Polymer structures with microvoid spaces and systems and methods for making same

Abstract

Aspects of the present disclosure include methods for making polymer structures having microvoid spaces. A method according to certain embodiments includes irradiating a polymerizable composition positioned between a build lift table and a build surface to produce such polymerizable composition, the polymerizable composition has: a polymerized region of the polymerizable composition having a microvoid space in contact with a build lift table and a non-polymerized region of the polymerizable composition in contact with a build surface; removing the build lift from the build surface; contacting the generated microvoid space with a non-reactive composition; and repeating in a manner sufficient to create a polymer structure having a clearly discernible microvoid space. Systems for preparing polymer structures according to the subject methods are also described. Also provided are polymer structures having clearly discernible microvoid spaces, such as where the microvoid spaces are filled with a non-polymerizable composition.

Description

[0001] Government Rights

[0002] This invention was made with government support under contract NSF GRFP (FELLOWSHIP) awarded by the National Science Foundation. The government has certain rights in this invention.

[0003] Cross - Reference to Related Applications

[0004] This application claims the benefit of the filing date of U.S. Provisional Patent Application Serial No. 63 / 416,789, filed Oct. 17, 2022, the disclosure of which is incorporated herein by reference in its entirety, under 35 U.S.C. § 119(e). This application relates to U.S. Provisional Patent Application Serial No. 63 / 321,052, filed Mar. 17, 2022, the disclosure of which is incorporated by reference.

[0005] Introduction

[0006] Additive manufacturing techniques for printing polymer resins have been used in applications such as personalized body protection, wearable electronics, and functionally graded materials. The printed materials have shown to have desirable mechanical, electrical, and chemically stable properties. Like other digital light projection (DLP) methods, continuous liquid interface production (CLIP) projects a series of rapid ultraviolet (UV) patterns to photopolymerize the resin layer - by - layer. Other DLP methods require layer - by - layer stratification between each exposure. CLIP produces polymer structures by resin renewal through a continuous liquid interface (dead zone) beneath the build surface, which is created by oxygen (a polymerization inhibitor) fed through a highly oxygen - permeable window at the bottom of the resin reservoir. The combination of improved optical projection and CLIP technology has allowed printers to achieve sub - micron lateral (XY) resolution at speeds 100 times faster than other 3D printing methods.

[0007] For fabricating negative spaces (channels, voids, etc.), the ability to achieve high Z - resolution is a general characteristic of microelectronics, microsensors, and microfluidic devices. Although CLIP is capable of resolving sub - micron features in the XY plane, its ability to resolve features at that scale in the build (Z) direction is severely limited in terms of negative feature size. This is due to UV light penetrating the previously fabricated layers, causing polymerization of unpolymerized resin trapped in the negative space. Summary of the Invention

[0008] The inventors of the present disclosure have found that when void spaces are formed in constructing a polymer structure, cure-through (e.g., UV penetration) of a reactive polymerizable composition injected (e.g., through a channel to a build surface) results in trapped polymerizable resin. Such cure-through can impede or prevent the formation of microvoid spaces in a polymer structure produced by continuous liquid interface production, including injection continuous liquid interface production. The present disclosure eliminates the negative polymerization and print-through effects of UV penetration.

[0009] Aspects of the present disclosure include methods for fabricating a polymer structure having microvoid spaces. A method according to certain embodiments includes irradiating a polymerizable composition positioned between a build elevator and a build surface to produce a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build elevator and a non-polymerized region of the polymerizable composition in contact with the build surface; moving the build elevator away from the build surface; contacting the resulting microvoid spaces with a non-reactive composition; and repeating in a manner sufficient to produce a polymer structure having resolved microvoid spaces. A system for preparing a polymer structure according to the subject method is also described. A polymer structure having resolved microvoid spaces is also provided, such as where the microvoid spaces are filled with a non-polymerizable composition.

[0010] In practicing the subject method according to some embodiments, an amount of polymerizable composition is conveyed through the resulting microvoid spaces in a manner sufficient to displace any polymerized material (e.g., trapped resin) in the microvoid spaces. In some instances, the polymerizable composition is injected into the microvoid spaces, such as where the microvoid spaces are microchannels formed within the polymer structure. In certain instances, conveying the polymerizable composition is sufficient to flush out trapped resin in the microvoid spaces so as to retain the negative space and eliminate print-through of the polymer structure. In some instances, the polymerizable composition is continuously conveyed through the resulting microvoid spaces into the space between the build elevator and the build surface of the liquid interface production module. In some instances, while moving the build elevator away from the build surface when producing the polymer structure, a non-reactive composition is continuously conveyed (e.g., through a conduit) into the microvoid spaces.

[0011] In some embodiments, the method includes contacting the generated microvoid space with a non-polymerizable composition. In some instances, the non-polymerizable composition is continuously contacted with the microvoid space while the polymeric structure is being generated. In some embodiments, the method includes filling at least a portion of the void volume of the microvoid space with the non-polymerizable composition. In some embodiments, the method includes filling 5% or more, such as 10% or more, such as 25% or more, such as 50% or more, and including 75% or more of the void volume of the microvoid space with the non-polymerizable composition. In some embodiments, the method includes filling the entire void volume of the microvoid space with the non-polymerizable composition. In certain instances, the non-polymerizable composition does not react with the polymerizable composition of the polymeric structure. In some instances, the microvoid space includes microchannels within the polymeric structure, such as where the microchannels extend through the polymeric structure. In some instances, the polymeric structure includes a plurality of microvoid spaces. In some instances, the non-polymerizable composition is a composition selected from water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric-field-responsive liquids, and gases.

[0012] In some embodiments, the polymerizable composition contacts the build lift and the build surface. In some instances, the method includes irradiating the polymerizable composition for a duration sufficient to bond a first polymerization zone of the polymerizable composition to the build lift. In some instances, the build lift moves in a predetermined increment of 0.5 μm to 1.0 μm. In some instances, the method includes adding the polymerizable composition to the build surface after each removal of the build lift from the build surface. In some instances, the method includes continuously adding the polymerizable composition to the build surface. In some instances, the polymerizable composition is continuously added to the build surface by injection via a conduit. In some embodiments, the method includes contacting a non-reactive composition (e.g., via a conduit) with the generated microvoid space after each removal of the build lift from the build surface. In some embodiments, the polymerizable composition is continuously polymerized while the build lift is being removed from the build surface. In some embodiments, the non-reactive composition is continuously transported through the microvoid space (e.g., microchannels formed within the polymeric structure) while the build lift is being removed from the build surface. In some embodiments, the non-reactive composition is injected (e.g., continuously) through a conduit into the microvoid space. In some instances, the method includes continuously adding the non-reactive composition to the build area. In some instances, the non-reactive composition is continuously added to the build area by injection via a conduit. In certain embodiments, the method includes removing the non-reactive composition (e.g., non-polymerizable composition) from the generated microvoid space of the polymeric structure.

[0013] Aspects of the present disclosure also include systems for manufacturing polymer structures having microvoid spaces. A system according to certain embodiments includes a light source and a photointerface polymerization module having a build lift and a build surface configured to produce a polymer structure having discernible microvoid spaces therein from a polymerizable composition positioned therebetween. In some embodiments, the photointerface polymerization module is configured to produce a polymer structure having one or more microchannels therein. In some instances, one or more of the microchannels extend through the polymer structure. In some embodiments, the system includes a processor having a memory operably coupled to the processor, wherein the memory includes instructions stored thereon that, when executed by the processor, cause the processor to a) irradiate a polymerizable composition positioned between the build lift and the build surface to produce a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; b) move the build lift away from the build surface; c) contact the resulting microvoid spaces with a non-reactive composition; and d) repeat steps a)-c) in a manner sufficient to produce a polymer structure having discernible microvoid spaces. In some instances, the system is configured to produce a polymer structure having microvoid spaces that include a non-polymerizable composition positioned therein.

[0014] In some embodiments, the memory includes instructions for contacting the resulting microvoid spaces with an amount of the polymerizable composition in a manner sufficient to displace the polymeric material in the microvoid spaces. In some instances, the memory includes instructions for continuously conveying the polymerizable composition through the resulting microvoid spaces to displace the polymeric material in the microvoid spaces. In some instances, the memory includes instructions for injecting the polymerizable composition into the resulting microvoid spaces to displace the polymeric material in the microvoid spaces. In some instances, the polymerizable composition is injected into the resulting microvoid spaces with a syringe. In certain instances, the system further includes an injection pump. In some instances, the memory includes instructions for continuously conveying the polymerizable composition through the resulting microvoid spaces into the space between the build lift and the build surface of the liquid interface production module.

[0015] In some instances, the system further includes a source of a non-polymerizable composition, the source of the non-polymerizable composition being operably coupled to the light interfacial polymerization module such that the non-polymerizable composition is continuously contacted with the microvoid space while a polymer structure is being produced. In some instances, the source communicates with the build region of the light interfacial polymerization module via a conduit. In some instances, the non-polymerizable composition is provided to the build region via a conduit, such as where the non-polymerizable composition is injected into the build region via a conduit. In some instances, the memory includes instructions to fill at least a portion of the void volume of the microvoid space with the non-polymerizable composition, such as 5% or more, such as 10% or more, such as 25% or more, such as 50% or more, and includes instructions to fill 75% or more of the void volume of the microvoid space, such as instructions to fill the entire void volume of the microvoid space with the non-polymerizable composition. In some embodiments, the memory includes instructions to produce a polymer structure having a plurality of microvoid spaces. In certain instances, the memory includes instructions to irradiate the polymerizable composition for a duration sufficient to bond a first polymerization zone of the polymerizable composition to the build lift. In some instances, the memory includes instructions to move the build lift in predetermined increments of from 0.5 μm to 1.0 μm. In some embodiments, the memory includes instructions to add the polymerizable composition to the build surface after each removal of the build lift from the build surface. In some instances, the memory includes instructions to add the non-polymerizable composition to the generated microvoid spaces after each removal of the build lift from the build surface. In some instances, the memory includes instructions to continuously polymerize the polymerizable composition while moving the build lift away from the build surface. In some embodiments, the memory includes instructions to continuously add the non-polymerizable composition to the generated microvoid spaces while moving the build lift away from the build surface. In certain embodiments, the memory includes instructions to remove the non-polymerizable composition from the generated microvoid spaces of the polymer structure.

[0016] In certain embodiments, the system includes a micro digital light projection system having a beam generator component and a light projection monitoring component. In some embodiments, the beam generator includes two projection lenses, such as magnifying lenses. In some embodiments, the light projection monitoring component includes a photodetector, such as a charge coupled device (CCD).

[0017] Aspects of the present disclosure also include a polymer structure having microvoid spaces, the microvoid spaces including a non-polymerizable composition positioned therein. In some instances, the non-polymerizable composition fills 75% or more of the void volume of the microvoid spaces, such as where the non-polymerizable composition fills the entire volume of the void volume of the microvoid spaces. In some instances, the non-polymerizable composition does not react with the polymer structure. In some instances, the microvoid spaces are microchannels within the polymer structure, such as microchannels that extend through the polymer structure. In some instances, the polymer structure includes a plurality of microvoid spaces. In some instances, the non-polymerizable composition is selected from water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric-field-responsive liquids, and gases. In some instances, the polymer structure is formed from a polymerizable material such as polycaprolactone, polyglycolic acid, polylactic acid, poly(lactic-co-glycolic) acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol-ene, acid anhydrides, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomers, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl esters, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof. In certain embodiments, aspects of the present disclosure include a polymer structure having discernible microvoid spaces, where the non-polymerizable composition has been removed.

[0018] Aspects of the present disclosure also include a non-transitory computer-readable storage medium for fabricating a polymer structure in a liquid interface production module. In some instances, the non-transitory computer-readable storage medium has instructions stored thereon that include: an algorithm for irradiating a polymerizable composition positioned between a build lift and a build surface to produce such a polymerizable composition having a polymerized region of the polymerizable composition with microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; an algorithm for moving the build lift away from the build surface; an algorithm for contacting the resulting microvoid spaces with a non-reactive composition; and an algorithm for repeating one or more steps in a manner sufficient to produce a polymer structure having discernible microvoid spaces. In some instances, the non-transitory computer-readable storage medium has an algorithm for injecting a polymerizable composition through a conduit using an injection pump. In some instances, the non-transitory computer-readable storage medium has an algorithm for producing a polymer structure having microvoid spaces that include a non-polymerizable composition positioned therein.

[0019] In some embodiments, the non - transitory computer - readable storage medium has an algorithm for contacting the generated microvoid space with an amount of polymerizable composition in a manner sufficient to displace the polymeric material in the microvoid space. In some instances, the non - transitory computer - readable storage medium has an algorithm for continuously conveying the polymerizable composition through the generated microvoid space to displace the polymeric material in the microvoid space. In some instances, the non - transitory computer - readable storage medium has an algorithm for injecting the polymerizable composition into the generated microvoid space to displace the polymeric material in the microvoid space. In some instances, the non - transitory computer - readable storage medium has an algorithm for injecting the polymerizable composition into the generated microvoid space using a syringe. In some instances, the non - transitory computer - readable storage medium has an algorithm for continuously conveying the polymerizable composition through the generated microvoid space into the space between the build lift and the build surface of the liquid interface production module.

[0020] In some instances, the non-transitory computer-readable storage medium has algorithms for contacting the non-polymerizable composition with the resulting microvoid spaces of the polymer structure. In some instances, the non-transitory computer-readable storage medium has algorithms for filling at least a portion of the void volume of the microvoid spaces with the non-polymerizable composition, such as 5% or more, such as 10% or more, such as 25% or more, such as 50% or more, and including 75% or more of the void volume of the microvoid spaces, such as an algorithm for filling the entire void volume of the microvoid spaces with the non-polymerizable composition. In some embodiments, the non-transitory computer-readable storage medium has algorithms for generating a polymer structure having a plurality of microvoid spaces. In certain instances, the non-transitory computer-readable storage medium has algorithms for irradiating the polymerizable composition for a duration sufficient to bond a first polymerization region of the polymerizable composition to the build lift. In some instances, the non-transitory computer-readable storage medium has algorithms for moving the build lift in predetermined increments of 0.5 μm to 1.0 μm. In some embodiments, the non-transitory computer-readable storage medium has algorithms for adding the polymerizable composition to the build surface after each removal of the build lift from the build surface. In some instances, the non-transitory computer-readable storage medium has algorithms for adding the non-polymerizable composition to the resulting microvoid spaces after each removal of the build lift from the build surface. In some instances, the non-transitory computer-readable storage medium has algorithms for continuously polymerizing the polymerizable composition while moving the build lift away from the build surface. In some embodiments, the non-transitory computer-readable storage medium has algorithms for continuously adding the non-polymerizable composition to the resulting microvoid spaces while moving the build lift away from the build surface. In certain embodiments, the non-transitory computer-readable storage medium has algorithms for removing the non-polymerizable composition from the resulting microvoid spaces of the polymer structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention may be best understood from the following detailed description when read in conjunction with the accompanying drawings. The following figures are included in the drawings:

[0022] Figure 1 Depicts the injection of a non-polymerizable composition into the resulting microvoid spaces (e.g., microchannels) according to certain embodiments.

