Engineering

Elastomer

Biomedical engineering

Materials science

Thermoforming

Honeycomb structure

Plane (geometry)

Absorption (acoustics)

Nanotechnology

3d printed

Mathematics

Geometry

Composite material

Thermoplastic polyurethane

Structural engineering

Stiffness

Honeycomb

Engineering physics

Materials & Design

Honeycomb structures display extraordinary stiffness-to-weight ratio when loaded in the out-of-plane direction. When realized using thermoplastic polyurethane (TPU), the structures offer the potential for repeatable and high specific energy absorption. Varying the cell size and wall thickness of TPU honeycombs facilitates changes in stiffness magnitude, though affords only modest capacity to alter the shape of the stress-strain curve. 3D printing facilitates advanced design exploration, beyond that of straight walls. Origami fold patterns have demonstrated the ability to influence the buckling behavior of tubular structures. Here we demonstrate the incorporation of origami folds into square honeycombs. The fold parameters facilitate significant tailoring of the stress-strain curve, allowing a range of profiles from quasi-rectangular to quasi-linear to be achieved; such structures can find applications in situation-specific energy absorption scenarios.

3D printed origami honeycombs with tailored out-of-plane energy absorption behavior