Projection Two-Photon Lithography for Sparse-Image Nanoscale 3D Printing
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Solution Overview
Problem
Existing 3D printing technologies face a trade-off between printing rate and resolution, particularly in achieving nanoscale features and porosities, due to proximity effects that lead to broadening and merging of closely spaced features.
Innovation Solution
A method and system employing a sequence of sparse images projected with temporally-focused femtosecond pulses to generate 3D structures with sub-micrometer features and porosities, using a polymer resist with specific concentrations of photoinitiator, radical quencher, and monomer, to mitigate proximity effects and enhance resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional 3D printing methods are used to achieve nanoscale features and porosities, then resolution is improved, but printing rate deteriorates due to the trade-off between printing rate and resolution
Solution Approach 1:
The patent segments the printing process into multiple sequential projections of sparse images, where each projection exposes only a subset of features. This allows the system to maintain high resolution by using sparse projections that avoid proximity effects, while improving overall printing rate by processing features in parallel batches rather than sequentially point-by-point
Solution Approach 2:
The patent employs periodic projection cycles where sparse images are projected in repeated sequences. Each cycle projects a sparse pattern, allows partial polymerization, then repeats with overlapping features to build up complete high-resolution structures. This periodic approach enables both rapid printing through batch processing and high resolution through cumulative feature definition
2Manufacturing precision
If closely spaced features are printed to achieve high resolution, then manufacturing precision is improved, but proximity effects cause feature broadening and merging that worsens manufacturing precision
Solution Approach 1:
The patent divides the complete feature pattern into multiple sparse image projections. Each sparse projection contains only a subset of features spaced far enough apart to avoid proximity effects. By segmenting the pattern this way, the system can print closely spaced features in the final structure while each individual projection step maintains feature integrity without broadening or merging
Solution Approach 2:
The patent performs preliminary projection of sparse patterns that establish feature locations without full intensity exposure. This preliminary action creates a framework that guides subsequent projections, allowing features to be defined in stages where proximity effects are minimized at each step while still achieving the final high-resolution closely-spaced feature structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves rapid printing of large and deterministic 3D structures with features less than 300 nm and pores finer than 700 nm at rates greater than 0.5 mm2/s per layer, overcoming the limitations of traditional 3D printing.
Implementation Method 1
projection two-photon lithography method
Implementation Method 2
generating, using the sequence of sparse images, a plurality of patterned light sheet on the polymer resist with a temporally-focused femtosecond pulse
Data Source
AI summary
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.