# US 12,214,546 B2 · Rapid, large volume, dead layer-free 3D printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,546 B2 - Document ID: US12214546B2 - Status: Granted - Kind: B2 - Application number: 17/436,754 - Filed: 2020-03-09 - Published: 2022-06-23 - Granted: 2025-02-04 - Earliest claimed: 2019-03-07 - Assignees: Northwestern University - Applicants: Northwestern University - Inventors: David A. Walker; James L. Hedrick, III; Chad A. Mirkin - Web page: https://patentgrep.com/patent/US12214546B2 ## CPC - B29C 64/129: characterised by the energy source therefor, e.g. by global irradiation combined with a mask - B29C 64/255: Enclosures for the building material, e.g. powder containers - B29C 64/30: Auxiliary operations or equipment - B29C 64/307: Handling of material to be used in additive manufacturing - B29C 64/357: Recycling - B29C 64/364: Conditioning of environment - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 40/10: Pre-treatment - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING ## Abstract Methods and apparatus comprising a dewetting material and a polymerization liquid that are immiscible and dewetting, and can be used for the formation of three-dimensional objects, wherein the method does not require a dead zone. Additionally, methods and apparatus that employ the use of a flowing dewetting material to provide a shearing interface to reduce interfacial adhesive forces. ## Claims ### Claim 1 A method of forming a three-dimensional object using an apparatus having a movable adhesion stage separate from a member, the method comprising: flowing a dewetting material across the member, the dewetting material having a build surface; providing a polymerization liquid on the dewetting material, wherein the polymerization liquid is immiscible with the dewetting material such that an interface is defined between the polymerization liquid and the dewetting material and a build region is defined between the interface and the adhesion stage; and exposing the polymerization liquid in the build region to a pattern of energy through at least a portion of the member and the dewetting material to polymerize the polymerization liquid and form a green polymer; and advancing the adhesion stage away from the build surface to form the three-dimensional object comprised of the green polymer, wherein the dewetting material is flowed across the member and is recirculated under conditions sufficient to dissipate heat and maintain a slip boundary between the green polymer and the dewetting material. ### Claim 2 (depends on 1) The method of claim 1, wherein the dewetting material is flowed across the member under laminar flow conditions. ### Claim 3 (depends on 1) The method of claim 1, wherein the dewetting material has a directionally uniform velocity profile across the build region during the formation of the three-dimensional object. ### Claim 4 (depends on 1) The method of claim 1, wherein the conditions sufficient to provide a slip boundary between the green polymer and the dewetting material comprises selecting the dewetting material and the polymerization liquid such that the dewetting material (D) and the polymerization liquid (PL) have a spreading coefficient, SpLvo, of less than 1 or a negative value. ### Claim 5 (depends on 1) The method of claim 1, wherein the conditions sufficient to provide a slip boundary between the green polymer and the dewetting material comprises selecting the dewetting material and the polymerization liquid such that a volumetric flux of the dewetting material near or at an interface with the green polymer is greater than zero. ### Claim 6 (depends on 5) The method of claim 5, wherein the volumetric flux is in a range of about 0.05 mm/s to about 10 mm/sec. ### Claim 7 (depends on 1) The method of claim 1, wherein the conditions sufficient to provide a slip boundary between the green polymer and the dewetting material comprises selecting the dewetting material and the polymerization liquid such that a print quality of the three-dimensional object is improved relative to the print quality of a three-dimensional object prepared from an identical system except the dewetting material is stationary. ### Claim 8 (depends on 1) The method of claim 1, wherein the conditions sufficient to provide a slip boundary between the green polymer and the dewetting material comprises selecting the dewetting material and the polymerization liquid such that a print quality of the three-dimensional object is improved relative to the print quality of a three-dimensional object prepared from an identical system except (a) the dewetting material is not dewetting relative to the polymerization liquid, or (b) the dewetting material is not dewetting relative to the polymerization liquid and the dewetting material is stationary. ### Claim 9 (depends on 1) The method of claim 1, wherein the method is performed in an oxygen-free environment. ### Claim 10 (depends on 1) The method of claim 1, wherein the dewetting material comprises an aqueous liquid, organic liquid, silicone liquid, or fluoro liquid. ### Claim 11 (depends on 1) The method of claim 1, wherein the polymerization liquid comprises a particulate or colloidal matter capable of binding together. ### Claim 12 (depends on 1) The method of claim 1, wherein the polymerization liquid comprises an oxygen-sensitive polymerization liquid. ### Claim 13 (depends on 1) The method of claim 1, wherein a temperature of the dewetting material, the polymerization liquid, green polymer, or a combination thereof does not exceed 150° C. ### Claim 14 (depends on 1) The method of claim 1 having a vertical print speed in a range of about 10 μm/s to about 300 μm/s. ### Claim 15 (depends on 1) The method of claim 1, wherein the polymerization is performed by electromagnetic irradiation, electricity, thermal activation, magnetic activation, or a combination thereof. ### Claim 16 (depends on 1) The method of claim 1, wherein advancing the adhesion stage away from the build surface comprises advancing the adhesion stage away from the build surface at a constant rate for a fixed distance and is then paused for a fixed amount of time, and optionally repeated. ### Claim 17 (depends on 1) The method of claim 1, wherein advancing the adhesion stage away from the build surface comprises advancing the adhesion stage away from the build surface at a variable rate for a fixed distance and is then paused for a fixed amount of time, and optionally repeated. ### Claim 18 (depends on 1) The method of claim 1, wherein advancing the adhesion stage away from the build surface comprises advancing the adhesion stage away from the build surface in a reciprocating manner.