[0023] Figure 2A Depicts a schematic of a conventional CLIP 3D printing method and the resulting bleed-through effect.

[0024] Figure 2B Depicts a process for generating a polymer structure and the resulting distinct microvoid spaces (i.e., negative structures) according to certain embodiments of the present disclosure.

[0025] Figure 2C Depicts the relationship between the light penetration depth and the minimum channel height for a process for generating polymer structures according to certain embodiments and other digital light processing systems.

[0026] Figure 2D Depicts the resulting polymer structures according to certain embodiments, including microfluidic dispensers, vascular perfusion beds, and microfluidic-enabled microarray patches, where the channels are filled with a dye for contrast. Scale bar is 5 mm.

[0027] Figures 3A - 3D Depicts a comparison between a model and experimental printing effects according to certain embodiments. Figure 3A Depicts the UV light accumulation in the formed microchannels (i.e., microvoid spaces), which results in a printing effect. Figure 3B Depicts Figure 3A the resulting polymer structure, where the microvoid spaces are filled. Figure 3C Depicts the UV light accumulation when a polymerizable composition is continuously delivered through the formed microchannels of a polymer structure. Figure 3D Depicts Figure 3C the resulting polymer structure, where the curved microvoid spaces are clearly distinguishable.

[0028] Figures 4A - 4D Depicts the mitigation of printing when generating polymer structures with varying microfluidic channel geometries and dimensions according to certain embodiments. Figure 4A Depicts the different microchannel pitches in polymer structures generated during fabrication with (iCLIP) and without (CLIP) injection of a polymerizable composition through the microchannels. Figure 4B Depicts the different microchannel diameters in polymer structures generated during fabrication with (iCLIP) and without (CLIP) injection of a polymerizable composition through the microchannels. Figure 4C Depicts the resolution of the varying microchannel pitch geometries in polymer structures generated during fabrication with (iCLIP) and without (CLIP) injection of a polymerizable composition through the microchannels. Figure 4D Depicts the resolution of the varying microchannel diameters in polymer structures generated during fabrication with (iCLIP) and without (CLIP) injection of a polymerizable composition through the microchannels. All scale bars are 1 mm.

[0029] Figures 5A - 5DDepicts the relationship between microchannel resolution and resin turnover when producing a polymer structure with microchannels according to certain embodiments. Figure 5A Depicts the variation of the resolution of a resin with a penetration depth of 237 μm with the turnover number. Figure 5B Depicts the variation of the resolution of varying microchannel dimensions with the turnover number. Figure 5C Depicts the variation of the resolution of varying microchannel geometries with the turnover number. Figure 5D Depicts the relationship between resin penetration depth and the minimum turnover rate.

[0030] Figures 6A - 6F Depicts a polymer structure having microvoid spaces (such as microchannels) positioned therein produced according to certain embodiments. Figure 6A Depicts a microfluidic microneedle patch. Figure 6B Depicts a microneedle patch having interconnected microfluidic channels. Figure 6C Depicts a microfluidic sensor backfilled with conductive gallium. Figure 6D Depicts a microfluidic microneedle patch having a 3D micromixer. Figure 6E Depicts a vascular perfusion chamber. Figure 6F Depicts a porous media separation column having a varying void fraction unit cell. All scales are 1 mm. Detailed Description

[0031] Aspects of the present disclosure include methods for manufacturing a polymer structure having microvoid spaces. Methods according to certain embodiments include irradiating a polymerizable composition positioned between a build lift and a build surface to produce such a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; moving the build lift away from the build surface; contacting the resulting microvoid spaces with a non-reactive composition; and repeating in a manner sufficient to produce a polymer structure having clearly discernible microvoid spaces. Systems for preparing polymer structures according to the subject methods are also described. Polymer structures having clearly discernible microvoid spaces are also provided, such as where the microvoid spaces are filled with a non-polymerizable composition.

[0032] Before describing the invention in more detail, it is to be understood that the invention is not limited to the particular embodiments described, and as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the invention is defined only by the appended claims.

[0033] In instances where a numerical range is provided, it should be understood that, unless the context clearly indicates otherwise, each intermediate value between the upper and lower limits of the range and any other stated value or intermediate value in the stated range, to the tenth lower unit, is encompassed within the present invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the present invention, subject to any explicit exclusions stated in the stated range. In instances where the stated range includes one or both of the limits, ranges excluding either or both of the included limits are also included in the present invention.

[0034] Certain ranges are presented herein with numerical values preceded by the term "about". The term "about" is used herein to provide literal support for the exact numerical values that follow, as well as numbers that are close to or near the numerical values that follow the recited term. In determining whether a number is close to or approximate to a specifically recited number, an unrecited number that is close to or approximate to the specifically recited number may be a number that provides substantially the same functionality as the specifically recited number in the context in which the number is given.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, representative illustrative methods and materials are now described.

[0036] All publications and patents cited in this specification are hereby incorporated by reference as if each individual publication or patent was specifically and individually indicated to be incorporated by reference and was incorporated by reference herein to disclose and describe the methods and / or materials related to the cited publications. Any citation of a publication is due to its publication prior to the filing date and should not be construed as an admission that the present invention is not entitled to antedate such publication by virtue of a prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may require independent verification.

[0037] It should be noted that, as used herein and in the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" include plural referents. It should also be noted that the claims may be drafted to exclude any optional elements. Thus, this statement is intended to serve as a basis for the use of exclusive terms such as "solely", "only", etc. in relation to the recitation of claim elements or the use of "negative" limitations.

[0038] As will be apparent to those skilled in the art upon reading this disclosure, each of the various embodiments described and shown herein has discrete components and features that can be readily separated from or combined with the features of any one of several other embodiments without departing from the scope or spirit of the invention. Any recited method can be performed in the order of the recited events or in any other order that is logically possible.

[0039] Although the apparatus and methods have been or will be described in terms of functional explanations for grammatical fluency, it should be clearly understood that unless expressly recited under 35 U.S.C. § 112, the claims should not be construed as being limited to structures that must in any way be restricted by "apparatus" or "step" limitations, but should be accorded the full scope of the defined meaning and equivalent meaning of the claims under the doctrine of judicial equivalents, and where the claims are expressly set forth under 35 U.S.C. § 112, should be accorded all statutory equivalent meanings under 35 U.S.C. § 112.

[0040] Method for manufacturing a polymer structure having microvoid spaces

[0041] Aspects of the present disclosure also include a method for manufacturing a polymer structure having microvoid spaces. The method according to certain embodiments includes irradiating a polymerizable composition positioned between a build lift and a build surface to produce such a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; moving the build lift away from the build surface; contacting the resulting microvoid spaces with a non-reactive composition; and repeating in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces. These steps are repeated in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces. For example, these steps can be repeated 2 or more times, such as 3 or more times, such as 4 or more times, such as 5 or more times, such as 10 or more times, such as 20 or more times, such as 30 or more times, such as 40 or more times, such as 50 or more times, such as 100 or more times, such as 250 or more times, for example 500 or more times, and including 1000 or more times. In certain instances, the resulting polymer structure has a non-polymerizable composition positioned therein.

[0042] In some embodiments, the polymerizable composition is irradiated with a beam generator component of a micro digital light projection system. In some instances, the light source is a broadband light source that emits light having a wavelength of 400 nm to 1000 nm. In some instances, the broadband light source is a halogen lamp, a deuterium arc lamp, a xenon arc lamp, a stable fiber-coupled broadband light source, a broadband LED having a continuous spectrum, a superluminescent diode, a semiconductor light-emitting diode, a broadband LED white light source, a multi-LED integrated white light source, and other broadband light sources or any combination thereof. In some instances, the light source is a narrowband light source that emits a specific wavelength or a narrow wavelength range. In some instances, the narrowband light source emits light having a narrow wavelength range, such as, for example, 50 nm or less, such as 40 nm or less, such as 30 nm or less, such as 25 nm or less, such as 20 nm or less, such as 15 nm or less, such as 10 nm or less, such as 5 nm or less, such as 2 nm or less, and includes a light source that emits light of a specific wavelength. In some instances, the polymerizable composition is irradiated with a narrowband light source such as a narrow-wavelength LED, a laser diode, or a broadband light source coupled with one or more optical bandpass filters, diffraction gratings, monochromators, or any combination thereof.

[0043] In certain embodiments, the light source is a stroboscopic light source, and the polymerizable composition is irradiated with periodic flashes, such as wherein the polymerizable composition is irradiated at a frequency of 0.01 kHz or greater, such as 0.05 kHz or greater, such as 0.1 kHz or greater, such as 0.5 kHz or greater, such as 1 kHz or greater, such as 2.5 kHz or greater, such as 5 kHz or greater, such as 10 kHz or greater, such as 25 kHz or greater, such as 50 kHz or greater, and includes 100 kHz or greater. In certain instances, the polymerizable composition is irradiated with a laser (such as a pulsed laser or a continuous-wave laser).

[0044] In some embodiments, the polymerizable composition is in contact with a build lift and a build surface. In some instances, the method includes irradiating the polymerizable composition for 1 second or longer to bond a first polymerization region of the polymerizable composition to the build lift, such as for 5 seconds or longer, such as for 10 seconds or longer, such as for 20 seconds or longer, such as for 30 seconds or longer, such as for 1 minute or longer, such as for 5 minutes or longer, and includes for 10 minutes or longer.

[0045] In some embodiments, after the first polymerization zone of the polymerizable composition is bonded to the build lift, the build lift is moved away from the build surface. In some instances, the build lift is moved in increments of 0.001 μm or greater, such as 0.005 μm or greater, such as 0.01 μm or greater, such as 0.05 μm or greater, such as 0.1 μm or greater, such as 0.5 μm or greater, such as 1 μm or greater, such as 2 μm or greater, such as 3 μm or greater, such as 4 μm or greater, such as 5 μm or greater, and including increments of 10 μm or greater. In certain instances, the build lift is moved in increments of 0.001 μm to 20 μm, such as 0.005 μm to 19 μm, such as 0.01 μm to 18 μm, such as 0.05 μm to 17 μm, such as 0.1 μm to 16 μm, such as 0.2 μm to 17 μm, such as 0.3 μm to 16 μm, such as 0.4 μm to 15 μm, such as 0.5 μm to 14 μm, such as 0.6 μm to 13 μm, such as 0.7 μm to 12 μm, such as 0.8 μm to 11 μm, and including 0.9 μm to 10 μm.

[0046] In certain instances, after the build lift is moved away from the build surface each time, the polymerizable composition is added to the build surface. In some instances, the polymerizable composition is added continuously to the build surface. In other instances, the polymerizable composition is added to the build surface at discrete intervals, each interval having a predetermined amount. In some embodiments, the polymerizable composition is selected from polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid-co-glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol-ene, acid anhydride, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl ester, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof. In certain instances, one or more of the polymerizable materials include carbon nanotubes, such as single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT). In some instances, the polymerizable composition has a viscosity of 100 cP to 7000 cP, such as 150 cP to 6500 cP, such as 200 cP to 6000 cP, such as 250 cP to 5500 cP, such as 300 cP to 5000 cP, such as 350 cP to 4500 cP, such as 400 cP to 4000 cP, such as 450 cP to 3500 cP, and including a viscosity of 500 cP to 3000 cP.

[0047] In some embodiments, the polymerizable composition is irradiated through a build surface. In some instances, the polymerizable composition is irradiated in the presence of a polymerization inhibitor. In certain embodiments, the polymerizable composition is continuously polymerized while the build platform is being removed from the build surface. In certain cases, the polymerization inhibitor is oxygen and the build surface is oxygen permeable. In certain instances, polymerizing the polymerizable composition in the presence of a polymerization inhibitor such as oxygen enables continuous (i.e., not layer-by-layer) production of a polymer structure having microvoid spaces, with a liquid "dead zone" at the interface between the build surface and the build polymer structure having the microvoid spaces. In some instances, the dead zone is created because oxygen acts as a polymerization inhibitor and passes through the oxygen-permeable build surface. Photopolymerization cannot occur in the oxygen-containing "dead zone" region, such that the region remains in a fluid state, and the polymerized components contact the build surface such that the build polymer structure does not physically adhere to the build surface.

[0048] In some embodiments, the polymerizable composition contacts the build platform and the build surface. In some instances, the method includes irradiating the polymerizable composition for a duration sufficient to bond a first polymerization zone of the polymerizable composition to the build platform. In some instances, the build platform is moved in increments of 0.001 μm or greater, such as 0.005 μm or greater, such as 0.01 μm or greater, such as 0.05 μm or greater, such as 0.1 μm or greater, such as 0.5 μm or greater, such as 1 μm or greater, such as 2 μm or greater, such as 3 μm or greater, such as 4 μm or greater, such as 5 μm or greater, and includes increments of 10 μm or greater. In certain instances, the build platform is moved in increments of 0.001 μm to 20 μm, such as 0.005 μm to 19 μm, such as 0.01 μm to 18 μm, such as 0.05 μm to 17 μm, such as 0.1 μm to 16 μm, such as 0.2 μm to 17 μm, such as 0.3 μm to 16 μm, such as 0.4 μm to 15 μm, such as 0.5 μm to 14 μm, such as 0.6 μm to 13 μm, such as 0.7 μm to 12 μm, such as 0.8 μm to 11 μm, and includes 0.9 μm to 10 μm.

[0049] In some instances, the method includes adding the polymerizable composition to the build surface after each removal of the build platform from the build surface. In some instances, the method includes continuously adding the polymerizable composition to the build surface. In some instances, the polymerizable composition is continuously added to the build surface by injection via a conduit.

[0050] In some instances, the polymerizable composition can be provided directly to the build plate from a liquid conduit and reservoir system. In some embodiments, the carrier includes one or more feed channels. The carrier feed channels are in fluid communication with a source of the polymerizable composition such as a reservoir and an associated pump. Different carrier feed channels can be in fluid communication with the same supply and operate simultaneously with each other, or different carrier feed channels can be individually controllable with respect to each other (e.g., by providing a pump and / or valve for each carrier feed channel). The individually controllable feed channels can be in fluid communication with a source (e.g., reservoir) containing the same polymerizable composition or can be in fluid communication with reservoirs containing different polymerizable compositions. If desired, in some embodiments, different polymerizable compositions can be fed alternately through the same feed channel by using a valve assembly.

[0051] In some embodiments, the polymerizable composition is delivered through two or more conduits to the space between the build lift and the build surface, such as three or more, such as four or more, such as five or more, such as six or more, such as seven or more, such as eight or more, such as nine or more, and including through ten or more different conduits. In some instances, the conduits are positioned inside the resulting polymer structure. In other instances, the conduits are positioned outside the resulting polymer structure. In certain instances, one or more of the conduits pass through the build lift, such as two or more of the conduits, such as three or more of the conduits, and including instances where the polymerizable composition is delivered through five or more of the conduits passing through the build lift.

