Method for producing additive manufactured object with heterogeneous properties

Abstract

Methods for manufacturing an object are provided herein. In some embodiments, the method includes receiving a digital data set representing an object, and applying energy to a curable material based on the digital data set to form the object. The object (400) may include at least two object portions (402, 404) formed from a curable material using different energy application parameters. The method may also include removing the residual curable material from the object (400). Different amounts of residual curable material may be removed from each of the at least two instrument portions (402, 404). After removing the residual curable material, each of the at least two object portions may have a different material property.

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit and priority of U.S. Provisional Patent Application Serial No. 63 / 371,435, filed on August 15, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0002] The present technology generally relates to manufacturing processes, and more particularly to methods for producing additive - manufactured objects having heterogeneous properties. Background Art

[0003] Additive manufacturing encompasses a variety of techniques involving the construction of three - dimensional objects from multiple layers of material. Typically, an additive - manufactured object formed from a single type of material exhibits uniform properties throughout the object. However, in some applications, it may be desirable for an additive - manufactured object to have heterogeneous properties such that different parts of the object exhibit different properties. Conventional additive - manufacturing techniques for producing objects with heterogeneous properties typically involve forming the object from multiple materials and / or using hybrid printing processes. However, such techniques generally require more complex equipment and specialized reagents and may therefore not be suitable for producing large quantities of additive - manufactured objects in a time - efficient and economical manner. Brief Description of the Drawings

[0004] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, the emphasis is on clearly illustrating the principles of the present disclosure.

[0005] Figure 1 is a flowchart providing an overview of a method for producing and post - processing an additive - manufactured object according to an embodiment of the present technology.

[0006] Figure 2 shows a partial schematic view of a system configured for additive manufacturing according to an embodiment of the present technology.

[0007] Figure 3 is a flowchart showing a method for producing an object having heterogeneous properties according to an embodiment of the present technology.

[0008] Figure 4A is a schematic view of an object including a first object portion and a second object portion according to an embodiment of the present technology.

[0009] Figure 4B is from Figure 4A schematic view of removing material from the object.

[0010] Figure 4C is Figure 4A schematic view of the object after material removal.

[0011] Figure 4DIs a schematic diagram of an object including a third object part having a gradient property according to an embodiment of the present technology.

[0012] Figure 5 Is a flowchart showing another method for generating an object having a heterogeneous property according to an embodiment of the present technology.

[0013] Figure 6A Is a partial schematic diagram of a system for generating an object having a heterogeneous property according to an embodiment of the present technology.

[0014] Figure 6B Is a partial schematic diagram of another system 600b for generating an object having a heterogeneous property according to an embodiment of the present technology.

[0015] Figure 7A Is a perspective view of an orthodontic appliance having a heterogeneous property according to an embodiment of the present technology.

[0016] Figure 7B Is a perspective view of a palatal expander having a heterogeneous property according to an embodiment of the present technology.

[0017] Figure 7C Is a perspective view of an attachment placement device having a heterogeneous property according to an embodiment of the present technology.

[0018] Figure 8A Shows a representative example of a tooth repositioning appliance configured according to an embodiment of the present technology.

[0019] Figure 8B Shows a tooth repositioning system including multiple appliances according to an embodiment of the present technology.

[0020] Figure 8C Shows an orthodontic treatment method using multiple appliances according to an embodiment of the present technology.

[0021] Figure 9 Shows a method for designing an orthodontic appliance according to an embodiment of the present technology.

[0022] Figure 10 Shows a method for digital planning of orthodontic treatment and / or designing or manufacturing appliances according to an embodiment of the present technology.

[0023] Figure 11 Is a graph showing the mechanical test results of samples manufactured using different energy doses.

[0024] Figure 12A Is a side view of a multi-layer sample.

[0025] Figure 12B Shows an experimental setup for a three-point bending test.

[0026] Figure 12C is a graph showing the mechanical test results of a multi-layer sample compared to a single-layer sample. DETAILED DESCRIPTION

[0027] The present technology relates to methods for producing additive manufacturing objects having heterogeneous properties. In some embodiments, for example, a method for producing an object includes receiving a digital data set representing the object and applying energy to a curable material based on the digital data set to form the object. The object can include at least two object portions that are formed from the curable material using different energy application parameters. For example, a first object portion can be formed using a first energy intensity and / or dose, and a second object portion can be formed using a different second energy intensity and / or dose. The different energy application parameters can be used to control the amount of residual curable material (e.g., residual monomers and / or oligomers) removed from each object portion in a subsequent material removal process (e.g., via solvent, heat, and / or vacuum). For example, the different energy application parameters can selectively change the local properties of each object portion, such as the degree of curing (e.g., degree of polymerization and / or degree of double bond conversion (DBC)) of the curable material within the object portion. The local properties of each object portion can affect the amount of residual curable material removed from the object portion (e.g., more material is removed from an object portion with a lower degree of curing), which in turn can affect the local material properties of the object portion.

[0028] As another example, a method for producing an object can include receiving an additive manufacturing object that includes a plurality of object portions. The method can also include using at least one sensor (e.g., an imaging device) to identify the location of a subset of the object portions on the object. Subsequently, energy can be applied to the identified subset of the object portions to selectively modify the material properties of the subset. For example, in some embodiments, the object is initially in a partially cured "green" state, and the applied energy can selectively change the degree of curing of the subset of the object portions while substantially not affecting the degree of curing of the remaining object portions.

[0029] The embodiments described herein can provide many advantages. For example, the techniques described herein can provide precise spatial control over the material properties of an object, which in turn can improve the functionality of the object. For example, in an embodiment where the object is an orthodontic device configured to apply a force to a patient's tooth, the force distribution generated by the device can be adjusted by controlling the local material properties of the device, thereby allowing for highly targeted forces for improved treatment efficacy. As another example, heterogeneous properties can be used to facilitate the separation of the object from sacrificial components (e.g., supports) that are not intended for use in the final product, thereby improving manufacturability and reducing the likelihood of inadvertent damage to the object. Additionally, the techniques described herein allow for the additive manufacturing of objects with heterogeneous properties from less material or even a single material type, thereby enhancing scalability and reducing the complexity and / or cost of such manufacturing processes.

[0030] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout the several views, and in which example embodiments are shown. However, the embodiments of the claims may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.

[0031] As used herein, the terms "vertical", "lateral", "upper", and "lower" may refer to the relative directions or positions of features of the embodiments disclosed herein in view of the orientation shown in the figures. For example, "upper" or "uppermost" may refer to a feature that is positioned closer to the top of the page than another feature. However, these terms should be construed broadly to include embodiments having other orientations, such as inverted or tilted orientations, where top / bottom, above / below, over / under, up / down, and left / right may be interchanged depending on the orientation.

[0032] The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed technology. Embodiments under any one heading may be used in combination with embodiments under any other heading. I. Overview of Additive Manufacturing Techniques

[0033] Figure 1 is a flowchart providing an overall overview of method 100 for producing and post-processing an additive manufacturing object according to an embodiment of the present technology. Method 100 can be used to produce many different types of additive manufacturing objects, such as orthodontic devices (e.g., aligners, palatal expanders, retainers, attachments).

[0034] Method 100 begins at block 102 with the production of an object using an additive manufacturing process. The additive manufacturing process may implement any suitable technique known to those skilled in the art. Additive manufacturing (also referred to herein as "3D printing") includes a variety of techniques for producing three-dimensional objects directly from a digital model through an additive process. In some embodiments, additive manufacturing includes depositing a precursor material (e.g., a polymer resin) onto a build platform. The precursor material may be cured, polymerized, melted, sintered, fused, and / or otherwise solidified to form a portion of the object and / or combine the portion with a previously formed portion of the object. In some embodiments, the additive manufacturing techniques provided herein build the object geometry in a layer-by-layer manner, where successive layers are formed in discrete build steps. Alternatively or in combination, the additive manufacturing techniques described herein may allow for the continuous build of the object geometry.

[0035] As described in more detail below, in some embodiments, the process of block 102 involves forming the object by applying energy to the precursor material, where different energy application parameters are used for different portions of the object. For example, a series of different energy intensities, doses, wavelengths, etc. may be used to form different portions of the object. The energy application parameters may be used to "program" the amount of residual precursor material removed from the object in a subsequent material removal process at block 104, as further discussed below. However, in other embodiments, the same energy application parameters may be used to form the entire object.

[0036] The methods described herein are applicable for use with a variety of additive manufacturing techniques. Examples of additive manufacturing techniques include, but are not limited to, the following: (1) Vat photopolymerization, where an object is built from a vat of liquid photopolymer resin, including techniques such as stereolithography (SLA), digital light processing (DLP), continuous liquid interface production (CLIP), two-photon induced photopolymerization (TPIP), and volumetric additive manufacturing; (2) Material jetting, where materials are jetted onto a build platform using a continuous or drop-on-demand (DOD) method; (3) Binder jetting, where alternating layers of build material (e.g., powder-based material) and binding material (e.g., liquid binder) are deposited via a printhead; (4) Material extrusion, where material is extruded through a nozzle, heated, and deposited layer by layer, such as fused deposition modeling (FDM), and direct ink writing (DIW); (5) Powder bed fusion, including techniques such as direct metal laser sintering (DMLS), electron beam melting (EBM), selective heat sintering (SHS), selective laser melting (SLM), and selective laser sintering (SLS); (6) Sheet lamination, including techniques such as laminated object manufacturing (LOM) and ultrasonic additive manufacturing (UAM); and (7) Directed energy deposition, including techniques such as laser engineered net shaping, directed light fabrication, direct metal deposition, and 3D laser cladding. Optionally, the additive manufacturing process can use a combination of two or more additive manufacturing techniques.

[0037] For example, an additive manufactured object can be produced using a vat photopolymerization process, in which light is used to selectively cure a curable material (e.g., polymer resin) in a vat or reservoir. Each layer of curable material can be selectively exposed in a single exposure (e.g., DLP) or by scanning a light beam over the layer (e.g., SLA). Depending on the relative positions of the vat, light source, and build platform, vat polymerization can be performed in a "top-down" or "bottom-up" method.

[0038] As another example, high-temperature lithography (also referred to as "thermal lithography") can be used to produce additive manufacturing objects. High-temperature lithography can include any photopolymerization process that involves heating a photopolymerizable material (e.g., a polymer resin). For example, high-temperature lithography can involve heating the material to a temperature of at least 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or 120°C. In some embodiments, the material is heated to a temperature within the range of 50°C to 120°C, 90°C to 120°C, 100°C to 120°C, 105°C to 115°C, or 105°C to 110°C. Heating can reduce the viscosity of the photopolymerizable material and / or increase the reactivity of the photopolymerizable material before and / or during curing. Thus, high-temperature lithography can be used to produce objects from materials that are highly viscous and / or have poor flowability, which can exhibit improved mechanical properties (e.g., stiffness, strength, stability) upon curing compared to other types of materials. For example, high-temperature lithography can be used to produce objects from materials having a viscosity of at least 5 Pa-s, 10 Pa-s, 15 Pa-s, 20 Pa-s, 30 Pa-s, 40 Pa-s, or 50 Pa-s at 20°C. Representative examples of high-temperature lithography processes that can be incorporated into the methods herein are described in the following documents: International Publication Nos. WO2015 / 075094, WO2016 / 078838, WO2018 / 032022, WO2020 / 070639, WO2021 / 130657, and WO2021 / 130661, the disclosures of each of which are incorporated herein by reference in their entirety.

[0039] In some embodiments, additive manufacturing objects are fabricated using continuous liquid interface production (also referred to as "continuous liquid interface printing"), wherein an object is continuously built from a reservoir of photopolymerizable resin by forming a gradient of partially cured resin between the build surface of the object and a polymerization-suppressing "dead zone". In some embodiments, a semi-permeable membrane is used to control the delivery of a photopolymerization inhibitor (e.g., oxygen) into the dead zone in order to form a polymerization gradient. Representative examples of continuous liquid interface production processes that can be incorporated into the methods herein are described in the following documents: U.S. Patent No. 10,162,264 and U.S. Patent Publication Nos. 2015 / 0097315, 2015 / 0097316, and 2015 / 0102532, the disclosures of each of which are incorporated herein by reference in their entirety.

[0040] As another example, by constructing a continuous movement of the platform during the irradiation phase (e.g., along the vertical or Z direction) such that the hardening depth of the irradiated photopolymer is controlled by the movement speed, a continuous additive manufacturing method can achieve the continuous construction of an object geometry. Thus, continuous polymerization of the material on the construction surface can be achieved. Such a method is described in U.S. Patent No. 7,892,474, the disclosure of which is incorporated herein by reference in its entirety. In another example, a continuous additive manufacturing method can involve extruding a composite material composed of a curable liquid material surrounding a solid strand. The composite material can be extruded along a continuous three-dimensional path to form an object. Such a method is described in U.S. Patent Publication No. 2014 / 0061974, the disclosure of which is incorporated herein by reference in its entirety. In yet another example, a continuous additive manufacturing method can utilize a "heliolithography" method, where while continuously rotating and raising the construction platform, a focused radiation is used to cure a liquid photopolymer. Thus, an object geometry can be continuously constructed along a helical construction path. Such a method is described in U.S. Patent Publication No. 2014 / 0265034, the disclosure of which is incorporated herein by reference in its entirety.

[0041] In another example, a volumetric additive manufacturing (VAM) process can be used to fabricate an additive manufacturing object, in which the entire object is produced from a 3D volume of resin in a single printing step, without the need for layer-by-layer construction. During the VAM process, energy is applied to irradiate the entire build volume, but the projected pattern is configured such that only certain voxels will accumulate a sufficient energy dose to be cured. Representative examples of VAM processes that can be incorporated into the present technology include tomographic volume printing, holographic volume printing, multiphoton volume printing, and xolography. For example, a tomographic VAM process can be performed by projecting a 2D optical pattern into a rotating volume of photosensitive material at a vertical and / or angular incidence to produce a cured 3D structure. A holographic VAM process can be performed by projecting a holographic light pattern into a stationary reservoir of photosensitive material. The xolography process can use a photo-switchable photoinitiator to induce local polymerization within a volume of photosensitive material when linearly exciting by crossing beams of different wavelengths. Additional details of VAM processes applicable to the present technology are described in the following documents: U.S. Patent No. 11,370,173, U.S. Patent Publication No. 2021 / 0146619, U.S. Patent Publication No. 2022 / 0227051, International Publication No. WO2017 / 115076, International Publication No. WO2020 / 245456, International Publication No. WO2022 / 011456, and U.S. Provisional Patent Application No. 63 / 181,645, the disclosures of each of which are incorporated herein by reference in their entirety.

[0042] In yet another example, an additive manufacturing object can be produced using a powder bed fusion process (e.g., selective laser sintering), which involves selectively fusing layers of powder material using a laser beam according to a desired cross-sectional shape to build the object geometry. For example, powders having photoreactive groups and / or that can undergo polymerization can be used to form an object via powder bed fusion in combination with the grayscale techniques described herein. As another example, an additive manufacturing object can be produced using a material extrusion process (e.g., fused deposition modeling), which involves selectively depositing filaments of material (e.g., a thermoplastic polymer) in a layer-by-layer manner to form the object. For example, according to the techniques described in U.S. Patent Publication No. 2022 / 0184883, light or other energy can be used to selectively cure portions of the extruded filaments, the entire disclosure of which is incorporated herein by reference. In yet another example, an additive manufacturing object can be produced using a material jetting process, which involves jetting or extruding one or more materials onto a build surface to form successive layers of the object geometry.

[0043] An additive manufacturing object can be made of any suitable material or combination of materials. As described above, in some embodiments, the additive manufacturing object is made partially or completely of a precursor material that consists of one or more reactive components that change morphology when exposed to energy (e.g., electromagnetic energy, acoustic energy, radiant energy). The change in morphology can include, for example, changing from a monomeric form to an oligomeric and / or polymeric form, from an amorphous form to a crystalline form, from a liquid or semi-liquid form to a solid or semi-solid form, from a particulate or filamentous form to a continuous solid form, or a combination thereof.

[0044] For example, the precursor material can be a curable material such as a resin. The resin can consist of one or more polymerizable components such as one or more monomers. The resin can initially be liquid at room temperature (e.g., 20 °C) or at an elevated temperature (e.g., a temperature in the range of 50 °C to 120 °C). When exposed to energy, the monomers can undergo a polymerization reaction such that the resin solidifies into the desired object geometry. A monomer can be any molecule or compound capable of forming bonds with other monomers to produce larger molecules with an increased molecular weight. For example, a monomer can be an ethylene monomer, a cyclic monomer, a monomer having a functional group capable of forming a covalent or ionic bond, etc. In some embodiments, the bonding reaction occurs multiple times such that the molecular weight of the resulting molecule increases with each successive bonding reaction. Examples of bonding reactions suitable for use with the techniques described herein include, but are not limited to, free radical polymerization, ionic polymerization, condensation polymerization, Diels - Alder reactions, photodimerization, carbene formation, nitrene formation, and suitable combinations thereof.

[0045] Alternatively or in combination, the polymerizable components can include reactive polymers and / or oligomers. The oligomers and / or polymers can react with each other, with monomers, and / or other components to form larger molecules, e.g., via any of the bonding reactions described above.

[0046] In some embodiments, the polymerizable components (e.g., low molecular weight monomers, oligomers, polymers) form a high modulus phase within the polymeric material. In such embodiments, this phase can provide sufficient strength to the green state object to withstand post - processing and / or can direct the final shape of the printed object. Alternatively, the polymerizable components can form a low modulus phase within the polymeric material or reduce the local modulus of the object.

[0047] In some embodiments, the polymerizable component includes one or more of the following: acrylate monomers, methacrylate monomers, thiol monomers, vinyl acetate monomers, vinyl ether monomers, vinyl chloride monomers, vinyl silane monomers, vinyl siloxane monomers, styrene monomers, allyl ether monomers, acrylonitrile monomers, butadiene monomers, norbornene monomers, maleic acid monomers, fumaric acid monomers, epoxide monomers, anhydride monomers, or hydroxy monomers. In some embodiments, the polymerizable component includes one or more reactive functional groups, such as one or more of the following: acrylate, methacrylate, acrylamide, vinyl group, vinyl ether, thiol, allyl ether, norbornene, vinyl acetate, maleate, fumarate, methylene malonate, maleimide, epoxide, ring-strained cyclic ether, ring-strained cyclic thioether, cyclic ester, cyclic carbonate, cyclic silane, cyclic siloxane, hydroxy, amine, isocyanate, blocked isocyanate, acyl chloride, active ester, oxetane, Diels - Alder reactive group, furan, cyclopentadiene, anhydride, groups favorable for photodimerization (e.g., anthracene, acenaphthylene, or coumarin), groups that photodegrade into reactive species (e.g., Norrish type 1 and type 2 materials), azides, derivatives thereof, or combinations thereof. Additional examples of polymerizable components that can be used are provided in U.S. Patent No. 10,495,973 and U.S. Patent Publication Nos. 2021 / 0147672, 2021 / 0395420, 2022 / 0380502, and 2023 / 0021953, the disclosures of which are incorporated herein by reference in their entireties.

[0048] The curable material can include various additives, such as catalysts, blockers, viscosity modifiers, fillers, binders, reactive diluents, solvents, pigments and / or dyes, stabilizers, surface-active compounds, etc. For example, in some embodiments, the curable material includes a catalyst that forms a reactive species for a catalytic bonding reaction when exposed to energy. The catalyst can be a photocatalyst that is activated by absorbing light (e.g., infrared light, visible light, or ultraviolet (UV) light) or otherwise generated. Examples of photocatalysts include, but are not limited to, photoinitiators (e.g., radical initiators, cationic initiators), photoacid generators, and photobase generators.

[0049] In some embodiments, the curable material includes a blocker that limits the depth of energy penetration into the curable material during an additive manufacturing process. For example, the blocker can be a light blocker that absorbs the irradiation wavelength that causes a photoreaction (e.g., activation of a photocatalyst or a photodimerization reaction).

[0050] In some embodiments, the curable material includes a viscosity modifier. The viscosity modifier can be a component that increases the viscosity of the curable material (e.g., filler, binder, thixotropic agent). Alternatively, the viscosity modifier can be a component that decreases the viscosity of the curable material (e.g., reactive diluent, solvent).

[0051] In some embodiments, the curable material includes a filler. The filler can be an organic or inorganic filler, such as fumed silica, core-shell particles, talc, titanium dioxide, sugar, nanocellulose, graphite, carbon black, carbon nanotubes, etc.

