13 research outputs found
Rigid Origami via Optical Programming and Deferred Self-Folding of a Two-Stage Photopolymer
We demonstrate the formation of shape-programmed,
glassy origami
structures using a single-layer photopolymer with two mechanically
distinct phases. The latent origami pattern consisting of rigid, high
cross-link density panels and flexible, low cross-link density creases
is fabricated using a series of photomask exposures. Strong optical
absorption of the polymer formulation creates depth-wise gradients
in the cross-link density of the creases, enforcing directed folding
which enables programming of both mountain and valley folds within
the same sheet. These multiple photomask patterns can be sequentially
applied because the sheet remains flat until immersed into a photopolymerizable
monomer solution that differentially swells the polymer to fold and
form the origami structure. After folding, a uniform photoexposure
polymerizes the absorbed solution, permanently fixing the shape of
the folded structure while simultaneously increasing the modulus of
the folds. This approach creates sharp folds by mimicking the stiff
panels and flexible creases of paper origami while overcoming the
traditional trade-off of self-actuated materials that require low
modulus for folding and high modulus for mechanical robustness. Using
this process, we demonstrate a waterbomb base capable of supporting
1500 times its own weight