[0052] In some embodiments, the method includes delivering two or more different polymerizable materials into the space between the build lift and the build surface. In some instances, a first polymerizable material is delivered into the space between the build lift and the build surface through a first conduit, and a second polymerizable material is delivered into the space between the build lift and the build surface through a second conduit. In certain embodiments, multiple different polymerizable materials are delivered into the space between the build lift and the build surface through multiple different conduits. For example, the number of different polymerizable materials delivered can be 2 or more, such as 3 or more, such as 4 or more, such as 5 or more, such as 6 or more, such as 7 or more, such as 8 or more, such as 9 or more, and including 10 or more. In some instances, multiple polymerizable materials are delivered through 2 or more different conduits, such as 3 or more, such as 4 or more, such as 5 or more, such as 6 or more, such as 7 or more, such as 8 or more, such as 9 or more, and including 10 or more different conduits.

[0053] Two or more different polymerizable materials can be delivered into the space between the build lift and the build surface simultaneously or in a predetermined sequential order. In some instances, two or more different polymerizable materials are delivered into the space between the build lift and the build surface, such as to form a blend or mixture of two or more different polymerizable materials (i.e., a mixed resin). In other instances, two or more different polymerizable materials are delivered sequentially into the space between the build lift and the build surface, such as to form layers of different polymerizable materials.

[0054] The polymerizable composition can be delivered through each conduit at varying rates, such as from 0.01 μL / s to 200 μL / s, such as from 0.05 μL / s to 150 μL / s, such as from 0.1 μL / s to 100 μL / s, such as from 0.5 μL / s to 90 μL / s, such as from 1 μL / s to 80 μL / s, such as from 2 μL / s to 70 μL / s, such as from 3 μL / s to 60 μL / s, such as from 4 μL / s to 50 μL / s, such as from 5 μL / s to 40 μL / s, such as from 6 μL / s to 30 μL / s, and including from 7 μL / s to 27 μL / s. In some instances, the rate for delivering the polymerizable composition is controlled by an injection pump. In some instances, the rate can be controlled by a flow restrictor valve positioned at the proximal or distal end of the conduit. In certain embodiments, the polymerizable composition is delivered into the space between the build lift and the build surface at a rate sufficient to produce a polymer structure at a rate of 0.01 mm / h or greater, such as 0.05 mm / h or greater, such as 0.1 mm / h or greater, such as 0.5 mm / h or greater, such as 1 mm / h or greater, such as 2 mm / h or greater, such as 3 mm / h or greater, such as 4 mm / h or greater, such as 5 mm / h or greater, such as 6 mm / h or greater, such as 7 mm / h or greater, such as 8 mm / h or greater, such as 9 mm / h or greater, such as 10 mm / h or greater, such as 15 mm / h or greater, such as 20 mm / h or greater, such as 25 mm / h or greater, such as 50 mm / h or greater, such as 75 mm / h or greater, such as 100 mm / h or greater, such as 150 mm / h or greater, and including delivering the polymerizable composition into the space between the build lift and the build surface at a rate sufficient to produce a polymer structure at a rate of 250 mm / h or greater through one or more conduits. For example, the polymerizable material can be delivered through one or more conduits at a rate sufficient to produce a polymer structure at a rate of from 1 mm / h to 250 mm / h, such as from 2 mm / h to 225 mm / h, such as from 3 mm / h to 200 mm / h, such as from 4 mm / h to 175 mm / h, such as from 5 mm / h to 150 mm / h, and including from 10 mm / h to 125 mm / h.

[0055] In some embodiments, a method of providing a polymerizable composition to a liquid interface polymerization module by injecting a continuous liquid interface production, such as that described in International Patent Application No. PCT / US23 / 15406, filed on March 16, 2023, the disclosure of which is incorporated herein by reference. In certain embodiments, the polymerizable composition is polymerized using a liquid interface polymerization module that is a continuous liquid interface production (CLIP) system, such as those described in International Patent Publication No. WO2014 / 126837; U.S. Patent Publication Nos. 2018 / 0064920; 2017 / 0095972; 2021 / 0246252 and U.S. Patent Publication Nos. 10,155,882; 10,792,857, the disclosures of which are incorporated herein by reference.

[0056] In some instances, the microvoid space generated within the polymer structure includes one or more microchannels. In some instances, one or more of the microchannels include one or more bifurcations, such as two or more bifurcations, such as three or more, such as four or more, such as five or more, and include ten or more different bifurcations. In some instances, the microchannels extend through the polymer structure. In some instances, the microchannels are fluidically interconnected. In some instances, the polymer structure has a single network of fluidically interconnected microchannels. In other instances, the polymer structure has multiple fluidically interconnected microchannel networks.

[0057] When practicing the methods of the present disclosure in accordance with some embodiments, an amount of polymerizable composition is delivered through the resulting microvoid space in a manner sufficient to displace any material (e.g., residual or trapped polymerized resin) in the microvoid space. In an embodiment, the polymerizable composition used to displace the material from the microvoid space can be the same polymerizable material used to form the polymer structure or, as needed, a different polymerizable material. In some instances, the polymerizable composition delivered through the microvoid space is non-reactive when injected through the microvoid space. "Non-reactive" means that the polymerizable composition delivered through the microvoid space does not react with the formed polymer structure and does not polymerize therein (such as to clog the microvoid space). In some instances, the polymerizable composition is injected into the microvoid space, such as where the microvoid space is a microchannel within the formed polymer structure. The polymerizable composition can be delivered through the resulting microvoid space at a rate sufficient to displace the material in the microvoid space, such as a rate of 0.01 μL / s or greater, such as 0.05 μL / s or greater, such as 0.1 μL / s or greater, such as 0.5 μL / s or greater, such as 1 μL / s or greater, such as 2 μL / s or greater, such as 3 μL / s or greater, such as 4 μL / s or greater, such as 5 μL / s or greater, such as 6 μL / s or greater, such as 7 μL / s or greater, such as 8 μL / s or greater, such as 9 μL / s or greater, such as 10 μL / s or greater, such as 15 μL / s or greater, such as 20 μL / s or greater, such as 25 μL / s or greater, such as 50 μL / s or greater, such as 75 μL / s or greater, such as 100 μL / s or greater, and including a rate of 250 μL / s or greater. For example, the polymerizable composition can be delivered through the resulting microvoid space at a rate of 0.01 μL / s to 200 μL / s, such as 0.05 μL / s to 150 μL / s, such as 0.1 μL / s to 100 μL / s, such as 0.5 μL / s to 90 μL / s, such as 1 μL / s to 80 μL / s, such as 2 μL / s to 70 μL / s, such as 3 μL / s to 60 μL / s, such as 4 μL / s to 50 μL / s, such as 5 μL / s to 40 μL / s, such as 6 μL / s to 30 μL / s, and including 7 μL / s to 27 μL / s. In certain instances, delivering the polymerizable composition is sufficient to flush out the trapped or residual resin in the microvoid space so as to retain the negative space and eliminate the ghosting of the polymer structure.

[0058] In some embodiments, while generating the polymeric structure (e.g., while moving a build lift away from a build surface when generating the polymeric structure), the polymerizable composition is delivered through the generated microvoid space at predetermined intervals. In some instances, the polymerizable composition is delivered through the microvoid space every 1 second or longer to displace any material (e.g., trapped polymerized resin) in the microvoid space, such as every 5 seconds or longer, such as every 10 seconds or longer, such as every 15 seconds or longer, such as every 30 seconds or longer, such as every 1 minute or longer, such as every 5 minutes or longer, such as every 10 minutes or longer, and including every 30 minutes or longer. In some instances, the polymerizable composition is continuously delivered through the generated microvoid space into the space between the build lift and the build surface of the liquid interface production module. In some instances, while moving the build lift away from the build surface when generating the polymeric structure, a non-reactive composition is continuously delivered (e.g., through a conduit) into the microvoid space.

[0059] In some embodiments, the method includes contacting the generated microvoid space with a non-polymerizable composition. In practicing the subject method, in some instances, while generating the polymeric structure, the non-polymerizable composition is continuously contacted with the microvoid space. In some embodiments, the method includes filling at least a portion of the void volume of the microvoid space with the non-polymerizable composition, such as 5% or more, such as 10% or more, such as 15% or more, such as 20% or more, such as 25% or more, such as 50% or more, such as 75% or more, and including 90% or more of the void volume of the microvoid space. In some embodiments, the method includes filling the entire void volume of the microvoid space with the non-polymerizable composition. In certain instances, the non-polymerizable composition does not react with the polymerizable composition of the polymeric structure. In some instances, the non-polymerizable composition fills one or more microchannels within the polymeric structure, such as where the non-polymerizable composition fills one or more microchannels extending through the polymeric structure. In some instances, the polymeric structure includes a plurality of microvoid spaces. In some instances, the non-polymerizable composition is a composition selected from water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric field-responsive liquids, and gases.

[0060] In some instances, the method includes adding the non-polymerizable composition to the build surface after each time the build lift is moved away from the build surface to fill the generated microvoid space. In some instances, the method includes continuously adding the non-polymerizable composition to the build surface to fill the generated microvoid space. In some instances, the non-polymerizable composition is continuously added to the build surface by injection via a conduit to fill the generated microvoid space.

[0061] In some instances, the non-polymerizable composition can be provided directly to the build plate from a liquid conduit and reservoir system. In some embodiments, the carrier includes one or more feed channels. The carrier feed channels are in fluid communication with a non-polymerizable composition supply source such as a reservoir and an associated pump. Different carrier feed channels can be in fluid communication with the same supply source and operate simultaneously with each other, or different carrier feed channels can be individually controllable with respect to each other (e.g., by providing a pump and / or valve for each carrier feed channel). The individually controllable feed channels can be in fluid communication with a reservoir containing the same polymerizable composition or can be in fluid communication with reservoirs containing different polymerizable compositions. If desired, in some embodiments, different polymerizable compositions can be fed alternately through the same feed channel by using a valve assembly.

[0062] Figure 1 Depiction of injecting a non-polymerizable composition into the resulting microvoid space (such as a microchannel) according to certain embodiments. As Figure 1 shown, a polymer structure is generated layer by layer by irradiating the polymerizable composition between the build lift and the build surface. Microvoid spaces, here microchannels, are formed within the polymer structure. During the formation of the microchannels at each layer, the non-polymerizable composition is injected into the formed microvoid space through a conduit via the build lift. The non-polymerizable composition in this embodiment is sufficient to prevent excessive polymerizable material from polymerizing in the formed microvoid space. Removal of the non-polymerizable composition is sufficient to produce a clearly discernible microvoid space, such as the depicted microchannel passing through the polymer structure. As described above, in some instances, additional polymerizable material (e.g., fresh resin for forming the polymer structure) can alternatively be injected through the formed microchannels at each layer to flush out residual or entrapped polymerized material.

[0063] System for manufacturing a polymer structure having microvoid spaces

[0064] Aspects of the present disclosure also include a system for manufacturing a polymer structure having microvoid spaces. A system according to certain embodiments includes a light source and a photointerface polymerization module having a build lift and a build surface configured to produce a polymer structure having clearly discernible microvoid spaces therein from a polymerizable composition positioned therebetween.

[0065] In some embodiments, the system includes a light source. In some embodiments, the light source is a broadband light source that emits light having a wide wavelength range, such as for example spanning 50 nm or greater, such as 100 nm or greater, such as 150 nm or greater, such as 200 nm or greater, such as 250 nm or greater, such as 300 nm or greater, such as 350 nm or greater, such as 400 nm or greater, and including spanning 500 nm or greater. For example, a suitable broadband light source emits light having wavelengths from 200 nm to 1500 nm. Another example of a suitable broadband light source includes a light source that emits light having wavelengths from 400 nm to 1000 nm. Any convenient broadband light source scheme can be employed, such as a halogen lamp, a deuterium arc lamp, a xenon arc lamp, a stable fiber-coupled broadband light source, a broadband LED having a continuous spectrum, a superluminescent diode, a semiconductor light emitting diode, a broadband LED white light source, a multi-LED integrated white light source, and other broadband light sources or any combination thereof.

[0066] In some embodiments, the light source is a narrowband light source that emits a specific wavelength or a narrow wavelength range. In some instances, the narrowband light source emits light having a narrow wavelength range, such as for example less than 50 nm, such as less than 40 nm, such as less than 30 nm, such as less than 25 nm, such as less than 20 nm, such as less than 15 nm, such as less than 10 nm, such as less than 5 nm, such as less than 2 nm, and including a light source that emits light of a specific wavelength (i.e., monochromatic light). Any convenient narrowband light source scheme can be employed, such as a narrow wavelength LED, a laser diode, or a broadband light source that is coupled to one or more optical bandpass filters, diffraction gratings, monochromators, or any combination thereof. The subject system can include one or more light sources as needed, such as two or more light sources, such as three or more light sources, such as four or more light sources, such as five or more light sources, and including ten or more light sources. The light sources can include a combination of light source types. For example, in an instance where two light sources are employed, the first light source can be a broadband white light source (e.g., a broadband white light LED), and the second light source can be a broadband near-infrared light source (e.g., a broadband near-infrared LED). In other instances where two light sources are employed, the first light source can be a broadband white light source (e.g., a broadband white light LED), and the second light source can be a narrow spectrum light source (e.g., a narrowband visible or near-infrared LED). In still other instances, the light sources are a plurality of narrowband light sources, each narrowband light source emitting a specific wavelength, such as an array of two or more LEDs, such as an array of three or more LEDs, such as an array of five or more LEDs, including an array of ten or more LEDs.

[0067] In some embodiments, the light source is a stroboscopic light source, where the polymerizable composition is irradiated with periodic flashes. Depending on the light source (e.g., flash lamp, pulsed laser), the frequency of the light strobe can vary and can be greater than 0.01 kHz, such as greater than 0.05 kHz, such as greater than 0.1 kHz, such as greater than 0.5 kHz, such as greater than 1 kHz, such as greater than 2.5 kHz, such as greater than 5 kHz, such as greater than 10 kHz, such as greater than 25 kHz, such as greater than 50 kHz, and including greater than 100 kHz. In these embodiments, the strobe light can be operatively coupled to a processor having a frequency generator that adjusts the strobe frequency. In some instances, the frequency generator of the strobe light is operatively coupled to a projection monitoring component of a micro digital light projection system such that the frequency of the strobe light is synchronized with the frequency of image capture on the build surface of the optical interface polymerization module. In certain instances, suitable stroboscopic light sources and frequency controllers include, but are not limited to, those described in U.S. Patent Nos. 5,700,692 and 6,372,506, the disclosures of which are incorporated herein by reference.