[0052] In some embodiments, the curable material includes a binder. The binder can be a high molecular weight polymer that is added to the curable material to increase viscosity and / or enhance various material properties after curing, such as polymethyl methacrylate, acrylonitrile butadiene styrene (ABS), etc.

[0053] In some embodiments, the curable material includes a reactive diluent. The reactive diluent can decrease the viscosity of the curable material while also reacting with one or more other components to form part of the object.

[0054] In some embodiments, the curable material includes a solvent. The solvent can decrease the viscosity of the curable material and / or make two or more components of the curable material compatible.

[0055] In some embodiments, the curable material includes a pigment and / or a dye. The pigment and / or dye (e.g., titanium dioxide, Red Dye #40, carbon black) can add color and / or other functions to the object.

[0056] In some embodiments, the curable material includes a stabilizer that is configured to stabilize one or more components (e.g., to prevent precipitation, aggregation, degradation). For example, the stabilizer can be an emulsifier that stabilizes the components of an emulsion.

[0057] In some embodiments, the curable material includes a surface-active compound. The surface-active compound can enhance the wetting or adhesion of the curable material and / or the object to another surface. Alternatively or in combination, the surface-active compound can facilitate the debonding of the curable material and / or the object from another surface. Examples of surface-active compounds include, but are not limited to, waxes, silicon compounds, silanes, fluorinated compounds, etc.

[0058] Optionally, some or all of the components of the curable material can perform more than one function within the curable material and / or the printed object. For example, a reactive diluent can be a monomer and can also be used as a viscosity modifier; carbon black can be a pigment and can also be a light blocker; and so on.

[0059] In some embodiments, an additive manufacturing object is formed from a single type of material such that the entire object has the same chemical composition, although local properties of the object may vary (e.g., in terms of degree of curing and / or crosslink density). For example, the entire object can be formed from the same curable material (which can include a single component or can include multiple components as described elsewhere herein). In embodiments using vat photopolymerization techniques (e.g., SLA, DLP), the object can be produced using a single vat of curable material rather than switching between multiple vats containing different material types.

[0060] Alternatively, an additive manufacturing object can be made from multiple different materials (e.g., at least two, three, four, five, or more different material types) such that different parts of the object can have different chemical compositions. The material types can differ from one another in terms of composition, curing conditions (e.g., curing energy wavelength), material properties before curing (e.g., viscosity), material properties after curing (e.g., stiffness, strength, transparency), and so on. In some embodiments, an additive manufacturing object is formed from multiple materials in a single manufacturing step. For example, a multi-tip extrusion device can be used to selectively dispense multiple types of materials from different material supply sources in order to produce an object from multiple different materials. Examples of such methods are described in U.S. Patent No. 6,749,414 and U.S. Patent No. 11,318,667, the disclosures of which are incorporated herein by reference in their entireties. Alternatively or in combination, an additive manufacturing object can be formed from multiple materials in multiple sequential manufacturing steps. For example, a first part of the object can be formed from a first material according to any method herein, and subsequently a second part of the object can be formed from a second material according to the methods herein, and so on until the entire object has been formed.

[0061] After producing an additive manufacturing object, the object can undergo one or more additional process steps, also referred to herein as “post-processing.” As described in detail below with respect to blocks 104 to 108, post-processing can include removing residual material from the object, applying (one or more) additional materials to the object, performing additional curing, and / or separating the object from any substrates, supports, and / or other structures not intended to be present in the final product.

[0062] For example, at block 104, method 100 continues to remove residual material from the additive manufactured object. Residual material can include uncured material (e.g., unpolymerized liquid resin), components that are not incorporated into the body of the object (e.g., additives), and / or other unwanted or excess material (e.g., debris) left on or within the object after the additive manufacturing process. For example, in some embodiments, the curable material includes at least one component to be removed, which may or may not be a monomer. The component to be removed can be a polymerizable component (e.g., unreacted monomer, free oligomer, and / or polymer), a photocatalyst, and / or other additives such as a light blocker, filler, dye, solvent, etc. The component to be removed may or may not be a reactive component in the curable material.

[0063] The residual material can be removed in many different ways, such as by exposing the object to a solvent (e.g., via spraying, dipping), heating or cooling the object, applying a vacuum to the object, applying mechanical force to the object (e.g., vibration, agitation, centrifugation), and / or other suitable techniques. Further details of the material removal processes applicable to the present technology are provided below.

[0064] In some embodiments, the amount of residual material removed from a particular part of the object varies based on the local properties of the object (e.g., degree of curing and / or crosslink density). As discussed in more detail below, the amount of material removed from each object part can be controlled based on the energy application parameters previously used to form that object part at block 102, and the amount of material removed can affect the local properties of that object part (e.g., modulus, glass transition temperature (T g g), elongation to break).

[0065] At block 106, method 100 can optionally include post-curing the additive manufactured object. Post-curing can be used in cases where the object remains in a partially cured "green" state after the additive manufacturing process of block 102. For example, the energy used to form the object in block 102 may only partially polymerize the curable material forming the object. Therefore, a post-curing step may be required to increase the degree of curing of the object to a final usable state. Post-curing can provide various benefits, such as improving the material properties of the object (e.g., stiffness, strength, T g g) and / or temperature stability. Post-curing can be performed by applying energy (e.g., UV, visible light, infrared, microwave) or a suitable combination thereof to the object.

[0066] In some embodiments, the post-curing process of block 106 involves applying energy to certain portions of the object to selectively modify one or more material properties of that portion, as described in more detail below. For example, the applied energy can selectively increase or decrease the degree of curing (e.g., degree of polymerization and / or DBC), crosslink density, etc. of the target object portion while having little or no effect on the remaining object portions. In other embodiments, the post-curing process of block 106 can involve applying energy uniformly to the entire object. Optionally, the post-curing process of block 106 can involve a first stage and a second stage, in the first stage, energy is applied only selectively to certain object portions, and in the second stage, energy is applied to the entire object. However, in other embodiments, the post-curing process of block 106 is optional and can be omitted.

[0067] At block 108, method 100 can include separating the additive manufacturing object from the substrate. In some embodiments, the substrate is the build platform that mechanically supports the object during the production and post-processing steps described herein. The additive manufacturing object can be connected to the substrate via sacrificial regions of cured material (e.g., supports and / or rafts). Thus, by applying pressure to break the sacrificial regions, the additive manufacturing object can be separated from the substrate. In some embodiments, the sacrificial regions are made of the same material as the object(s), but can be configured to have weaker mechanical properties (e.g., increased brittleness) than the objects using the techniques described herein. Once separated, the additive manufacturing object can be prepared for packaging, shipping, and use.

[0068] Method 100 can be modified in many different ways. For example, although the above steps of method 100 are described with respect to a single object, method 100 can be used to produce and post-process any suitable number of objects, such as dozens, hundreds, or thousands of additive manufacturing objects, sequentially and simultaneously. As another example, the order of the processes shown in Figure 1 can be changed. Some processes of method 100 can be omitted, such as any of the processes of blocks 106 and / or 108. Method 100 can also include Figure 1Additional processes not shown, such as applying surface treatments, polishing, cleaning, etc. For example, method 100 may include a surface cleaning process before the post-curing process of block 106. The surface cleaning process may involve removing residual material (e.g., unpolymerized resin) from one or more surfaces of the additive manufacturing object, e.g., by washing (e.g., spraying or dipping in a solvent), heating, cooling, applying mechanical force (e.g., centrifugation), etc. In some embodiments, the surface cleaning process is distinguished from the material removal process of block 104 in that the surface cleaning process is designed to remove only residual material from the object surface and not a significant amount of residual material (e.g., less than 10%, 5%, 2%, or 1% of the residual material) from other parts of the object (e.g., inside the object).

[0069] Figure 2 A representative example of a system 200 for additive manufacturing configured according to an embodiment of the present technology is shown. System 200 can be used to produce any embodiment of the objects described herein. For example, system 200 can be used to produce an object according to Figure 1 block 102 of method 100.

[0070] System 200 includes a printer assembly 202 configured to produce an additive manufacturing object 204 (“object 204”) using any of the additive manufacturing processes described herein. Printer assembly 202 is configured to deposit a curable material 206 (e.g., a polymer resin or other curable precursor material) onto a build platform 208 (e.g., a tray, plate, film, sheet, or other planar substrate) to form object 204. In the illustrated embodiment, printer assembly 202 includes a carrier film 210 configured to transport curable material 206 to build platform 208. Carrier film 210 can be a flexible material loop having an outer surface and an inner surface. The outer surface of carrier film 210 can adhere to and carry a thin layer of curable material 206. The inner surface of carrier film 210 can contact one or more rollers 212 that rotate to move carrier film 210 in a continuous circular path, e.g., in the direction indicated by arrow 214.

[0071] The printer assembly 202 may also include a material source 216 (shown schematically) configured to apply a curable material 206 to the carrier film 210. In the illustrated embodiment, the material source 216 is located at the upper portion of the printer assembly 202. However, in other embodiments, the material source 216 may be at different locations within the printer assembly 202. The material source 216 may include nozzles, ports, reservoirs, etc. that deposit the curable material 206 onto the outer surface of the carrier film 210. The material source 216 may also include one or more doctor blades 220 (e.g., doctor blade, recoater blade) that smooth the deposited curable material 206 into a relatively thin, uniform layer. For example, the curable material 206 may be formed into a layer having a thickness in the range of 200 microns to 300 microns or any other desired thickness.

[0072] The curable material 206 may be conveyed by the carrier film 210 toward the build platform 208. In the illustrated embodiment, the build platform 208 is located below the printer assembly 202. However, in other embodiments, the build platform 208 may be positioned at different locations within the printer assembly 202. The distance between the carrier film 210 and the build platform 208 may be adjustable such that the curable material 206 can be in direct contact with the surface of the build platform 208 (when printing the initial layer of the object 204) or with the surface of the object 204 (when printing subsequent layers of the object 204). For example, the build platform 208 may include or be coupled to a motor (not shown) that raises and / or lowers the build platform 208 to a desired height during the manufacturing process.

[0073] The printer assembly 202 includes an energy source 218 (e.g., a projector or light engine) that outputs energy 220 (e.g., light, such as UV light) having a wavelength configured to partially or fully cure a curable material 206. The carrier film 210 may be partially or fully transparent to the wavelength of the energy 220 to allow the energy 220 to pass through the carrier film 210 and reach the portion of the curable material 206 above the build platform 208. Optionally, a transparent plate 222 may be disposed between the energy source 218 and the carrier film 210 to guide the carrier film 210 into a specific position (e.g., height) relative to the build platform 208. During operation, the energy 220 may be patterned or scanned onto the curable material 206 in a suitable pattern to form a layer of cured material on the build platform 208 and / or on a previously formed portion of the object 204. The geometry of the cured material may correspond to the desired cross-sectional geometry of the object 204. Parameters for operating the energy source 218 (e.g., energy intensity, energy dose, exposure time, exposure pattern, exposure wavelength, energy density, power density) may be set based on instructions from a controller 224, as described in further detail below.

[0074] Once an object cross-section has been formed, the build platform 208 may be lowered by a predetermined amount to separate the cured material from the carrier film 210. The remaining curable material 206 may be carried away from the build platform 208 by the carrier film 210 and returned to the material source 216. The material source 216 may deposit additional curable material 206 onto the carrier film 210 and / or smooth the curable material 206 to reform a uniform layer of curable material 206 on the carrier film 210. Subsequently, the curable material 206 may be recycled back to the build platform 208 to produce another layer of the object 204. This process may be repeated to iteratively build individual object layers on the build platform 208 until the object 204 is complete. Subsequently, the object 204 and the build platform 208 may be removed from the system 200 for post-processing.

[0075] In some embodiments, the system 200 is used in a high-temperature lithography process that utilizes a highly viscous curable material 206 (e.g., a highly viscous resin). Accordingly, the printer assembly 202 may include one or more heat sources (heating plates, infrared lamps, etc.) for heating the curable material 206 to reduce the viscosity to a range suitable for additive manufacturing. For example, the printer assembly 202 may include a first heat source 226a and a first heat source 226b, the first heat source 226a being positioned against a section of the carrier film 210 before the build platform 208, and the second heat source 226b being positioned against a section of the carrier film 210 after the build platform 208. Alternatively or in combination, the printer assembly 202 may include heat sources at other locations.

[0076] System 200 also includes a controller 224 (schematically shown), which is operatively coupled to the printer assembly 202 and the build platform 208 to control their operation. The controller 224 can be or include a computing device that includes one or more processors and a memory storing instructions for performing the additive manufacturing operations described herein. For example, the controller 224 can receive a digital data set (e.g., a three-dimensional model) representing the object 204 to be manufactured, determine a plurality of object cross-sections to build the object 204 from the curable material 206, and can transmit instructions to the energy source 218 to output energy 220 to form the object cross-section. As described above and in more detail below, the controller 224 can control the energy application parameters of the energy source 218, such as energy intensity, energy dose, exposure time, exposure pattern, energy wavelength, and / or the type of energy of the energy 220 applied to the curable material 206. Optionally, the controller 224 can also determine and control other operating parameters, such as the positioning (e.g., height) of the build platform 208 relative to the carrier film 210, the movement speed and direction of the carrier film 210, the amount of curable material 206 deposited by the material source 216, the thickness of the material layer on the carrier film 210, and / or the heat applied to the curable material 206.

[0077] Although Figure 2 a representative example of a system 200 for additive manufacturing is shown, this is not intended to be limiting, and the methods described herein can be implemented using other types of additive manufacturing systems, such as material jetting systems, binder jetting systems, material extrusion systems, powder bed fusion systems, sheet lamination systems, or directed energy deposition systems. II. Method for generating objects with heterogeneous properties

[0078] In some embodiments, the present technology provides methods for generating objects having spatially controlled property variations, which may also be interchangeably referred to herein as objects having "heterogeneous properties", "variable properties", or "anisotropic properties". For example, an object having heterogeneous properties may include a plurality of object portions at different spatial locations within the object. The plurality of object portions may differ from one another in at least one material property, such as one or more of the following: modulus (e.g., elastic modulus, flexural modulus, storage modulus), glass transition temperature, elongation at break, elongation at yield, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusivity, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, and / or durability. In some embodiments, the object includes two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, or more object portions having different material properties. Each of these object portions may differ from at least one other object portion in one, two, three, four, five, or more material properties.

[0079] Figure 3 is a flow chart showing a method 300 for generating an object having heterogeneous properties according to an embodiment of the present technology. The method 300 may be performed using any suitable system or apparatus, such as Figure 2 system 200. In some embodiments, some or all of the processes of the method 300 are implemented in the form of computer-readable instructions (e.g., program code) configured to be executed by one or more processors of a computing device such as Figure 2 controller 224. The method 300 may be combined with other methods described herein, such as Figure 1 method 100.

[0080] The method 300 begins at block 302 by receiving a digital data set representing an object. The digital data set may be or include any suitable data type depicting the geometry of the object to be fabricated. For example, the object may be an orthodontic device (e.g., an aligner, a palatal expander, a retainer, an attachment placement device) for treating a patient's teeth, and the digital data set may be or include a three-dimensional model of the device (e.g., in STL format, CLI format, CAD format).

[0081] In some embodiments, the digital data set includes instructions for producing an object via an additive manufacturing process such as DLP, SLA, or any other technique described herein. For example, in embodiments where the additive manufacturing process involves building an object from multiple material layers, the digital data set can include instructions for slicing the object geometry into a plurality of cross-sections corresponding to the multiple material layers. As another example, in embodiments where the additive manufacturing process involves applying energy to a curable material to form an object, the digital data set can include instructions for controlling one or more energy application parameters to be used in forming the object, such as energy intensity, energy dose (e.g., energy intensity × exposure time), exposure time, energy wavelength, and / or energy type.

[0082] In some embodiments, the instructions include a plurality of coordinates (e.g., pixel or voxel coordinates), where each coordinate represents a location in the object. The instructions can also include a plurality of values, each value associated with a corresponding coordinate and representing a setting of an energy application parameter for the corresponding location in the object. For example, the value can represent an energy intensity level, an exposure time period, an energy dose level, etc. to be used when forming a portion of the object at the associated coordinate location. If there are only two options for the energy application parameter, the value can be a binary value, or if there are more than two options for the energy application parameter (e.g., a continuous range of options, or three or more discrete options), the value can be a non-binary (e.g., grayscale) value. For example, the energy dose per pixel (for DLP) or per laser hatch (for SLA) can be represented by a grayscale value, where white represents a higher (e.g., maximum) energy dose, black represents a lower (e.g., minimum or zero) energy dose, and gray represents an intermediate energy dose (e.g., one or more dose levels between the minimum and maximum dose levels). The energy dose per pixel for DLP can be changed by adjusting the energy intensity and / or exposure time of that pixel, while the energy dose per laser hatch for SLA can be changed by adjusting the energy intensity and / or scan speed of that laser hatch.

[0083] At block 304, method 300 continues to apply energy to the curable material to form an object. Any suitable type of energy can be used, such as electromagnetic energy (e.g., infrared light, visible light, ultraviolet light, microwaves), acoustic energy, and / or radiant energy (e.g., α radiation, β radiation, neutron radiation). The energy can cause changes in the curable material to build the geometry of the object, such as chemical reactions (e.g., polymerization), melting, coalescence, hardening, curing, etc. For example, the curable material can include one or more polymerizable components, such as monomers, reactive oligomers, and / or reactive polymers. The polymerizable components can undergo a polymerization reaction when exposed to energy (e.g., light). The curable material can optionally include additives that facilitate the polymerization reaction and / or serve other functions in the curable material, as described elsewhere herein. In some embodiments, the object is formed from a single type of curable material (e.g., a single bucket of starting material for a vat-based process). For example, the object can be formed from the curable material by a repeated series of layer-by-layer energy exposures to produce a three-dimensional structure.

[0084] The energy can be applied to the curable material in such a way that different parts of the object are formed using different energy application parameters, such as different energy intensities, doses, exposure times, wavelengths, and / or energy types. For example, the object can include a first object portion formed using a first set of energy application parameters (e.g., a first energy dose), a second object portion formed using a second set of energy application parameters different from the first (e.g., a second energy dose), a third object portion formed using a third set of energy application parameters different from the first and second (e.g., a third energy dose), and so on.

[0085] For example, Figure 4A is a schematic diagram of an object 400 including a first object portion 402 and a second object portion 404 according to an embodiment of the present technology. In some embodiments, the first object portion 402 is formed using a first energy intensity, and the second object portion 404 is formed using a different second energy intensity. The ratio of the first energy intensity to the second energy intensity can be greater than or equal to 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. The first energy intensity can be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100% of the maximum possible energy intensity; and / or the second energy intensity can be no more than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 1% of the maximum possible energy intensity.

[0086] Alternatively or in combination, the first object portion 402 may be formed using a first energy dose, and the second object portion 404 may be formed using a second energy dose. The ratio of the first energy dose to the second energy dose may be greater than or equal to 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. The first energy dose may be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100% of the maximum possible energy dose; and / or the second energy dose may not exceed 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 1% of the maximum possible energy dose.

[0087] Alternatively or in combination, the first object portion 402 may be formed using a first exposure time, and the second object portion 404 may be formed using a second exposure time, and the ratio of the first exposure time to the second exposure time may be greater than or equal to 1.5, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. The first exposure time may be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100% of the maximum possible exposure time; and / or the second exposure time may not exceed 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 1% of the maximum possible exposure time.

[0088] Alternatively or in combination, the first object portion 402 may be formed using a first energy wavelength, and the second object portion 404 may be formed using a second energy wavelength. The first energy wavelength may be shorter than the second energy wavelength, and vice versa. For example, the first wavelength may be greater or less than the second energy wavelength by at least 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 75 nm, or 100 nm. The first and second energy wavelengths may be independently selected from any of the following: 100 nm to 200 nm, 200 nm to 300 nm, 300 nm to 400 nm, 300 nm to 350 nm, 350 nm to 400 nm, 350 nm to 375 nm, 375 nm to 400 nm, 400 nm to 500 nm, 400 nm to 450 nm, 400 nm to 425 nm, 500 nm to 600 nm, 600 nm to 700 nm, 700 nm to 800 nm, 800 nm to 900 nm, 900 nm to 1000 nm, or 1000 nm to 1100 nm.

