, which enable community engagement and empowerment, access to locally sourced, healthy produce, and resilient urban food systems. Further, depending on the printable material selected, such structures can serve to sequester carbon dioxide and reduce waste.

[0116] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selectedembodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. An additively manufactured structure for supporting plant growth, the structure comprising: a wall defining an internal surface and an external surface that comprises a plurality of vessels formed at different locations, wherein the plurality of vessels each comprises an opening that leads to a storage volume, wherein the plurality of vessels further comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume, wherein at least a portion of the wall is additively manufactured and each of the plurality of vessels is configured to receive a growth medium and a portion of a plant; and at least one irrigation conduit configured to receive water and in fluid communication with at least a portion of the plurality of vessels.

2. The additively manufactured structure of claim 1, the wall further comprising an insulation layer defined by a plurality of sheets defining at least one gap therebetween, wherein the at least one gap is configured to receive an insulating medium.

3. The additively manufactured structure of claim 2, wherein the at least one gap has an average width of less than or equal to about 25 mm.

4. The additively manufactured structure of claim 1, wherein the wall further comprises an irrigation layer comprising a porous material through which water is transported and that supplies water to the at least one irrigation conduit.

5. The additively manufactured structure of claim 4, wherein the porous material is selected from the group consisting of: sand, silt, clay, and combinations thereof.

6. The additively manufactured structure of claim 1, wherein a region on the external surface above at least one of the respective vessels has a concave shape configured to direct water into the storage volume of the at least one respective vessel.

7. The additively manufactured structure of claim 1, wherein the storage volume is greater than or equal to about 500 cm3.

8. The additively manufactured structure of claim 1, wherein the wall is disposed on a planar substrate and defines a first end adjacent to the planar substrate and a second end opposite to the first end, wherein a portion of the plurality of vessels with a maximum storagevolume are disposed at the first end of the wall and a portion of the plurality of vessels with a minimum storage volume are disposed at the second end.

9. The additively manufactured structure of claim 1, wherein the wall comprises a thermoplastic polymer.

10. The additively manufactured structure of claim 9, wherein the thermoplastic polymer comprises polyethylene terephthalate glycol (PETG).

11. The additively manufactured structure of claim 1, wherein the wall comprises a composite comprising a polymer and a reinforcement material.

12. The additively manufactured structure of claim 11, wherein the reinforcement material is selected from the group consisting of: carbon fibers, wood particles, cellulose-based fibers, and combinations thereof.

13. The additively manufactured structure of claim 1, wherein the wall comprises a printable material selected from the group consisting of: concrete, clay, dirt, bio-materials, hempcrete, and combinations thereof.

14. The additively manufactured structure of claim 1, wherein the wall is disposed in a vertical orientation on a planar substrate and the plurality of vessels are vertically oriented along the external surface.

15. The additively manufactured structure of claim 1, wherein the wall is disposed in a vertical orientation on a planar substrate and the additively manufactured structure further comprises at least one slab that is parallel to the planar substrate and substantially horizontal to and in contact with the wall.

16. The additively manufactured structure of claim 15, further comprising an irrigation channel along a region where the at least one slab is in contact with the wall.

17. A method of designing a pattern for additively manufacturing a structure for supporting plant growth, the method comprising: discretizing a surface that will define an additively manufactured structure; generating a rough mesh of interconnected geometry from the discretized surface; subdividing the rough mesh; and modifying the mesh to account for additive manufacturing fabrication constraints to define a pattern for additive manufacturing that defines a wall having an external surface that comprises a plurality of vessels formed at different locations, wherein the plurality of vessels each comprises an opening that leads to a storage volume, wherein the plurality of vesselsfurther comprises at least a first vessel having a first storage volume and a second vessel having a second storage volume distinct from the first storage volume, wherein each of the plurality of vessels is configured to receive a growth medium and a portion of a plant.

18. The method of claim 17, wherein the discretizing comprises using a Voronoi algorithm and the rough mesh comprises a plurality of Voronoi cells.

19. The method of claim 18, wherein an upper portion of each of the plurality of Voronoi cells is articulated as a concave surface and the generating the rough mesh of interconnected geometry guides tangential merging of interior layers for stability during the additive manufacturing process.

20. The method of claim 17, wherein the subdividing the rough mesh comprises using a Catmull-Clark algorithm.

21. The method of claim 17, further comprising after the modifying the mesh, slicing the surface, batching the surface, and developing a toolpath for an automated printer.

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