Methods and systems for forming a three-dimensional object and methods for generating a scaled digital model for printing a three-dimensional object

A method for producing a three-dimensional (3D) object with use of a 3D printer including at least two excitation lights including a first excitation light and a second excitation light, the method comprising:

• a) providing a volume including a photohardenable composition comprising a photohardenable component and a dual wavelength photoinitiator wherein exposure of the photohardenable composition to a first excitation light including a first wavelength and a second excitation light including a second wavelength induces a crosslinking or polymerization reaction in the photohardenable composition;
• b) generating a scaled model of two-dimensional cross-sectional digital slices of the 3D object to be printed, wherein each cross-sectional digital slice includes an arrangement including a grid of pixels to be illuminated and pixels not to be illuminated during printing of the slice, and wherein generating the scaled model of the digital slice comprises assigning an intensity level to each pixel to be illuminated at a position in the arrangement with the second excitation light based on at least the position in the arrangement of each pixel to be illuminated with the second excitation light relative to one or more propagating rays of the first excitation light to which the pixel will be exposed during printing of the scaled digital slice;
• c) exposing a selected two-dimensional cross-sectional plane in the volume of the photohardenable composition to at least a light sheet including the first excitation light comprising the first wavelength and an optical image including the second excitation light comprising second wavelength to form a cross-sectional slice of the 3D object, wherein the optical image comprises a two-dimensional cross-sectional slice of the 3D object generated from a scaled digital slice of the 3D object;
• and
• optionally d) repeating step c) one or more times wherein, for a repeated step, one or both of the selected location and optical image is the same as or different from a previous selected location and/or a previous optical image.

A method for improving cure rate homogeneity across a light sheet traversal direction through a photohardenable composition, the method comprising:

• a) providing a volume including the photohardenable composition, wherein the photohardenable composition includes a dual wavelength photoinitiator;
• b) slicing a digital model corresponding to at least a portion of a 3D object into a plurality of two-dimensional sequential slices of the digital model of the 3D object, each digital slice including an arrangement including pixels to be illuminated by the second excitation light during printing of a slice and pixels not to be illuminated by the second excitation light during printing of the slice;
• c) generating a scaled model of each digital slice wherein each pixel in a digital slice to be illuminated with the second excitation is assigned an intensity level based on at least its position in the arrangement relative to one or more propagating rays of the first excitation light to which the pixel will be exposed during printing of the scaled digital slice;
• d) exposing a selected two-dimensional cross-sectional plane in the volume of the photohardenable composition to at least a light sheet including a first excitation light comprising a first wavelength and an optical image including a second excitation light comprising a second wavelength to form a cross-sectional slice of the 3D object, wherein the optical image comprises the scaled digital slice corresponding to the selected two-dimensional cross-sectional slice of the 3D object generated from the scaled model of the 3D object;
• and
• optionally e) repeating step c) one or more times wherein, for a repeated step one or both of the two-dimensional cross-sectional plane in the volume and the optical image is the same as or different from a previous selected two-dimensional cross-sectional plane in the volume and/or a previous optical image,
• wherein the cure rate across a light sheet traversal direction through the photohardenable composition of the cross-sectional slices of the 3D object being printed is more homogeneous than printing without use of the scaled digital slices.