[0089] Referring again to Figure 3, the energy application parameters used in the process of block 304 can be configured to spatially control the amount of residual curable material (e.g., monomers, oligomers, and / or polymers) that will be removed from different parts of the object in a subsequent material removal process (e.g., the process of block 306). Specifically, the energy application parameters used to form a particular object part can affect the local properties of that object part. Conversely, the local properties of an object part can affect the amount of residual curable material removed from that object part. The ability to vary the parameters of the applied energy at different spatial locations (e.g., along the x, y, and / or z directions) in order to program the amount of residual curable material to be removed can also be referred to herein as "grayscaling" or "gray programming".

[0090] The applied energy can control the amount of residual curable material to be removed from a particular object part in various ways, such as by causing heating, melting, coalescence, hardening, chemical reactions (e.g., chemical bond formation, chemical bond breakage), morphological changes, phase changes, and / or other changes in the local properties of the curable material that affect material removal. For example, object parts formed using different energy application parameters can exhibit differences in one or more of the following local properties: degree of curing of the curable material (e.g., degree of polymerization of the curable material, DBC of the curable material), crosslink density, phase (state), crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, and / or melting point.

[0091] For example, in some embodiments, the curable material includes polymerizable components, and the applied energy causes polymerization of the polymerizable components. Object parts formed using a higher energy dose, higher energy intensity, and / or longer exposure time can exhibit a higher degree of curing of the curable material (e.g., higher degree of polymerization and / or DBC). Conversely, object parts formed using a lower energy dose, lower energy intensity, and / or shorter exposure time can exhibit a lower degree of curing of the curable material (e.g., lower degree of polymerization and / or DBC). In some embodiments, it is easier to remove residual curable material from an object part with a higher degree of curing, and more difficult to remove residual curable material from an object part with a lower degree of curing.

[0092] Alternatively or in combination, energies of different wavelengths can be used to control the degree of curing and thus the amount of residual curable material present in the object portion. For a given photoinitiator, a shorter energy wavelength can have a higher molar absorptivity than a longer energy wavelength, and thus it can exhibit a smaller penetration depth into the curable material than the longer energy wavelength. Thus, a shorter energy wavelength can be applied to a particular layer at a higher energy intensity and / or for a longer exposure time without curing the material of the previous layer, while using a higher energy intensity and / or a longer exposure time and a longer energy wavelength can cause curing of the previous layer. Thus, a shorter energy wavelength can be used to selectively increase the degree of curing within a portion of a layer to reduce the amount of residual curable material (e.g., free monomers) within that portion. In some embodiments, a longer energy wavelength is first applied to create a layer of cured material, and subsequently a shorter energy wavelength is selectively applied to one or more portions of the layer to increase the degree of curing at one or more portions of the layer. This technique can be used to selectively increase the green state strength of certain object portions and / or create a greater difference in the properties of the object across different object portions, as described further below. Optionally, a certain degree of curing of the previous layer is acceptable, e.g., if it is desired for the previous layer to exhibit a higher green state strength.

[0093] In some embodiments, the object includes at least two object portions formed using different energy application parameters, such as a first object portion and a second object portion. For example, again referring to Figure 4A , the first object portion 402 can have a degree of curing of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%; the second object portion 404 can have a degree of curing of no more than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 1%. Alternatively or in combination, the first object portion 402 can have a degree of polymerization of at least 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, or 2000; the second object portion 404 can have a degree of polymerization of no more than 1500, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 50, 20, or 10. Alternatively or in combination, the first object portion 402 can have a DBC of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%; and the second object portion 404 can have a DBC of no more than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 1%.

[0094] Again referring to Figure 3, Optionally, the applied energy to the block 304 can cause a chemical reaction that adds or removes a capping agent from a polymerizable component (e.g., monomer, oligomer, or polymer). The capping agent can be added to or removed from the chain ends and / or side groups on the chain. The capping agent can affect material removal in various ways, such as by changing the solubility, diffusivity, permeability, degradability (e.g., by solvent and / or heat), etc. of the polymerizable component.

[0095] The process of block 304 can use any suitable type of energy, such as electromagnetic energy (e.g., including any wavelength from gamma waves to microwaves), acoustic energy (e.g., ultrasonic energy), radiation (e.g., electron beam, alpha particles), or a suitable combination thereof. For example, ultrasonic energy applied directly in contact or indirectly via a medium through an ultrasonic horn can create a heating zone at or near the contact point that changes the local properties of the curable material.

[0096] As another example, electromagnetic energy can produce photoreactions (e.g., dimerization, isomerization, cleavage, catalyst generation), which change the local properties of the curable material. For example, photo-isomerization can be used to program the amount of material to be removed. Molecules such as azobenzene can undergo isomerization, which changes their properties (e.g., crystallinity, pH, color, shape, solubility, ligation, chelation). During the removal process, these changes can facilitate or impede the removal of the molecules. For example, a morphological change from amorphous to crystalline can reduce solubility in a solvent and thus impede solvent-based removal. Alternatively, a morphological change from crystalline to amorphous can increase solubility in a solvent and thus enhance solvent-based removal. In embodiments using small molecules, a morphological change from crystalline to non-crystalline can change the vapor pressure and / or boiling point of the material to be removed, which can change the effectiveness of vacuum-based extraction. As another example, photoreactions can be used to change chelation to metal ions, which can cause changes in properties such as vapor pressure, solubility, melting point, etc. In another example, photoreactions can cause groups to cleave from the polymer matrix, generating low molecular weight components that can be removed. Conversely, photoreactions can cause low molecular weight components to bond to the polymer matrix, thus impeding removal.

[0097] The energy application parameters related to the target amount of material removal can be determined in many different ways. For example, suitable energy application parameters can be identified from a calibration curve, a look-up table, or other suitable data structures that show the experimentally determined relationship between the values of specific energy application parameters and the corresponding amounts of material removed. Alternatively or in combination, simulations, mathematical models, and / or trained machine learning algorithms can be used to determine the appropriate energy application parameters.

[0098] At block 306, method 300 includes removing residual curable material from the object. The residual curable material to be removed can include one or more components of the curable material that are not intended to be present in the final product, such as reactive components (e.g., free monomers, oligomers, and / or polymers) that have not polymerized or otherwise been incorporated into the body of the object, non-reactive components, and / or other unwanted or excess materials remaining on or within the object after the process of block 304. For example, the object can be placed in a suitable device (e.g., a chamber) configured to effect material removal via one or more suitable techniques such as solvents, vacuum, heating, etc. Other details and examples of material removal techniques applicable to the present technology are described below.

[0099] The amount of residual curable material removed from each object part can be related to the energy application parameters used to form that object part. Specifically, the energy application parameters can spatially control the local properties (e.g., via reaction, heating, melting, coalescence, and / or hardening) of each object part to selectively enhance or impede material removal from that object part, such that different amounts of material are removed from object parts formed using different energy application parameters. For example, the applied energy can affect the degree of cure. For example, due to reduced steric hindrance, it may be easier to remove residual curable material from object parts with a lower degree of cure. Object parts with a lower degree of cure may also exhibit increased permeability to solvents and / or solubility in solvents, which can also enhance material removal.

[0100] In some embodiments, the amount of material removed from an object part affects the material properties of the object part. Any reference herein to the material properties of an object or object part can refer to the material properties before post-processing (e.g., when the object is in the green state before post-curing), after post-processing (e.g., after post-curing), or both. Examples of material properties that can be affected by material removal include, but are not limited to, any of the following: modulus (e.g., storage modulus), T g , elongation at break, elongation at yield, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusivity, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, and durability. For example, a larger amount of material removal can be associated with a reduced modulus, a reduced T g and / or a reduced hardness. Conversely, a smaller amount of material removal can be associated with an increased modulus, an increased T g and / or an increased hardness. Thus, the material properties of an object part can be programmed by controlling the energy application parameters used to form that object part.

[0101] For example, in some embodiments, the residual curable material includes at least one polymerizable component (e.g., monomer, reactive oligomer, or reactive polymer) having a sufficiently low molecular weight to facilitate extraction, e.g., by solvent, boiling, evaporation, sublimation, and / or other suitable techniques. The molecular weight of the low molecular weight component (e.g., weight average molecular weight and / or number average molecular weight) can be less than or equal to 2000 g / mol, 1500 g / mol, 1000 g / mol, 750 g / mol, 500 g / mol, 250 g / mol, or 100 g / mol. Optionally, higher molecular weight components can also be used if longer extraction times are employed.

[0102] When forming the curable material into an object during the process of block 304, the applied energy can first statistically polymerize the low molecular weight components (e.g., due to concentration, reactivity ratios, diffusivity) to form a polymer network. Optionally, the polymer network can also include crosslinking to enhance stability. The dose of the applied energy can control the extent to which the low molecular weight components are incorporated into the formed polymer network. For example, a higher energy dose can be associated with a greater incorporation of low molecular weight components, while a lower energy dose can be associated with a lesser incorporation of low molecular weight components.

[0103] Subsequently, during the process of block 306, the residual low molecular components that have not been incorporated into the polymer network can be removed from the object. For example, when the green state object is exposed to a solvent, the polymer network can swell to allow the residual low molecular weight components to diffuse out of the object more quickly. In some embodiments, object portions with fewer low molecular weight components incorporated into the polymer network (e.g., associated with a lower degree of cure) exhibit a lower modulus, while object portions with more low molecular weight components incorporated into the polymer network (e.g., associated with a higher degree of cure) exhibit a higher modulus.

[0104] In some embodiments, the curable material includes multiple components, such that a first component is preferentially removed compared to a second component. For example, the first component can be a low molecular weight component and the second component can be a high molecular weight component. Due to reduced volume and / or steric hindrance, the low molecular weight component is more easily removed than the high molecular weight component. Alternatively or in combination, the first component can have a higher solubility in the solvent used for the removal process, while the second component can have a lower solubility in the solvent. The preferential removal of the first component can be used to spatially control local material properties. In some embodiments, for example, the first component is a high T g component, while the second component is a low T g component. Thus, the local T gIt can be adjusted by controlling the amount of the first component to be preferentially removed.

[0105] The material removal process of the frame 306 can include many different techniques. For example, in some embodiments, the residual curable material is removed by exposing the object to one or more solvents, e.g., by partially or fully immersing the object in the (one or more) solvent(s), spraying the (one or more) solvent(s) onto the object, and / or into the object. The solvent can be selected to enhance the removal of the residual curable material while avoiding degradation, dissolution, and / or deformation (e.g., swelling) of the curable material that has been incorporated into the object (“printed material”). For example, the solvent can be at least a medium, good, or very good solvent for the residual curable material to ensure substantially complete extraction (e.g., at least 80%, 90%, 95%, 99%, or 99.9%) of the residual curable material within a reasonable length of time (e.g., not exceeding 24 hours, 12 hours, 6 hours, 4 hours, 2 hours, 1 hour, 30 minutes, 10 minutes, 5 minutes, 2 minutes, or 1 minute). In some embodiments, the solvent is characterized based on the amount that can be absorbed into the material, e.g., a “poor” solvent exhibits absorption in the range of 0 wt% to 1 wt%, a “medium” solvent exhibits absorption in the range of 1 wt% to 5 wt%, a “good” solvent exhibits absorption in the range of 5 wt% to 15 wt%, and a “very good” solvent exhibits absorption greater than 15 wt%. The solvent absorption amount can vary based on the local properties of the material (such as degree of curing, morphology, crystallinity, hydrophobicity, hydrophilicity, etc.). Additionally, temperature can affect solubility, so temperature can be used to facilitate extraction (e.g., a higher temperature can be used to reduce the extraction time).

[0106] In some embodiments, the solvent is also a good or very good solvent for the printed material, since the solvent can readily penetrate into the printed material to facilitate the diffusion of the residual curable material out of the object. However, in other embodiments, the solvent can be a medium or poor solvent for the printed material, since the penetration of the solvent into the printed material is limited, but the residual curable material can still diffuse out of the printed material and into the solvent. For example, in embodiments where the printed material is a generally hydrophobic resin and the residual curable material includes a hydrophilic component (e.g., poly(ethylene glycol) (PEG) oligomers), water can be used as the solvent. In such embodiments, water is a poor solvent for the hydrophobic resin and will not substantially diffuse into the hydrophobic resin. However, water can still be a good solvent for the hydrophilic component, such that any hydrophilic component present in the hydrophobic resin can preferentially diffuse out of the resin and into the water over time. In some embodiments, the method is used for relatively thin objects (e.g., objects having a maximum thickness less than or equal to 1 cm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm) to reduce the amount of time required to extract the residual curable material.

[0107] In some embodiments, pores and / or channels are present in the object to facilitate the removal of material. The method can allow for the efficient removal of residual material on a reasonable time scale (e.g., not exceeding 24 hours, 12 hours, 6 hours, 4 hours, 2 hours, 1 hour, 30 minutes, 10 minutes, 5 minutes, 2 minutes, or 1 minute), even when the object is relatively thick (e.g., having a maximum thickness greater than 1 cm) and / or when the solvent is a medium or poor solvent for the printed material. In some embodiments, such channels and / or pores can be used in conjunction with the grayscale techniques described herein to facilitate the preferential removal of material from certain object portions. For example, the porosity of an object portion can be controlled by varying the energy application parameters used to form that object portion.

[0108] In some embodiments, depending on the local properties of each object portion, a solvent is selected to penetrate different object portions in different ways. For example, an object can include a first object portion that exhibits reduced solvent penetration and a second object portion that exhibits increased solvent penetration. The first object portion can be formed according to the techniques herein to have a higher degree of curing (e.g., a higher degree of polymerization and / or a higher DBC); and the second object portion can be formed according to the techniques herein to have a lower degree of curing (e.g., a lower degree of polymerization and / or a lower DBC). The increased solvent penetration can be related to an increase in the amount of residual curable material removed, while the reduced solvent penetration can be related to a decrease in the amount of residual curable material removed. Solvent penetration can be quantified in various ways, such as by measuring the weight percentage increase of the object, nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and / or other spectroscopic techniques.

[0109] Optionally, the solvent itself and / or components added to the solvent can be configured to degrade high molecular weight components into lower molecular weight components that are more easily removed. For example, water (e.g., at physiological, low, or high pH) can be used to degrade certain polymers or oligomers into smaller components. The solvent can also be heated to further enhance the degradation (e.g., depolymerization).

[0110] The choice of solvent can also depend on other factors, such as the intended use of the object, the level of precision required for the object geometry, the removability of the solvent, toxicity, biocompatibility, cost, etc. For example, the solvent can have properties that make it easier to remove from the object, such as a high vapor pressure, a low boiling point, etc. In addition, the solvent can be biocompatible, food grade, and / or otherwise generally considered safe, for example, to limit any potential hazards to living organisms that may come into contact with the object if the solvent is not completely removed prior to use. The solvent can be a polar solvent (e.g., a polar protic solvent or a polar aprotic solvent) or a nonpolar solvent. The solvent can be an organic solvent or an inorganic solvent.

[0111] Examples of solvents suitable for the present technology include, but are not limited to: acetic acid, acetone, acetonitrile, ammonia, benzene, butanol, butyl acetate, camphor, carbon tetrachloride, chloroform, cyclohexanone, diethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, ethyl acetate, ethyl cellosolve, ethyl lactate, ethylene glycol, eugenol, glycerol, heptane, hexane, isoamyl acetate, isopropyl acetate, isopropanol, liquid or low melting point sugars, low melting point or high melting point waxes, menthol, methanol, methylene chloride, phenol, propanol, propylene carbonate, propylene glycol, pressurized gases, silicone oils (e.g., aliphatic and / or aromatic), soapy water, supercritical carbon dioxide, tetrahydrofuran, toluene, triacetin, turpentine, vanillin, vegetable oils, water, xylene, and suitable combinations thereof. In some embodiments, multiple types of solvents can be used simultaneously or sequentially to remove residual curable material. Optionally, the process of block 306 can involve performing multiple solvent washes. Some or all of the solvent washes can use the same solvent, or some or all of the solvent washes can use different solvents.

[0112] Alternatively or in combination, residual curable material can be removed by heating the object and / or applying a vacuum to the object. In such embodiments, the component(s) to be removed can have a low enough molecular weight to facilitate removal by boiling, evaporation, and / or sublimation, as described above. Optionally, the component(s) to be removed can initially have a higher molecular weight and can subsequently be converted to a lower molecular weight component via photoinduced degradation (e.g., by light to break photodimers into smaller molecules), heating (e.g., by a thermal reverse Diels - Alder reaction), solvents, other chemicals, etc. In such embodiments, the degradation process can be performed before and / or simultaneously with the material removal process.

[0113] Optionally, after the residual curable material has been removed, additional post - processing of the object can be performed. For example, the object can undergo post - curing, e.g., as described above with respect to Figure 1 block 106. The energy used for post - curing can be the same type of energy as that used in block 304, or it can be a different type of energy. Post - curing can increase the degree of curing, cause a phase change (e.g., phase condensation), cause annealing, etc., which in turn can further modulate the material properties of the object (e.g., increase modulus, T getc.). Additionally, post-curing can reduce or eliminate the reactivity of any residual curable material (e.g., monomer) that was not removed, which can be beneficial in reducing toxicity. In some embodiments, residual curable material that was not removed prior to post-curing can be incorporated into the polymer network during post-curing, which can reduce or eliminate any differences in modulus that might otherwise be observed. For example, post-curing can cause any low molecular weight components that remain to be incorporated into the polymer network. Thus, it may be beneficial or necessary to extract at least 80%, 90%, 95%, 99%, or 99.9% of any residual curable material intended to be removed prior to post-curing the object. However, in other embodiments, post-curing is not performed. For example, if the material properties of the object in the green state are already sufficient for the intended use (e.g., if the modulus, T g etc. are already above a predetermined threshold), then post-curing can be omitted.

[0114] As another example, in embodiments where a solvent is used to remove residual curable material, post-treatment of the object can include removing the solvent (e.g., removing at least 90%, 95%, 98%, 99%, or 99.9% of the solvent), such as by exposing the object to heat and / or vacuum for a sufficient time to remove the solvent. In some embodiments, the solvent removal process takes no more than 24 hours, 12 hours, 6 hours, 4 hours, 2 hours, 1 hour, 30 minutes, 10 minutes, 5 minutes, 2 minutes, or 1 minute. In another example, post-treatment of the object can include any of the following: removing a support and / or other sacrificial components, mechanical trimming, cleaning, polishing, washing, rinsing with additional solvent, coating with a coating and / or surface treatment, and / or injecting an active compound (e.g., a drug, a fragrance).

[0115] The amount of material removed from a particular object portion can be varied as needed using the techniques described herein. For example, the amount of material removed from an object portion can be less than or equal to 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% of the residual curable material initially present in the object portion. Alternatively or in combination, the amount of material removed can be at least 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% of the residual curable material initially present in the object portion. The amount of material removed can be in the range of 10% to 80%, 10% to 50%, 30% to 80%, or 1% to 60% of the residual curable material initially present in the object portion. In embodiments where coordinates (e.g., pixels or voxels) are used to define the object geometry, each coordinate can be programmed to remove a different amount of material based on the maximum amount of material that can be removed for a particular material. For example, the amount of material removed can be programmed to be at least 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or 99.9% of the maximum amount of material that can be removed.

[0116] For example, Figure 4B FIG. Figure 4B is a schematic illustration of removing material from an object 400 in accordance with an embodiment of the present technique. The amount of material removed from the first object portion 402 can be different from the amount of material removed from the second object portion 404. For example, the amount of material removed from the first object portion 402 can be less than or equal to 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the amount of material removed from the second object portion 404.

[0117] Referring again to Figure 3 , after the material removal process of block 306, method 300 can further include evaluating the amount of material removed from one or more object portions or from the entire object. Any suitable technique can be used to determine the amount of material removed, such as based on changes in weight, absorbance, reflectance, density, refractive index, color; using FTIR spectroscopy, Raman spectroscopy, etc. This determination can be used to confirm whether the object was produced according to specifications, for example, for quality control purposes.

