Linear Volumetric 3D Printing: Dual-Wavelength Initiation and Inhibition for Light-Induced Direct Growth

Abstract This study introduces an advanced volumetric additive manufacturing (AM) method, named light-induced direct growth (LIDG), which leverages dual-wavelength photoinitiation and inhibition to push the boundaries of printing complexity. Traditional vat photopolymerization is valued for its high precision in producing detailed polymer structures, yet it is challenged by the need to balance speed and resolution, the reliance on support structures for complex geometries, and issues with material stability during the fabrication process. The volumetric LIDG technique effectively addresses these limitations through the innovative use of dual-wavelength light sources: blue light initiated photopolymerization, while UV light provides selective inhibition. This dual-wavelength system enables targeted polymerization, allowing for the rapid fabrication of complex, overhanging structures without additional support, thus significantly enhancing the efficiency of the printing process. Additionally, this study explores refined resin formulations and optimized curing methods, which contribute to improved stability and uniformity of the printed materials. These advancements make the LIDG method particularly well-suited for applications in fields that demand high precision and material integrity, such as optics, medical implants, and soft robotics. Overall, the LIDG approach with dual-wavelength control represents a substantial breakthrough in volumetric AM, overcoming the inherent constraints of conventional methods and enabling the faster, more accurate production of intricately detailed components across a range of applications.