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3D printing may be set to change the world by letting us make all sorts of bespoke objects, but there鈥檚 one little problem: the printers can only print items smaller than themselves. Until now, that is.

at the Massachusetts Institute of Technology鈥檚 Self-Assembly Lab and colleague have come up with a way for standard 3D printers to print out large-scale objects. 鈥淚t鈥檚 challenging the notion that we always need a machine that鈥檚 bigger than the thing it鈥檚 printing,鈥� says Tibbits.

The approach, called Hyperform, converts the object to be printed into a single long chain made from interlocking links. An algorithm works out how that chain can be packed together into the smallest cube possible using a Hilbert curve 鈥� a fractal-based pattern that is the most efficient way of squeezing a single line into a small as space as possible. The resulting cube is small enough to be printed inside a standard printer.

Hand assembly

Once this cube is printed, the chain can be unravelled and assembled by hand to create the desired object. That鈥檚 possible because each link in the chain has notches that allow it to bend only in a certain way. 鈥淵ou have to fold it by hand and click it into place,鈥� says Tibbits. Hyperform won the technology festival in Linz, Austria, earlier this month.

But printing cubes made of such densely packed chains was too much for most of the consumer printers that Tibbits and his team tried. 鈥淲e blew a lot of printers at first,鈥� he says. So they teamed up with who, after a successful Kickstarter crowdfunding campaign, have just started shipping their Form 1 3D printer.

The Form 1 is capable of much higher resolution than standard consumer 3D printers. Instead of printing out layer upon layer of plastic, it uses stereolithography, in which a pool of liquid plastic is added to the base of the printer and a laser traces out the pattern required, causing the liquid plastic to cure and solidify. The technique can form layers just 25 microns thick, with details as small as 300 microns.

Hyperform has so far been used to create large structures such as a chandelier, and Tibbits sees it as being perfect for producing large 3D-printed consumer products. But the Form 1 printer uses resins which have limitations in terms of strength. 鈥淭here is a range of things that are largish that we can do right away,鈥� says Tibbits. 鈥淏ut if you want to make large-scale furniture or buildings, there needs to be an approach to make them stronger.鈥�

4D printing

Manually clicking each link into place isn鈥檛 ideal either. That鈥檚 where Tibbits鈥� other work in so-called 4D printing might help. 4D printing uses materials that are 3D-printed to produce an intermediate object which, when exposed to water, will bend and twist itself into the final structure. 鈥淵ou can see how Hyperform and 4D printing are pointing towards each other,鈥� he says.

Cl茅ment Moreau, CEO of French 3D printing firm , says projects like Hyperform are shaping the future of 3D printing. 鈥淭his is yet another example of how 3D printing is more of a flexible manufacturing process than injection moulding because it constantly opens up new possibilities in terms of materials used and shapes which can be printed.鈥