[0118] After the residual curable material has been removed, depending on the amount of material removed from each object portion, different portions of the object can exhibit different material properties. For example, Figure 4C4 is a schematic diagram of an object 400 after material removal according to an embodiment of the present technology. After material removal (e.g., before and / or after post-curing), a first object portion 402 can have a first modulus (e.g., elastic modulus, flexural modulus, and / or storage modulus), and a second object portion 404 can have a second modulus less than the first modulus. The first modulus (e.g., at room temperature (such as 20° C. or 25° C.) and / or 37° C.) may be at least 100 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, or 1000 MPa; and the second modulus (e.g., at room temperature (such as 20° C. or 25° C.) and / or 37° C.) may be no greater than 900 MPa, 800 MPa, 700 MPa, 600 MPa, 500 MPa, 400 MPa, 300 MPa, 200 MPa, or 100 MPa. The first modulus may be at least 50 MPa, 100 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, or 500 MPa higher than the second modulus. Alternatively or in combination, the first object portion 402 may have a first T g , and the second object portion 404 may have a smaller T than the first g The second T g . First T g may be at least 50°C, 75°C, 80°C, 100°C, 125°C, 150°C, 175°C or 200°C; and the second T g It may be no higher than 175°C, 150°C, 125°C, 100°C, 80°C or 75°C. The first T g Can be higher than the second T g At least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C.

[0119] Alternatively, if Figure 4DAs shown, the object 400 may include a third object portion 406 between a first object portion 402 and a second object portion 404. In some embodiments, the third object portion 406 exhibits a graded property. Specifically, the property of the third object portion 406 may be as follows: (1) at a location adjacent to or near the first object portion 402, the property of the third object portion 406 is the same as or similar to the property of the first object portion 402; (2) at a location adjacent to or near the second object portion 404, the property of the third object portion 406 is the same as or similar to the property of the second object portion 404; and (3) at the center of the third object portion 406 that is away from the first object portion 402 and the second object portion 404, the third object portion 406 has an intermediate property between the properties of the first object portion 402 and the second object portion 404. The graded property of the third object portion 406 may be created passively (e.g., via a chemical process such as diffusion of a resin component) and / or may be created actively (e.g., by changing the energy dose and / or other energy application parameters during the formation of the third object portion 406 to create a gradient). Optionally, when the energy wavelength used to cure the first object portion 402 also results in partial curing of the third object portion 406, the graded property of the third object portion 406 may be created.

[0120] Referring again to Figure 3 , the number and spatial configuration of object portions having different material properties may be varied in a variety of ways depending on the desired function of the object. For example, in an embodiment where the object is an orthodontic appliance configured to be worn in a patient's mouth, the different object portions may correspond to different parts of the appliance. As another example, in an embodiment where the object includes functional components (e.g., components intended to be present in the final product) and sacrificial components (e.g., components not intended to be present in the final product such as supports), the first object portion may be or include a functional component and the second object portion may be or include a sacrificial component. Optionally, the object portions may be arranged in one or more patterns such as a grid, stripes, stitches, zigzags, gradients, etc. The geometry and location of the (one or more) patterns may be varied as needed. For example, the pattern may be designed to distribute stress over a larger portion of the object, transfer stress from one part of the object to another part of the object, and / or reduce stress concentration by avoiding sharp transitions between properties.

[0121] In some embodiments, the material properties of the object after the residual curable material has been removed (e.g., with and / or without post-curing) are configured such that the object exhibits no or little deformation (e.g., warping, bending, shrinking) after production, and the geometry of the object before material removal is substantially the same as the geometry of the object after material removal. For example, in an embodiment where the object is an orthodontic appliance intended to be worn on teeth, the object can be configured to exhibit substantially no deformation at room temperature (e.g., 20 °C or 25 °C) and / or under physiological conditions (e.g., 37 °C, in contact with physiological fluids) in order to maintain the desired force distribution on the teeth. Optionally, the object may exhibit some elastic deformation at room temperature and / or under physiological conditions, but little or no plastic deformation. In other embodiments, the object may exhibit deformation in certain cases, as described in more detail below. As another example, in an embodiment where the object will undergo post-processing for mechanical strengthening (e.g., centrifugation to remove residual resin), the object can be configured to exhibit sufficient rigidity to avoid being damaged during the post-processing. Thus, after the material removal process, and before and / or after post-curing, some or all parts of the object may exhibit one or more of the following material properties: a T of at least 50 °C, 75 °C, 80 °C, 100 °C, 125 °C, 150 °C, 175 °C or 200 °C g ; a modulus (e.g., elastic modulus, flexural modulus, and / or storage modulus) of at least 100 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa or 1000 MPa; and / or an elongation at break of at least 40%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%, 300%, 400% or 500% (e.g., measured at 1.7 mm / min at room temperature (such as 20 °C or 25 °C) and / or at 37 °C).

[0122] Alternatively or in combination, some or all parts of the object may exhibit deformation after manufacture, but may be symmetrically arranged to limit any overall deformation of the object due to different degrees of swelling, shrinkage, etc. For example, some or all parts of the object may be arranged to be axisymmetric about one or more of the following: a vertical axis, a horizontal axis, a mesial-distal axis, a buccal-lingual axis, and / or an occlusal-gingival axis.

[0123] In some embodiments, the amount of deformation exhibited by a particular object part is predictable (e.g., based on experimental data, simulations, machine learning models). Thus, the instructions for manufacturing the object (e.g., a three-dimensional model) can be adjusted to compensate for the predicted deformation such that the final object geometry after deformation substantially matches the expected object geometry.

[0124] Optionally, after fabrication, the object can be configured to respond to external stimuli (e.g., solvent, light, heat) to change its geometry, color, clarity, hardness, etc. based on the heterogeneous material properties of the object. For example, the object can include some "soft" object portions that are less dense, less hard, and / or more hydrophilic than other "hard" object portions. When placed in water, the object can change its shape based on the swelling of the soft object portions relative to the hard object portions. This method can be used to implement 4D printing.

[0125] Method 300 can vary in many different ways. In some embodiments, for example, method 300 can include Figure 3 additional processes not shown. For example, method 300 can optionally include performing a slight post-treatment after the process of block 304 and before the process of block 306, such as removing supports, cleaning the material from the object, solvent washing, annealing the object, etc. In some embodiments, such slight post-treatment does not remove a significant amount of the residual curable material from the object (e.g., less than 10%, 5%, 2%, or 1% of the residual curable material). In another example, method 300 can also include post-curing and / or other post-treatment after the process of block 306, as described above.

[0126] As yet another example, method 300 can include programming the amount of material to be removed using another energy application process different from the energy application process of block 304. The energy used to program the removal of the material can be different from the energy used to form the object. In such an embodiment, the process of block 304 can include applying a first energy (e.g., a first energy wavelength, a first energy type) to the curable material to form the object. Simultaneously or sequentially, a second energy (e.g., light of a second wavelength, a second energy type) can be applied to at least one object portion. The second energy can change the local properties of the object portion, which selectively affects (e.g., increases or decreases) the amount of material removed from the object portion relative to the remaining object portions. For example, the second energy can interact with a photoacid generator present in the curable material to produce an acid that selectively degrades the object portion, thereby allowing more residual material to be removed. As described elsewhere herein, similar methods can be used in conjunction with photobase generators, selective heating during curing, and / or other types of energy deposition. Additional examples of processes where the energy used to form the object is different from the energy used to program material removal are described in detail below in connection with Figures 5 to 6B an example.

[0127] In addition, although method 300 is described herein with respect to a single object, method 300 can be used to produce any suitable number of objects, such as dozens, hundreds, or thousands of objects. In such embodiments, some or all of the objects can have a spatially distributed customized geometry and / or material properties. For example, in an embodiment where the object is an orthodontic device, each object can be customized for a specific patient and / or for a specific treatment stage of the patient.

[0128] Figure 5 is a flowchart showing another method 500 for producing an object having heterogeneous properties according to an embodiment of the present technology. Method 500 can be performed using any suitable system or device, such as the embodiments described in conjunction with Figure 6A and Figure 6B In some embodiments, some or all of the processes of method 500 are implemented as computer-readable instructions (e.g., program code) configured to be executed by one or more processors of a computing device. Method 500 can be combined with any other method described herein, such as Figure 1 method 100 of Figure 3 and / or method 300 of

[0129] Method 500 begins at block 502, where an object formed using an additive manufacturing process is received. The object can be an orthodontic device, such as an aligner, palatal expander, retainer, attachment placement device, etc. The additive manufacturing process can implement any of the techniques described elsewhere herein, such as DLP, SLA, etc. For example, the additive manufacturing process can include applying energy to a curable material to form the object according to Figure 1 block 102 of Figure 3 and / or block 304 of

[0130] Any suitable type of energy can be used, such as electromagnetic energy, acoustic energy, and / or radiant energy. The energy can cause a change in the curable material to build the geometry of the object, such as a chemical reaction, melting, coalescence, hardening, curing, etc. In some embodiments, the object is formed from a single type of curable material (e.g., a single barrel of starting material for a vat-based process). The object can be in a green state before any post-curing occurs, or can be in a post-cured state. Optionally, the object may have undergone some minor post-processing, such as removal of supports, cleaning of materials from the object, solvent washing, etc.

[0130] In some embodiments, the additive manufacturing process involves programming material removal by using applied energy to form an object having heterogeneous material properties, as previously described with respect to Figure 3as described by method 300. In such an embodiment, the object produced at block 502 may already include multiple object parts having different material properties, and the subsequent processes of method 500 can be used to further enhance the existing differences in material properties and / or create new object parts having different material properties. However, in other embodiments, the object produced at block 502 can have substantially uniform material properties such that the subsequent processes of method 500 are used to selectively change the material properties of certain portions of the object.

[0131] At block 504, method 500 continues by identifying the locations of a subset of object parts. An additive manufactured object can include multiple object parts, such as two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50 or more object parts. For example, as described elsewhere herein, object parts can correspond to different parts of an orthodontic appliance, functional or sacrificial parts of an object, etc. The process of block 504 can include selecting a subset of object parts whose material properties are to be adjusted, also referred to herein as "target object parts". For example, the selected subset can include at least two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50 or more target object parts. The object can optionally include some object parts whose material properties are intended to remain substantially unaffected, also referred to herein as "remaining object parts". In some embodiments, the object includes at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50 or more remaining object parts. Alternatively, the object can not include any remaining object parts.

[0132] In some embodiments, the target object parts are identified using at least one sensor configured to obtain sensor data of the object. The (one or more) sensors can include one or more of the following sensor types: imaging devices (e.g., cameras, scanners), distance sensors (e.g., ultrasonic sensors, time-of-flight sensors, rangefinders), or combinations thereof. The (one or more) sensors can generate sensor data representing the location of each target object part on or within the object. For example, in embodiments where the (one or more) sensors include an imaging device, the imaging device can generate two-dimensional and / or three-dimensional image data of the object geometry. fiducial markers can be located on the object and / or on a substrate (e.g., build platform) supporting the object to facilitate identification of the object and / or target object parts.

[0133] Sensor data generated by one or more sensors can be analyzed to identify the location of a target object portion. For example, image data can be analyzed via computer vision techniques, trained machine learning models, etc. to determine the location of the target object portion relative to the remaining object portions. In some embodiments, the identification process includes comparing the sensor data with a digital representation of the object. The digital representation can be a three-dimensional model of the object that includes location information of the target object portion and / or the remaining object portions. Optionally, the digital representation can be or include a digital data set representing a target distribution of the material properties of the object. For example, the digital data set can include location information of the object portion (e.g., a set of coordinates defining the geometry of the object portion), and one or more desired material properties of the object portion.

[0134] In some embodiments, the object has a customized geometry (e.g., for a specific patient and / or for a specific treatment stage), such that the location of the target object portion can vary from object to object. In such embodiments, the process of block 504 can also include receiving an identifier of the object using at least one sensor, and subsequently identifying the location of the target object portion based on the identifier. For example, the identifier can be received from a label, marker (e.g., RFID marker), code (e.g., barcode), etc. associated with the object (e.g., embedded in the object or attached to the object, embedded in or attached to a substrate or other structure supporting the object). Subsequently, the identifier can be used to retrieve a digital representation depicting the customized geometry of the object, which can be used to identify the location of the target object portion as described above. In other embodiments, however, in other embodiments, some or all of the objects can have a uniform (e.g., standard) geometry, such that the location of the target object portion is the same or similar among the objects.

[0135] At block 506, method 500 includes applying a first energy to a subset of the object portions (target object portions). The first energy can be configured to modify at least one material property of the target object portion. For example, the first energy can cause heating, melting, coalescence, degradation, hardening, softening, chemical reactions (e.g., chemical bond formation, chemical bond breakage), morphological changes, phase changes (e.g., amorphous to crystalline, crystalline to amorphous), and / or other changes that affect the material properties.

[0136] The first energy can be any suitable type of energy, such as electromagnetic energy, acoustic energy, and / or radiant energy. In some embodiments, the first energy includes electromagnetic energy (e.g., UV, infrared, or visible light) that produces a photoreaction (e.g., dimerization, isomerization, cleavage, catalyst generation) that alters the material properties of a portion of the target object. The wavelength of the electromagnetic energy can be selected based on the material composition of the portion of the target object. For example, the wavelength can be in the UV range to produce photocuring of the portion of the target object. As another example, the wavelength can be in the infrared range to produce thermal curing and / or preheating of the portion of the target object. In another example, the wavelength can be configured to initiate a reverse photodimerization reaction to break bonds within the portion of the target object. The first energy can be the same type of energy used in an additive manufacturing process to form an object or can be a different type of energy.

[0137] Examples of material properties that can be modified by the first energy include, but are not limited to, any of the following: modulus (e.g., storage modulus), T g ensile strength, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusivity, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, and / or durability. For example, the first energy can be configured to increase or decrease the modulus of the portion of the target object by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%, 300%, 400%, or 500%. The first energy can increase or decrease the modulus of the portion of the target object by at least 50 MPa, 100 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, or 500 MPa. Alternatively or in combination, the first energy can be configured to increase or decrease the T g of the portion of the target object by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%, 300%, 400%, or 500%. The first energy can increase or decrease the T g of the portion of the target object by at least 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, or 50 °C.

[0138] In some embodiments, the first energy alters one or more local properties of the target object portion (e.g., degree of cure, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, melting point), which in turn affects the material properties of the target object portion. For example, the first energy can increase the degree of cure of the target object portion, such as by promoting bond formation (e.g., polymerization) between one or more reactive components of the target object portion, which can then increase the modulus and / or T g . Conversely, the first energy can decrease the degree of cure of the target object portion, e.g., by promoting bond breakage within the polymer network of the target object portion (e.g., depolymerization, degradation, depolymerization), which can then decrease the modulus and / or T g .

[0139] Optionally, the first energy can affect the material properties of the target object portion by altering one or more local properties that enhance or reduce material removal, as previously described herein with respect to Figure 3 Method 300. In such embodiments, the process of block 506 can also include removing material from the target object portion (e.g., via solvent, heating, vacuum) using the techniques discussed above in connection with Figure 3 .

[0140] In some embodiments, the object includes a plurality of target object portions that are intended to have different material properties. The material properties of a particular object portion can be related to the energy application parameters of the first energy used to process that object portion. Thus, some or all of the target object portions can be processed using different energy application parameters (e.g., different energy intensities, doses, exposure times, wavelengths, and / or energy types) in order to produce a desired spatial distribution of material properties. For example, the object can include a first target object portion processed using a first set of energy application parameters (e.g., a first energy dose), a second target object portion processed using a second set of energy application parameters different from the first set (e.g., a second energy dose), a third target object portion processed using a third set of energy application parameters different from the first and second sets (e.g., a third energy dose), etc., as described previously in connection with Figure 3 Method 300.

[0141] In some embodiments, the first energy is applied only selectively to the target object portion. Thus, after the process of block 506, the remaining object portion can exhibit little or no change in material properties. In such embodiments, the first energy can be applied by at least one energy source that is spatially controlled to avoid exposing the remaining object portion to the first energy. As discussed below in connection with Figure 6A and Figure 6BDescribe examples of suitable configurations for one or more energy sources.

[0142] At block 508, method 500 optionally includes applying a second energy to the entire object. The second energy can be configured to post-cure the entire object including the target object portion and the remaining object portion to further develop the material properties of the entire object. The second energy can include any suitable type of energy, such as electromagnetic energy, acoustic energy, and / or radiant energy. The second energy can be the same type of energy as the first energy, or can be a different type of energy. In some embodiments, the second energy is the same type of energy as the first energy, but is applied using different parameters (e.g., different intensity, dose, exposure time, and / or wavelength). For example, the second energy can be applied using a lower intensity, dose, and / or exposure time than the first energy. As another example, the second energy can have a different wavelength than the first energy, which can cause the penetration depth of the second energy to be different from the penetration depth of the first energy, as described herein. However, in other embodiments, block 508 is optional and can be omitted, for example, if the object is already in a post-curing step when received at block 502.

[0143] In some embodiments, the material properties of the final object (e.g., with and / or without post-curing) are configured such that the object exhibits little or no deformation (e.g., warping, bending, shrinking) after manufacturing, as previously described with respect to Figure 3 method 300. Thus, after the process of block 506 and / or the process of block 508, some or all portions of the object can exhibit one or more of the following material properties: a T of at least 50°C, 75°C, 80°C, 100°C, 125°C, 150°C, 175°C, or 200°C g ; a modulus (e.g., elastic modulus, flexural modulus, and / or storage modulus) of at least 100 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, or 1000 MPa; and / or an elongation at break of at least 40%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%, 300%, 400%, or 500% (e.g., measured at 1.7 mm / min at room temperature and / or 37°C). Alternatively or in combination, some or all object portions can exhibit deformation after production, but can be symmetrically arranged to limit any overall deformation of the object, and / or the object geometry can be adjusted to compensate for any predicted deformation, as previously described with respect to Figure 3 method 300. Optionally, after production, the object can be configured to deform or otherwise respond controllably to external stimuli, as previously described with respect to Figure 3as described in method 300.

[0144] Method 500 can vary in many different ways. In some embodiments, for example, method 500 can include Figure 5 additional processes not shown in. For example, method 500 can optionally include performing a light post-treatment before the process of block 502, after the process of block 502 and before the process of block 504, and / or after the process of block 506 and before the process of block 508. Such light post-treatment can include removing supports, cleaning materials from the object, solvent washing, etc. In another example, method 500 can also include a post-treatment after the process of block 508, such as applying a surface treatment, polishing, washing, etc.

[0145] In addition, although method 500 is described herein with respect to a single object, method 500 can be used to produce any suitable number of objects, such as dozens, hundreds, or thousands of objects. In such embodiments, some or all of the objects can have a spatially distributed customized geometry and / or material properties. For example, in an embodiment where the object is an orthodontic device, each object can be customized for a particular patient and / or for a particular treatment stage of the patient. Thus, method 500 can be repeated multiple times for different objects, where the energy application is customized for the specific geometry of each object.

[0146] Figure 6A is a partial schematic view of a system 600a for producing an object 602 having heterogeneous properties according to an embodiment of the present technology. System 600a can be used to implement any method described herein, such as Figure 5 method 500.

[0147] Object 602 can include a plurality of object parts, such as a first object part 604 and a second object part 606. When received by system 600a, object 602 can be in an initial (e.g., green) state, where the first object part 602 and the second object part 604 have the same or similar material properties. In the final (e.g., post-cured) state of object 602, the first object part 604 can be designed to have a different set of material properties from the second object part 606.

[0148] The object 602 can be received from an additive manufacturing system (not shown) and positioned on a conveyor belt 608 (or other suitable mechanism) configured to transport the object 602 through various sections of the system 600a. The object 602 can be placed on the conveyor belt 608 in a random position and / or orientation, or can be placed in a predetermined position and / or orientation. For example, in an embodiment where the object 602 is produced on a substrate (e.g., a build platform) in a known position and / or orientation, the substrate can be placed on the conveyor belt 608 in a predetermined arrangement such that the position and / or orientation of the object 602 relative to the components of the system 600a are known.

[0149] In some embodiments, the conveyor belt 608 first transports the object 602 to a sensing area 610 adjacent to or near at least one sensor 612. The sensor 612 (e.g., an imaging device) can be configured to generate sensor data (e.g., an image) of the object 602. The sensor 612 can be operatively coupled to a controller 614 (e.g., a computing device) that analyzes the sensor data to identify the position of the first object portion 604 within the object 602, as previously described.

[0150] In some embodiments, the sensor 612 has a field of view large enough such that the entire object 602 can be imaged without moving the object 602 and / or the sensor 612. Alternatively, the object 602 can be moved relative to the sensor 612, the sensor 612 can be moved relative to the object 602, or a combination thereof. Additionally, although Figure 6A the embodiments described include a single sensor 612, in other embodiments, the system 600a can include multiple sensors 612, such as two, three, four, five, 10, 20, or more sensors 612. In embodiments using multiple sensors 612, some or all of the sensors 612 can be different sensor types, and / or some or all of the sensors 612 can be positioned at different locations relative to the object 602.

