IP Library › Granted Patent US 12,623,408
Granted Patent B2
US 12,623,408 · App. 17/149,423 · Granted May 12, 2026

Stereolithography with micron scale control of properties

Inventors: Robert R. McLeod (Boulder, CO); Asais Camila Uzcategui (Denver, CO); John Elliott Hergert (Denver, CO); Archish Muralidharan (Denver, CO)
Assignee: The Regents of the University of Colorado, a Body Corporate
B29C64/393B29C64/124B29C64/264B33Y50/02B33Y70/00B29K2023/0691B29K2105/0002B29K2105/24B29K2995/0094
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Quick Facts
Patent No.
US 12,623,408
App. No.
17/149,423
Granted
May 12, 2026
Kind
B2
Abstract

Stereolithography with micron scale control of properties is described herein. In one aspect, a computer-implemented method for 3-D printing of a material can include generating a functional relation predicting one or more physical properties of the material resulting from printing parameters; algebraically or numerically solving the functional relation to generate a second functional relation predicting expected printing parameters resulting in the one or more physical properties; and printing the material via a photopolymerization printer according to the set of printing parameters determined by the second functional relation.

Claims (43)

1 . A computer-implemented method for 3-dimensional (3-D) printing of a material, the method comprising:

generating a functional relation predicting one or more physical properties of the material resulting from printing parameters, wherein the one or more physical properties of the material is selected from the group consisting of a cross link density, a swellability, a Young's modulus, a diffusivity coefficient, a shear modulus, a stiffness factor, a viscoelasticity factor, and a coefficient of friction;

algebraically or numerically inverting the functional relation to generate a second functional relation;

determining a set of printing parameters from the second functional relation; and

printing the material having the one or more physical properties via a vat photopolymerization printer according to the set of determined printing parameters.

2 . The computer-implemented method of claim 1 , wherein the printing is further implemented according to a printing pattern on the micron scale.

3 . The computer-implemented method of claim 1 , wherein generating the functional relation further comprises:

measuring or calculating a physical property of the material as a function of exposure time, post-exposure time, and light intensity;

identifying an equation to model the measurements or calculations which include a number of unknown parameters; and

fitting the measurements or calculations to the model to estimate values of the unknown parameters.

4 . The computer-implemented method of claim 3 , wherein the equation for modeling the physical property of the material comprises:

C

p

=

x

3

+

ax

+

b

x

3

+

cx

+

d

where a, b, c, and d are fitting parameters, and x is a variable of the exposure time, post-exposure time, and light intensity.

5 . The computer-implemented method of claim 1 , wherein the set of printing parameters comprises at least one of a layer thickness, an energy dose, an optical intensity, an exposure time, and a cure depth.

6 . The computer-implemented method of claim 1 , wherein the vat photopolymerization printer is a stereolithography (SLA) printer or a digital light processing (DLP) printer.

7 . The computer-implemented method of claim 1 , wherein printing the material comprises printing multiple layers of the material.

8 . The computer-implemented method of claim 1 , wherein the material originates from a single vat of precursor solution or resin of the printer.

9 . The computer-implemented method of claim 1 , wherein printing the material results in a functionally graded material (FGM).

10 . A non-transitory computer-readable medium including instructions executable by a processor for printing a material, the instructions comprising:

generating a functional relation predicting one or more physical properties of the material resulting from printing parameters, wherein the one or more physical properties of the material is selected from the group consisting of a cross link density, a swellability, a Young's modulus, a diffusivity coefficient, a shear modulus, a stiffness factor, a viscoelasticity factor, and a coefficient of friction;

algebraically or numerically inverting the functional relation to generate a second functional relation;

determining a set of printing parameters from the second functional relation; and

printing the material having the one or more physical properties via a vat photopolymerization printer according to the set of determined printing parameters.

11 . The non-transitory computer-readable medium of claim 10 , wherein the printing is further implemented according to a printing pattern on the micron scale.

