IP Library › Granted Patent US 12,528,246
Granted Patent B2
US 12,528,246 · App. 18/608,097 · Granted Jan 20, 2026

Projection two-photon lithography method and system for rapid printing of 3D structures with sub-micrometer features and porosities

Inventors: Sourabh Kumar Saha (Atlanta, GA); Harnjoo Kim (Atlanta, GA); Rushil Pingali (Atlanta, GA)
Assignee: Georgia Tech Research Corporation
B29C64/135B29C64/273B33Y10/00B33Y30/00B33Y70/00
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Quick Facts
Patent No.
US 12,528,246
App. No.
18/608,097
Granted
Jan 20, 2026
Kind
B2
Abstract

Systems, methods, devices, and compositions of matter for 3D printing methods and systems that can be used for rapid nanoscale 3D printing of large and deterministic 3D structures with sub-micrometer features and porosities. The method includes storing or determining a plurality of interspersed features for a three-dimensional (3D) structure to project as a sequence of sparse images on the same plane to generate closely spaced fine features on a polymer resist; and generating, using the sequence of sparse images, a plurality of patterned light sheet on the polymer resist with a temporally-focused femtosecond pulse, the light sheet having patterns.

Claims (25)

1 . A method comprising:

storing or determining a plurality of interspersed features for a three-dimensional (3D) structure to project as a sequence of sparse images on the same plane to generate closely spaced fine features on a polymer resist; and

generating, using the sequence of sparse images, a plurality of patterned light sheet on the polymer resist with a temporally-focused femtosecond pulse, the light sheet having patterns,

wherein the polymer resist comprises a photoinitiator, a radical quencher, and a monomer, wherein the concentration of the photoinitiator is less than one third the concentration of the radical quencher, the radical quencher includes dissolved oxygen, and wherein the solubility threshold DOC of the resist is less than 10%.

2 . The method of claim 1 , wherein the plurality of interspersed features stored in a sequence of sparse images when projected to the polymer resist generate a 3D structure that mitigate proximity effects for densely packed features.

3 . The method of claim 2 , wherein the sequence of sparse images have selected pattern period higher than half of the sum of the width of a focal spot and width of a polymerized feature.

4 . The method of claim 1 , wherein duration, intensity, and/or size of focused light spot of the femtosecond pulse are determined based on an optical dosage per pulse (D p ) model.

5 . The method of claim 1 further comprising:

generating, using the sequence of sparse images, a plurality of patterned light sheet with a temporally-focused femtosecond pulse on a second layer of polymer resist (e.g., to form the 3D structure), the light sheet having sub-micrometer patterns.

6 . The method of claim 1 , wherein the method is a part of a P-TPL operation configured to generate a 3D structure with features less than 300 nm, pores finer than 700 nm, and at rates greater than 0.5 mm 2 /s per layer.

7 . The method of claim 1 , wherein the method is a part of a P-TPL operation configured to generate a 3D structure at rates greater than 0.5 mm 2 /s per layer.

8 . The method of claim 1 , wherein the 3D structure is for at least one of: micro-robotic component, micro-fluidic component, scaffold for bioengineered tissue, mechanical metamaterial, photonic components, or a structured electrode.

9 . A system comprising:

a memory having instructions for a plurality of interspersed features for a 3D structure to project as a sequence of sparse images on the same plane to generate closely spaced fine features on a polymer resist; and

lithography equipment configured to generate using the sequence of sparse images a plurality of patterned light sheet on the polymer resist with a temporally-focused femtosecond pulse, wherein the light sheet has patterns,

wherein the polymer resist comprises a photoinitiator, a radical quencher, and a monomer, wherein the concentration of the photoinitiator is less than one third the concentration of the radical quencher, the radical quencher includes dissolved oxygen, and wherein the solubility threshold DOC of the resist is less than 10%.

10 . The system of claim 9 , wherein the plurality of interspersed features stored in the sequence of sparse images when projected to the polymer resist generate a 3D structure that mitigate proximity effects for densely packed features.

11 . The system of claim 9 , wherein the sequence of sparse images have selected pattern period higher than half of the sum of the width of a focal spot and width of a polymerized feature.

12 . The system of claim 9 , wherein duration, intensity, and/or size of focused light spot of the femtosecond pulse are determined based on an optical dosage per pulse model.

13 . The system of claim 9 , wherein the lithography equipment is configured to generate using the sequence of sparse images, a second plurality of patterned light sheet with a temporally-focused femtosecond pulse on a second layer of polymer resist, the light sheet having sub-micrometer patterns.

14 . The system of claim 9 , wherein the system is configured to generate a 3D structure with features less than 300 nm, pores finer than 700 nm, and at rates greater than 0.5 mm 2 /s per layer.

15 . The system of claim 9 , wherein the system is configured to generate a 3D structure at rates greater than 0.5 mm 2 /s per layer.

16 . The system of claim 9 , wherein the lithography equipment is a P-TPL system.

17 . A polymer resist comprising:

a photoinitiator, a radical quencher, and a monomer, wherein the concentration of the photoinitiator is less than one-third the concentration of the radical quencher, wherein the radical quencher includes dissolved oxygen, and wherein the solubility threshold DOC of the resist is less than 10%.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 3, 2025
From: SAHA, SOURABH KUMAR; KIM, HARNJOO; PINGALI, RUSHIL
To: GEORGIA TECH RESEARCH CORPORATION
Reel/Frame 069731/0549 →
Continuity (2)
Provisional Application 63490723 · Mar 16, 2023
Related Publication 20240351272A1 · Oct 24, 2024
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