We characterize three commercial resins suitable for three-dimensional two-photon printing of mm3volume micro-optical components for visible light –IP-S, IP-n162, and IP-Visio– under different print modes and post-processing conditions. Due to the combination of cured resin absorption and bulk scattering, we find a maximum total printed thickness of 4 mm (or greater) for at least 50% transmittance of red light, up to 2 mm for green light, and large maximum thickness variation for blue light (0.1 to 1 mm). 
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                            Counting All Photons: Efficient Optimization of Visible Light 3D Printing
                        
                    
    
            Abstract The utility of visible light for 3D printing has increased in recent years owing to its accessibility and reduced materials interactions, such as scattering and absorption/degradation, relative to traditional UV light‐based processes. However, photosystems that react efficiently with visible light often require multiple molecular components and have strong and diverse absorption profiles, increasing the complexity of formulation and printing optimization. Herein, a streamlined method to select and optimize visible light 3D printing conditions is described. First, green light liquid crystal display (LCD) 3D printing using a novel resin is optimized through traditional empirical methods, which involves resin component selection, spectroscopic characterization, time‐intensive 3D printing under several different conditions, and measurements of dimensional accuracy for each printed object. Subsequent analytical quantification of dynamic photon absorption during green light polymerizations unveils relationships to cure depth that enables facile resin and 3D printing optimization using a model that is a modification to the Jacob's equation traditionally used for stereolithographic 3D printing. The approach and model are then validated using a distinct green light‐activated resin for two types of projection‐based 3D printing. 
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                            - Award ID(s):
- 1720595
- PAR ID:
- 10509907
- Publisher / Repository:
- Wiley-VCH
- Date Published:
- Journal Name:
- Advanced Materials Technologies
- Volume:
- 8
- Issue:
- 23
- ISSN:
- 2365-709X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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