[0068] In some embodiments, the light source includes one or more lasers. Lasers of interest can include pulsed lasers or continuous wave lasers. The type and number of lasers used in the subject methods can vary and can be gas lasers such as helium-neon lasers, argon lasers, krypton lasers, xenon lasers, nitrogen lasers, CO2 lasers, CO lasers, argon-fluoride (ArF) excimer lasers, krypton-fluoride (KrF) excimer lasers, xenon-chloride (XeCl) excimer lasers, or xenon-fluoride (XeF) excimer lasers or combinations thereof. In other instances, the beam generator includes dye lasers such as stilbene, coumarin, or rhodamine lasers. In yet other instances, the beam generator includes metal-vapor lasers such as helium-cadmium (HeCd) lasers, helium-mercury (HeHg) lasers, helium-selenium (HeSe) lasers, helium-silver (HeAg) lasers, strontium lasers, neon-copper (NeCu) lasers, copper lasers, or gold lasers and combinations thereof. In yet other instances, the beam generator includes solid-state lasers such as ruby lasers, Nd:YAG lasers, NdCrYAG lasers, Er:YAG lasers, Nd:YLF lasers, Nd:YVO4 lasers, Nd:YCa4O(BO3)3 lasers, Nd:YCOB lasers, titanium sapphire lasers, thulium YAG lasers, ytterbium YAG lasers, yttrium oxide lasers, or cerium-doped lasers and combinations thereof. In yet other instances, the light source includes semiconductor diode lasers, optically pumped semiconductor lasers (OPSL), or frequency-doubled or frequency-tripled implementations of any of the above lasers.

[0069] In some embodiments, the light source includes one or more tubelenses configured with adjustable focal lengths. In some instances, the tubelens is a telecentric lens. In certain instances, the tubelens is configured for wide field of view imaging. In some instances, the tubelens has an adjustable focal length ranging from 10 mm to 1000 mm, such as 20 mm to 900 mm, such as 30 mm to 800 mm, such as 40 mm to 700 mm, such as 50 mm to 600 mm, such as 60 mm to 500 mm, such as 70 mm to 400 mm, such as 80 mm to 300 mm, and includes an adjustable focal length of 100 mm to 200 mm.

[0070] In some embodiments, the light source includes one or more projection lenses, such as two or more projection lenses, such as three or more projection lenses, such as four or more projection lenses, and includes five or more projection lenses. In some instances, the projection lens provides a magnification of two times or greater, such as three times or greater, such as four times or greater, such as five times or greater, such as six times or greater, such as seven times or greater, such as eight times or greater, such as nine times or greater, and includes a magnification of ten times or greater. In some instances, the projection lens provides a de-magnification with a magnification ratio ranging from 0.1 to 0.95, such as a magnification ratio of 0.2 to 0.9, such as a magnification ratio of 0.3 to 0.85, such as a magnification ratio of 0.35 to 0.8, such as a magnification ratio of 0.5 to 0.75, and includes a magnification ratio of 0.55 to 0.7, for example, a magnification ratio of 0.6.

[0071] In some embodiments, the light source includes one or more beam splitters. A beam splitter can be any optical component configured to propagate a light beam along two or more different and spatially separated optical paths such that a predetermined portion of the light propagates along each optical path. The beam splitter can be any convenient beam splitting scheme, such as using a triangular prism, a silvered mirror prism, a dichroic mirror prism, and other types of beam splitters. The beam splitter can be formed from any suitable material as long as the beam splitter can propagate the desired amount and wavelength of light along each optical path. For example, beam splitters of interest can be formed from glass (e.g., N-SF10, N-SF11, N-SF57, N-BK7, N-LAK21, or N-LAF35 glass), silica (e.g., fused silica), quartz, crystals (e.g., CaF2 crystal), zinc selenide (ZnSe), F2, germanium titanate (Ge) (e.g., S-TIH11), borosilicate (e.g., BK7). In certain embodiments, the beam splitter is formed from a polymeric material such as, but not limited to, polycarbonate, polyvinyl chloride (PVC), polyurethane, polyether, polyamide, polyimide, or copolymers of these thermoplastics such as PETG (ethylene glycol modified polyethylene terephthalate), and other polymeric plastic materials.In certain embodiments, the beam splitter is formed from a polyester, where the polyesters of interest can include, but are not limited to, poly(alkylene terephthalates), such as poly(ethylene terephthalate) (PET), bottle grade PET (a copolymer made from monoethylene glycol, terephthalic acid, and other comonomers such as isophthalic acid, cyclohexanedimethanol, etc.), poly(butylene terephthalate) (PBT), and poly(hexylene terephthalate); poly(alkylene adipates), such as poly(ethylene adipate), poly(1,4-butylene adipate), and poly(hexylene adipate); poly(alkylene suberates), such as poly(ethylene suberate); poly(alkylene sebacates), such as poly(ethylene sebacate); poly(ε-caprolactone) and poly(β-propiolactone); poly(isophthalate alkylene), such as poly(isophthalate ethylene); poly(2,6-naphthalate alkylene), such as poly(2,6-naphthalate ethylene); poly(alkylene sulfonyl-4,4'-dibenzoate), such as poly(ethylene sulfonyl-4,4'-dibenzoate); poly(p-phenylene alkylene dicarboxylate), such as poly(p-phenylene ethylene dicarboxylate); poly(trans-1,4-cyclohexane diyl alkylene dicarboxylate), such as poly(trans-1,4-cyclohexane diyl ethylene dicarboxylate); poly(1,4-cyclohexane-dimethylene alkylene dicarboxylate), such as poly(1,4-cyclohexane-dimethylene ethylene dicarboxylate); poly([2.2.2]-bicyclooctane-1,4-dimethylene alkylene dicarboxylate), such as poly([2.2.2]-bicyclooctane-1,4-dimethylene ethylene dicarboxylate); lactic acid polymers and copolymers, such as (S)-polylactide, (R,S)-polylactide, poly(tetramethyl glycolide), and poly(lactide-co-glycolide); and polycarbonates of bisphenol A, 3,3'-dimethylbisphenol A, 3,3',5,5'-tetrachlorobisphenol A, 3,3',5,5'-tetramethylbisphenol A; polyamides, such as poly(p-phenylene terephthalamide); polyethylene terephthalate (e.g., MylarTM polyethylene terephthalate), combinations thereof, etc.

[0072] In an embodiment, the micro digital light projection system includes a light projection monitoring component having a photodetector. The photodetector can be any convenient light detection scheme, including but not limited to a photosensor or a photodetector, such as an active pixel sensor (APS), an avalanche photodiode (APD), a quadrant photodiode, an image sensor, a charge-coupled device (CCD), an intensified charge-coupled device (ICCD), a light-emitting diode, a photon counter, a bolometer, a thermoelectric detector, a photoresistor, a photovoltaic cell, a photodiode, a photomultiplier tube, a phototransistor, a quantum dot photoconductor or a photodiode and combinations thereof, and other photodetectors. In certain embodiments, the photodetector is a photomultiplier tube, such as a photomultiplier tube having an effective detection surface area in the range of 0.01 cm 2 to 10 cm 2 such as 0.05 cm 2 to 9 cm 2 such as, such as 0.1 cm 2 to 8 cm 2 such as 0.5 cm 2 to 7 cm 2 and includes 1 cm 2 to 5 cm 2 .

[0073] In certain embodiments, the light projection monitoring component includes one or more photodetectors that are optically coupled to a slit. Depending on the size of the effective detection surface of the photodetector, the slit according to certain examples has a rectangular (or other polygonal) opening having a width of 0.01 mm to 2 mm, such as 0.1 mm to 1.9 mm, such as 0.2 mm to 1.8 mm, such as 0.3 mm to 1.7 mm, such as 0.4 mm to 1.6 mm, and includes a width of 0.5 mm to 1.5 mm; and a length of 0.01 mm to 2 mm, such as 0.1 mm to 1.9 mm, such as 0.2 mm to 1.8 mm, such as 0.3 mm to 1.7 mm, such as 0.4 mm to 1.6 mm, and includes a length of 0.5 mm to 1.5 mm. In certain examples, the width of the slit is 1 mm or less, such as 0.9 mm or less, such as 0.8 mm or less, such as 0.7 mm or less, such as 0.6 mm or less, such as 0.5 mm or less, and includes a width of 0.4 mm or less. In certain examples, the light detection system includes a photodetector that is optically coupled to a slit having a plurality of openings, such as a slit having 2 or more openings, such as 3 or more openings, such as 4 or more openings, such as 5 or more openings, such as 6 or more openings, such as 7 or more openings, such as 8 or more openings, such as 9 or more openings, and includes a slit having 10 or more openings.

[0074] Light can be measured by a photodetector at one or more wavelengths, such as at 2 or more wavelengths, such as at 5 or more different wavelengths, such as at 10 or more different wavelengths, such as at 25 or more different wavelengths, such as at 50 or more different wavelengths, for example at 100 or more different wavelengths, such as at 200 or more different wavelengths, such as at 300 or more different wavelengths, and including measuring light at 400 or more different wavelengths. Light can be measured continuously or at discrete intervals. In some instances, the detector of interest is configured to measure light continuously. In other instances, the detector of interest is configured to measure at discrete intervals, such as every 0.001 milliseconds, every 0.01 milliseconds, every 0.1 milliseconds, every 1 millisecond, every 10 milliseconds, every 100 milliseconds, and including measuring light every 1000 milliseconds or some other interval.

[0075] In certain embodiments, the micro digital light projection system is a digital light processing (DLP) system with a digital micromirror device, such as those described in U.S. Patent Publication Nos. 2017 / 0095972; 2022 / 0250313; 2022 / 0048242 and U.S. Patent Nos. 11,358,342; 11,141,910, the disclosures of which are incorporated herein by reference.

[0076] In some embodiments, the system includes a processor having a memory operably coupled to the processor, wherein the memory includes instructions stored thereon that, when executed by the processor, cause the processor to a) irradiate a polymerizable composition positioned between a build lift and a build surface to produce a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; b) move the build lift away from the build surface; c) contact the resulting microvoid spaces with a non-reactive composition; and d) repeat steps a)-c) in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces. In some instances, the system is configured to produce a polymer structure having microvoid spaces that include a non-polymerizable composition positioned therein. These steps are repeated in a manner sufficient to produce a polymer structure having microvoid spaces in which there is a non-polymerizable composition. For example, these steps may be repeated 2 or more times, such as 3 or more times, such as 4 or more times, such as 5 or more times, such as 10 or more times, such as 20 or more times, such as 30 or more times, such as 40 or more times, such as 50 or more times, such as 100 or more times, such as 250 or more times, for example 500 or more times, and including 1000 or more times.

[0077] In some embodiments, the memory includes instructions to irradiate the polymerizable composition for a duration sufficient to bond a first polymerized region of the polymerizable composition to the build lift. In some instances, the memory includes instructions to irradiate the polymerizable composition for 1 second or longer to bond a first polymerized region of the polymerizable composition to the build lift, such as for 5 seconds or longer, such as for 10 seconds or longer, such as for 20 seconds or longer, such as for 30 seconds or longer, such as for 1 minute or longer, such as for 5 minutes or longer, and including for 10 minutes or longer.

[0078] In some embodiments, the memory includes instructions to move a build stage in predetermined increments to build a polymeric structure. In some instances, the memory includes instructions to move the build stage in increments of 0.001 μm or greater, such as 0.005 μm or greater, such as 0.01 μm or greater, such as 0.05 μm or greater, such as 0.1 μm or greater, such as 0.5 μm or greater, such as 1 μm or greater, such as 2 μm or greater, such as 3 μm or greater, such as 4 μm or greater, such as 5 μm or greater, and includes increments of 10 μm or greater. In certain instances, the memory includes instructions to move the build stage in increments of 0.001 μm to 20 μm, such as 0.005 μm to 19 μm, such as 0.01 μm to 18 μm, such as 0.05 μm to 17 μm, such as 0.1 μm to 16 μm, such as 0.2 μm to 17 μm, such as 0.3 μm to 16 μm, such as 0.4 μm to 15 μm, such as 0.5 μm to 14 μm, such as 0.6 μm to 13 μm, such as 0.7 μm to 12 μm, such as 0.8 μm to 11 μm, and includes 0.9 μm to 10 μm.

[0079] In certain instances, the memory includes instructions to add a polymerizable composition to the build surface after each removal of the build stage from the build surface. In some instances, the memory includes instructions to continuously add the polymerizable composition to the build surface. In other instances, the memory includes instructions to continuously add the polymerizable composition to the build surface at discrete intervals, each interval having a predetermined amount. In some embodiments, the polymerizable composition is selected from polycaprolactone, polyglycolic acid, polylactic acid, polylactic-co-glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol-ene, acid anhydrides, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl esters, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof. In certain instances, one or more of the polymerizable materials includes carbon nanotubes, such as single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT). In some instances, the polymerizable composition has a viscosity of 100 cP to 7000 cP, such as 150 cP to 6500 cP, such as 200 cP to 6000 cP, such as 250 cP to 5500 cP, such as 300 cP to 5000 cP, such as 350 cP to 4500 cP, such as 400 cP to 4000 cP, such as 450 cP to 3500 cP, and includes a viscosity of 500 cP to 3000 cP.

[0080] In some instances, the polymerizable composition can be provided directly to the build plate from a liquid conduit and reservoir system. In some embodiments, the carrier includes one or more feed channels. The carrier feed channels are in fluid communication with a polymerizable composition source such as a reservoir and an associated pump. Different carrier feed channels can be in fluid communication with the same supply source and operate simultaneously with each other, or different carrier feed channels can be individually controllable with respect to each other (e.g., by providing a pump and / or valve for each carrier feed channel). The individually controllable feed channels can be in fluid communication with a source (e.g., a reservoir) containing the same polymerizable composition, or can be in fluid communication with reservoirs containing different polymerizable compositions. If desired, in some embodiments, different polymerizable compositions can be fed alternately through the same feed channel by using a valve assembly.

[0081] In some embodiments, the system includes two or more conduits for delivering the polymerizable composition to the space between the build lift and the build surface, such as three or more, such as four or more, such as five or more, such as six or more, such as seven or more, such as eight or more, such as nine or more, and includes ten or more different conduits. In some instances, the conduits are positioned inside the resulting polymer structure. In other instances, the conduits are positioned outside the resulting polymer structure. In certain instances, one or more of the conduits pass through the build lift, such as two or more of the conduits, such as three or more of the conduits, and includes instances where the polymerizable composition is delivered through five or more of the conduits passing through the build lift.

[0082] In some embodiments, the system is configured to deliver two or more different polymerizable materials into the space between the build lift and the build surface. In some instances, the system is configured to deliver a first polymerizable material into the space between the build lift and the build surface through a first conduit and a second polymerizable material into the space between the build lift and the build surface through a second conduit. In certain embodiments, the system is configured to deliver a plurality of different polymerizable materials into the space between the build lift and the build surface through a plurality of different conduits. For example, the number of different polymerizable materials delivered can be two or more, such as three or more, such as four or more, such as five or more, such as six or more, such as seven or more, such as eight or more, such as nine or more, and including ten or more. In some instances, the system is configured to deliver a plurality of polymerizable materials through two or more different conduits, such as three or more, such as four or more, such as five or more, such as six or more, such as seven or more, such as eight or more, such as nine or more, and including ten or more different conduits.

[0083] In some embodiments, the system is configured to deliver two or more different polymerizable materials into the space between the build lift and the build surface simultaneously or in a predetermined sequential order. In some instances, the system is configured to deliver two or more different polymerizable materials into the space between the build lift and the build surface, such as to form a blend or mixture of two or more different polymerizable materials (i.e., a mixed resin). In other instances, the system is configured to deliver two or more different polymerizable materials sequentially into the space between the build lift and the build surface, such as to form layers of different polymerizable materials.