[0151] Subsequently, the conveyor belt 608 can transport the object 602 to a first processing area 616 adjacent to or near a first energy source 618 (e.g., a laser). The first energy source 618 can be configured to apply a first energy targeted at the first object portion 604 in order to selectively modify the material properties of the first object portion 604 according to the techniques described in method 500 above with respect to Figure 5 For example, in Figure 6AIn an embodiment, the first energy source 618 is coupled to an actuatable device 620 (e.g., a robotic arm or gimbal) that allows the first energy source 618 to be moved to a plurality of different poses (e.g., positions and / or orientations) relative to the object 602. In such an embodiment, the controller 614 can determine the pose of the first energy source 618 such that the first energy is targeted at the first object portion 604 rather than the second object portion 606. The controller 614 can cause the actuatable device 620 to move the first energy source 618 to the determined pose and then activate the first energy source 618 to apply the first energy to the first object portion 604. Alternatively or in combination, the object 602 can be moved to a plurality of different poses relative to the first energy source 618. For example, the controller 614 can control the conveyor belt 608 to reposition the object 602 such that the first object portion 604 is within the output range of the first energy source 618 and the second object portion 606 is outside the output range of the second energy source 624.

[0152] Subsequently, the conveyor belt 608 can transport the object 602 to a second processing area 622 adjacent to or near the second energy source 624 (e.g., a UV lamp). The second energy source 624 can be configured to apply a second energy to the entire object 602 including the first object portion 604 and the second object portion 606 in order to adjust the material properties of the entire object 602. For example, the second energy source 624 can be configured to post-cure the object 602 as described previously with respect to Figure 5 method 500.

[0153] In some embodiments, the conveyor belt 608 then transports the object 602 to an output area 628 where additional post-processing can occur, such as trimming, applying a surface treatment, polishing, washing, etc. Subsequently, the object 602 can be prepared for packaging and use.

[0154] The controller 614 can be or include a computing device that includes one or more processors and a memory storing instructions for controlling the operation of the system 600a. For example, the controller 614 can be operatively coupled to the conveyor belt 608 to control the speed and / or direction of movement of the conveyor belt 608. The controller 614 can also be operatively coupled to the sensor 612 to send instructions to the sensor 612 (e.g., instructions for obtaining sensor data of the object) and receive the sensor data generated by the sensor 612. The controller 614 can also be operatively coupled to the first energy source 618 and / or the second energy source 624 to control the energy application parameters used, such as energy intensity, dose, exposure time, wavelength, etc.

[0155] Figure 6AThe system 600a can be modified in many different ways. For example, although the system 600a is shown as including a single chamber 626 that contains both the first energy source 618 and the second energy source 624, in other embodiments, the first energy source 618 can be located in a first chamber and the second energy source 624 can be located in a second separate chamber. Additionally, although Figure 6A a single sensor 612, the first energy source 618, and the second energy source 624 are shown, in other embodiments, the system 600a can include any suitable number of sensors 612, first energy sources 618, and / or second energy sources 624. Additionally, the system 600a can include Figure 6A components not shown in the figure, such as at least one additional sensor that is configured to monitor the object 602 at the first processing region 616, the second processing region 622, and / or the output region 628 to generate feedback indicating whether the applied energy has the desired result (e.g., whether the first object portion 604 is sufficiently cured by the first energy from the first energy source 618, whether the object 602 is sufficiently cured by the second energy from the second energy source 624, and whether any off-target curing has occurred). Optionally, some components of the system 600a can be omitted, such as the second energy source 624.

[0156] Figure 6B is a partial schematic view of another system 600b for post-curing an object 602 according to an embodiment of the present technology. The system 600b can generally be similar to Figure 6A the system 600a, except that the first processing region 616 includes a plurality of first energy sources 630a to 630c. The first energy sources 630a to 630c can be stationary and in a fixed position and / or orientation relative to the object 602. Each of the first energy sources 630a to 630c can be configured to output energy along a different direction. In such an embodiment, the controller 614 can be configured to identify one or more of the first energy sources 630a to 630c that output energy along a direction towards the first object portion 604 and can activate only those sources in order to selectively apply energy to the first object portion 604.

[0157] Although Figure 6B three first energy sources 630a to 630c are shown, in other embodiments, the system 600b can include a different number of first energy sources, such as two, four, five, 10, or more. Optionally, some or all of the first energy sources 630a to 630c can be movable to further improve the targeting of the first object portion 604.

[0158] The present technology can be used to produce many different types of objects having heterogeneous properties. For example, Figure 7AFIG. 0 is a perspective view of an orthodontic appliance 700 (“appliance 700”) having heterogeneous properties in accordance with an embodiment of the present technology. In the illustrated embodiment, appliance 700 includes a housing 702 having a plurality of tooth receiving cavities configured to reposition one or more teeth. In the illustrated embodiment, appliance 700 includes a first portion 704 having a first set of material properties and a second portion 706 having a different second set of material properties. The first portion 704 and the second portion 706 can be produced using any of the systems and methods described herein.

[0159] In Figure 7A , the first portion 704 is the mesial portion of the appliance and the second portion 706 is the distal portion of the appliance. In other embodiments, the first portion 704 and the second portion 706 can each independently be selected from any of the following appliance portions: a portion adjacent or near one or more teeth, a portion spaced apart from one or more teeth, a portion adjacent or near the palate, a portion adjacent or near an attachment, an outer portion, an inner portion, a distal portion, a mesial portion, an occlusal portion, a gingival portion, an interdental portion, a buccal portion, a lingual portion, and / or suitable combinations thereof. Additionally, in other embodiments, appliance 700 can include additional portions manufactured with different material properties, such as three, four, five, 10, 20, or more portions having different material properties.

[0160] For example, multiple portions of the appliance adjacent or near the interdental regions of the teeth can have different properties than other portions of the appliance to provide improved tooth repositioning forces. In some embodiments, the interdental regions of the appliance have increased stiffness and / or strength compared to the remainder of the appliance, since the interdental regions may be more prone to breakage due to stress concentration when the appliance is placed on and / or removed from the patient's teeth. Alternatively, the interdental regions of the appliance can have reduced stiffness compared to the remaining regions of the appliance, for example, to reduce stress concentration.

[0161] As another example, multiple portions of the appliance configured to engage an attachment on a tooth can have different properties than other portions of the appliance to enhance control of the forces applied to the tooth via the attachment. In another example, in embodiments where appliance 700 is manufactured with a plurality of supports (not shown) for additive manufacturing, appliance 700 can have different material properties than the supports. In some embodiments, inverse photo-dimerization is used to mechanically weaken the supports such that it is easier to remove appliance 700 from the supports during post-processing.

[0162] Figure 7BIs a perspective view of an expander 708 with heterogeneous properties according to an embodiment of the present technology. The expander 708 (also referred to herein as a "palatal expander" or "arch expander") is another type of orthodontic device that can be produced using the techniques described herein. The expander 708 includes an expander portion 710 configured to be positioned adjacent to the patient's palate and a tooth engagement portion 712 coupled to opposite sides of the expander portion 710 and including a plurality of tooth receiving cavities. During use, the expander portion 710 can apply a force to teeth on opposite sides of the patient's oral cavity to expand the patient's palate.

[0163] In some embodiments, the expander portion 710 has different material properties than the tooth engagement portion 712. For example, the expander portion 710 can have a higher modulus, T g and / or strength than the tooth engagement portion 712 in order to apply sufficient force to widen the palate. This configuration can be achieved using any of the methods described herein. For example, the expander portion 710 can be selectively preheated, cured, and / or post-cured to enhance the mechanical properties of the expander portion 710 relative to the tooth engagement portion 712.

[0164] Figure 7C Is a perspective view of an attachment 714 of an attachment placement device with heterogeneous properties according to an embodiment of the present technology. The attachment 714 can be considered a type of orthodontic device since it can be used in conjunction with another device (e.g., Figure 7A the device 700) to apply a force to the patient's teeth. In the illustrated embodiment, the attachment 714 is attached to a sacrificial structure 716 that is configured to support the attachment 714 during manufacturing and / or post-processing. The sacrificial structure 716 can include a plurality of elongate support members 718 (e.g., struts) coupled to the attachment 714, a frame 720 coupled to the support members 718 and surrounding the attachment 714, and a base 722 coupled to the frame 720. This configuration can be beneficial for facilitating the manufacture, post-processing, and / or manipulation of the relatively small attachment 714.

[0165] In some embodiments, the sacrificial structure 716 is part of an attachment placement device configured to position the attachment 714 at a predetermined location on the patient's teeth. In such embodiments, the base 722 can be shaped to couple to the patient's teeth such that the attachment 714 is adjacent to the teeth at the desired location. Subsequently, the attachment 714 can be coupled to the tooth surface, and the support members 718 can be separated from the attachment 714 to allow removal of the attachment placement device while leaving the attachment 714 in place.

[0166] In some embodiments, the attachment 714 has different material properties than the sacrificial structure 716. For example, the attachment 714 may require higher mechanical strength and may thus be selectively cured using a higher energy intensity. In contrast, the sacrificial structure 716 may require less mechanical strength but greater flexibility for durability and / or operation and may thus be selectively cured using a lower energy intensity.

[0167] Although Figures 7A to 7C embodiments describe devices having uniform material properties over a relatively large area, the techniques herein can be used to create patterns of different material properties such as gradients, lattices, stripes, stitches, zigzags, etc. The geometry and location of the patterned properties can vary as needed. For example, the pattern can be designed to distribute stress over a larger portion of the device, transfer stress from one part of the device to another part of the device, and / or reduce stress concentration by avoiding sharp transitions between properties. III. Dental instrument and associated method

[0168] Figure 8A A representative example of a tooth repositioning device 800 configured in accordance with an embodiment of the present technology is shown. The device 800 can be manufactured and post-processed using any of the systems, methods, and devices described herein. The device 800 (also referred to herein as an "appliance") can be worn by a patient to effect progressive repositioning of an individual tooth 802 in the jaw. The device 800 can include a housing (e.g., a continuous polymeric housing or a segmented housing) having a tooth receiving cavity that receives and elastically repositions the tooth. The device 800 or portions thereof can be indirectly produced using a physical model of the tooth. For example, the device (e.g., a polymeric device) can be formed using a physical model of the tooth and appropriate sheets of (multi)layer polymeric material. In some embodiments, a physical appliance is directly produced from a digital model of the appliance, e.g., using additive manufacturing techniques.

[0169] The appliance 800 can be configured to fit over all of the teeth in the upper or lower jaw, or less than all of the teeth. The appliance 800 can be specifically designed to accommodate the patient's teeth (e.g., the morphology of the tooth receiving cavities matches the morphology of the patient's teeth), and can be manufactured based on a positive or negative model of the patient's teeth generated by an impression, scan, etc. Alternatively, the appliance 800 can be a general purpose appliance configured to receive teeth, and not necessarily shaped to match the morphology of the patient's teeth. In some cases, the appliance 800 only relocates certain teeth received by the appliance 800, while other teeth can provide a base or anchoring area for holding the appliance 800 in place when a force is applied to one or more teeth that are the target of the relocation. In some cases, some, most, or even all of the teeth can be relocated at some point during treatment. The moved teeth can also be used as a base or anchor for holding the appliance while the patient wears the orthodontic device. In a preferred embodiment, no wires or other devices are provided to hold the appliance 800 in place above the teeth. However, in some cases, it may be desirable or necessary to provide a single attachment 804 or other anchoring element on the tooth 802, with a corresponding receptacle 806 or hole in the appliance 800, such that the appliance 800 can apply a selected force on the tooth. Representative examples of appliances, including those for the Invis ( ) systems are described in a number of patents and patent applications of Align Technology, Inc., including, for example, U.S. Patent Nos. 6,450,807 and 5,975,893, as well as on the company's website, which is accessible on the World Wide Web (see, for example, the URL "invisalign.com"). Examples of tooth-mounted attachments suitable for orthodontic appliances are also described in patents and patent applications of Align Technology, Inc., including, for example, U.S. Patent Nos. 6,309,215 and 6,830,450.

[0170] Figure 8BFIG. 810 shows a tooth repositioning system 810 according to an embodiment of the present technology, including a plurality of instruments 812, 814, 816. Any of the instruments described herein may be designed and / or provided as part of a set of multiple instruments for use in a tooth repositioning system. Each instrument may be configured such that the tooth receiving cavity has a geometry corresponding to the intermediate or final tooth arrangement anticipated for that instrument. By placing a series of progressive position adjustment instruments on a patient's teeth, the patient's teeth can be gradually repositioned from an initial tooth arrangement to a target tooth arrangement. For example, the tooth repositioning system 810 may include a first instrument 812 corresponding to the initial tooth arrangement, one or more intermediate instruments 814 corresponding to one or more intermediate arrangements, and a final instrument 816 corresponding to the target arrangement. The target tooth arrangement may be the planned final tooth arrangement selected for the patient's teeth at the end of all planned orthodontic treatment. Alternatively, the target arrangement may be one of some intermediate arrangements for the patient's teeth during orthodontic treatment, which may include a variety of different treatment scenarios, including but not limited to cases where surgery is recommended, cases suitable for interproximal reduction (IPR), cases where progress checks are scheduled, cases where anchor placement is optimal, cases where palatal expansion is desired, cases involving restorative dentistry (e.g., inlays, onlays, crowns, bridges, implants, veneers, etc.), and the like. Thus, it should be understood that the target tooth arrangement may be any planned final arrangement (resulting arrangement) of the patient's teeth following one or more progressive repositioning phases. Similarly, the initial tooth arrangement may be any initial arrangement of the patient's teeth, followed by one or more progressive repositioning phases.

[0171] Figure 8CIllustrated is a method 820 for orthodontic treatment using multiple instruments according to an embodiment of the present technology. The method 820 can be implemented using any instrument or group of instruments described herein. In block 822, a first orthodontic instrument is applied to the patient's teeth to reposition the teeth from a first tooth alignment to a second tooth alignment. In block 824, a second orthodontic instrument is applied to the patient's teeth to reposition the teeth from the second tooth alignment to a third tooth alignment. The method 820 can be repeated as needed using any suitable number of sequential instruments and combinations thereof to progressively reposition the patient's teeth from an initial alignment to a target alignment. All of the instruments of the instrument set can be generated in the same phase or in groups or batches (e.g., at the start of a treatment phase); alternatively, the instruments can be produced one at a time, and the patient can wear each instrument until the patient can no longer feel the pressure of each instrument on the teeth or until the maximum amount of tooth movement expressed for the given phase has been achieved. Multiple different instruments (e.g., a set) can be designed and even produced before the patient wears any of the multiple instruments. After a suitable period of wearing the instrument, the patient can replace the current instrument with the next instrument in the series until no instruments remain. The instruments are generally not fixed to the teeth, and the patient can place and replace the instruments at any time during the course of treatment (e.g., patient-removable instruments). The final instrument or several instruments in the series can have one or more selected geometries for overcorrecting the tooth alignment. For example, one or more instruments can have a geometry that would (if fully achieved) move an individual tooth beyond the tooth alignment that has been selected as "final". Such overcorrection may be desirable to counteract potential relapse after the repositioning method has ended (e.g., movement that would allow the individual teeth to return back toward their pre-corrected positions). Overcorrection can also be beneficial for accelerating the correction rate (e.g., an instrument with a geometry positioned beyond the desired intermediate or final position can cause the individual teeth to shift toward that position at a greater rate). In such a case, the use of the instrument can be terminated before the teeth reach the position defined by the instrument. Additionally, overcorrection can be intentionally applied to compensate for any inaccuracies or limitations of the instrument.

[0172] Figure 9 Illustrated is a method 900 for designing an orthodontic instrument according to an embodiment of the present technology. The method 900 can be applied to any embodiment of the orthodontic instrument described herein. Some or all steps of the method 900 can be performed by any suitable data processing system or device, e.g., one or more processors configured with suitable instructions.

[0173] In block 902, a movement path for moving one or more teeth from an initial alignment to a target alignment is determined. The initial alignment can be determined from a model or scan of the patient's teeth or oral tissues, for example, using a wax bite, direct contact scanning, x-ray imaging, tomography, sonogram imaging, and other techniques for obtaining information about the position and structure of teeth, jaws, gums, and other orthodontically relevant tissues. From the acquired data, a digital data set representing the initial (e.g., pre-treatment) alignment of the patient's teeth and other tissues can be derived. Optionally, the initial digital data set is processed to segment the tissue components from each other. For example, a data structure digitally representing an individual tooth crown can be generated. Advantageously, a digital model of a complete tooth can be generated, including measured or extrapolated hidden surfaces and root structures, as well as the surrounding bone and soft tissues.

[0174] The target alignment of the teeth (e.g., the desired and expected final result of orthodontic treatment) can be received from a clinician in the form of a prescription, can be calculated from basic orthodontic principles, and / or can be extrapolated from a clinical prescription calculation. Using the specification of the desired final positions of the teeth and the digital representation of the teeth themselves, the final position and surface geometry of each tooth can be specified to form a complete model of the tooth alignment at the end of the desired treatment.

[0175] If the initial and target positions of each tooth are available, a movement path can be defined for the movement of each tooth. In some embodiments, the movement path is configured to move the tooth in the fastest way with a minimum amount of back-and-forth movement to bring the tooth from its initial position to its desired target position. The tooth path can optionally be segmented, and segments can be calculated such that the movement of each tooth within a segment remains within threshold limits of linear and rotational translation. In this way, the endpoints of each path segment can constitute a clinically feasible repositioning, and the set of segment endpoints can constitute a clinically feasible sequence of tooth positions such that moving from one point in the sequence to the next does not cause tooth collisions.

[0176] In block 904, a force system for generating the movement of the one or more teeth along the movement path is determined. The force system can include one or more forces and / or one or more torques. Different force systems can result in different types of tooth movement, such as tipping, translation, rotation, extrusion, intrusion, root movement, etc. Biomechanical principles, modeling techniques, force calculation / measurement techniques, etc., including knowledge and methods commonly used in orthodontics, can be used to determine the appropriate force system to be applied to the teeth to accomplish the tooth movement. When determining the force system to be applied, sources including literature, force systems determined experimentally or by virtual modeling, computer-based modeling, clinical experience, minimization of unwanted forces, etc., can be considered.

[0177] Determination of the force system can include constraints on the allowed forces, such as allowed directions and magnitudes, as well as the desired movement caused by the applied forces. For example, in producing a palatal expander, different patients may require different movement strategies. For example, the amount of force required to separate the palate can depend on the patient's age, since very young patients may not yet have fully formed sutures. Thus, in adolescent patients and other patients with not yet fully closed palatal sutures, a lower magnitude of force can be utilized to effect palatal expansion. Slower palatal movement can also contribute to bone growth to fill the expanded sutures. For other patients, a more rapid expansion may be required, which can be achieved by applying greater forces. These requirements can be combined as needed to select the structure and materials of the instrument; for example, by selecting a palatal expander capable of applying large forces to tear the palatal sutures and / or cause rapid palatal expansion. Subsequent instrument phases can be designed to apply different amounts of force, such as first applying large forces to tear the sutures and subsequently applying smaller forces to keep the sutures separated or to gradually expand the palate and / or dental arch.

[0178] Determination of the force system can also include modeling the patient's facial structure, such as the skeletal structure of the jaw and palate. Scan data of the palate and dental arch, such as X-ray data or 3D optical scan data, for example, can be used to determine parameters of the skeletal and muscular systems of the patient's oral cavity in order to determine the forces sufficient to provide the desired expansion of the palate and / or dental arch. In some embodiments, the thickness and / or density of the palatal suture can be measured or input by a professional therapist. In other embodiments, the professional therapist can select an appropriate treatment based on the patient's physiological characteristics. For example, the nature of the palate can also be estimated based on factors such as the patient's age; for example, younger adolescent patients may require smaller forces than older patients to expand the sutures, since the sutures are not yet fully formed.

