Properties and role of interfaces in multimaterial 3D printed composites

Area of Science:

• Materials Science
• Additive Manufacturing
• Polymer Science

Background:

• Polyjet printing fabricates heterogeneous architectures using photopolymers.
• Interfaces between photopolymers can form before or after UV curing.
• Understanding interface properties is crucial for designing advanced composites.

Purpose of the Study:

• To analyze the properties of interfaces in 3D printed composites.
• To investigate photopolymer blending and its effect on mechanical properties.
• To characterize the impact of finite-size interfaces on composite behavior.

Main Methods:

• Fabrication of digital materials with varying volume fractions of compliant and stiff photopolymers.
• Nanoindentation to measure mechanical properties at the micrometer level across bimaterial interfaces.
• Testing of layered composites with alternating compliant and stiff layers in different orientations.

Main Results:

• Interfaces formed before UV curing showed material blending, while those formed after were sharp.
• Material blending occurred over a length scale larger than individual droplet size.
• Composite structure and function varied with printing orientation and interface characteristics, affecting deformation.

Conclusions:

• Interface characteristics significantly influence the mechanical properties and deformation mechanisms of 3D printed composites.
• Tailoring interfaces is essential for developing architectured materials with specific functionalities.
• Findings are relevant for the development of advanced 3D printed materials with controlled interfaces.