[0084] In some instances, the system is configured to deliver the polymerizable composition through each conduit at a varying rate, such as from 0.01 μL / s to 200 μL / s, such as from 0.05 μL / s to 150 μL / s, such as from 0.1 μL / s to 100 μL / s, such as from 0.5 μL / s to 90 μL / s, such as from 1 μL / s to 80 μL / s, such as from 2 μL / s to 70 μL / s, such as from 3 μL / s to 60 μL / s, such as from 4 μL / s to 50 μL / s, such as from 5 μL / s to 40 μL / s, such as from 6 μL / s to 30 μL / s, and including from 7 μL / s to 27 μL / s. In some instances, the rate for delivering the polymerizable composition is controlled by an injection pump. In some instances, the conduit includes a flow rate limiting valve at the proximal end or the distal end to control the rate of delivering the polymerizable composition. In certain embodiments, the system is configured to deliver the polymerizable composition into the space between the build lift and the build surface at a rate sufficient to produce a polymer structure at a rate of 0.01 mm / h or greater, such as 0.05 mm / h or greater, such as 0.1 mm / h or greater, such as 0.5 mm / h or greater, such as 1 mm / h or greater, such as 2 mm / h or greater, such as 3 mm / h or greater, such as 4 mm / h or greater, such as 5 mm / h or greater, such as 6 mm / h or greater, such as 7 mm / h or greater, such as 8 mm / h or greater, such as 9 mm / h or greater, such as 10 mm / h or greater, such as 15 mm / h or greater, such as 20 mm / h or greater, such as 25 mm / h or greater, such as 50 mm / h or greater, such as 75 mm / h or greater, such as 100 mm / h or greater, such as 150 mm / h or greater, and including where the system is configured to deliver the polymerizable composition through one or more conduits into the space between the build lift and the build surface at a rate sufficient to produce a polymer structure at a rate of 250 mm / h or greater. For example, the polymerizable material can be delivered through one or more conduits at a rate sufficient to produce a polymer structure at a rate of from 1 mm / h to 250 mm / h, such as from 2 mm / h to 225 mm / h, such as from 3 mm / h to 200 mm / h, such as from 4 mm / h to 175 mm / h, such as from 5 mm / h to 150 mm / h, and including from 10 mm / h to 125 mm / h.

[0085] In some embodiments, the system includes a source of polymerizable composition that is in communication with a build region to add the polymerizable composition to a build surface. In some instances, the source is configured to add the polymerizable composition to the build region via a conduit, such as by injecting the polymerizable composition via the conduit. In certain embodiments, the system of interest includes a photointerfacial polymerization module having an injection system for providing the polymerizable composition to the build surface, as described in International Patent Application No. PCT / US23 / 15406, filed March 16, 2023, the disclosure of which is incorporated herein by reference. In certain embodiments, the liquid interfacial polymerization module as a continuous liquid interface production (CLIP) system includes those described in International Patent Publication No. WO 2014 / 126837; U.S. Patent Publication Nos. 2018 / 0064920; 2017 / 0095972; 2021 / 0246252 and U.S. Patent Publication Nos. 10,155,882; 10,792,857, the disclosures of which are incorporated herein by reference.

[0086] In some embodiments, the system includes a processor having a memory operably coupled to the processor, where the memory includes instructions stored thereon for causing a generated microvoid space to contact a quantity of polymerizable composition in a manner sufficient to displace polymeric material in the microvoid space. In an embodiment, the polymerizable composition for displacing material from the microvoid space can be the same polymerizable material used to form the polymer structure or can be a different polymerizable material as needed. In some instances, the polymerizable composition delivered through the microvoid space is non-reactive when injected through the microvoid space.

[0087] In some instances, the memory includes instructions to inject a polymerizable composition into the microvoid space, such as where the microvoid space is a microchannel formed within a polymer structure. In some instances, the memory includes instructions to convey the polymerizable composition m through the resulting microvoid space at a rate sufficient to displace the material within the microvoid space, such as a rate of 0.01 μL / s or greater, such as 0.05 μL / s or greater, such as 0.1 μL / s or greater, such as 0.5 μL / s or greater, such as 1 μL / s or greater, such as 2 μL / s or greater, such as 3 μL / s or greater, such as 4 μL / s or greater, such as 5 μL / s or greater, such as 6 μL / s or greater, such as 7 μL / s or greater, such as 8 μL / s or greater, such as 9 μL / s or greater, such as 10 μL / s or greater, such as 15 μL / s or greater, such as 20 μL / s or greater, such as 25 μL / s or greater, such as 50 μL / s or greater, such as 75 μL / s or greater, such as 100 μL / s or greater, and includes a rate of 250 μL / s or greater. In certain instances, the memory includes instructions to convey the polymerizable composition through the resulting microvoid space at a rate of 0.01 μL / s to 200 μL / s, such as 0.05 μL / s to 150 μL / s, such as 0.1 μL / s to 100 μL / s, such as 0.5 μL / s to 90 μL / s, such as 1 μL / s to 80 μL / s, such as 2 μL / s to 70 μL / s, such as 3 μL / s to 60 μL / s, such as 4 μL / s to 50 μL / s, such as 5 μL / s to 40 μL / s, such as 6 μL / s to 30 μL / s, and includes 7 μL / s to 27 μL / s. In certain instances, the memory includes instructions to convey a polymerizable composition sufficient to flush out the resin trapped within the microvoid space in order to retain the negative space and eliminate the printing through of the polymer structure.

[0088] In some embodiments, the memory includes instructions for delivering the polymerizable composition through the generated microvoid space at a predetermined interval while generating the polymer structure (e.g., while moving the build lift away from the build surface when generating the polymer structure). In some instances, the memory includes instructions for delivering the polymerizable composition through the microvoid space every 1 second or longer to displace any material (e.g., trapped polymerized resin) in the microvoid space, such as every 5 seconds or longer, such as every 10 seconds or longer, such as every 15 seconds or longer, such as every 30 seconds or longer, such as every 1 minute or longer, such as every 5 minutes or longer, such as every 10 minutes or longer, and including every 30 minutes or longer. In some instances, the memory includes instructions for continuously delivering the polymerizable composition through the generated microvoid space into the space between the build lift and the build surface of the liquid interface production module. In some instances, the memory includes instructions for continuously (e.g., through a conduit) delivering a non-reactive composition into the microvoid space while moving the build lift away from the build surface when generating the polymer structure.

[0089] In some embodiments, the memory includes instructions for contacting the generated microvoid space with a non-polymerizable composition. In some instances, the memory includes instructions for continuously contacting the non-polymerizable composition with the microvoid space while generating the polymer structure. In some embodiments, the system further includes a source of the non-polymerizable composition that is operably coupled to the optical interface polymerization module such that the non-polymerizable composition can contact the microvoid space continuously or at a predetermined interval while generating the polymer structure. In some instances, the system includes a source of the non-polymerizable composition selected from water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric field-responsive liquids, and gases.

[0090] In some instances, the memory includes instructions for adding the non-polymerizable composition to the build surface to fill the generated microvoid space after each time the build lift is moved away from the build surface. In some instances, the memory includes instructions for continuously adding the non-polymerizable composition to the build surface to fill the generated microvoid space. In some instances, the non-polymerizable composition is continuously added to the build surface via injection through a conduit to fill the generated microvoid space. In certain embodiments, the memory includes instructions for removing the non-polymerizable composition from the generated microvoid space of the polymer structure.

[0091] In some instances, the memory includes at least a portion of the void volume of the microvoid space, such as 5% or more, such as 10% or more, such as 15% or more, such as 20% or more, such as 25% or more, such as 50% or more, such as 75% or more, and includes instructions for filling 90% or more of the void volume of the microvoid space, such as instructions for filling the entire void volume of the microvoid space, with a non-polymerizable composition. In some instances, the system is configured to deliver the non-polymerizable composition through a conduit at a varying rate to fill at least a portion of the void volume of the microvoid space, such as from 0.01 μL / s to 200 μL / s, such as from 0.05 μL / s to 150 μL / s, such as from 0.1 μL / s to 100 μL / s, such as from 0.5 μL / s to 90 μL / s, such as from 1 μL / s to 80 μL / s, such as from 2 μL / s to 70 μL / s, such as from 3 μL / s to 60 μL / s, such as from 4 μL / s to 50 μL / s, such as from 5 μL / s to 40 μL / s, such as from 6 μL / s to 30 μL / s, and includes from 7 μL / s to 27 μL / s. In some instances, the rate for delivering the non-polymerizable composition to fill at least a portion of the void volume of the microvoid space is controlled by an injection pump.

[0092] In some embodiments, the system further includes a source of a polymerizable composition. In some instances, the source is configured to continuously deliver the polymerizable composition to a build surface. In some instances, the system is configured to add the polymerizable composition to the build surface after each removal of the build lift from the build surface. In some embodiments, the polymerizable composition is selected from polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid-co-glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol-ene, acid anhydrides, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl esters, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof. In certain instances, one or more of the polymerizable materials include carbon nanotubes, such as single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT). In some instances, the polymerizable composition delivered through the conduit has a viscosity of 100 cP to 7000 cP, such as 150 cP to 6500 cP, such as 200 cP to 6000 cP, such as 250 cP to 5500 cP, such as 300 cP to 5000 cP, such as 350 cP to 4500 cP, such as 400 cP to 4000 cP, such as 450 cP to 3500 cP, and includes a viscosity of 500 cP to 3000 cP.

[0093] In some embodiments, the light source is configured to shine through the build surface. In some instances, at least a portion of the build surface is permeable to a polymerization inhibitor, such as where the polymerization inhibitor is oxygen.

[0094] In certain embodiments, the liquid interface polymerization module includes a continuous liquid interface production (CLIP) system, such as the systems described in International Patent Publication No. WO 2014 / 126837; U.S. Patent Publication Nos. 2018 / 0064920; 2017 / 0095972; 2021 / 0246252; and U.S. Patent Nos. 10,155,882; 10,792,857, the disclosures of which are incorporated herein by reference.

[0095] Aspects of the present disclosure further include computer-controlled systems, where the systems further include one or more computers for full or partial automation of the methods described herein. In an embodiment, the system includes an input module, a processing module, and an output module. The subject system can include both hardware components and software components, where the hardware components can take the form of one or more platforms, for example in the form of a server, such that the functional elements, i.e., those elements of the system that perform specific tasks of the system (such as managing input and output of information, processing information, etc.), can be performed by executing software applications on and across one or more computer platforms represented by the system.

[0096] The system can include a display and an operator input device. The operator input device can be, for example, a keyboard, a mouse, etc. The processing module includes a processor that has access to a memory on which instructions for performing the steps of the subject method are stored. The processing module can include an operating system, a graphical user interface (GUI) controller, a system memory, a memory storage device, and an input-output controller, a cache memory, a data backup unit, and many other devices. The processor can be a commercially available processor, or it can be one of other processors that are available or will become available. The processor executes the operating system, and the operating system interfaces with the firmware and hardware in a well-known manner and helps the processor coordinate and execute the functions of the various computer programs, which can be written in various programming languages, such as Java, Perl, C++, other high-level or low-level languages, and combinations thereof, as known in the art. The operating system, typically in cooperation with the processor, coordinates and executes the functions of the other components of the computer. The operating system also provides scheduling, input-output control, file and data management, memory management, and communication control and related services according to known techniques. The processor can be any suitable analog or digital system.

[0097] The system memory can be any one of a variety of known or future memory storage devices. Examples include any commonly available random access memory (RAM), magnetic media such as an internal (resident) hard disk or magnetic tape, optical media such as read and write optical discs, flash memory devices, or other memory storage devices. The memory storage device can be any one of a variety of known or future devices, including optical disc drives, tape drives, removable hard disk drives, or floppy disk drives. This type of memory storage device typically reads from and / or writes to a program storage medium (not shown), such as an optical disc, magnetic tape, removable hard disk, or floppy disk, respectively. Any one of these program storage media, or other program storage media that are now in use or may be developed in the future, can be considered a computer program product. It should be understood that these program storage media typically store computer software programs and / or data. Computer software programs, also known as computer control logic, are typically stored in the system memory and / or in a program storage device used in conjunction with the memory storage device.

[0098] In some embodiments, a computer program product is described that has a computer-usable medium having control logic (computer software program, including program code) stored therein. When executed by a processor computer, the control logic causes the processor to perform the functions described herein. In other embodiments, some functions are implemented primarily in hardware using, for example, a hardware state machine. It will be apparent to those skilled in the relevant art how to implement a hardware state machine to perform the functions described herein.

[0099] A memory can be any suitable device in which a processor can store and retrieve data, such as a magnetic, optical, or solid-state storage device (including a disk or optical disc or magnetic tape or RAM, or any other suitable device, whether fixed or portable). The processor can include a general-purpose digital microprocessor that is appropriately programmed by a computer-readable medium carrying the necessary program code. The program can be provided to the processor remotely via a communication channel or pre-stored in a computer program product, such as a memory or some other portable or fixed computer-readable storage medium, using any of those devices connected to the memory. For example, a disk or optical disc can carry the programming and can be read by a disk writer / reader. The system of the present invention also includes, for example, programming, algorithms in the form of a computer program product, for practicing the methods described above. The programming according to the present invention can be recorded on a computer-readable medium, such as any medium that can be directly read and accessed by a computer. Such media include, but are not limited to: magnetic storage media, such as floppy disks, hard disk storage media, and magnetic tapes; optical storage media, such as CD-ROMs; electrical storage media, such as RAM and ROM; portable flash drives; and hybrids of these categories, such as magnetic / optical storage media.

[0100] The processor can also access a communication channel to communicate with a user at a remote location. A remote location means that the user does not directly interact with the system, but relays input information from an external device, such as a computer connected to a wide area network (“WAN”), telephone network, satellite network, or any other suitable communication channel, including a mobile phone (i.e., a smart phone), to the input manager.

[0101] In some embodiments, the system according to the present disclosure can be configured to include a communication interface. In some embodiments, the communication interface includes a receiver and / or a transmitter for communicating with a network and / or another device. The communication interface can be configured for wired or wireless communication, including but not limited to radio frequency (RF) communication (e.g., radio frequency identification (RFID), Zigbee communication protocol, Wi-Fi, infrared, wireless universal serial bus (USB), ultra-wideband (UWB), communication protocols, and cellular communication, such as code division multiple access (CDMA) or global system for mobile communications (GSM).

[0102] In one embodiment, the communication interface is configured to include one or more communication ports, such as physical ports or interfaces, such as USB ports, RS-232 ports, or any other suitable electrical connection port, to allow data communication between the subject system and other external devices, such as computer terminals configured for similar complementary data communication (e.g., in a doctor's office or in a hospital environment).

[0103] In one embodiment, the communication interface is configured for infrared communication, communication, or any other suitable wireless communication protocol to enable the subject system to communicate with other devices such as computer terminals and / or networks, communication-enabled mobile phones, personal digital assistants, or any other communication device that the user may use in combination.

[0104] In one embodiment, the communication interface is configured to provide a connection for data transmission using the Internet Protocol (IP) via a cellular phone network, Short Message Service (SMS), a wireless connection to a personal computer (PC) on a local area network (LAN) connected to the Internet, or a WiFi connection to the Internet at a WiFi hotspot.

