Multicolor Digital Light Processing 3D Printing Enables Dissolvable Supports for Freestanding and Non-Assembly...

Area of Science:

• Additive Manufacturing
• Polymer Chemistry
• Materials Science

Background:

• Digital Light Processing (DLP) 3D printing offers rapid, precise, and low-waste fabrication but is limited by resin chemistry, hindering the creation of complex geometries like freestanding structures and non-assembly parts.
• Current DLP technologies struggle with geometries featuring floating overhangs (e.g., hooks) and integrated mobile components (e.g., joints) due to support structure limitations.

Purpose of the Study:

• To develop novel photocurable resins for DLP 3D printing that enable the fabrication of previously inaccessible complex geometries.
• To introduce a multimaterial 3D printing strategy utilizing resins that selectively form soluble thermoplastics and insoluble thermosets upon exposure to different light wavelengths.

Main Methods:

• Development and characterization of novel acrylate- and epoxy-based photocurable resins designed to react to specific light colors.
• Implementation of a simultaneous UV and visible light exposure process for rapid multimaterial 3D printing.
• Evaluation of the dissolvability of thermoplastic support structures in ethyl acetate and assessment of surface finish and throughput compared to manual support removal.

Main Results:

• Successful development of resins that form soluble thermoplastics and insoluble thermosets, enabling selective support removal.
• Demonstration of a rapid multimaterial 3D printing process (∼0.75 mm/min) capable of producing dissolvable supports.
• Achieved comparable or improved surface finishes and higher throughput compared to traditional support removal methods.
• Fabrication of complex proof-of-concept structures including hooks, chains, and joints, validated by computed tomography.

Conclusions:

• The novel resin chemistry and multimaterial printing process overcome limitations in DLP 3D printing, allowing for the creation of intricate geometries.
• Dissolvable supports fabricated using green solvents offer an efficient and effective alternative to manual support removal.
• This work establishes fundamental design principles for multimaterial resin systems, paving the way for advanced additive manufacturing applications.