Fabrication of non-homogeneous articles via additive manufacturing using three-dimensional voxel-based models

Abstract

The invention provides systems and methods for manufacture of a non-homogeneous article using a 3D voxel-based model of the article and a rapid prototyping device. Use of a voxel-based model provides processing advantages and offers improved realism of the manufactured object with regard to non-homogeneous (i) color, (ii) translucency, and/or (iii) hardness, for example.

What is claimed is: 
     
         1 . A method for manufacturing an aesthetically-acceptable non-homogeneous object, the method comprising the steps of:
 (a) defining a 3D voxel representation for the non-homogeneous object to be manufactured, wherein each of a plurality of voxels is assigned one or more values representing one or more of the following prescribed physical properties M: color, translucency, and hardness;   (b) using the 3D voxel representation to: (i) define a set of 3D dots to produce a shape of each of a plurality of successive Z-layers of the object to be manufactured and (ii) define the one or more prescribed physical properties at each dot making up each of the successive Z-layers of the object to be manufactured;   (c) defining a transfer function T(M) that identifies a pigment, a resin, or both a pigment and a resin to produce a material having the one or more prescribed physical properties for each 3D dot to be printed; and   (d) using a 3D printer to deposit the pigment and/or the resin identified by the transfer function at each dot of each of the plurality of successive Z-layers of the object, thereby producing the non-homogeneous object.   
     
     
         2 . The method of  claim 1 , wherein step (b) comprises using multivariate interpolation to define the one or more prescribed physical properties at each 3D dot. 
     
     
         3 . The method of  claim 2 , wherein the multivariate interpolation is trilinear interpolation. 
     
     
         4 . The method of  claim 1 , wherein the transfer function T(M) identifies multiple pigments and/or multiple resins. 
     
     
         5 . The method of  claim 1 , wherein the non-homogeneous object is one or more teeth. 
     
     
         6 . The method of  claim 1 , wherein a value of the one or more prescribed physical properties varies within the object and/or within each of the Z-layers of the object. 
     
     
         7 . The method of  claim 1 , wherein the 3D printer is a rapid prototyping device. 
     
     
         8 . The method of  claim 1 , wherein the one or more prescribed physical properties comprises translucency, and wherein step (d) comprises depositing at least two different resins with embedded crystalline particles at a given dot, the combination of which resins produces the translucency prescribed for the given dot. 
     
     
         9 . The method of  claim 1 , wherein the embedded crystalline particles have a known size distribution. 
     
     
         10 . The method of  claim 1 , wherein one or more of the voxels has at least one associated real world dimension that is no greater than about 10 microns. 
     
     
         11 . The method of  claim 1 , wherein the 3D voxel representation defined in step (a) is partitioned into a hierarchy of blocks, wherein each block: (i) has one or more spatial properties in common; and/or (ii) has one or more of the prescribed physical properties in common. 
     
     
         12 . A system for fabricating a non-homogeneous article, the system comprising:
 a user interface configured to receive input from a user;   a design application in communication with the user interface, wherein the design application is configured to create a 3D voxel-based model of a non-homogeneous article, wherein each voxel is assigned one or more physical properties; and   a rapid prototyping machine for fabrication of the non-homogeneous article, wherein said rapid prototyping machine is configured to fabricate the artificial tooth via additive manufacturing using the 3D voxel-based model, wherein properties of the voxels of the model correspond to properties of the voxels of the fabricated article.   
     
     
         13 . The system of  claim 12 , wherein the physical properties comprise at least one of color, translucency, hardness, modulus, and dynamic modulus. 
     
     
         14 . The system of  claim 12 , wherein the system is configured to perform additive manufacturing by providing successive layers or parcels of material.