IASS Working Group 21: Advanced manufacturing and materials Form and Force Competition and exhibition of innovative lightweight structures
Polydon : a dynamic inflatable polyhedron
Léo DEMONT*,a, Félix CHAMEROYa, Clara CHOTILa, Nicolas LEDUC*,b, Cyril DOUTHE*
*. Laboratoire NAVIER, UMR 8205, Ecole des Ponts, IFSTTAR, CNRS, UPE 6-8 Avenue Blaise Pascal, 77455, Champs-sur-Marne, France,
a. Dynamorphe, 21 Rue Tandou 75019, Paris, France, firstname.lastname@example.org
b. ENS Architecture Paris Malaquais, 14 rue Bonaparte, 75006, Paris, France
Polydon is a dynamic inatable structure that can
expand gradually from 3.8 to 4.7m large. Its de-
ployable membrane ① is pressured by a fan ③ and
a rope-pulley system ② adjusts the membrane’s
shape by pulling fold vertices. Thus, Polydon of-
fers various spatial conditions, depending on
the membrane fold state dened by the user.
Dynamorphe  has previously investigated interactive deployable-inatable structures
with Diodon, using Ron Resch’s triangular deployable origami pattern . The present
pavilion investigates non-developable deployable membranes by reinterpreting prior art
by Kovàcs et al.  exploring mechanics of bar-hinge expandable polyhedral structures.
Figure 3. Isometric cut view of Polydon.
Starting from a regular dodecahedron, Poly-
don has been added folded tucks  and
adapted to t architectural and fabrication
constraints. Base face is enlarged to improve
spatial comfort, while most folds are opti-
mized for developability and facet planarity.
Figure 4. Ron Resch’s origami pattern and Diodon. Figure 5. Kovàcs expandable dodecahedron and
Figure 6. Modelling steps.
① Deployable membrane
② Adjustable rope-pulley platform
Membrane is made of
sewn exible sheet mate-
rials. Its folding is ensured
by rigidication with FRP
rods fastened into sewed
sleeves. It is pressured
by a small 50W domestic
fan. The membrane sup-
port is a steel pipe frame
assembled with tubular
weight is 25kg, ove-
rall weight is 175kg.
Figure 1. Polydon expansion.
 Dynamorphe collective webpage: http://dyna-
 R. Resch, «The topological design of sculptural and
architectural systems», Proceedings of the June 4-8,
1973, national computer conference and exposition
,pp. 643-650, 1973.
 F. Kovács, T. Tarnai, P. Fowler and S. Guest, «A
class of expandable polyhedral structures», Interna-
tional Journal of Solids and Structures, vol. 41, no.
3-4, pp. 1119-1137, 2004. Available: 10.1016/j.ijsols-
tr.2003.09.046 [Accessed 8 March 2019].
 T. Tachi, «Designing Freeform Origami Tessella-
tions by Generalizing Resch’s Patterns», Journal of
Mechanical Design, vol. 135, no. 11, 2013. Available:
Figure 2. Sewing plan.