[0179] In block 906, a design of an orthodontic instrument configured to produce a force system is determined. The design can include instrument geometry, material composition, and / or material properties, and can be determined in various ways, such as using a treatment or force application simulation environment. The simulation environment can include, for example, a computer modeling system, a biomechanical system, or a device, etc. Optionally, a digital model of the instrument and / or teeth can be generated, such as a finite element model. The finite element model can be created using computer program application software obtained from various suppliers. To create a solid geometry model, a computer-aided engineering (CAE) or computer-aided design (CAD) program can be used, such as those available from Autodesk, Inc. of San Rafael, California Software products. To create and analyze finite element models, program products from multiple vendors can be used, including the finite element analysis package from ANSYS, Inc. of Canonsburg, Pennsylvania, and the SIMULIA (Abaqus) software product from Dassault Systèmes of Waltham, Massachusetts.

[0180] Optionally, one or more can be selected for testing or force modeling. As described above, the desired tooth movement and the force system required or desired to effect the desired tooth movement can be identified. Using a simulation environment, candidate designs can be analyzed or modeled to determine the actual force system generated by the use of the candidate device. Optionally, one or more modifications can be made to the candidate device, and the force modeling can be further analyzed as described, for example, to iteratively determine the device design that produces the desired force system.

[0181] In block 908, instructions are generated for producing an orthodontic device incorporating the design. The instructions can be configured to control a production system or apparatus to produce an orthodontic device having the specified design. In some embodiments, the instructions are configured to manufacture the orthodontic device using direct production (e.g., stereolithography, selective laser sintering, fused deposition modeling, 3D printing, continuous direct production, multi-material direct production, etc.) according to the various methods presented herein. In alternative embodiments, the instructions can be configured to indirectly produce the device, e.g., by thermoforming.

[0182] Although the above steps illustrate method 900 for designing an orthodontic device according to some embodiments, those of ordinary skill in the art will recognize some variations based on the teachings described herein. Some steps can include sub-steps. Some steps can be repeated as often as needed. One or more steps of method 900 can be performed using any suitable manufacturing system or apparatus, such as the embodiments described herein. Some steps can be optional, and the order of the steps can be changed as needed.

[0183] Figure 10 Method 1000 for digitally planning orthodontic treatment and / or the design or manufacture of a device according to an embodiment is shown. Method 1000 can be applied to any treatment procedure described herein and can be executed by any suitable data processing system.

[0184] In block 1002, a digital representation of a patient's teeth is received. The digital representation can include surface topography data of the patient's oral cavity (including teeth, gingival tissue, etc.). The surface topography data can be generated by directly scanning the oral cavity, a physical model (positive or negative model) of the oral cavity, or an impression of the oral cavity using a suitable scanning device (e.g., a hand-held scanner, a desktop scanner, etc.).

[0185] In block 1004, one or more treatment phases are generated based on the digital representation of the teeth. The treatment phases can be progressive repositioning phases of an orthodontic treatment procedure that is designed to move one or more of the patient's teeth from an initial tooth alignment to a target alignment. For example, the treatment phases can be generated by determining the initial tooth alignment indicated by the digital representation, determining the target tooth alignment, and determining the movement paths necessary for one or more teeth in the initial alignment to achieve the target tooth alignment. The movement paths can be optimized based on minimizing the total distance of the movement, preventing collisions between teeth, avoiding more difficult-to-achieve tooth movements, or any other suitable criteria.

[0186] In block 1006, at least one orthodontic appliance is produced based on the generated treatment phases. For example, a set of appliances can be produced, each appliance being shaped according to the tooth alignment specified by a treatment phase, such that the patient can sequentially wear the appliances to progressively reposition the teeth from the initial alignment to the target alignment. The set of appliances can include one or more of the orthodontic appliances described herein. The production of the appliance can include creating a digital model of the appliance for use as an input to a computer-controlled production system. As needed, direct production methods, indirect production methods, or a combination thereof can be used to form the appliance.

[0187] In some cases, the design and / or production of the appliance may not require staging of the various alignments or treatment phases. As Figure 10 shown by the dashed line in, the design and / or production of an orthodontic appliance, and possibly a particular orthodontic treatment, can include using a representation of the patient's teeth (e.g., including receiving a digital representation of the patient's teeth (block 1002)), and subsequently designing and / or producing the orthodontic appliance based on the representation of the patient's teeth in the alignment represented by the received representation.

[0188] As described herein, the techniques described herein can be used to directly produce dental appliances, such as an appliance and / or a series of appliances having a tooth receiving cavity, which are configured to move a person's teeth from an initial alignment towards a target alignment according to a treatment plan. The appliance can include a mandibular repositioning element, such as that described in U.S. Patent No. 10,912,629, entitled "Dental Appliances with Repositioning Jaw Elements," filed on November 30, 2015; U.S. Patent No. 10,537,406, entitled "Dental Appliances with Repositioning Jaw Elements," filed on September 19, 2014; and U.S. Patent No. 9,844,424, entitled "Dental Appliances with Repositioning Jaw Elements," filed on February 21, 2014; all of which are incorporated herein by reference in their entirety.

[0189] The techniques used herein can also be used to fabricate attachment placement devices, e.g., instruments for positioning pre-fabricated attachments on a person's teeth in accordance with one or more aspects of a treatment plan. Examples of attachment placement devices (also referred to as "attachment placement templates" or "attachment fabrication templates") can be found at least in the following documents: U.S. Patent No. 17 / 249,218, entitled "Flexible 3D Printed Orthodontic Device," filed on February 24, 2021; U.S. Patent No. 16 / 366,686, entitled "Dental Attachment Placement Structure," filed on March 27, 2019; U.S. Patent No. 15 / 674,662, entitled "Devices and Systems for Creation of Attachments," filed on August 11, 2017; U.S. Patent No. 11,103,330, entitled "Dental Attachment Placement Structure," filed on June 14, 2017; U.S. Patent No. 14 / 963,527, entitled "Dental Attachment Placement Structure," filed on December 9, 2015; U.S. Patent No. 14 / 939,246, entitled "Dental Attachment Placement Structure," filed on November 12, 2015; U.S. Patent No. 14 / 939,252, entitled "Dental Attachment Formation Structures," filed on November 12, 2015; and U.S. Patent No. 9,700,385, entitled "Attachment Structure," filed on August 22, 2014; all of which are incorporated herein by reference in their entirety.

[0190] The techniques described herein can be used to fabricate a progressive palatal expander and / or a series of progressive palatal expanders for expanding a person's palate from an initial position towards a target position in accordance with one or more aspects of a treatment plan. Examples of progressive palatal expanders can be found at least in the following documents: U.S. Patent No. 16 / 380,801, entitled "Releasable Palatal Expanders," filed on April 10, 2019; U.S. Patent No. 16 / 022,552, entitled "Devices, Systems, and Methods for Dental Arch Expansion," filed on June 28, 2018; U.S. Patent No. 11,045,283, entitled "Palatal Expander with Skeletal Anchorage Devices," filed on June 8, 2018; U.S. Patent No. 15 / 831,159, entitled "Palatal Expanders and Methods of Expanding a Palate," filed on December 4, 2017; U.S. Patent No. 10,993,783, entitled "Methods and Apparatuses for Customizing a Rapid Palatal Expander," filed on December 4, 2017; and U.S. Patent No. 7,192,273, entitled "System and Method for Palatal Expansion," filed on August 7, 2003; all of which are hereby incorporated by reference in their entirety. Example

[0191] The following examples are included to further describe some aspects of the technology and should not be used to limit the scope of the technology. Example 1: Mechanical properties of samples fabricated using different energy doses

[0192] This example describes the mechanical properties of samples fabricated via DLP using different energy doses. The resin formulation includes: (1) a monofunctional methacrylate-based reactive diluent having a low molecular weight and a high T g ; (2) an oligomeric crosslinker having four functional groups with an Mw of about 2 kDa and a low T g ; (3) having a high molecular weight and a low T gA low - molecular - weight cross - linker with four functional groups; (4) a photoinitiator, and (5) a UV blocker. Using a Cubicure Caligma DLP printer, a rectangular sample of 50 mm x 4 mm x 1 mm was printed in the xzy printing direction at a wavelength of 365 nm and a printing temperature of 60 °C. Sample 1 was printed using a 3 / 3 DLP energy dose (“full white”), corresponding to a light intensity of 45 mW / cm 2 and an exposure time of 1 second. Sample 2 was printed using a 1 / 3 DLP energy dose (“full gray”), corresponding to a light intensity of 45 mW / cm 2 and an exposure time of 1 / 3 second. After printing, the green - state samples were soaked in isopropyl alcohol for 10 minutes, air - dried overnight, dried at 60 °C for 2 hours, and then post - cured at 100 mW / cm 2 intensity at 385 nm for 10 minutes. Subsequently, the samples were mechanically tested using a TA Instruments DMA Q850 dynamic mechanical analyzer, which had a three - point bending setup at 5% strain. The samples were immersed in water at 37 °C during the test.

[0193] Figure 11 is a graph showing the stress relaxation curves at 5% strain obtained for Sample 1 (triangles) and Sample 2 (squares). The storage modulus of Sample 1 at 37 °C was 920 MPa; the storage modulus of Sample 1 at 37 °C was 920 MPa; the storage modulus of Sample 2 at 37 °C was 710 MPa (about 30% lower than that of Sample 1). Assuming that compared with Sample 1, the lower energy dose used to print Sample 2 reduced the DBC of Sample 2, thus allowing more reactive diluent to be removed from Sample 2 during isopropyl alcohol soaking. Since the reactive diluent has the highest polymer modulus among all formulation components, the storage modulus of Sample 2 after post - treatment is lower than that of Sample 1. Example 2: Mechanical properties of multi-layer samples

[0194] This example describes the mechanical properties of a multi - layer sample fabricated via grayscale DLP patterning.

[0195] Figure 12A is a side - view of the structure of Sample 3. The dimensions of Sample 3 are 50 mm x 4 mm x 1 mm. Sample 3 consists of three layers: two 200 - μm outer layers printed using a 1 / 3 DLP energy dose (“gray pixels”), and a 600 - μm inner layer printed using a 3 / 3 DLP energy dose (“white pixels”). The resin formulation and printing protocol are the same as those described in Example 1 above.

[0196] Figure 12BShows the experimental setup for the three-point bending test of Sample 3. The test was conducted in water at 37 °C using the protocol described in Example 1 above.

[0197] Figure 12C Is a graph showing the stress relaxation curves of Sample 1 (triangle), Sample 2 (square), and Sample 3 (circle) at 5% strain. The initial modulus of Sample 3 (multilayer) is higher than that of Sample 2 (fully gray) and lower than that of Sample 1 (fully white). Example 3: Glycosylation formulations for fabricating objects with heterogeneous properties

[0198] This example describes a glycosyl formulation for manufacturing an object with heterogeneous properties.

[0199] The sugar is mixed with a high molecular weight amphiphilic monomer, an oligomeric photoinitiator, and a water-soluble light blocker. The formulation is used to produce a layered printed object using SLA. The object geometry includes an outer sphere and an inner cube within the outer sphere. The outer sphere is formed with a 50% light dose, while the inner cube is formed with a 100% light dose. After printing, the object is placed in water for a predetermined time, which corresponds to the preferential dissolution of the sugar from the outer sphere. After drying and curing with sufficient light to cause the remaining monomers to react completely, the inner cube contains more sugar than the outer sphere, causing differences in modulus, flavor, color, transparency, and other properties. The object can also exhibit varying responses during later use. For example, if the object is placed back in water, the outer sphere can control the rate of water diffusion into the inner cube. Thus, after a long time, the inner cube can swell with water to create an internal osmotic pressure and / or can slowly release the sugar into the outer sphere and the surrounding water. Additional examples

[0200] For convenience, additional examples of aspects of the present technology are described below as numbered clauses (1, 2, 3, etc.). These are provided as examples and do not limit the claimed technology.

[0201] 1. A method, comprising: Receiving a digital data set representing a dental instrument; Applying energy to a curable material based on the digital data set to form a dental instrument, wherein the dental instrument includes at least two instrument parts formed from the curable material using different energy application parameters; and removing residual curable material from the dental instrument, wherein different amounts of residual curable material are removed from each of the at least two instrument parts, and wherein after removing the residual curable material, each of the at least two instrument parts has a non- different material properties, and each of the at least two instrument parts has one or more of the following: (1) a glass transition temperature of at least 80°C or (2) a modulus of at least 200 MPa.

[0202] 2. The method according to clause 1, wherein the at least two instrument parts include a first instrument part and a second instrument part, and different energy application parameters are selected to enhance the removal of residual curable material from the first instrument part compared to the second instrument part.

[0203] 3. The method according to clause 1, wherein the at least two instrument parts include a first instrument part and a second instrument part, and different energy application parameters are selected to reduce the removal of residual curable material from the first instrument part compared to the second instrument part.

[0204] 4. The method according to any one of clauses 1 to 3, wherein removing residual curable material from the dental instrument includes one or more of the following: exposing the dental instrument to a solvent, applying heat to the dental instrument, or applying a vacuum to the dental instrument.

[0205] 5. The method according to any one of clauses 1 to 4, wherein the residual curable material comprises residual monomer, residual oligomer, or a combination thereof.

[0206] 6. The method according to any one of clauses 1 to 5, wherein the different energy application parameters include differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

[0207] 7. The method according to any one of clauses 1 to 6, wherein the different energy application parameters cause the at least two instrument parts to differ from each other in one or more of the following: degree of curing of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0208] 8. The method according to any one of clauses 1 to 7, wherein the different material properties of the at least two instrument parts are produced by different amounts of residual curable material removed from each of the at least two instrument parts.

[0209] 9. The method according to any one of clauses 1 to 8, wherein the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0210] 10. The method according to any one of clauses 1 to 9, wherein the curable material includes a resin.

[0211] 11. The method according to any one of clauses 1 to 10, wherein the dental device is formed from a single type of curable material.

[0212] 12. The method according to any one of clauses 1 to 11, wherein energy is applied to the curable material according to an additive manufacturing process.

[0213] 13. A method comprising: Receiving a digital data set representing a dental device; Applying energy to a curable material based on the digital data set to form a dental device, wherein the dental device includes at least two device portions formed using different energy application parameters; and Removing residual curable material from the dental device by exposing the dental device to a solvent, wherein the solvent is selected to penetrate differently into the at least two device portions such that different amounts of residual curable material are removed from each of the at least two device portions, and wherein after removing the residual curable material, each of the at least two device portions has different material properties.

[0214] 14. The method according to clause 13, wherein the at least two device portions include a first device portion and a second device portion, and the different energy application parameters are selected to enhance the penetration of the solvent into the first device portion compared to the second device portion.

[0215] 15. The method according to clause 13, wherein the at least two device portions include a first device portion and a second device portion, and the different energy application parameters are selected to reduce the penetration of the solvent into the first device portion compared to the second device portion.

[0216] 16. The method according to any one of clauses 13 to 15, wherein the solvent comprises one or more of acetic acid, acetone, acetonitrile, ammonia, benzene, butanol, butyl acetate, camphor, carbon tetrachloride, chloroform, cyclohexanone, diethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, isoamyl acetate, ethyl cellosolve, ethyl lactate, ethylene glycol, eugenol, glycerol, heptane, hexane, isoamyl acetate, isopropyl acetate, isopropanol, liquid or low melting point sugar, low melting point or high melting point wax, menthol, methanol, dichloromethane, phenol, propanol, propylene carbonate, propylene glycol, pressurized gas, silicone oil, soapy water, supercritical carbon dioxide, tetrahydrofuran, toluene, triacetin, turpentine, vanillin, vegetable oil, water, xylene.

[0217] 17. The method according to any one of clauses 13 to 16, wherein the residual curable material comprises residual monomers, residual oligomers or a combination thereof.

[0218] 18. The method according to any one of clauses 13 to 17, wherein the different energy application parameters comprise differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength or energy type.

[0219] 19. The method according to any one of clauses 13 to 18, wherein the different energy application parameters cause the at least two instrument parts to differ from each other in one or more of the following: degree of curing of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area or melting point.

[0220] 20. The method according to any one of clauses 13 to 19, wherein the different material properties comprise differences in one or more of the following: modulus, glass transition temperature, elongation at break, elongation at yield, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology or durability.

[0221] 21. A method comprising: receiving a dental instrument formed using an additive manufacturing process, the dental instrument comprising a plurality of instrument parts; identifying the location on the dental instrument of a subset of the instrument parts based on sensor data; and applying energy to the subset of the instrument parts to selectively modify one or more material properties.

[0222] 22. The method according to clause 21, wherein the dental instrument is received in a partially cured state, and the energy is configured to increase the degree of cure of a subset of the instrument parts.

[0223] 23. The method according to clause 21, wherein the dental instrument is received in a partially cured state, and the energy is configured to decrease the degree of cure of a subset of the instrument parts.

[0224] 24. The method according to clause 21, wherein the dental instrument is received in a post-cured state.

[0225] 25. The method according to any one of clauses 21 to 24, wherein applying energy to a subset of the instrument parts causes one or more of the following changes in the subset of the instrument parts: degree of cure, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0226] 26. The method according to any one of clauses 21 to 25, wherein the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, elongation at yield, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0227] 27. The method according to any one of clauses 21 to 26, further comprising applying a second energy to the entire dental instrument.

[0228] 28. The method according to clause 27, wherein the second energy is different from the energy applied to the subset of the instrument parts.

[0229] 29. The method according to clause 28, wherein the second energy is different from the energy in one or more of the following aspects: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

[0230] 30. The method according to any one of clauses 21 to 29, wherein the dental instrument is a first dental instrument, and the method further comprises: receiving a second dental instrument formed using an additive manufacturing process, the second dental instrument comprising a plurality of second instrument parts, wherein the second dental instrument has a different geometry from the first dental instrument; identifying the location of a subset of the second instrument parts on the second dental instrument based on sensor data; and applying energy to the subset of the second instrument parts so as to selectively modify the subset of the second instrument parts One or more material properties.

[0231] 31. A system for manufacturing a dental instrument, the system comprising: At least one sensor; At least one energy source configured to output energy; A processor; and A memory operatively coupled to the processor and storing instructions that, when executed by the processor, cause the system to perform operations including: Receiving sensor data of an additive manufactured dental instrument having a plurality of instrument parts from the at least one sensor, Determining the location of a subset of the instrument parts on the additive manufactured dental instrument based on the sensor data, and applying energy from the at least one energy source to the subset of the instrument parts so as to selectively modify One or more material properties of the subset of the instrument parts.

[0232] 32. The system according to clause 31, wherein the at least one sensor includes an imaging device.

[0233] 33. The system according to clause 31 or 32, wherein the at least one energy source is movable to a plurality of different postures.

[0234] 34. The system according to any one of clauses 31 to 33, wherein the at least one energy source includes a plurality of energy sources configured to output energy in different directions.

[0235] 35. The system according to any one of clauses 31 to 34, wherein the additive manufactured dental instrument is received in a partially cured state, and the energy is configured to increase or decrease the degree of curing of the subset of the instrument parts.

[0236] 36. The system according to any one of clauses 31 to 35, wherein applying energy to the subset of the instrument parts causes one or more of the following changes in the subset of the instrument parts: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0237] 37. A system according to any of clauses 31 to 36, wherein the one or more material properties include one or more of: modulus, glass transition temperature, elongation at break, elongation at yield, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology or durability.

[0238] 38. The system of any of clauses 31 to 37, further comprising at least one second energy source configured to output a second energy, wherein operation further comprises applying the second energy to the entire additively manufactured dental instrument.

[0239] 39. The system of any of clauses 31 to 38, further comprising at least one second sensor configured to detect an identifier associated with the additively manufactured dental instrument.

[0240] 40. The system of clause 39, wherein the operations further comprise: Retrieval of digital data representing a target distribution of material properties of an additively manufactured dental device based on an identifier Set, and Positions of a subset of the device parts on the additively manufactured dental device are determined based on the target distribution.

[0241] 41. A method comprising: receiving a digital data set representing an object; Applying energy to a curable material based on the digital data set to form an object, wherein the object includes at least two object portions formed from a curable material using different energy application parameters; and Removing residual curable material from an object, wherein a different amount of residual curable material is removed from each of the at least two object parts, as well as wherein, after removing the residual curable material, each of the at least two object portions has different material properties, and each of the at least two object portions has (1) A glass transition temperature of at least 80°C and / or (2) a modulus of at least 200 MPa.

[0242] 42. The method of clause 41, wherein the curable material comprises a resin.

[0243] 43. The method according to clause 41 or 42, wherein the curable material is provided in a liquid or semi-liquid state, and applying energy to the curable material causes the curable material to transform into a solid or semi-solid state.

