Wait a Second, Did You Say 4D Printing??

By now, most people are at least passingly familiar with the emerging technology of 3D printing. Additive manufacturing, as it is otherwise known, has been steadily developing and has now come into its own as a functional, competitive manufacturing technology.

Product design and manufacturing have been heavily influenced by 3D printing. But still, this is a relatively new technology that is only now starting to break out into the mainstream. But now here we are, already talking about the next big thing: 4D printing. The development of this new technology is poised to fundamentally shift the design paradigms.

What Is 4D Printing?

4D printing is not really a whole new class of thing. Rather, it is an impressive advancement in 3D printing technologies, applied with extraordinary cleverness. It’s 3D printing, but with an added dimension!The fourth dimension to which its name refers is time, or change.

They call it 4D printing because the object that is printed actually changes over time, unfolding into a larger shape or reacting somehow with the environment. That might not sound so impressive. But imagine using additive manufacturing to produce self-reconfiguring objects, things made from programmable materials that adapt themselves automatically, changing their shape like a robot or, if you can imagine it, almost like a living thing!

But these objects aren’t living, and they aren’t even really mechanical. But they are designed from smart materials that allow them to change their form without any assembly or manual intervention.

Right now, this technology is only in its infancy. But the design studio Nervous System is already selling 4D printed jewelry. While these are only the first baby steps in this exciting new field of design, there is a lot more coming up just around the corner. We’re talking about robot-like behavior without any robotics!

How 4D Printing Works

It might be better to think of 4D printing more as a clever way of applying 3D printing technologies, rather than as a specific technique in and of itself. 4D printing is the use of additive manufacturing to produce an object which, because of its inherent material properties, reconfigures itself into a new shape. This means that, like 3D printing, 4D printing is more of a concept than a specific technology. That is, there’s more than one way to go about it.

Unfoldable Designs

The Kinematic project by Nervous System demonstrates a simple but brilliant method for printing designs which then unfold into larger objects. This is four-dimensional in a pretty basic sense, in as much as the change over time amounts to the piece unfolding to take it’s ‘natural’ form. What’s inspired about this technique, though, is that it allows designers to create pieces that are bigger than their 3D printer would otherwise allow, potentially improving the efficiency of smaller printers and expanding design potential.

Kinematics works by applying generative algorithms to slice up the surface of a design into a network of interlocked triangles. Their software then digitally models the crumpling or folding of these interlocked triangles into a bundle, and from that bundle a printable STL file is developed. The object is then printed, with inner hinges connecting all the interlocked triangles, in it’s crumpled form. When removed from the printer, the object unfolds into its “natural” state.

What’s especially cool about this system is that it allows for any three-dimensional shape to be transformed into an articulated, flexible structure, which can be printed in its folded up form. While this technology is still very much in a conceptual stage, it’s not hard to see how it might be put to all manner of uses in the future. It could greatly expand the potential of consumer-grade 3D printers, for example, allowing for much larger objects to be printed using relatively small printers.

This technology could also be useful in construction and engineering. Maybe, someday soon, large structural parts will be printed in collapsed form using on-site printers, to be expanded on the spot. Or you could have shelters or bridges, ready to leap out fully-formed from a 3D printed block.

Water-Reactive Materials

While shapes that can be folded down are pretty cool, it doesn’t quite capture the programmable, self-assembling promise of 4D printing. Sure they change over time, but they aren’t quite changing themselves. At the forefront of more adaptable methods of 4D printing is a technique that creates objects that can dramatically alter their shape when exposed to water, all of their own accord.

This technique was developed through a collaboration between MIT’s Self-Assembly Lab and Stratasys. Using nothing but the ingenious design of the object’s material properties, they have designed strands that spell out MIT or fold into cubes, demonstrating the precision which can be reached with this still nascent technology.

The technology works by composing in a single print an object which has variegated material properties throughout. These differentiated areas respond differently when exposed to water, caused the form to contract or expand in programmable ways.

Other researchers have also gotten involved. Harvard researchers have unveiled a 4D printing project that uses a gelatinous ink containing miniature cellulose fibers laid out on precise arrangements. By varying the alignment of the cellulose fibers, they can control how the material will react when exposed to water, allowing for highly complex shape-changing behavior.

What’s especially intriguing about the Harvard team’s approach is that they take their inspiration for the process from the natural structures of plants and other natural substances. And this suggests a truly exciting possibility for this emerging technology: the capacity for inert, manufactured materials to mimic living tissue.

From pipes that can automatically respond to environmental changes, to structures that assemble themselves, to clothing that ‘knows’ when it’s raining and can adapt — it’s hard to know where exactly this technology will lead, but the possibilities are extraordinary. While research is still in the early stages, it probably won’t be long before we see 4D printed products in use in the real world.

It might not be too long before CAD designers have to start thinking four-dimensionally. In the meanwhile, Cad Crowd’s roster of top-tier CAD design freelancers are ready to help you with your three-dimensional projects! Check out examples of their work in the gallery, and get a free quote today.