Additive Manufacturing of Self-healing Polymer Composites

3D printed components typically show poorer mechanical strength and thereby increased potential for material damage during fabrication and use. Here, we incorporate self-healing properties towards extending the lifetimes of 3D printed polymeric objects. Inspired by biological self-healing, in which a damage event triggers an autonomic healing response, microcapsules containing healing agents are embedded within the 3D printed composites during fabrication. During a damage event these microcapsules rupture, release the healing agent, and heal the surrounding material by polymerization, entanglement, and/or cross-linking. Microcapsules containing healing agents are either incorporated into the host polymer matrix or are coated onto polymer filaments to create 3D printed objects. Microcapsule distribution within composites is visualized using X-ray Nano-CT imaging. Self-healing properties are evaluated via examination of the healing efficiency and mechanical strength of the 3D printed objects. Overall, these are promising approaches to the inclusion of self-healing behavior in 3D printed composites.