Abstract
Fabrication of structures in
unstructured environments is a promising field to expand the application
spaces of additive manufacturing (AM). One potential application is to
add new components directly onto existing structures. In this paper, we
developed a versatile, reconfigurable direct ink write (DIW)
manufacturing method in tandem with a two-stage hybrid ink designed to
fabricate high-strength, self-supporting parts in unconventional
printing spaces, such as underneath a build surface or horizontally. Our
two-stage hybrid DIW ink combines a photopolymer and a tough epoxy
resin. The photopolymer can be cured rapidly to enable layer-by-layer
printing complex structures. It also possesses adequate adhesion to
allow the fabrication of large volume structures on a diversity of
substrates including acrylic, wood, glass, aluminum, and concrete. The
epoxy component can be cured after 72 hours in ambient conditions with
further increased adhesion strengths. We demonstrated the capabilities
of the reconfigurable DIW extrusion nozzle method to print complex
structures in inverted and horizontal environments. Finally, via the
addition of DIW-deposited conductive paths, we created a functional 3D
printed structure capable of in-situ deformation monitoring. This work
has the potential to be used for applications such as appending new
parts to existing structures for increasing functionality, repair, and
structure health monitoring.