[0105] In one embodiment, the subject system is configured to wirelessly communicate with a server device via the communication interface, for example using a common standard such as 802.11 or an RF protocol or an IrDA infrared protocol. The server device can be another portable device such as a smart phone, a personal digital assistant (PDA), or a notebook computer; or a larger device such as a desktop computer, an appliance, etc. In some embodiments, the server device has a display such as a liquid crystal display (LCD), and an input device such as buttons, a keyboard, a mouse, or a touch screen.

[0106] In some embodiments, the communication interface is configured to automatically or semi-automatically transfer data stored in the subject system, such as data stored in an optional data storage unit, to a network or a server device using one or more of the above communication protocols and / or mechanisms.

[0107] The output controller may include a controller for any of a variety of known display devices for presenting information to a user, whether human or machine, local or remote. If one of the display devices provides visual information, that information can generally be organized logically and / or physically as an array of image elements. The graphical user interface (GUI) controller may include any one of a variety of known or future software programs for providing a graphical input and output interface between the system and the user and for processing user input. The functional elements of a computer may communicate with each other via a system bus. Some of these communications may be accomplished using a network or other type of remote communication in alternative embodiments. According to known techniques, the output manager may also provide information generated by the processing module to a user at a remote location, for example, via the Internet, telephone, or satellite network. The data presentation of the output manager may be implemented according to various known techniques. As some examples, the data may include SQL, HTML, or XML documents, e-mails, or other files, or data in other forms. The data may include Internet URL addresses such that the user may retrieve additional SQL, HTML, XML, or other documents or data from remote sources. One or more platforms present in the subject system may be any type of known computer platform or a type to be developed in the future, but they will generally fall into a class of computers commonly referred to as servers. However, they may also be mainframe computers, workstations, or other computer types. They may be connected via any known or future type of cable or other communication system, including wireless systems, whether networked or otherwise. They may be co-located, or they may be physically separated. A variety of operating systems may be employed on any of the computer platforms in the computer platform, which may depend on the type and / or brand of the selected computer platform. Suitable operating systems include Windows Windows XP, Windows 7, Windows 8, iOS, Sun Solaris, Linux, OS / 400, Compaq Tru64 Unix, SGI IRIX, Siemens Reliant Unix, etc.

[0108] A polymer structure having clearly distinguishable microvoid spaces

[0109] Aspects of the present disclosure also include polymer structures having clearly distinguishable microvoid spaces prepared by the subject methods described herein. In some instances, the polymer structure includes a plurality of microvoid spaces. In some instances, the microvoid spaces include one or more different microchannels, such as two or more, such as three or more, such as four or more, such as five or more and including ten or more different microchannels. In some instances, one or more of the microchannels include one or more bifurcations, such as two or more bifurcations, such as three or more, such as four or more, such as five or more, and including ten or more bifurcations. In some instances, the microchannels extend through the polymer structure. In some instances, the microchannels are fluidically interconnected. In some instances, the polymer structure has a single network of fluidically interconnected microchannels. In other instances, the polymer structure has a plurality of fluidically interconnected microchannel networks. In some embodiments, each microchannel has a diameter of 0.01 μm or greater, such as 0.05 μm or greater, such as 0.1 μm or greater, such as 0.5 μm or greater, such as 1 μm or greater, such as 2 μm or greater, such as 3 μm or greater, such as 4 μm or greater, such as 5 μm or greater, such as 10 μm or greater, such as 15 μm or greater, such as 20 μm or greater, such as 25 μm or greater, such as 50 μm or greater, such as 75 μm or greater, and including 100 μm or greater. In certain instances, each microchannel has a diameter of from 0.01 μm to 75 μm, such as from 0.05 μm to 50 μm, such as from 0.1 μm to 25 μm, such as from 0.5 μm to 20 μm.

[0110] Depending on the polymer structure and the size of the microvoid spaces, each distinguishable microvoid space has a volume of 0.001 μL or greater, such as 0.005 μL or greater, such as 0.01 μL or greater, such as 0.05 μL or greater, such as 0.1 μL or greater, such as 0.2 μL or greater, such as 0.3 μL or greater, such as 0.4 μL or greater, such as 0.5 μL or greater, such as 1 μL or greater, such as 2 μL or greater, such as 3 μL or greater, such as 4 μL or greater, such as 5 μL or greater, such as 6 μL or greater, such as 7 μL or greater, such as 8 μL or greater, such as 9 μL or greater, such as 10 μL or greater, such as 15 μL or greater, such as 20 μL or greater, and including 25 μL or greater. In some instances, each microvoid space has a volume of from 0.01 μL to 2.5 μL, such as from 0.02 μL to 2.4 μL, such as from 0.03 μL to 2.3 μL, such as from 0.04 μL to 2.2 μL, such as from 0.05 μL to 2.1 μL, such as from 0.06 μL to 2.0 μL, such as from 0.07 μL to 1.9 μL, such as from 0.08 μL to 1.8 μL, such as from 0.09 μL to 1.7 μL, and including cases where each microvoid space has a volume of from 1 μL to 1.5 μL. In some instances, the distinguishable microvoid spaces in the polymer structure have a cumulative volume (i.e., the total volume of all microvoid spaces) of 0.1 μL or greater, such as 0.2 μL or greater, such as 0.3 μL or greater, such as 0.4 μL or greater, such as 0.5 μL or greater, such as 1 μL or greater, such as 2 μL or greater, such as 3 μL or greater, such as 4 μL or greater, such as 5 μL or greater, such as 6 μL or greater, such as 7 μL or greater, such as 8 μL or greater, such as 9 μL or greater, such as 10 μL or greater, such as 15 μL or greater, such as 20 μL or greater, and including 25 μL or greater.

[0111] In some instances, the polymer structure of interest includes a non-polymerizable composition positioned therein. In some instances, the non-polymerizable composition fills 5% or more of the void volume of the microvoid space (i.e., the negative space within the polymer structure), such as 10% or more, such as 15% or more, such as 20% or more, such as 25% or more, such as 50% or more, such as 75% or more, such as 90% or more, such as 95% or more, such as 97% or more, such as 99% or more, and includes the case where the non-polymerizable composition fills the entire volume of the void volume of the microvoid space. In some instances, the non-polymerizable composition does not react with the polymer structure. In some instances, the non-polymerizable composition positioned within the void volume of the polymer structure is water, a Newtonian liquid, a shear-thinning liquid, a shear-thickening liquid, a magnetorheological liquid, an electric field-responsive liquid, and a gas. In certain embodiments, aspects of the present disclosure include a polymer structure having a microvoid space, wherein the non-polymerizable composition has been removed.

[0112] In an embodiment, the polymeric structure is formed from a polymerizable material, which may include but is not limited to polycaprolactone, polyglycolic acid, polylactic acid, polylactic-co-glycolic acid, polyethylene glycol, thiol-ene, anhydride, polyacrylic acid, polymethyl methacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, ethylene carbonate, vinyl ester, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof. In certain embodiments, the polymeric structure is formed from polyethylene glycol dimethacrylate (PEGDMA). In certain embodiments, the polymeric structure is formed from trimethylolpropane triacrylate (TMPTA) monomers. In certain embodiments, the polymerizable material is selected from polycarbonate, polyvinyl chloride (PVC), polyurethane, polyether, polyamide, polyimide, or copolymers of these thermoplastics, such as PETG (ethylene glycol-modified polyethylene terephthalate), and other polymeric plastic materials.In certain embodiments, the beam splitter is formed from a polyester, where the polyesters of interest can include, but are not limited to, poly(alkylene terephthalates), such as poly(ethylene terephthalate) (PET), bottle-grade PET (a copolymer made from monoethylene glycol, terephthalic acid, and other comonomers such as isophthalic acid, cyclohexanedimethanol, etc.), poly(butylene terephthalate) (PBT), and poly(hexylene terephthalate); poly(alkylene adipates), such as poly(ethylene adipate), poly(1,4-butylene adipate), and poly(hexylene adipate); poly(alkylene suberates), such as poly(ethylene suberate); poly(alkylene sebacates), such as poly(ethylene sebacate); poly(ε-caprolactone) and poly(β-propiolactone); poly(isophthalic acid alkylene esters), such as poly(ethylene isophthalate); poly(2,6-naphthalenedicarboxylic acid alkylene esters), such as poly(ethylene 2,6-naphthalenedicarboxylate); poly(alkylene sulfonyl-4,4'-dibenzoates), such as poly(ethylene sulfonyl-4,4'-dibenzoate); poly(p-phenylene alkylene dicarboxylates), such as poly(p-phenylene ethylene dicarboxylate); poly(trans-1,4-cyclohexane diyl alkylene dicarboxylates), such as poly(trans-1,4-cyclohexane diyl ethylene dicarboxylate); poly(1,4-cyclohexane-dimethylene alkylene dicarboxylates), such as poly(1,4-cyclohexane-dimethylene ethylene dicarboxylate); poly([2.2.2]-bicyclooctane-1,4-dimethylene alkylene dicarboxylates), such as poly([2.2.2]-bicyclooctane-1,4-dimethylene ethylene dicarboxylate); lactic acid polymers and copolymers, such as (S)-polylactide, (R,S)-polylactide, poly(tetramethyl glycolide), and poly(lactide-co-glycolide); and polycarbonates of bisphenol A, 3,3'-dimethylbisphenol A, 3,3',5,5'-tetrachlorobisphenol A, 3,3',5,5'-tetramethylbisphenol A; polyamides, such as poly(p-phenyleneterephthalamide); polyethylene terephthalate (e.g., MylarTM polyethylene terephthalate), combinations thereof, and the like. In some embodiments, the polymeric structure is formed from one or more polymerizable materials, such as two or more different polymerizable materials, such as three or more, and including four or more different polymerizable materials. In certain instances, one or more of the polymerizable materials include carbon nanotubes, such as single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT).

[0113] non-transitory computer-readable storage medium

[0114] Aspects of the present disclosure further include non - transitory computer - readable storage media having instructions for practicing the subject methods. A computer - readable storage medium can be employed on one or more computers for full or partial automation of a system for practicing the methods described herein. In certain embodiments, instructions in accordance with the methods described herein can be encoded on a computer - readable medium in the form of “programming,” where the term “computer - readable medium” as used herein refers to any non - transitory storage medium that participates in providing instructions and data to a computer for execution and processing. Examples of suitable non - transitory storage media include floppy disks, hard disks, optical disks, magneto - optical disks, CD - ROMs, CD - Rs, magnetic tapes, non - volatile memory cards, ROMs, DVD - ROMs, Blu - ray disks, solid - state disks, and network - attached storage (NAS), whether such devices are internal or external to a computer. A file containing information can be “stored” on a computer - readable medium, where “stored” means recording the information such that it can be accessed and retrieved by a computer at a later time. The computer - implemented methods described herein can be executed using programming written in one or more of any number of computer programming languages. Such languages include, for example, Python, Java, Java Script, C, C#, C++, Go, R, Swift, PHP, and any number of others.

[0115] In some instances, the non - transitory computer - readable storage medium has instructions stored thereon, the instructions including: an algorithm for irradiating a polymerizable composition positioned between a build lift and a build surface to produce such a polymerizable composition having: a polymerized region of the polymerizable composition having microvoid spaces in contact with the build lift and a non - polymerized region of the polymerizable composition in contact with the build surface; an algorithm for moving the build lift away from the build surface; an algorithm for contacting the resulting microvoid spaces with a non - reactive composition; and an algorithm for repeating one or more steps in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces. In some instances, the non - transitory computer - readable storage medium has an algorithm for injecting a polymerizable composition through a conduit using an injection pump. In some instances, the non - transitory computer - readable storage medium has an algorithm for producing a polymer structure having microvoid spaces that include a non - polymerizable composition positioned therein.

[0116] In some embodiments, the non-transitory computer-readable storage medium has an algorithm for contacting the generated microvoid space with an amount of polymerizable composition in a manner sufficient to displace the polymeric material in the microvoid space. In some instances, the non-transitory computer-readable storage medium has an algorithm for continuously transporting the polymerizable composition through the generated microvoid space to displace the polymeric material in the microvoid space. In some instances, the non-transitory computer-readable storage medium has an algorithm for injecting the polymerizable composition into the generated microvoid space to displace the polymeric material in the microvoid space. In some instances, the non-transitory computer-readable storage medium has an algorithm for injecting the polymerizable composition into the generated microvoid space using a syringe. In some instances, the non-transitory computer-readable storage medium has an algorithm for continuously transporting the polymerizable composition through the generated microvoid space into the space between the build lift and the build surface of the liquid interface production module.

[0117] In some instances, the non-transitory computer-readable storage medium has an algorithm for bringing an unpolymerizable composition into contact with the resulting microvoid spaces of a polymer structure. In some instances, the non-transitory computer-readable storage medium has an algorithm for filling at least a portion of the void volume of the microvoid spaces with an unpolymerizable composition, such as 5% or more, such as 10% or more, such as 25% or more, such as 50% or more, and including 75% or more of the void volume of the microvoid spaces, such as an algorithm for filling the entire void volume of the microvoid spaces with an unpolymerizable composition. In some embodiments, the non-transitory computer-readable storage medium has an algorithm for generating a polymer structure having a plurality of microvoid spaces. In certain instances, the non-transitory computer-readable storage medium has an algorithm for irradiating a polymerizable composition for a duration sufficient to bond a first polymerization zone of the polymerizable composition to a build lift table. In some instances, the non-transitory computer-readable storage medium has an algorithm for moving the build lift table in predetermined increments of 0.5 μm to 1.0 μm. In some embodiments, the non-transitory computer-readable storage medium has an algorithm for adding a polymerizable composition to the build surface after each removal of the build lift table from the build surface. In some instances, the non-transitory computer-readable storage medium has an algorithm for adding an unpolymerizable composition to the resulting microvoid spaces after each removal of the build lift table from the build surface. In some instances, the non-transitory computer-readable storage medium has an algorithm for continuously polymerizing the polymerizable composition while moving the build lift table away from the build surface. In some embodiments, the non-transitory computer-readable storage medium has an algorithm for continuously adding an unpolymerizable composition to the resulting microvoid spaces while moving the build lift table away from the build surface. In certain embodiments, the non-transitory computer-readable storage medium has an algorithm for removing the unpolymerizable composition from the resulting microvoid spaces of the polymer structure.

[0118] A non-transitory computer-readable storage medium can be employed on one or more computer systems having a display and an operator input device. The operator input device can be, for example, a keyboard, a mouse, etc. The processing module includes a processor that can access a memory storing instructions for performing the steps of the subject method. The processing module can include an operating system, a graphical user interface (GUI) controller, a system memory, a memory storage device, and an input-output controller, a cache memory, a data backup unit, and many other devices. The processor can be a commercially available processor, or it can be one of other processors that are available or will become available. The processor executes the operating system, and the operating system interfaces with the firmware and hardware in a well-known manner and helps the processor to coordinate and execute the functions of various computer programs, which can be written in various programming languages, such as those mentioned above, other high-level or low-level languages, and combinations thereof, as known in the art. The operating system, usually in cooperation with the processor, coordinates and executes the functions of the other components of the computer. The operating system also provides scheduling, input-output control, file and data management, memory management, and communication control and related services according to known techniques.

