Figure 4. Structures fabricated via the inverted deposition
configuration. (a) A bio-inspired “beehive.” (b) Conical structure with large overhangs and small base fabricated with
zero support material. (c) Twisted conical structure. (d) Load bearing arch. (e) Fully cured inverted arch
supporting a 1 kg weight.
Alternatively, this printing technique can be configured to fabricate
structures horizontally, effectively enabling production of 90⁰
overhangs with zero support material (Figure 5a). By
reorienting the extrusion nozzle, the zero-support horizontal beams
could be fabricated such that layers are deposited parallel to the build
plate similar to conventional DIW printing. The rapid
photopolymerization affords rigidity to the structure, allowing it to
resist the increasing bending moment imparted by the cumulative weight
of the horizontal beam. To further demonstrate the capabilities of these
unstructured/alternative build orientations, we deposited conductive ink
paths on the surface of a horizontally printed beam to create a
functional 3D printed structure to sense deflection (Figure 5b,
Video 3). The results of normalized resistance over time for the 50 mm
horizontal beam sensor subjected to cyclic deflection three times at δ =
0.4, 0.8, and 1.2, 1.6, and 2.0 mm are presented in Figure 5c.