Multi-color dual wavelength vat photopolymerization 3D printing via spatially controlled acidity

Kyle C H Chin; Grant Ovsepyan; Andrew J Boydston

doi:10.1038/s41467-024-48159-7

Multi-color dual wavelength vat photopolymerization 3D printing via spatially controlled acidity

Nat Commun. 2024 May 8;15(1):3867. doi: 10.1038/s41467-024-48159-7.

Authors

Kyle C H Chin¹, Grant Ovsepyan¹, Andrew J Boydston^{2

3

4}

Affiliations

¹ Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI, 53706, USA.
² Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI, 53706, USA. aboydston@wisc.edu.
³ Department of Chemistry, University of Wisconsin, Madison, WI, 53706, USA. aboydston@wisc.edu.
⁴ Department of Materials Science and Engineering, University of Wisconsin, Madison, WI, 53706, USA. aboydston@wisc.edu.

Abstract

Dual wavelength vat photopolymerization (DW-VP) has emerged as a powerful approach to create multimaterial objects. However, only a limited range of properties have been showcased. In this work, we report the 3D printing (3DP) of multi-color objects from a single resin vat using DW-VP. This was accomplished by concurrently curing resin with visible light and modulating local resin color with 365-nm ultraviolet (UV) light. The key advance was to use a photoacid generator (PAG) in combination with pH responsive dyes in the 3DP resins. The specific color is dictated by the extent of reaction, or local acidity in our case, and controlled by the light dosage and pattern of UV light applied. Multi-color object formation was implemented in two-step processes involving first 3DP to set the object structure, followed by UV exposure, as well as single processes that leveraged DW-VP to create a broad range of vibrant colors and patterns.

Grants and funding

W911NF-20-2-0182-P00005-(76555-EG-MUR)/United States Department of Defense | United States Army | U.S. Army Research, Development and Engineering Command | Army Research Office (ARO)