Liquid interface techniques for additive fabrication and related systems and methods

Abstract

According to some aspects, an additive fabrication apparatus is provided configured to form layers of material on a build platform, each layer of material being formed so as to contact a supporting liquid or a film disposed within a container, in addition to the build platform, a liquid photopolymer, and/or a previously formed layer of a material. The additive fabrication apparatus may comprise a container and a leveling element, wherein the leveling element is configured to move across a liquid-liquid interface to promote or create a flat interface between the two liquids. According to some aspects, the additive fabrication comprises a film disposed between two liquids, wherein the film maintains or provides a flat surface at the interface of the two liquids.

What is claimed is: 
     
         1 . An additive fabrication apparatus configured to form a plurality of layers of material on a build platform by directing actinic radiation onto a liquid photopolymer arranged over a supporting liquid, the additive fabrication apparatus comprising:
 a container;   the build platform;   the supporting liquid arranged within the container; and   at least one controller configured to determine whether or not the height of the supporting liquid is below a desired height based at least in part on the sensor data.   
     
     
         2 . The additive fabrication apparatus of  claim 1 , wherein the at least one controller is further configured to cause the additive fabrication apparatus to deposit supporting liquid into the container. 
     
     
         3 . The additive fabrication apparatus of  claim 1 , further comprising a leveling element arranged at least partially within the supporting liquid; and wherein the at least one controller is further configured to cause the leveling element to move through the supporting liquid. 
     
     
         4 . The additive fabrication apparatus of  claim 3 , wherein the leveling element further comprises a flow catch configured to prevent flow liquid on a trailing side of the leveling element. 
     
     
         5 . The additive fabrication apparatus of  claim 4 , wherein a bottom edge of the flow catch is perforated. 
     
     
         6 . The additive fabrication apparatus of  claim 3 , wherein a top side of the leveling element and a bottom side of the leveling element comprise different materials. 
     
     
         7 . The additive fabrication apparatus of  claim 1 , wherein the leveling element is configured to move through the liquid interface between the supporting liquid and the liquid photopolymer. 
     
     
         8 . The additive fabrication apparatus of  claim 1 , wherein the supporting liquid has a dielectric constant of at least zero but no greater than 20. 
     
     
         9 . The additive fabrication apparatus of  claim 1 , further comprising the liquid photopolymer arranged over the supporting liquid. 
     
     
         10 . The additive fabrication apparatus of  claim 1 , wherein the supporting liquid is selected from the group consisting of corn syrup, salt water, Epson salt water, glycerol, Novac 7000, a Fluorinert™, or heavy water. 
     
     
         11 . An additive fabrication apparatus configured to form a plurality of layers of material on a build platform by directing actinic radiation onto a liquid photopolymer, the additive fabrication apparatus comprising:
 a container;   the build platform;   a supporting liquid arranged within the container;   a liquid photopolymer arranged over the supporting liquid; and   a leveling element arranged at least partially within the supporting liquid, the leveling element configured to apply suction to at least the liquid photopolymer to cause redistribution of the liquid photopolymer.   
     
     
         12 . The additive fabrication apparatus of  claim 11 , wherein the leveling element is arranged entirely within the supporting liquid. 
     
     
         13 . The additive fabrication apparatus of  claim 12 , wherein the leveling element is shaped to comprise a cavity formed in a top surface of the leveling element, wherein the cavity comprises side walls which extend down from the top surface to a closed bottom of the cavity within the leveling element. 
     
     
         14 . The additive fabrication apparatus of  claim 11 , wherein the supporting liquid is denser than the liquid photopolymer. 
     
     
         15 . The additive fabrication apparatus of  claim 11 , wherein the supporting liquid has a dielectric constant of at least zero but no greater than 20. 
     
     
         16 . The additive fabrication apparatus of  claim 11 , wherein the supporting liquid comprises a fluorinated hydrocarbon. 
     
     
         17 . The additive fabrication apparatus of  claim 11 , wherein the supporting liquid is selected from the group consisting of corn syrup, salt water, Epson salt water, glycerol, Novac 7000, a Fluorinert™, or heavy water. 
     
     
         18 . The additive fabrication apparatus of  claim 11 , wherein the leveling element comprises a polymeric material. 
     
     
         19 . The additive fabrication apparatus of  claim 11 , further comprising a sensor configured to generate sensor data indicative of a height of the supporting liquid. 
     
     
         20 . The additive fabrication apparatus of  claim 11 , wherein the controller is further configured to adjust a height of the leveling element.