[0119] Kit

[0120] Kits for practicing certain methods described herein are also provided. In certain embodiments, the kit includes one or more of the polymer structures described above. In some instances, the kit includes a polymerizable composition for preparing the polymer structure. In certain embodiments, the kit includes a non-reactive composition, such as a non-polymerizable composition for contacting the resulting microvoid space. For example, the kit can further include one or more of a quantity of water, a Newtonian liquid, a shear-thinning liquid, a shear-thickening liquid, a magnetorheological liquid, an electric-field-responsive liquid, and a gas. In certain embodiments, the kit will further include instructions for practicing the subject method or means for obtaining them (e.g., a website URL directing the user to a web page providing the instructions), where the instructions can be printed on a substrate, where the substrate can be one or more of a package insert, a package, a reagent container, etc. Yet another form of these instructions is a computer-readable medium on which information has been recorded, such as a disk, a compact disc (CD), a portable flash drive, a USB storage device, a DVD, a Blu-ray disc, etc.), and so on. Yet another form in which these instructions can exist is a website address via which information at a removed site can be accessed via the Internet.

[0121] Notwithstanding the appended claims, the present disclosure is also defined by the following clauses:

[0122] 1. A method of manufacturing a polymer structure comprising microvoid spaces, the method comprising:

[0123] a) Irradiate a polymerizable composition positioned between a build lift and a build surface of a liquid interface production module to produce a polymerizable composition that includes: a polymerized region of the polymerizable composition that includes microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface;

[0124] b) Move the build lift away from the build surface;

[0125] c) Contact the resulting microvoid spaces with a non-reactive composition; and

[0126] d) Repeat steps a)-c) in a manner sufficient to produce a polymer structure with clearly distinguishable microvoid spaces.

[0127] 2. The method according to claim 1, wherein the resulting microvoid spaces include one or more microchannels in the polymer structure.

[0128] 3. The method according to claim 2, wherein one or more of the microchannels extend through the polymer structure.

[0129] 4. The method according to any one of claims 1-3, wherein the method includes contacting the resulting microvoid spaces with an amount of the polymerizable composition in a manner sufficient to displace the polymeric material in the microvoid spaces.

[0130] 5. The method according to claim 4, wherein the amount of the polymerizable composition is continuously conveyed through the resulting microvoid spaces to displace the polymeric material in the microvoid spaces.

[0131] 6. The method according to any one of claims 2-5, wherein the polymerizable composition is injected through the resulting microvoid spaces.

[0132] 7. The method according to any one of claims 2-6, wherein the polymerizable composition is conveyed through the resulting microvoid spaces into the space between the build lift and the build surface of the liquid interface production module.

[0133] 8. The method according to any one of claims 6-7, wherein the polymerizable composition is injected through the resulting microvoid spaces with a syringe.

[0134] 9. The method according to claim 8, wherein the syringe is operably coupled to an injection pump.

[0135] 10. The method according to any one of claims 1-3, wherein the method includes contacting the resulting microvoid spaces with a non-polymerizable composition.

[0136] 11. The method according to claim 10, wherein while generating the polymer structure, the non-polymerizable composition is brought into contact with the generated microvoid space.

[0137] 12. The method according to claim 11, wherein while generating the polymer structure, the non-polymerizable composition is continuously brought into contact with the microvoid space.

[0138] 13. The method according to any one of claims 10 - 12, wherein the method includes filling at least a part of the void volume of the microvoid space with the non-polymerizable composition.

[0139] 14. The method according to claim 13, wherein the method includes filling 5% or more of the void volume of the microvoid space with the non-polymerizable composition.

[0140] 15. The method according to any one of claims 10 - 14, wherein the non-polymerizable composition does not react with the polymerizable composition of the polymer structure.

[0141] 16. The method according to any one of claims 10 - 15, wherein the non-polymerizable composition is selected from the group consisting of water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric-field-responsive liquids, and gases.

[0142] 17. The method according to any one of claims 10 - 16, wherein the method further includes removing the non-polymerizable composition from the generated microvoid space of the polymer structure.

[0143] 18. The method according to any one of claims 1 - 17, wherein the polymer structure includes a plurality of microvoid spaces.

[0144] 19. The method according to any one of claims 1 - 18, wherein the polymerizable composition is in contact with the build lift table and the build surface.

[0145] 20. The method according to claim 19, wherein the method includes irradiating the polymerizable composition for a duration sufficient to bond a first polymerization region of the polymerizable composition to the build lift table.

[0146] 21. The method according to any one of claims 1 - 20, wherein the build lift table moves in a predetermined increment of 0.5 μm to 1.0 μm.

[0147] 22. The method according to any one of claims 1 - 21, wherein the method further includes adding a polymerizable composition to the build surface after each time the build lift table is moved away from the build surface.

[0148] 23. The method according to claim 22, wherein the method further comprises contacting the resulting microvoid space with the non-reactive composition after each removal of the build lift from the build surface.

[0149] 24. The method according to any one of claims 1-23, wherein the polymerizable composition is continuously polymerized while the build lift is being removed from the build surface.

[0150] 25. The method according to claim 24, wherein the non-reactive composition is in continuous contact with the resulting microvoid space while the build lift is being removed from the build surface.

[0151] 26. The method according to any one of claims 1-25, wherein the polymerizable composition comprises a polymerizable material selected from the group consisting of: polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid-co-glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol-ene, acid anhydride, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl ester, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof.

[0152] 27. The method according to claim 26, wherein the polymerizable composition comprises polyethylene glycol dimethacrylate (PEGDMA).

[0153] 28. The method according to any one of claims 26-27, wherein the polymerizable material comprises carbon nanotubes.

[0154] 29. The method according to claim 28, wherein the polymerizable material comprises one or more of single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT).

[0155] 30. A system for manufacturing a polymer structure comprising microvoid spaces, the system comprising:

[0156] A light source; and

[0157] A photointerface polymerization module comprising a build lift and a build surface, configured to produce a polymer structure including clearly distinguishable microvoid spaces from a polymerizable composition positioned therebetween.

[0158] 31. The system according to claim 30, wherein the photointerface polymerization module is configured to produce a polymer structure having one or more microchannels therein.

[0159] 32. The system according to claim 31, wherein one or more of the microchannels extend through the polymer structure.

[0160] 33. The system according to any one of claims 30 - 32, wherein the system further comprises a processor, the processor comprising a memory operably coupled to the processor, wherein the memory comprises instructions stored thereon, which when executed by the processor, cause the processor to:

[0161] a) irradiate a polymerizable composition positioned between a build lift and a build surface to produce such a polymerizable composition comprising: a polymerized region of the polymerizable composition comprising microvoid spaces in contact with the build lift and a non - polymerized region of the polymerizable composition in contact with the build surface;

[0162] b) move the build lift away from the build surface;

[0163] c) bring the produced microvoid spaces into contact with a non - reactive composition; and

[0164] d) repeat steps a) - c) in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces.

[0165] 34. The system according to claim 33, wherein the memory comprises instructions for bringing the produced microvoid spaces into contact with an amount of the polymerizable composition in a manner sufficient to displace the polymeric material in the microvoid spaces.

[0166] 35. The system according to claim 34, wherein the memory comprises instructions for continuously transporting the polymerizable composition through the produced microvoid spaces to displace the polymeric material in the microvoid spaces.

[0167] 36. The system according to any one of claims 33 - 35, wherein the polymerizable composition is injected through the produced microvoid spaces.

[0168] 37. The system according to any one of claims 33 - 36, wherein the memory comprises instructions for continuously transporting the polymerizable composition through the produced microvoid spaces into the space between the build lift and the build surface of the liquid interface production module.

[0169] 38. The system according to any one of claims 30 - 37, wherein the system further comprises an injection pump.

[0170] 39. The system according to any one of claims 30 - 33, wherein the memory comprises instructions for bringing the produced microvoid spaces into contact with a non - polymerizable composition.

[0171] 40. The system according to claim 39, wherein the system further comprises a source of non-polymerizable composition, which is operatively coupled to the photointerface polymerization module such that the non-polymerizable composition is in continuous contact with the microvoid space while the polymer structure is being produced.

[0172] 41. The system according to any one of claims 39 - 40, wherein the memory comprises instructions for filling at least a portion of the void volume of the microvoid space with the non-polymerizable composition.

[0173] 42. The system according to claim 41, wherein the memory comprises instructions for filling 5% or more of the void volume of the microvoid space with the non-polymerizable composition.

[0174] 43. The system according to any one of claims 39 - 42, wherein the non-polymerizable composition does not react with the polymerizable composition of the polymer structure.

[0175] 44. The system according to any one of claims 39 - 43, wherein the non-polymerizable composition is selected from the group consisting of water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electric-field-responsive liquids, and gases.

[0176] 45. The system according to any one of claims 33 - 44, wherein the memory comprises instructions for producing a polymer structure comprising a plurality of microvoid spaces.

[0177] 46. The system according to any one of claims 33 - 45, wherein the memory comprises instructions for irradiating the polymerizable composition for a duration sufficient to bond a first polymerization region of the polymerizable composition to the build lift platform.

[0178] 47. The system according to any one of claims 33 - 46, wherein the memory comprises instructions for moving the build lift platform in a predetermined increment of 0.5 μm to 1.0 μm.

[0179] 48. The system according to any one of claims 33 - 47, wherein the memory comprises instructions for contacting the generated microvoid space with a fluid composition after each time the build lift platform is moved away from the build surface.

[0180] 49. The system according to any one of claims 33 - 48, wherein the memory comprises instructions for adding a polymerizable composition to the build surface after each time the build lift platform is moved away from the build surface.

[0181] 50. The system according to claim 49, wherein the memory includes instructions for adding a non-polymerizable composition to the resulting microvoid space each time the build lift is moved away from the build surface.

[0182] 51. The system according to any one of claims 33 - 50, wherein the memory includes instructions for continuously polymerizing the polymerizable composition while moving the build lift away from the build surface.

[0183] 52. The system according to claim 51, wherein the memory includes instructions for continuously contacting the non-reactive composition with the resulting microvoid space while moving the build lift away from the build surface.

[0184] 53. The system according to any one of claims 33 - 52, wherein the memory includes instructions for removing the non-polymerizable composition from the resulting microvoid space of the polymer structure.

[0185] 54. The system according to any one of claims 30 - 53, wherein the system includes a micro digital light projection system, the micro digital light projection system comprising:

[0186] A beam generator component; and

[0187] A light projection monitoring component.

[0188] 55. The system according to claim 54, wherein the beam generator component includes:

[0189] A light source;

[0190] A tube lens; and

[0191] One or more projection lenses.

[0192] 56. The system according to any one of claims 54 - 55, wherein the beam generator component includes two projection lenses.

[0193] 57. The system according to claim 56, wherein the projection lens is a magnifying lens.

[0194] 58. The system according to claim 57, wherein the projection lens provides a magnification of 2 to 10 times.

[0195] 59. The system according to any one of claims 54 - 58, wherein the light projection monitoring component includes a photodetector.

[0196] 60. The system according to claim 59, wherein the photodetector includes a charge-coupled device (CCD).

[0197] 61. The system according to any one of 30 - 60, wherein the polymerizable composition comprises a polymerizable material selected from the group consisting of: polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid - co - glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol - ene, acid anhydride, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl ester, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof.

[0198] 62. The system according to 61, wherein the polymerizable composition comprises polyethylene glycol dimethacrylate (PEGDMA).

[0199] 63. The system according to any one of 61 - 62, wherein the polymerizable material comprises carbon nanotubes.

[0200] 64. The system according to 63, wherein the polymerizable material comprises one or more of single - walled carbon nanotubes (SWCNT) or multi - walled carbon nanotubes (MWCNT).

[0201] 65. A polymer structure, the polymer structure comprising clearly distinguishable microvoid spaces, the microvoid spaces comprising a non - polymerizable composition positioned therein.

[0202] 66. The polymer structure according to 65, wherein the non - polymerizable composition fills at least a portion of the void volume of the microvoid spaces.

[0203] 67. The polymer structure according to 66, wherein the non - polymerizable composition comprises 5% or more of the void volume of the microvoid spaces.

[0204] 68. The polymer structure according to any one of 65 - 67, wherein the non - polymerizable composition does not react with the polymer structure.

[0205] 69. The polymer structure according to any one of 65 - 68, wherein the microvoid spaces comprise microchannels within the polymer structure.

[0206] 70. The polymer structure according to 69, wherein the microchannels extend through the polymer structure.

[0207] 71. The polymer structure according to any one of 65 - 70, wherein the polymer structure comprises a plurality of microvoid spaces.

[0208] 72. The polymer structure according to any one of 65 - 71, wherein the non - polymerizable composition is selected from the group consisting of Newtonian liquids, shear - thinning liquids, shear - thickening liquids, magnetorheological liquids, electric - field - responsive liquids, and gases.

[0209] 73. The polymer structure according to any one of 65 - 72, wherein the polymer structure is formed from polymerizable materials selected from the group consisting of polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid - co - glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol - ene, acid anhydrides, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl esters, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof.

[0210] 74. The polymer structure according to 73, wherein the polymer structure is formed from polyethylene glycol dimethacrylate (PEGDMA).

[0211] 75. The polymer structure according to any one of 73 - 74, wherein the polymerizable material includes carbon nanotubes.

[0212] 76. The polymer structure according to 75, wherein the polymerizable material includes one or more of single - walled carbon nanotubes (SWCNT) or multi - walled carbon nanotubes (MWCNT).

[0213] 77. A polymer structure, the polymer structure including clearly distinguishable microvoid spaces.

[0214] 78. The polymer structure according to 77, wherein the microvoid spaces include microchannels within the polymer structure.

[0215] 79. The polymer structure according to 78, wherein the microchannels extend through the polymer structure.

[0216] 80. The polymer structure according to any one of 77 - 79, wherein the polymer structure includes a plurality of microvoid spaces.

[0217] 81. The polymer structure according to any one of 77 - 80, wherein the polymer structure is formed from polymerizable materials selected from the group consisting of: polycaprolactone, polyglycolic acid, polylactic acid, polylactic acid - co - glycolic acid, polyethylene glycol, polyethylene glycol dimethacrylate (PEGDMA), thiol - ene, acid anhydride, polyacrylic acid, polymethyl methacrylate, trimethylolpropane triacrylate (TMPTA) monomer, polyvinyl alcohol, polyvinylpyrrolidone, ethylene carbonate, vinyl ester, acrylamide, hyaluronic acid, chitosan, collagen, gelatin, carboxymethyl cellulose, and blends or copolymers thereof.

[0218] 82. The polymer structure according to 81, wherein the polymer structure is formed from polyethylene glycol dimethacrylate (PEGDMA).

[0219] 83. The polymer structure according to any one of 81 - 82, wherein the polymerizable material comprises carbon nanotubes.