12 . The non-transitory computer-readable medium of claim 10 , wherein

generating the functional relation further comprises:

measuring or calculating a physical property of the material as a function of exposure time, post-exposure time, and light intensity;

identifying an equation to model the measurements or calculations which include a number of unknown parameters; and

fitting the measurements or calculations to the model to estimate values of the unknown parameters.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 12, 2023
From: MCLEOD, ROBERT R.; UZCATEGUI, ASAIS CAMILA; HERGERT, JOHN ELLIOTT; MURALIDHARAN, ARCHISH
To: THE REGENTS OF THE UNIVERSITY OF COLORADO, A BODY CORPORATE
Reel/Frame 064226/0582 →
CONFIRMATORY LICENSE Recorded Oct 4, 2021
From: UNIVERSITY OF COLORADO
To: NATIONAL SCIENCE FOUNDATION
Reel/Frame 057697/0438 →
CONFIRMATORY LICENSE Recorded Jun 30, 2021
From: UNIVERSITY OF COLORADO
To: NATIONAL SCIENCE FOUNDATION
Reel/Frame 056719/0770 →
Continuity (2)
Provisional Application 62960956 · Jan 14, 2020
Related Publication 20210229364A1 · Jul 29, 2021
References Cited (18)
US 20160229222A1 · Stecker · 2016 [cited by examiner]
US 20180022034A1 · Sutter · 2018 [cited by examiner]
US 20220363010A1 · Kostenko · 2022 [cited by examiner]
Uzcategui et al. (“Understanding and Improving Mechanical Properties in 3D Printed Parts Using a Dual-Cure Acrylate-Based Resin for Stereolithography”, Adv. Eng. Mater. 2018, 20, 1800876 (Year: 2018). [cited by examiner]
Langtangen et al., “Scaling of Differential Equations”, SpringerOpen 2016 (Year: 2016). [cited by examiner]
Vitale et al. (“Frontal conversion and uniformity in 3D printing by photopolymerisation”); Materials 2016, 9, 760; published Sep. 7, 2016 (Year: 2016). [cited by examiner]
Choy et al., Functionally graded material by additive manufacturing, Proceedings of the 2nd International Conference on Progress in Additive Manufacturing (Pro-AM 2016), 206-211 (Year: 2016). [cited by examiner]
Birman, et al., “Modeling and analysis of functionally graded materials and structures”, American Society of Mechanical Engineers Digital Collection, 60, 2007, 195-216. [cited by applicant]
Canal, et al., “Correlation between mesh size and equilibrium degree of swelling of polymeric networks”, J. Biomed. Mater. Res., 23, 1989, 1183-1193. [cited by applicant]
Cox, et al., “Tunable Mechanical Anisotropy, Crack Guiding, and Toughness Enhancement in Two-Stage Reactive Polymer Networks”, Adv. Eng. Mater., 21:1900578, 2019. [cited by applicant]
Fiedler, et al., “Enhanced mechanical properties of photo-clickable thiol-ene PEG hydrogels through repeated photopolymerization of in-swollen macromer”, Soft Matter, 12, 2016, 9095-9104. [cited by applicant]
Gojzewski, et al., “Layer-by-Layer Printing of Photopolymers in 3D: How Weak is the Interface?”, ACS Appl. Mater. Interfaces, 12, 2020, 8908-8914. [cited by applicant]
Kuang, et al., “Grayscale digital light processing 3D printing for highly functionally graded materials”, Sci. Adv., 5, 2019. [cited by applicant]
Muralidharan, et al., “Stereolithographic 3D Printing for Deterministic Control over Integration in Dual-Material Composites”, Adv. Mater. Technol., 2019. [cited by applicant]
Uzcategui, et al., “Understanding and Improving Mechanical Properties in 3D printed Parts Using a Dual-Cure Acrylate-Based Resin for Stereolithography”, Adv. Eng. Mater., 20, 2018. [cited by applicant]
Vitale, et al., “Frontal Conversion and Uniformity in 3D Printing by Photopolymerisation”, Materials, 9, 2016, 760. [cited by applicant]
Yin, et al., “Orthogonal programming of heterogeneous micro-mechanoenvironments and geometries in three-dimensional bio-stereolithography”, Nat. Commun., 9, 2018. [cited by applicant]
Zhao, et al., “Indentation experiments and simulations of nonuniformly photocrosslinked polymers in 3D printed structures”, Addit. Manuf., 35:101420, 2020. [cited by applicant]