Two Folded Tripods, One Possible Shape: Resch Origami Locks Into a 7 m Aluminium Shell
MIT CBA, Bologna, Innsbruck and Tokyo fold CNC-cut aluminium into Resch tripod cells that lock rigid. A 7 m shell, built in days with screwdrivers.
Two tripods, folded from flat aluminium, pressed together. That pairing is the whole idea. On its own, each tripod-shaped cell can still move. Paired, the block has zero degrees of freedom. Lead author Alfonso Parra Rubio of MIT’s Center for Bits and Atoms (CBA) puts it this way: “The way the unit cells are designed, the structure can only exist in one configuration.” No hinge is left to wander, and no mechanism hides in the folds.
The proof hangs in the atrium of the Boston Public Library. It is a 23-foot (about 7 m) shell of folded aluminium, shown for the annual Fab Lab Conference and Symposium. According to MIT News, a team with no professional construction experience built the whole structure “in a matter of days”. “We are demonstrating structural origami on building scales,” Parra Rubio says.
The system behind the shell
Read it as a pipeline with four stages:
- Input: flat sheet, such as aluminium, cut on CNC mills.
- Transform: each outline folds into a tripod unit cell taken from a Resch tessellation.
- Lock: two cells pair into one rigid block.
- Assemble: hand tools such as screwdrivers, with no large-scale welding, as Tech Xplore reported.
In this method, the key check sits in the middle stage: proving that every cell actually folds. Erik Strand at CBA co-developed the solver, and he describes the split plainly: “we solve each cell independently to make sure that it is foldable, and then we globally assemble them after that.” Each cell is checked locally, and the shell is assembled globally. On the site side, Parra Rubio’s line is the one to pin above any fabrication bench: “The connection is the same everywhere, even though each unit cell is different.”
In simulations, the team reports that the blocks are about 3.5 times stiffer than those made with some other origami-based techniques, using about two-thirds as much material. Read that figure carefully. It is a simulated comparison within structural origami. It is not a claim against steel or concrete, and no loads or spans were reported.
←TODAY: In 2026, a 7 m aluminium shell goes up in days from CNC-cut sheet and screwdrivers.
→3012: Zurich-3012 ships shelter as flat stacks of unique cells that share one joint.
Fulcrum: A unique shape for every part becomes affordable once the connection stays identical.
The people under the pattern
The pattern carries a name worth saying out loud. Ron Resch (1939–2009) was an artist and computer scientist. He taught architecture at the University of Illinois and later computer science at the University of Utah. His tessellations from the 1960s are the source geometry here. His Vegreville egg in Alberta (1975) carried the idea into anodised aluminium: about 9 m long, made of 1,108 triangles and 524 hexagons.
The paper’s authors took that lineage and built the engineering that lets it assemble. They are Parra Rubio, Riccardo Foschi (University of Bologna), Rupert Maleczek (University of Innsbruck), Tomohiro Tachi (University of Tokyo) and Neil Gershenfeld, the CBA director. Parra Rubio developed the pairing method while working in Tachi’s lab in Tokyo.
The European thread is real. Funding came in part from the University of Bologna and the Austrian Research Agency. Innsbruck has also folded at scale before. On 13 May 2016, the university’s newsroom reports, Maleczek, Scheiber and Filz of the Institut für Gestaltung built a pavilion of 600 folded double cones from cardboard only 0.8 mm thick.
Where it lands first
The team names these applications: deployable disaster-relief shelters, facades, sound-dampening panels, lightweight aircraft parts and modular robots. Their stated next steps are larger architectural structures and a user-friendly design interface. Gershenfeld’s claim is that “folding metal is a method that is ready to be used for building structures.” James Coleman, cofounder of SumPoint, says the approach “maintains a seamless digital thread from design through erection.” The trade-off is plain: when every cell is unique, the work shifts from welding to labelling. Every part needs its address, and the model has to stay the reference all the way to the last screw.
Atelier: For a Zürich studio that runs Rhino alongside Archicad, this is first a question about facades and acoustic ceilings, and only later a question about structure. Unique panels with one repeated joint change how you brief a metal fabricator. Monday move: give one designer half a day to model, unroll and laser-cut a single cell. Then bring the folded result to your next facade coordination meeting.
Hack: Draw the flat seed of one Resch-style triangle twist in GhPython before you think about the shell. The central triangle is rotated by a twist angle. That rotation is what gives the surrounding fold lines somewhere to go when the sheet collapses into a tripod. Run this in a GhPython component in Grasshopper for Rhino:
import Rhino.Geometry as rg, math
s, t = 50.0, math.radians(30) # side radius in mm, twist angle
pts = [rg.Point3d(s*math.cos(t+k*2*math.pi/3), s*math.sin(t+k*2*math.pi/3), 0) for k in range(3)]
a = rg.Polyline(pts + [pts[0]]).ToNurbsCurve() # central triangle, offset it for the fold linesChange t with a slider and watch the twist open and close. Once you have folded the cell as a surface, Rhino’s UnrollSrf gives you the cut outline. From there, the PAZ Grasshopper↔Archicad Library can carry the panel outlines into the Archicad model.
Model one cell, unroll it, fold it from card, and only then draw the shell.
Sources & Further Reading
PAZ Kaffi · multidisciplinary editorial, led by PAZ Academy
