Continuous liquid supply multi-material DLP 3D printing

Abstract Digital light processing (DLP) 3D printing has been considered as one of the most sustainable additive manufacturing methods for high-speed and high-resolution construction across various fields. Recent investigations focus on curing surface and resin formation regulation to realize printing continuity. However, heat accumulation from light-curing exotherm is aggravated and multi-material printing is compromised with the realization of printing continuity. Here, we propose a continuous liquid supply 3D printing strategy through introducing supplied liquid into one-droplet 3D printing system. Timely curing of slices can be maintained inside droplet reservoir along with on-demand resin supply, decreased heat accumulation and unlimited printing volume can thus be realized. Additionally, supply species, quantity and distribution are controllable in slices, leading to continuous mode of muti-material printing. Multi-material 3D structures with controllable morphologies and distributions can be prepared with enhanced interfacial mechanical properties and clear boundaries, and has been applied in material distribution defined 3D anti-counterfeiting and magnetic-responsive moving trajectories, which guarantees a high efficiency and sustainable multi-material 3D fabrication route.