If you’ve seen Interstellar (I haven’t yet, but my husband did on a plane recently and hasn’t stopped talking about it), you’re probably a bit confused about dimensions (not to mention the plot), what with wormholes and past/future and all… To add to your headache (or to give you one, if you haven’t been dwelling on such spatial issues), today I want to show you a freaky, totally freaky form of printing.
Not 2d printing.
Not 3d printing.
Yes, printing in four dimensions. Most of us are familiar already with the idea of 3d printing, many of us have even tried using one of the nifty contraptions available. So, how is 4d printing even possible, let alone conceivable?
It comes down to the definition of the 4th dimension. In this case, it’s time. How can you manifest time in printing? You have horizontal, vertical and depth change, and now also along the time spectrum. Your printed object changes with time.
The technical term is “embedded transformation”. A 3d printer extrudes a shape in plastic or rubber. When submitted to a “passive energy source” (energy from the environment, or inherent in materials, as opposed to “active energy” such as electricity that requires generation), the shape then acts like a wire-less robot, changing itself, folding, bending, twisting, until it becomes something else.
Self-assembly has been around for a while, and is also pretty amazing. Components autonomously find other components and join up to form a new form. Either on a molecular level or with larger objects such as balloons or construction pieces, the possibilities are quite staggering, but also complicated, and not yet efficient.
With 4d printing, it is the shape itself that transforms. That is the main breakthrough, with all the simplicity and efficiency that self-transformation implies.
MIT’s Self-Assembly Lab, together with printer-tech company Stratasys and software company AutoDesk, are leading the research on this type of 4d printing, but other labs and sectors are getting interested.
At the moment the passive energy source that has been used in the experiments is water. Water-based transformation is nothing new. Do you remember those little dinosaur figures that we had when we were little, that grew when you soaked them? With 4d printing, certain areas transform more than others on contact with water, resulting in the “movement” of the material. The beauty of the technology is that the 3d printer controls with precision where those areas are.
Water is what works now, but before long we will be printing shapes that transform on contact with a certain gas (such as oxygen), upon a change in the temperature, on movement, or as a reaction to gravity. It’s getting exciting.
The practical applications right now are limited, but knowing that it’s possible will open up new branches of science in architecture, engineering, design, medicine, aviation, defense, sport, you name it. Imagine that the tires on your car could “transform” according to weather conditions. Wood can be mashed up and reconstructed at a molecular level (yes, “printed”) with inlays programmed to bend or fold. Imagine shipping a bookcase flat and having it assemble itself at its destination. One of the most intriguing possibilities, and I say this as someone who has just finished reading “The Martian” (highly recommendable!), is the possibility of printing self-constructing structures in space.
So, these forms have embedded “knowledge”. We know that time is a dimension. Is knowledge, also? Calling knowledge a “dimension” could well ignite a stream of vigorous philosophical and semantical debate, and while it would be fun, it is beyond the scope of this humble blog. But I’m inclined to say, why not? As with the other dimensions we know about, knowledge has infinite scope and is impossible to define by boundaries. So it has dimension-like properties. And knowledge as a dimension definitely has a poetic ring to it. Which means that the technology being developed by the materials geniuses is not, actually, 4d at all. It’s 5d. 5d printing. If your head didn’t hurt before, I bet it does now.
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For more on 3d printing, check out my Flipboard magazine “3d printing”: