Kirigami — cut paper — is the variant of origami that allows you to cut the sheet as well as fold it. That single permission enormously expands the set of shapes a flat sheet can become, and [Matthew Lim] has used it to build three-dimensional designs that convert between a flat configuration and a functional object with no bolts, glue or fasteners of any kind.
The range runs from a phone grip to a sizeable side table.
The 1797 precedent
The demonstration starts somewhere unexpected: folding an origami crane with a smaller crane on its back.
This is documented in a 1797 book on the many ways to fold a crane — and it contains one of the first known instances of cuts being made in the single sheet, the cut portion becoming the second, much smaller crane. The same book extends the idea into an origami grid that folds into a grid of cranes after a series of cuts.
Later this got the name kirigami. The point of the history is that the technique is not a modern parametric-design invention; it is a 230-year-old discovery about what cutting buys you, which contemporary work is now putting through a solver.
The modern underpinning cited is a 2024 paper by Liu et al. on cylindrical origami with tunable mechanical behaviour — which is the formal version of the same insight: the cut pattern determines the mechanical properties of the resulting structure, so you can design stiffness and bistability rather than discovering them.
Why cuts change the engineering, not just the geometry
Worth drawing out, because it explains why kirigami turns up in robotics and aerospace rather than only in craft.
A folded sheet is constrained by its own continuity. Every crease has to be compatible with every other, the material cannot pass through itself, and a flat sheet has zero Gaussian curvature it cannot change by folding alone. That is a tight design space.
A cut relaxes a constraint. It lets one region move relative to another in ways continuity forbade, and it allows the sheet to locally behave as though it had curvature. Crucially, a well-placed cut also creates a stop — two edges that meet and prevent further motion. That is where the locking comes from.
So the mechanism Lim is exploiting is not just that cuts permit more shapes. It is that cuts let you build a kinematic linkage out of one piece of material, including its end stops, with no hardware.
The prototyping path is the practical lesson
The sequence is the useful part for anyone wanting to try this:
Laser cutter and FDM printer to prototype and test increasingly advanced versions of the pop-up mechanism. Cut pattern in flat sheet, test the fold, iterate.
Then full-size furniture in plywood panels with 3D-printed hinges.
That progression — paper, then laser-cut sheet, then plywood with printed hardware — is the correct order and it is cheap at every step before the last. A kirigami mechanism either works or does not work as a pattern, and you can find that out on card in an afternoon. The expensive materials come in only once the geometry is settled.
And the table reconfigures. The mechanism locks into each new position to make a relatively stable new shape — so it is not a single-transition flat-pack but a piece of furniture with multiple states.
Where this actually goes
Hackaday’s own framing is right that these mechanisms are “even if not immediately practical,” and the three applications it names are the real ones:
Robotics. A compliant mechanism that is one piece of material with no joints to wear or lubricate is attractive for soft and small-scale robotics, and the mechanical behaviour is designed into the cut pattern.
Flat-pack furniture. The current state of the art is panels plus a bag of cam locks. A sheet that becomes a table without fasteners is a different product.
Space. The application that drives most serious research in this area, because every gram and cubic millimetre counts — a structure that ships flat and deploys into a rigid shape is exactly what a spacecraft wants, and deployable solar arrays and antennae already use origami and kirigami patterns for this reason.
The through-line is that all three care about the same property: a large, rigid, functional object that was recently a flat sheet.