[0244] 44. The method according to any one of clauses 41 to 43, wherein the curable material comprises a plurality of low molecular weight components that react upon application of energy to form higher molecular weight components.

[0245] 45. The method according to any one of clauses 41 to 44, wherein the object is formed from a single type of curable material.

[0246] 46. The method according to any one of clauses 41 to 45, wherein energy is applied to the curable material according to an additive manufacturing process.

[0247] 47. The method according to clause 46, wherein the digital data set comprises instructions for producing the object via an additive manufacturing process.

[0248] 48. The method according to clause 46 or 47, wherein the additive manufacturing method comprises a vat polymerization process.

[0249] 49. The method according to any one of clauses 41 to 48, wherein the digital data set comprises instructions for applying energy to the curable material with different energy application parameters.

[0250] 50. The method according to clause 49, wherein the instructions for applying energy to the curable material comprise: a plurality of coordinates, each coordinate representing a position in the object, and a plurality of grayscale values, each grayscale value associated with a corresponding coordinate and representing an energy application parameter for a corresponding position in the object position.

[0251] 51. The method according to any one of clauses 41 to 50, wherein the energy comprises one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

[0252] 52. The method according to any one of clauses 41 to 51, wherein at least two object portions comprise a first object portion and a second object portion, and different energy application parameters are selected to enhance removal of residual curable material from the first object portion compared to the second object portion.

[0253] 53. The method according to any one of clauses 41 to 51, wherein the at least two object portions comprise a first object portion and a second object portion, and different energy application parameters are selected to reduce removal of residual curable material from the first object portion compared to the second object portion.

[0254] 54. A method according to any one of clauses 41 to 53, wherein the different energy application parameters include differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

[0255] 55. A method according to any one of clauses 41 to 54, wherein the different energy application parameters cause the at least two object portions to differ from each other in one or more of the following: degree of curing of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0256] 56. A method according to any one of clauses 41 to 55, wherein the different material properties of the at least two object portions are produced by different amounts of residual curable material removed from each of the at least two object portions.

[0257] 57. A method according to any one of clauses 41 to 56, wherein the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0258] 58. A method according to any one of clauses 41 to 57, wherein removing residual curable material from the object includes one or more of the following: exposing the object to a solvent, applying heat to the object, or applying a vacuum to the object.

[0259] 59. A method according to any one of clauses 41 to 58, wherein the geometry of the object before removing the residual curable material is substantially the same as the geometry of the object after removing the residual curable material.

[0260] 60. A method according to any one of clauses 41 to 59, wherein applying energy to the curable material to form the object includes: forming a first object portion using a first set of energy application parameters, and forming a second object portion using a second set of energy application parameters different from the first set of energy application parameters.

[0261] 61. A method according to clause 60, wherein the first object portion and the second object portion are symmetrically arranged such that, after removing the residual curable material, the object exhibits substantially no deformation.

[0262] 62. The method according to any one of clauses 41 to 61 further includes post-curing the object after the residual curable material has been removed.

[0263] 63. The method according to clause 62, wherein after post-curing, each of the at least two object parts exhibits one or more of the following: a glass transition temperature of at least 80 °C, an elongation at break of at least 50% at 1.7 mm / min, or a modulus of at least 200 MPa.

[0264] 64. The method according to clause 62 or 63, wherein after post-curing, the entire object exhibits one or more of the following: a glass transition temperature of at least 80 °C, an elongation at break of at least 50% at 1.7 mm / min, or a modulus of at least 200 MPa.

[0265] 65. The method according to any one of clauses 41 to 64, wherein the object includes a dental instrument.

[0266] 66. A method includes: Receiving a digital data set representing an object; Applying energy to a curable material based on the digital data set to form an object, wherein the object includes at least two object parts formed using different energy application parameters; and Removing residual curable material from the object by exposing the object to a solvent, wherein the solvent is selected to penetrate differently into the at least two object parts such that different amounts of residual curable material are removed from each of the at least two object parts, and wherein after removing the residual curable material, each of the at least two object parts has different material properties. wherein the solvent is selected to penetrate differently into the at least two object parts such that different amounts of residual curable material are removed from each of the at least two object parts, and wherein after removing the residual curable material, each of the at least two object parts has different material properties. wherein the solvent is selected to penetrate differently into the at least two object parts such that different amounts of residual curable material are removed from each of the at least two object parts, and wherein after removing the residual curable material, each of the at least two object parts has different material properties. wherein the solvent is selected to penetrate differently into the at least two object parts such that different amounts of residual curable material are removed from each of the at least two object parts, and wherein after removing the residual curable material, each of the at least two object parts has different material properties.

[0267] 67. The method according to clause 66, wherein the curable material includes a resin.

[0268] 68. The method according to clause 66 or 67, wherein the curable material is provided in a liquid or semi-liquid state, and applying energy to the curable material causes the curable material to transform into a solid or semi-solid state.

[0269] 69. The method according to any one of clauses 66 to 68, wherein the curable material includes a plurality of low molecular weight components that react upon application of energy to form higher molecular weight components.

[0270] 70. The method according to any one of clauses 66 to 69, wherein the object is formed from a single type of curable material.

[0271] 71. The method according to any one of clauses 66 to 70, wherein energy is applied to the curable material according to an additive manufacturing process.

[0272] 72. The method according to clause 71, wherein the digital data set includes instructions for producing the curable material via an additive manufacturing process.

[0273] 73. The method according to clause 71 or 72, wherein the additive manufacturing process includes a vat polymerization process.

[0274] 74. The method according to any one of clauses 66 to 73, wherein the digital data set includes instructions for applying energy to the curable material with different energy application parameters.

[0275] 75. The method according to clause 74, wherein the instructions for applying energy to the curable material include: a plurality of coordinates, each coordinate representing a position in the object, and a plurality of gray values, each gray value associated with a corresponding coordinate and representing an energy application parameter for the corresponding position in the object position.

[0276] 76. The method according to any one of clauses 66 to 75, wherein the energy includes one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

[0277] 77. The method according to any one of clauses 66 to 76, wherein the at least two object parts include a first object part and a second object part, and different energy application parameters are selected to enhance the penetration of the solvent into the first object part compared to the second object part.

[0278] 78. The method according to any one of clauses 66 to 77, wherein the at least two object parts include a first object part and a second object part, and different energy application parameters are selected to reduce the penetration of the solvent into the first object part compared to the second object part.

[0279] 79. The method according to any one of clauses 66 to 78, wherein the solvent includes one or more of acetic acid, acetone, acetonitrile, ammonia, benzene, butanol, butyl acetate, camphor, carbon tetrachloride, chloroform, cyclohexanone, diethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, ethyl acetate, ethyl cellosolve, ethyl lactate, ethylene glycol, eugenol, glycerol, heptane, hexane, isoamyl acetate, isopropyl acetate, isopropanol, liquid or low melting point sugars, low melting point or high melting point waxes, menthol, methanol, dichloromethane, phenol, propanol, propylene carbonate, propylene glycol, pressurized gas, silicone oil, soapy water, supercritical carbon dioxide, tetrahydrofuran, toluene, triacetin, turpentine, vanillin, vegetable oil, water, xylene.

[0280] 80. A method according to any one of clauses 66 to 79, wherein the different energy application parameters include differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

[0281] 81. A method according to any one of clauses 66 to 80, wherein the different energy application parameters cause the at least two object portions to differ from each other in one or more of the following: degree of curing of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0282] 82. A method according to any one of clauses 66 to 81, wherein the different material properties of the at least two object portions are produced by different amounts of residual curable material removed from each of the at least two object portions.

[0283] 83. A method according to any one of clauses 66 to 82, wherein the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0284] 84. A method according to any one of clauses 66 to 83, wherein the geometry of the object before removal of the residual curable material is substantially the same as the geometry of the object after removal of the residual curable material.

[0285] 85. A method according to any one of clauses 66 to 84, wherein applying energy to the curable material to form the object includes: forming a first object portion using a first set of energy application parameters, and forming a second object portion using a second set of energy application parameters different from the first set of energy application parameters.

[0286] 86. A method according to clause 85, wherein the first object portion and the second object portion are symmetrically arranged such that, after removal of the residual curable material, the object exhibits substantially no deformation.

[0287] 87. A method according to any one of clauses 66 to 86, further comprising post - processing the object after the residual curable material has been removed.

[0288] 88. The method according to clause 87, wherein the post-processing includes one or more of the following: post-curing the object, cleaning the object, polishing the object, or removing additional material from the object.

[0289] 89. The method according to any one of clauses 66 to 88, wherein the object includes a dental instrument. 90. A method comprising: Receiving an object formed using an additive manufacturing process, the object including a plurality of object parts; Identifying the location of a subset of the object parts on the object based on sensor data; and Applying energy to the subset of the object parts so as to selectively modify one or more material properties of the subset of the object parts.

[0290] 91. The method according to clause 90, wherein the object is formed of a resin.

[0291] 92. The method according to clause 90 or 91, wherein the object is formed of a single type of material.

[0292] 93. The method according to any one of clauses 90 to 92, wherein the sensor data includes image data of the object.

[0293] 94. The method according to any one of clauses 90 to 93, wherein the energy includes one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

[0294] 95. The method according to any one of clauses 90 to 94, wherein the energy is applied by at least one movable energy source.

[0295] 96. The method according to any one of clauses 90 to 95, wherein the energy is applied by a plurality of energy sources.

[0296] 97. The method according to any one of clauses 90 to 96, wherein the object is received in a partially cured state, and the energy is configured to increase the degree of curing of the subset of the object parts.

[0297] 98. The method according to any one of clauses 90 to 96, wherein the object is received in a partially cured state, and the energy is configured to reduce the degree of curing of the subset of the object parts.

[0298] 99. The method according to any one of clauses 90 to 96, wherein the object is received in a post-cured state.

[0299] 100. The method according to any one of clauses 90 to 99, wherein applying energy to a subset of the object portions causes a change in one or more of the following in the subset of the object portions: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0300] 101. The method according to any one of clauses 90 to 100, wherein the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0301] 102. The method according to any one of clauses 90 to 101, further comprising applying a second energy to the entire object.

[0302] 103. The method according to clause 102, wherein the second energy is different from the energy applied to the subset of the object portions.

[0303] 104. The method according to clause 103, wherein the second energy is different from the energy in one or more of the following aspects: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

[0304] 105. The method according to any one of clauses 90 to 104, wherein the object includes a dental instrument.

[0305] 106. The method according to clause 105, wherein the dental instrument is a palatal expander having a tooth-engaging portion and an expander portion, and energy is applied to the tooth-engaging portion or the expander portion.

[0306] 107. The method according to clause 106, wherein selectively applying energy causes the expander portion to have a higher strength than the tooth-engaging portion.

[0307] 108. The method according to any one of clauses 90 to 107, wherein the object includes a functional component coupled to one or more supports, and energy is applied to the functional component or the one or more supports.

[0308] 109. The method according to clause 108, wherein applying energy causes the functional component to have a higher strength than the one or more supports.

[0309] 110. The method according to any one of clauses 90 to 109 further includes determining a target distribution of the material properties of the object, wherein the positions of the subsets of the object parts correspond to the target distribution.

[0310] 111. The method according to clause 110 further includes: receiving an identifier of the object, and retrieving a digital data set representing the target distribution of the material properties of the object based on the identifier.

[0311] 112. The method according to clause 111, wherein the identifier is received from a label associated with the object.

[0312] 113. The method according to any one of clauses 90 to 112, wherein the object is a first object, and the method further includes: receiving a second object formed using an additive manufacturing process, the second object including a plurality of second object parts, wherein the second object has a different geometry from the first object; identifying the positions of the subsets of the second object parts on the second object based on the sensor data; and applying energy to the subsets of the second object parts to selectively modify one or more material properties of the subsets of the second object parts.

[0313] 114. A system for manufacturing an object, the system including: at least one sensor; at least one energy source configured to output energy; a processor; and a memory operatively coupled to the processor and storing instructions that, when executed by the processor, cause the system to perform operations including: receiving sensor data of an additive manufacturing object having a plurality of object parts from the at least one sensor, determining the positions of the subsets of the object parts on the additive manufacturing object based on the sensor data, and applying energy from the at least one energy source to the subsets of the object parts to selectively modify one or more material properties of the subsets of the object parts.

[0314] 115. The system according to clause 114 further includes an additive manufacturing device configured to form the additive manufacturing object from a curable material.

[0315] 116. The system according to clause 115, wherein the additive manufacturing device is configured to form the additive manufacturing object from a single type of curable material.

[0316] 117. A system according to any of clauses 114 to 116, wherein the at least one sensor comprises an imaging device.

[0317] 118. The system of any one of clauses 114 to 117, wherein the at least one energy source is configured to output one or more of: electromagnetic energy, acoustic energy, or radiant energy.

[0318] 119. A system according to any one of clauses 114 to 118, wherein the at least one energy source is movable to a plurality of different postures.

[0319] 120. The system of clause 119, wherein the operations further comprise: Determine the posture of the at least one energy source so that the energy output by the at least one energy source is Target a subset of the image part, and The at least one energy source is moved into a posture.

[0320] 121. A system according to clause 119 or 120, wherein the at least one energy source is connected to a robotic arm.

[0321] 122. A system according to any one of clauses 114 to 121, wherein the at least one energy source comprises a plurality of energy sources configured to output energy in different directions.

[0322] 123. The system of clause 122, wherein the operations further comprise: One or more energy sources are identified that output energy toward the subset of the subject portion, and the one or more energy sources are activated to apply energy to the subset of the subject portion.

[0323] 124. A system according to any of clauses 114 to 123, wherein the additively manufactured object is received in a partially cured state and the energy is configured to increase the degree of cure of a subset of the object portions.

[0324] 125. A system according to any of clauses 114 to 123, wherein the additively manufactured object is received in a partially cured state and the energy is configured to reduce the degree of cure of a subset of the object portions.

[0325] 126. A system according to any of clauses 114 to 123, wherein the additively manufactured object is received in a post-cured state.

[0326] 127. The system according to any one of clauses 114 to 126, wherein applying energy to a subset of the object parts causes a change in one or more of the following in the subset of the object parts: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

[0327] 128. The system according to any one of clauses 114 to 127, wherein the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

[0328] 129. The system according to any one of clauses 114 to 128, further comprising at least one second energy source configured to output a second energy, wherein the operation further comprises applying the second energy to the entire additive manufacturing object.

[0329] 130. The system according to any one of clauses 114 to 129, further comprising at least one second sensor configured to detect an identifier associated with the additive manufacturing object.

[0330] 131. The system according to clause 130, wherein the operation further comprises: retrieving a digital data set representing a target distribution of material properties of the additive manufacturing object based on the identifier, and determining the location of the subset of the object parts on the additive manufacturing object based on the target distribution.

[0331] 132. The system according to any one of clauses 114 to 131, further comprising a conveyor belt configured to convey the additive manufacturing object from a first position near the at least one sensor to a second position near the at least one energy source.

[0332] 133. A non - transitory computer - readable storage medium including instructions that, when executed by one or more processors of a computing system, cause the computing system to perform operations including: receiving sensor data of an additive manufacturing object having a plurality of object parts; determining the location of a subset of the object parts on the additive manufacturing object based on the sensor data; and applying energy to the subset of the object parts to selectively modify one or more material properties of the subset of the object parts.

[0333] Conclusion

[0334] Although many embodiments have been described above with respect to systems, devices, and methods for manufacturing dental instruments, the present technology can be applied to other applications and / or other scenarios, such as drug delivery, molecular detection, and manufacturing other types of objects having spatially controlled properties (e.g., objects including wrinkled regions, hinges, reinforcement regions, etc.). Additionally, other embodiments beyond those described herein are also within the scope of the present technology. For example, although certain implementations of the methods herein are described with respect to objects formed from curable materials, this is not limiting, and the present technology can also be applied to objects formed using other types of precursor materials, such as materials for forming 3D objects via sintering, melting, laminating, etc. Further, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. Thus, one of ordinary skill in the art will understand that the technology can have other embodiments with additional elements, or that the technology can have other embodiments without several of the features shown and described above with reference to Figures 1 to 12C the embodiments shown and described.

[0335] The various processes described herein can be implemented, in part or in whole, using program code that includes instructions that can be executed by one or more processors of a computing system to implement specific logical functions or steps in the processes. The program code can be stored on any type of computer-readable medium, such as a storage device including a magnetic disk or hard drive. A computer-readable medium containing code or portions of code can include any suitable medium known in the art, such as a non-transitory computer-readable storage medium. The computer-readable medium can include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing and / or transmitting information, including but not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology; compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage device; magnetic tape cartridges, tapes, magnetic disk storage or other magnetic storage devices; solid state drive (SSD) or other solid state storage devices; or any other medium that can be used to store the desired information and can be accessed by a system device.

[0336] The description of embodiments of the present technology is not intended to be exhaustive or to limit the present technology to the precise forms disclosed above. Where context permits, singular or plural terms may also respectively include plural or singular terms. Although specific embodiments and examples of the present technology have been described above for illustrative purposes, as will be recognized by those skilled in the relevant art, various equivalent modifications are possible within the scope of the present technology. For example, although steps are presented in a given order, alternative embodiments may perform the steps in a different order. The various embodiments described herein may also be combined to provide additional embodiments.

[0337] As used herein, the terms "generally", "substantially", "about" and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by a person of ordinary skill in the art.

[0338] In addition, unless the word "or" is explicitly limited to only a single item that excludes other items when referring to a list of two or more items, the use of "or" in such a list will be interpreted to include (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. As used herein, the phrase "A and / or B" means A alone, B alone, and A and B. In addition, the term "comprising" is used throughout to mean including at least the (one or more) recited features, such that any greater number of the same features and / or other types of other features are not excluded.

[0339] To the extent that any material incorporated by reference herein conflicts with the present disclosure, the present disclosure shall control.

[0340] It should also be understood that specific embodiments have been described herein for purposes of illustration, but various modifications can be made without departing from the present technology. Additionally, although the advantages associated with certain embodiments of the present technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the present disclosure and the associated technology may cover other embodiments not expressly shown or described herein.

Claims

1. A method, comprising: receiving a digital data set representative of a dental instrument; applying energy to a curable material based on the digital data set to form the dental instrument, wherein the dental instrument comprises at least two instrument parts, and the at least two instrument parts are formed from the curable material using different energy application parameters; and removing residual curable material from the dental instrument, wherein different amounts of residual curable material are removed from each of the at least two instrument parts, and wherein after removing the residual curable material, each of the at least two instrument parts has different material properties, and each of the at least two instrument parts has one or more of the following: (1) a glass transition temperature of at least 80 °C or (2) a modulus of at least 200 MPa.

2. The method according to claim 1, wherein, the at least two instrument parts comprise a first instrument part and a second instrument part, and the different energy application parameters are selected to enhance the removal of the residual curable material from the first instrument part compared to the second instrument part.

3. The method according to claim 1, wherein, the at least two instrument parts comprise a first instrument part and a second instrument part, and the different energy application parameters are selected to reduce the removal of the residual curable material from the first instrument part compared to the second instrument part.

4. The method according to any one of claims 1 to 3, wherein, removing the residual curable material from the dental instrument comprises one or more of the following: exposing the dental instrument to a solvent, applying heat to the dental instrument, or applying a vacuum to the dental instrument.

5. The method according to any one of claims 1 to 4, wherein, the residual curable material comprises residual monomers, residual oligomers, or a combination thereof.

6. The method according to any one of claims 1 to 5, wherein, the different energy application parameters comprise differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

7. The method according to any one of claims 1 to 6, wherein, the different energy application parameters cause the at least two instrument parts to differ from each other in one or more of the following: degree of cure, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point of the curable material.

8. The method according to any one of claims 1 to 7, wherein, the different material properties of the at least two instrument parts are produced by different amounts of the residual curable material removed from each of the at least two instrument parts.

9. The method according to any one of claims 1 to 8, wherein, The different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

10. The method according to any one of claims 1 to 9, wherein, the curable material comprises a resin.

11. The method according to any one of claims 1 to 10, wherein, the dental instrument is formed from a single type of curable material.

12. The method according to any one of claims 1 to 11, wherein, the energy is applied to the curable material according to an additive manufacturing process.

13. A method, comprising: receiving a digital data set representing a dental instrument; applying energy to a curable material based on the digital data set to form the dental instrument, wherein the dental instrument comprises at least two instrument parts formed using different energy application parameters; and removing residual curable material from the dental instrument by exposing the dental instrument to a solvent, wherein the solvent is selected to penetrate differently into the at least two instrument parts such that different amounts of the residual curable material are removed from each of the at least two instrument parts, and wherein, after removing the residual curable material, each of the at least two instrument parts has different material properties.

