“Advancing composite & multimaterial manufacturing via in-situ tomography and rotational multimaterial 3D printing”
Fibrous and helical architectures are ubiquitous in natural systems due to their unique mechanical behavior and functionality. Synthetic materials based on these architectures have the potential to transform the engineering landscape for applications ranging from aerospace to soft robotics. In this talk, I will present research from two fields aimed at advancing the manufacturing of composite and multimaterial systems based on these architectures. First, I will show how in-situ X-ray computed tomography has been used to provide new insights on microstructure evolution during processing of fiber-reinforced ceramic matrix composites for more efficient aerospace engines. Key findings include elucidating coupled effects of capillary number, fiber movement and preferred flow channeling on axial permeability of fiber beds, development of a unified taxonomy of pyrolysis crack geometries, and quantification of the effects of local microstructural dimensions on pyrolysis crack formation. Second, I will present a rotational multimaterial 3D printing system that enables subvoxel control over the local orientation of architected filaments. This system enables fabrication of helical filaments with programmable helix angle, layer thickness, and interfacial area between multiple materials within a given cylindrical voxel. Using this system, we have fabricated functional artificial muscles composed of helical dielectric elastomer actuators, and “springy” filaments and lattices composed of stiff springs within a compliant matrix.