[0220] 84. The polymer structure according to 83, wherein the polymerizable material comprises one or more of single - walled carbon nanotubes (SWCNT) or multi - walled carbon nanotubes (MWCNT).

[0221] Experiment

[0222] The following examples are provided by way of illustration and not limitation. Specifically, the following examples are specific embodiments for implementing the present disclosure. The examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. Efforts have been made to ensure the accuracy of the numbers used (e.g., amounts, temperatures, etc.), but of course some experimental errors and deviations should be allowed.

[0223] High - resolution stereolithography - Negative space achieved through hydrodynamic control

[0224] In this example, a method for fabricating a polymer structure with microvoid spaces (e.g., high - resolution injection CLIP (iCLIP)) is used to achieve micron X, Y, and Z resolution using the synergistic control of high - resolution optical control and hydrodynamics. Conventional digital light projection (e.g., CLIP) uses the projection of ultraviolet (UV) light to cure a layer of photo - polymerizable resin layer by layer. These processes use resin replenishment at the build surface by creating a continuous liquid interface (dead zone), and the resin is sucked into the gap by the suction generated when the cured part is gradually pulled away from the window ( Figure 2A ). The dead zone is created and maintained by the continuous supply of oxygen (a polymerization inhibitor), which is fed through a highly oxygen - permeable window at the bottom of the resin reservoir. The light transmission is controlled by high - resolution optics that can precisely direct the UV light path to cure a single layer of resin in the X - Y plane with high resolution. AsFigure 2A As shown, light will exponentially decay outside the intended layer, resulting in reduced part resolution due to over-curing or bleed-through in the negative space ( Figure 2A ). Specifically, the penetration depth of the resin represents the characteristic length over which exponential decay occurs within the resin. Bleed-through limits the ability of the stereolithography process to resolve negative features relative to the characteristic penetration depth.

[0225] In the method of the present disclosure according to certain embodiments, a fresh stream of polymerizable resin is continuously fed through the build platform to displace the entrapped resin, thereby preserving the designed negative space and eliminating bleed-through ( Figure 2B ). Thus, the methods described herein are capable of fabricating channels with a significantly smaller height / diameter ratio than previously achievable, enabling channel resolution that matches or exceeds the penetration depth of the resin ( Figure 2C ). Fabricating high-resolution negative spaces using a greater variety of materials enables 3D printing of high-resolution microsystem devices such as vascular beds and microfluidics-supported microneedles ( Figure 2D and Figures 6A - 6F the examples depicted therein).

[0226] Modeling halftoning

[0227] In all DLP-based processes, including CLIP, the XY resolution is limited by the size of the projected pixels, while the Z resolution is affected by the penetration depth of the resin. A greater penetration depth results in more UV light accumulating in the resin, which can inadvertently cause bleed-through. Using Beer-Lambert’s Law E N , the cumulative UV exposure energy per unit area after N exposures during part fabrication is determined. The equation for E N is as follows:

[0228] Equation 1:

[0229] where n is the number of layers from the dead zone, I0 is the intensity of the UV radiation at the dead zone, t is the UV exposure time, s is the layer slice thickness per exposure, and D p is the penetration depth determined by the material properties of the resin at a UV wavelength of 385 nm.

[0230] E N depends on the resin D p , which determines the depth to which UV energy can penetrate and accumulate in the negative space. The system of the present disclosure according to certain embodiments displaces the entrapped resin with fresh resin, maintaining a constant turnover, which minimizes the final E N within the microchannel, eliminating the need to reduce the D p of the resin for better Z-axis resolution.requirements

[0231] Equation 1 can be used to predict the UV dose accumulation within the entire 3D printed microstructure. When the critical energy of the trapped resin is exceeded, overprinting occurs (indicated by the blue shading in Figure 3A ). Figure 3 shows the dose accumulation in the serpentine microchannel when generating a polymer structure with and without (CLIP) injection of the polymerizable composition through the microchannel (iCLIP) during fabrication. Under CLIP conditions, without resin turnover, the accumulation model predicts that overprinting hinders the microfluidic channels ( Figure 3A ). This model is supported by the resulting CLIP prints ( Figure 3B ). In contrast, continuous flow of fresh resin through the microchannel displaces the trapped resin before the trapped resin reaches the critical threshold, preserving the serpentine microchannel and alleviating the overprinting effect ( Figure 3C ). This is supported by the resulting iCLIP prints ( Figure 3D ).

[0232] Microchannel retention

[0233] The ability to generate a polymer structure with injection of the polymerizable composition through the microchannel (iCLIP) during fabrication was investigated to maintain the resolution of the negative space in various geometric configurations and channel resolutions. First, to evaluate the performance of iCLIP in resolving various microfluidic geometries, microchannels with a diameter of 200 μm were designed and the pitch angle was varied in the range of 0° to 90° ( Figure 4A ). The 0° pitch channel used as a control was shown to be the least sensitive to overprinting as it was never exposed to UV light below the fabricated channel. In contrast, as the height of the channel along the vertical z-axis decreased, the 90° pitch channel had the highest risk of channel blockage. Optical microscopy images of the cross-sectional profiles of the printed microchannels showed that accurate resolution of the channels was consistently achieved by injecting fresh resin through the microchannel (iCLIP) during fabrication, regardless of their pitch ( Figure 4A and Figure 4C ). The 90° pitch was fully resolved near the injection port, while the diameter of the channels away from the injection source was smaller. It is speculated that this is due to insufficient resin flow before the channels become blocked. To further evaluate the ability of iCLIP to maintain high-resolution negative space, a bifurcated microfluidic network with a 30° pitch was designed and printed, varying the channel diameter from 50 μm to 200 μm. Optical microscopy images of the cross-sectional profiles of the printed microchannels confirmed the accurate microchannel resolution achieved by iCLIP ( Figure 4B and Figure 4D ).

[0234] Process characterization

[0235] To further evaluate the generation of polymer structures in the case of injecting a polymerizable composition through microchannels (iCLIP) during fabrication, the effect of the injection rate of fresh polymerizable resin on channel resolution was determined. The dimensionless turnover number (Tu) represents the ratio of the injection rate to the fabrication rate of the negative space (the rate of printing the microchannel volume). For a given set of printing parameters, Tu quantifies the number of printed layers cleared by fresh resin prior to subsequent UV light exposure. For example, when the injection rate is zero, traditional CLIP printing is simulated and Tu = 0. When the injection rate matches the fabrication rate, Tu = 1, and when the injection rate exceeds the fabrication rate, Tu > 1. The dimensionless channel diameter is defined as d / D, where d is the resulting channel diameter measured by optical microscopy after printing, and D is the designed channel diameter.

[0236] Figure 5 evaluates the relationship between microchannel resolution and resin turnover when generating polymer structures with microchannels according to certain embodiments. Under conditions where the polymerizable composition (i.e., fresh resin) is not injected through the formed microchannels (CLIP) (Tu = 0), the channels are not clearly distinguishable due to bleed-through. As Tu increases, d / D approaches 1, indicating the minimum Tu required to resolve a given microfluidic structure. Notably, in this case, for a resin with D p of 237 μm, achieving a Tu greater than 17.5 was shown to be crucial for accurate microchannel resolution ( Figure 5A ). To further explore the effect of Tu, the effect of channel design and geometry on the minimum Tu was determined. First, the minimum Tu required to resolve microfluidic channels with diameters ranging from 100 μm to 300 μm at a center-to-center distance of 30° was determined ( Figure 5B ). Subsequently, the minimum Tu required to resolve a microchannel with a fixed diameter of 200 μm while varying the center-to-center distance angle (including 30°, 45°, and 60°) was determined ( Figure 5C ). Among the variations in channel diameter and center-to-center distance, the minimum Tu for a resin with D p of 237 μm showed the least variation, remaining within 15% of each other at all times.

[0237] The effect of D p on the minimum Tu was explored. Figure 5D Shows how the D p of various resins affects the required Tu to achieve accurate negative features. For this study, the effect of varying Tu on the ability to resolve 100 μm bifurcating microchannels at a center-to-center distance of 30° was determined. For resins with varying D in the range of 65 μm to 237 μmp Different resins with values, and the corresponding minimum Tu for accurate resolution increases with D p value increases. The increase in D p allows the UV light to penetrate deeper into the printed part, and a larger amount of resin replacement is required for each manufactured layer. In some embodiments, if the original resin has accumulated a dose exceeding a critical threshold (which is denoted as E*), the precise channel resolution may include replacing the resin in the channel before printing each subsequent layer. By following a derivation process similar to Jacobs' working curve, the relationship between Tu and the threshold dose is represented as shown in Equation 2:

[0238] Equation 2: Turnover number

[0239] where E o is the layer exposure dose, and E* is the threshold dose. Figure 5D A graph showing the variation of the turnover number with the resin penetration depth is shown. According to Equation 2, the minimum turnover number required to accurately resolve negative features is linearly proportional to the penetration depth; the slope of this line is This analysis shows that for a given penetration depth and exposure dose during part manufacturing, the minimum resin turnover to achieve high-resolution negative features is determined. Additionally, based on the slope of this line, the value of the critical threshold dose can be extracted for any set of experimental parameters. Specifically, in some instances, the resin that has accumulated more than 70% of the dose should be removed from the slope to cure the layer.

[0240] High-resolution polymer structures and applications

[0241] The method for preparing a polymer structure according to the present disclosure (e.g., iCLIP) can be used to fabricate free-form structures with microscale feature resolution in the XY and Z coordinates. This process control framework is used to construct various microsystems ranging from personalized medical technologies to microelectromechanical systems (Figure 6).

[0242] Advances in bioengineering and materials science have led to the development of personalized medical technologies that are capable of diagnosing and treating diseases from the "human perspective". Among these technologies, microneedles have emerged as a promising solution for transdermal drug delivery due to their minimally invasive nature. A microfluidic element with microneedle technology is shown to provide new fluid management capabilities for transdermal drug delivery and unique fill-finish opportunities for such devices ( Figure 6A and Figure 6B ). In Figure 6CExamples of microelectromechanical systems fabricated with freeform-designed geometries are shown, where microfluidic sensors are embedded with gallium metal conductive elements. Additionally, the methods described herein can be used to fabricate interlocking vascular perfusion networks for a molecular blood transport system, as Figure 6E shown. The systems of the present disclosure have shown the ability to print porous perfusion networks to perform enhanced separation ([[]] Figure 6F ).

[0243] Conclusion

[0244] The methods of the present disclosure enable freeform fabrication of microsystems using fluid control methods rather than using optical dyes. According to certain embodiments, such methods can resolve microscale negative space, thereby breaking the relationship between resin penetration depth and negative feature resolution. This overcomes the resolution limitation and enables printing of high-resolution microsystems in materials and designs that were previously impossible. In certain instances, the method includes injecting different types of displacing agents, including non-polymerizable fluids such as water and air, to allow for clearly distinguishable negative space.

[0245] Although the foregoing invention has been described in relatively great detail for purposes of clarity of understanding by way of illustration and example, it will be apparent to those of ordinary skill in the art that certain changes and modifications may be made thereto in light of the teachings of the present invention without departing from the spirit or scope of the appended claims.

[0246] Accordingly, the foregoing merely illustrates the principles of the invention. It is to be understood that those skilled in the art will be able to devise a variety of arrangements, which, although not explicitly described or shown herein, embody the principles of the invention and are included within the spirit and scope of the invention. Additionally, all of the examples and conditional language recited herein are principally intended to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to further the art, and are to be construed as not being limited to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention as well as specific examples thereof are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function regardless of structure. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

[0247] Accordingly, the scope of the present invention is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of the present invention are embodied by the appended claims. In the claims, 35 U.S.C. § 112(f) or 35 U.S.C. § 112(6) is expressly defined as being invoked for a limitation in a claim only when the exact phrase "means for" or the exact phrase "step for" is recited at the beginning of that limitation in the claim; if this exact phrase is not used in a limitation in the claim, then 35 U.S.C. § 112(f) or 35 U.S.C. § 112(6) is not invoked.

Claims

1. A method of manufacturing a polymer structure comprising microvoid spaces, the method comprising: a) irradiating a polymerizable composition positioned between a build lift and a build surface of a liquid interface production module to produce a polymerizable composition comprising a polymerized region of the polymerizable composition containing microvoid spaces in contact with the build lift and a non-polymerized region of the polymerizable composition in contact with the build surface; b) moving the build lift away from the build surface; c) contacting the resulting microvoid spaces with a non-reactive composition; and d) repeating steps a)-c) in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces.

2. The method according to claim 1, wherein the resulting microvoid spaces comprise one or more microchannels in the polymer structure, the microchannels extending through the polymer structure.

3. The method according to any one of claims 1-2, wherein the method comprises delivering an amount of the polymerizable composition through the resulting microvoid spaces in a manner sufficient to displace the polymeric material in the microvoid spaces.

4. The method according to any one of claims 1-2, wherein the method comprises contacting the resulting microvoid spaces with a non-polymerizable composition.

5. The method according to claim 4, wherein the non-polymerizable composition is in continuous contact with the microvoid spaces while the polymer structure is being produced.

6. The method according to any one of claims 4-5, wherein the non-polymerizable composition does not react with the polymerizable composition of the polymer structure.

7. The method according to claim 6, wherein the non-polymerizable composition is selected from the group consisting of water, Newtonian liquids, shear-thinning liquids, shear-thickening liquids, magnetorheological liquids, electro-responsive liquids, and gases.

8. The method according to any one of claims 1-7, wherein the method further comprises adding the polymerizable composition to the build surface after each time the build lift is moved away from the build surface.

9. The method according to claim 8, wherein the method further comprises contacting the resulting microvoid spaces with the non-reactive composition after each time the build lift is moved away from the build surface.

10. A system for manufacturing a polymer structure comprising microvoid spaces, the system comprising: a light source; and a photointerface polymerization module comprising a build lift and a build surface, configured to produce a polymer structure having clearly distinguishable microvoid spaces from a polymerizable composition positioned therebetween.

11. The system according to claim 10, wherein the photointerface polymerization module is configured to produce a polymer structure having one or more microchannels therein.

12. The system according to any one of claims 10-11, wherein the system further comprises a processor, the processor including a memory operably coupled to the processor, wherein the memory includes instructions stored thereon, which when executed by the processor, cause the processor to: a) irradiating a polymerizable composition positioned between a build lift and a build surface to produce a polymerizable composition comprising: comprise a polymerized region of the polymerizable composition containing the microvoid space in contact with the build lift table and a non-polymerized region of the polymerizable composition in contact with the build surface; b) move the build lift table away from the build surface; c) contact the resulting microvoid space with a non-reactive composition; and d) repeat steps a)-c) in a manner sufficient to produce a polymer structure having clearly distinguishable microvoid spaces.

13. The system according to claim 12, wherein the memory includes instructions for conveying an amount of the polymerizable composition through the resulting microvoid space in a manner sufficient to displace the polymeric material in the microvoid space.

14. The system according to any one of claims 10-12, wherein the memory includes instructions for contacting the resulting microvoid space with a non-polymerizable composition.

15. A polymer structure comprising clearly distinguishable microvoid spaces, the microvoid spaces including a non-polymerizable composition positioned therein.

Images