14. The method according to claim 13, wherein, the at least two instrument parts include a first instrument part and a second instrument part, and the different energy application parameters are selected to enhance the penetration of the solvent into the first instrument part compared to the second instrument part.

15. The method according to claim 13, wherein, the at least two instrument parts include a first instrument part and a second instrument part, and the different energy application parameters are selected to reduce the penetration of the solvent into the first instrument part compared to the second instrument part.

16. The method according to any one of claims 13 to 15, wherein, the solvent comprises one or more of acetic acid, acetone, acetonitrile, ammonia, benzene, butanol, butyl acetate, camphor, carbon tetrachloride, chloroform, cyclohexanone, diethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, ethyl acetate, ethyl cellosolve, ethyl lactate, ethylene glycol, eugenol, glycerol, heptane, hexane, isopentyl acetate, isopropyl acetate, isopropanol, liquid or low melting point sugar, low melting point or high melting point wax, menthol, methanol, dichloromethane, phenol, propanol, propylene carbonate, propylene glycol, pressurized gas, silicone oil, soapy water, supercritical carbon dioxide, tetrahydrofuran, toluene, triacetin, turpentine, vanillin, vegetable oil, water, xylene.

17. The method according to any one of claims 13 to 16, wherein, the residual curable material comprises residual monomer, residual oligomer, or a combination thereof.

18. The method according to any one of claims 13 to 17, wherein, the different energy application parameters include differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

19. The method according to any one of claims 13 to 18, wherein, the different energy application parameters cause the at least two instrument parts to differ from each other in one or more of the following aspects: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point of the curable material.

20. The method according to any one of claims 13 to 19, wherein, the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

21. A method, comprising: receiving a dental instrument formed using an additive manufacturing process, the dental instrument including a plurality of instrument parts; identifying the location on the dental instrument of a subset of the instrument parts based on sensor data; and applying energy to the subset of the instrument parts to selectively modify one or more material properties of the subset of the instrument parts.

22. The method according to claim 21, wherein, the dental instrument is received in a partially cured state, and the energy is configured to increase the degree of curing of the subset of the instrument parts.

23. The method according to claim 21, wherein, the dental instrument is received in a partially cured state, and the energy is configured to decrease the degree of curing of the subset of the instrument parts.

24. The method according to claim 21, wherein, the dental instrument is received in a post-cured state.

25. The method according to any one of claims 21 to 24, wherein, applying the energy to the subset of the instrument parts causes one or more of the following changes in the subset of the instrument parts: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

26. The method according to any one of claims 21 to 25, wherein, the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

27. The method according to any one of claims 21 to 26 further comprises applying a second energy to the entirety of the dental instrument.

28. The method according to claim 27, wherein, the second energy is different from the energy applied to a subset of the instrument parts.

29. The method according to claim 28, wherein, the second energy is different from the energy in one or more of the following aspects: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

30. The method according to any one of claims 21 to 29, wherein, the dental instrument is a first dental instrument, and the method further comprises: receiving a second dental instrument formed using an additive manufacturing process, the second dental instrument comprising a plurality of second instrument parts, wherein the second dental instrument has a geometric shape different from that of the first dental instrument; identifying the positions of a subset of the second instrument parts on the second dental instrument based on sensor data; and applying the energy to the subset of the second instrument parts so as to selectively modify one or more material properties of the subset of the second instrument parts.

31. A system for manufacturing a dental instrument, the system comprising: at least one sensor; at least one energy source configured to output energy; a processor; and a memory operatively coupled to the processor and storing instructions which, when executed by the processor, cause the system to perform operations, the operations including: receiving sensor data of an additively manufactured dental instrument having a plurality of instrument parts from the at least one sensor, determining the positions of a subset of the instrument parts on the additively manufactured dental instrument based on the sensor data, and applying energy from the at least one energy source to the subset of the instrument parts so as to selectively modify one or more material properties of the subset of the instrument parts.

32. The system according to claim 31, wherein, the at least one sensor includes an imaging device.

33. The system according to claim 31 or 32, wherein, the at least one energy source is movable to a plurality of different postures.

34. The system according to any one of claims 31 to 33, wherein, the at least one energy source includes a plurality of energy sources configured to output energy in different directions.

35. The system according to any one of claims 31 to 34, wherein, the additively manufactured dental instrument is received in a partially cured state, and the energy is configured to increase or decrease the degree of curing of a subset of the instrument parts.

36. The system according to any one of claims 31 to 35, wherein, applying the energy to the subset of the instrument parts causes one or more of the following changes in the subset of the instrument parts: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

37. The system according to any one of claims 31 to 36, wherein, The one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusivity, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

38. The system according to any one of claims 31 to 37, further comprising at least one second energy source configured to output a second energy, wherein, the operation further comprises applying the second energy to the entirety of the additive manufactured dental device.

39. The system according to any one of claims 31 to 37, further comprising at least one second sensor configured to detect an identifier associated with the additive manufactured dental device.

40. The system according to claim 39, wherein, the operation further comprises: retrieving a digital data set representing a target distribution of material properties of the additive manufactured dental device based on the identifier, and determining a location on the additive manufactured dental device of a subset of the device portions based on the target distribution.

41. A method, comprising: receiving a digital data set representing an object; applying energy to a curable material to form the object based on the digital data set, wherein the object comprises at least two object portions formed from the curable material using different energy application parameters; and removing residual curable material from the object, wherein different amounts of the residual curable material are removed from each of the at least two object portions, and wherein after removing the residual curable material, each of the at least two object portions has different material properties and each of the at least two object portions has (1) a glass transition temperature of at least 80 °C and / or (2) a modulus of at least 200 MPa.

42. The method according to claim 41, wherein, the curable material comprises a resin.

43. The method according to claim 41 or 42, wherein, the curable material is provided in a liquid or semi-liquid state, and applying the energy to the curable material causes the curable material to transform into a solid or semi-solid state.

44. The method according to any one of claims 41 to 43, wherein, the curable material comprises a plurality of low molecular weight components that react upon application of the energy to form higher molecular weight components.

45. The method according to any one of claims 41 to 44, wherein, the object is formed from a single type of curable material.

46. The method according to any one of claims 41 to 45, wherein, the energy is applied to the curable material according to an additive manufacturing process.

47. The method according to claim 46, wherein, the digital data set comprises instructions for producing the object via the additive manufacturing process.

48. The method according to claim 46 or 47, wherein, The additive manufacturing process includes a vat polymerization process.

49. The method according to any one of claims 41 to 48, wherein, the digital data set includes instructions for applying the energy to the curable material with the different energy application parameters.

50. The method according to claim 49, wherein, the instructions for applying the energy to the curable material include: a plurality of coordinates, each coordinate representing a position in the object, and a plurality of gray values, each gray value associated with a corresponding coordinate and representing an energy application parameter for the corresponding position in the object.

51. The method according to any one of claims 41 to 50, wherein, the energy includes one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

52. The method according to any one of claims 41 to 51, wherein, the at least two object parts include a first object part and a second object part, and the different energy application parameters are selected to enhance the removal of the residual curable material from the first object part compared to the second object part.

53. The method according to any one of claims 41 to 51, wherein, the at least two object parts include a first object part and a second object part, and the different energy application parameters are selected to reduce the removal of the residual curable material from the first object part compared to the second object part.

54. The method according to any one of claims 41 to 53, wherein, the different energy application parameters include differences in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

55. The method according to any one of claims 41 to 54, wherein, the different energy application parameters cause the at least two object parts to differ from each other in one or more of the following aspects: the degree of curing of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

56. The method according to any one of claims 41 to 55, wherein, the different material properties of the at least two object parts are produced by different amounts of the residual curable material removed from each of the at least two object parts.

57. The method according to any one of claims 41 to 56, wherein, the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

58. The method according to any one of claims 41 to 57, wherein, removing the residual curable material from the object includes one or more of the following: exposing the object to a solvent, applying heat to the object, or applying a vacuum to the object.

59. The method according to any one of claims 41 to 58, wherein, the geometry of the object before removing the residual curable material is substantially the same as the geometry of the object after removing the residual curable material.

60. The method according to any one of claims 41 to 59, wherein, applying the energy to the curable material to form the object includes: forming a first object portion using a first set of energy application parameters, and forming a second object portion using a second set of energy application parameters different from the first set of energy application parameters.

61. The method according to claim 60, wherein, the first object portion and the second object portion are symmetrically arranged such that after removing the residual curable material, the object exhibits substantially no deformation.

62. The method according to any one of claims 41 to 61, further comprising post-curing the object after the residual curable material has been removed.

63. The method according to claim 60, wherein, after post-curing, each of the at least two object portions exhibits one or more of the following: a glass transition temperature of at least 80 °C, an elongation at break of at least 50% at 1.7 mm / min, or a modulus of at least 200 MPa.

64. The method according to claim 60, wherein, after post-curing, the whole of the object exhibits one or more of the following: a glass transition temperature of at least 80 °C, an elongation at break of at least 50% at 1.7 mm / min, or a modulus of at least 200 MPa.

65. The method according to any one of claims 41 to 64, wherein, the object includes a dental instrument.

66. A method, comprising: receiving a digital data set representing an object; applying energy to a curable material to form the object based on the digital data set, wherein the object includes at least two object portions formed using different energy application parameters; and removing residual curable material from the object by exposing the object to a solvent, wherein the solvent is selected to penetrate differently into the at least two object portions such that different amounts of the residual curable material are removed from each of the at least two object portions, and wherein after removing the residual curable material, each of the at least two object portions has different material properties.

67. The method according to claim 66, wherein, the curable material includes a resin.

68. The method according to claim 66 or 67, wherein, the curable material is provided in a liquid or semi-liquid state, and applying the energy to the curable material causes the curable material to transform into a solid or semi-solid state.

69. The method according to any one of claims 66 to 68, wherein, the curable material includes a plurality of low molecular weight components that react upon application of the energy to form higher molecular weight components.

70. The method according to any one of claims 66 to 69, wherein, the object is formed from a single type of curable material.

71. The method according to any one of claims 66 to 70, wherein, the energy is applied to the curable material according to an additive manufacturing process.

72. The method according to claim 71, wherein, the digital data set includes instructions for producing the curable material via the additive manufacturing process.

73. The method according to claim 71 or 72, wherein, the additive manufacturing process includes a vat polymerization process.

74. The method according to any one of claims 66 to 73, wherein, the digital data set includes instructions for applying the energy to the curable material with the different energy application parameters.

75. The method according to claim 74, wherein, the instructions for applying the energy to the curable material include: a plurality of coordinates, each coordinate representing a position in the object, and a plurality of gray values, each gray value associated with a corresponding coordinate and representing an energy application parameter for the corresponding position in the object.

76. The method according to any one of claims 66 to 75, wherein, the energy includes one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

77. The method according to any one of claims 66 to 76, wherein, the at least two object parts include a first object part and a second object part, and the different energy application parameters are selected to enhance the penetration of the solvent into the first object part compared to the second object part.

78. The method according to any one of claims 66 to 77, wherein, the at least two object parts include a first object part and a second object part, and the different energy application parameters are selected to reduce the penetration of the solvent into the first object part compared to the second object part.

79. The method according to any one of claims 66 to 78, wherein, the solvent includes one or more of acetic acid, acetone, acetonitrile, ammonia, benzene, butanol, butyl acetate, camphor, carbon tetrachloride, chloroform, cyclohexanone, diethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, ethyl acetate, ethyl cellosolve, ethyl lactate, ethylene glycol, eugenol, glycerol, heptane, hexane, isoamyl acetate, isopropyl acetate, isopropanol, liquid or low melting point sugar, low melting point or high melting point wax, menthol, methanol, dichloromethane, phenol, propanol, propylene carbonate, propylene glycol, pressurized gas, silicone oil, soapy water, supercritical carbon dioxide, tetrahydrofuran, toluene, triacetin, turpentine, vanillin, vegetable oil, water, xylene.

80. The method according to any one of claims 66 to 79, wherein, the different energy application parameters include a difference in one or more of the following: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

81. The method according to any one of claims 66 to 80, wherein, The different energy application parameters cause the at least two object portions to differ from each other in one or more of the following aspects: degree of cure of the curable material, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swellability, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

82. The method according to any one of claims 66 to 81, wherein, the different material properties of the at least two object portions are produced by different amounts of residual curable material removed from each of the at least two object portions.

83. The method according to any one of claims 66 to 82, wherein, the different material properties include differences in one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

84. The method according to any one of claims 66 to 83, wherein, the geometry of the object before removal of the residual curable material is substantially the same as the geometry of the object after removal of the residual curable material.

85. The method according to any one of claims 66 to 84, wherein, applying the energy to the curable material to form the object includes: forming a first object portion using a first set of energy application parameters, and forming a second object portion using a second set of energy application parameters different from the first set of energy application parameters.

86. The method according to claim 85, wherein, the first object portion and the second object portion are symmetrically arranged such that after removal of the residual curable material, the object exhibits substantially no deformation.

87. The method according to any one of claims 66 to 86, further comprising post-treating the object after the residual curable material has been removed.

88. The method according to claim 87, wherein, the post-treatment includes one or more of the following: post-curing the object, cleaning the object, polishing the object, or removing additional material from the object.

89. The method according to any one of claims 66 to 88, wherein, the object includes a dental instrument.

90. A method, comprising: receiving an object formed using an additive manufacturing process, the object including a plurality of object portions; identifying the location on the object of a subset of the object portions based on sensor data; and applying energy to the subset of the object portions so as to selectively modify one or more material properties of the subset of the object portions.

91. The method according to claim 90, wherein, the object is formed of a resin.

92. The method according to claim 90 or 91, wherein, the object is formed of a single type of material.

93. The method according to any one of claims 90 to 92, wherein, The sensor data includes image data of the object.

94. The method according to any one of claims 90 to 93, wherein, the energy includes one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

95. The method according to any one of claims 90 to 94, wherein, the energy is applied by at least one movable energy source.

96. The method according to any one of claims 90 to 95, wherein, the energy is applied by a plurality of energy sources.

97. The method according to any one of claims 90 to 96, wherein, the object is received in a partially cured state, and the energy is configured to increase the degree of curing of a subset of the object portions.

98. The method according to any one of claims 90 to 96, wherein, the object is received in a partially cured state, and the energy is configured to decrease the degree of curing of a subset of the object portions.

99. The method according to any one of claims 90 to 96, wherein, the object is received in a post-cured state.

100. The method according to any one of claims 90 to 99, wherein, applying the energy to a subset of the object portions causes one or more of the following changes in the subset of the object portions: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

101. The method according to any one of claims 90 to 100, wherein, the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

102. The method according to any one of claims 90 to 101, further comprising applying a second energy to the entirety of the object.

103. The method according to claim 102, wherein, the second energy is different from the energy applied to the subset of the object portions.

104. The method according to claim 103, wherein, the second energy differs from the energy in one or more of the following aspects: energy intensity, energy dose, exposure time, energy wavelength, or energy type.

105. The method according to any one of claims 90 to 104, wherein, the object includes a dental instrument.

106. The method according to claim 105, wherein, the dental instrument is a palatal expander having a tooth engaging portion and an expander portion, and the energy is applied to the tooth engaging portion or the expander portion.

107. The method according to claim 106, wherein, selectively applying the energy causes the expander portion to have a higher strength than the tooth engaging portion.

108. The method according to any one of claims 90 to 107, Wherein, the object includes a functional component coupled to one or more supports, and the energy is applied to the functional component or the one or more supports.

109. The method according to claim 108, wherein, applying the energy causes the functional component to have a higher strength than the one or more supports.

110. The method according to any one of claims 90 to 109, further comprising determining a target distribution of material properties of the object, wherein, the positions of a subset of the object portions correspond to the target distribution.

111. The method according to claim 110, further comprising: receiving an identifier of the object, and retrieving, based on the identifier, a digital data set representing the target distribution of material properties of the object.

112. The method according to claim 111, wherein, the identifier is received from a tag associated with the object.

113. The method according to any one of claims 90 to 112, wherein, the object is a first object, and the method further comprises: receiving a second object formed using the additive manufacturing process, the second object including a plurality of second object portions, wherein the second object has a different geometry from the first object; identifying, based on sensor data, the positions of a subset of the second object portions on the second object; and applying the energy to the subset of the second object portions so as to selectively modify one or more material properties of the subset of the second object portions.

114. A system for manufacturing an object, the system comprising: at least one sensor; at least one energy source configured to output energy; a processor; and a memory operatively coupled to the processor and storing instructions that, when executed by the processor, cause the system to perform operations, the operations including: receiving sensor data of an additive manufacturing object having a plurality of object portions from the at least one sensor, determining the positions of a subset of the object portions on the additive manufacturing object based on the sensor data, and applying energy from the at least one energy source to the subset of the object portions so as to selectively modify one or more material properties of the subset of the object portions.

115. The system according to claim 114, further comprising an additive manufacturing device configured to form the additive manufacturing object from a curable material.

116. The system according to claim 115, wherein, the additive manufacturing device is configured to form the additive manufacturing object from a single type of curable material.

117. The system according to any one of claims 114 to 116, wherein, the at least one sensor includes an imaging device.

118. The system according to any one of claims 114 to 117, wherein, the at least one energy source is configured to output one or more of the following: electromagnetic energy, acoustic energy, or radiant energy.

119. The system according to any one of claims 114 to 118, wherein, the at least one energy source is movable to a plurality of different postures.

120. The system according to claim 119, wherein, the operation further comprises: determining an attitude of the at least one energy source such that the energy output by the at least one energy source targets a subset of the object portions, and moving the at least one energy source into the attitude.

121. The system according to claim 119 or 120, wherein, the at least one energy source is coupled to a robotic arm.

122. The system according to any one of claims 114 to 121, wherein, the at least one energy source includes a plurality of energy sources configured to output energy in different directions.

123. The system according to claim 119, wherein, the operation further comprises: identifying one or more energy sources that output energy to a subset of the object portions, and activating the one or more energy sources to apply the energy to the subset of the object portions.

124. The system according to any one of claims 114 to 123, wherein, the additive manufacturing object is received in a partially cured state, and the energy is configured to increase the degree of curing of a subset of the object portions.

125. The system according to any one of claims 114 to 123, wherein, the additive manufacturing object is received in a partially cured state, and the energy is configured to reduce the degree of curing of a subset of the object portions.

126. The system according to any one of claims 114 to 123, wherein, the additive manufacturing object is received in a post-cured state.

127. The system according to any one of claims 114 to 126, wherein, applying the energy to the subset of the object portions causes one or more of the following changes in the subset of the object portions: degree of curing, crosslink density, phase, crystallinity, morphology, permeability, solubility, viscosity, swelling, reactivity, degradability, porosity, particle connectivity, surface area, or melting point.

128. The system according to any one of claims 114 to 127, wherein, the one or more material properties include one or more of the following: modulus, glass transition temperature, elongation at break, yield elongation, strength, solubility, hardness, scratch resistance, roughness, degradability, color, refractive index, energy absorption, energy dissipation, energy reflection, energy scattering, transparency, diffusion, pH, porosity, morphology, chemical composition, molecular recognition, molecular absorption, molecular release, phase separation, morphology, or durability.

129. The system according to any one of claims 114 to 128, further comprising at least one second energy source configured to output a second energy, wherein, the operation further comprises applying the second energy to the entirety of the additive manufacturing object.

130. The system according to any one of claims 114 to 129, further comprising at least one second sensor configured to detect an identifier associated with the additive manufacturing object.

131. The system according to claim 130, wherein, the operation further comprises: Retrieve a digital data set representing a target distribution of material properties of the additive manufacturing object based on the identifier, and Determine a location of a subset of the object portions on the additive manufacturing object based on the target distribution.

132. The system according to any one of claims 114 to 131, further comprising a conveyor belt configured to convey the additive manufacturing object from a first position near the at least one sensor to a second position near the at least one energy source.

133. A non-transitory computer-readable storage medium comprising instructions that, when executed by one or more processors of a computing system, cause the computing system to perform operations, the operations comprising: Receiving sensor data of an additive manufacturing object having a plurality of object portions; Determining a location of a subset of the object portions on the additive manufacturing object based on the sensor data; and Applying energy to the subset of the object portions to selectively modify one or more material properties of the subset of the object portions.

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