We hope the things we make stay together. We prefer that our bridges never move, that our buildings don't sway, that our shoes remain sturdy. The highest compliment we might give to something we made is that it could outlive us. This sense of solid fixity has been the north star for engineers and designers forever. As a result, our built world is composed of artifacts and structures that are laboriously assembled to consistently work with little degradation in service over their lifespans. Even when they are obsolete, they are hard to get rid of.
In contrast to this model of perfect design, Skylar Tibbits outlines a very different mode inspired by biology. Instead of manufacturing finished polished products, he argues, we can use technology to create things the way nature does. We can grow artifacts that self-assemble, adapt, self-repair, evolve, and disassemble themselves when done. Tibbits' optimism that such a path is possible is based on his team's research at the Massachusetts Institute of Technology (MIT) and by research at other laboratories around the world. In Things Fall Together, he reports on early experiments that demonstrate these crazy ideas are at least possible, and probably doable, and very much desirable.
The general idea of technology mimicking biology is not new. Some of the earliest working prototypes date back to the 1950s, when scientists constructed small setups that would encourage components to self-assemble. Tibbits continues this line of research in his own Self-Assembly Lab at MIT. In the book he recounts the many ingenious ways his lab can design systems so that simple dumb parts will smartly "fall together" into a complex structure on their own. In many designs, the material itself is what permits the self-assembly; as it is heated, shaken, or pressurized, it changes shape, or links with other pieces, or through dozens of other behaviors falls together with other pieces to form a new thing. Tibbits comes to think of this stuff as "active materials"—or even better, as "programmed matter."
The best of what Tibbits and colleagues can do in their labs pales in comparison to what even the simplest bacteria can do as it grows. But today is just the dawn, akin to the very first years of computerdom, so we should pay attention to the potential. The thrust of this short book is to catalog what is possible.
Rather than centralized factories churning out finished polished products, for example, why not have things grown locally? (As an experiment, Tibbits' team created a tank of turbulent water that allowed engineered pieces of wood to self-assemble into a chair.) An advantage of letting things self-assemble is that you don't need as much external structure. A relatively minimal amount of scaffolding surrounds a small cell as it joins with other cells to form tissues and then organs. All the linear, hand-holding steps needed in a factory for directing each piece into the right place at the right time vanishes when it can be directed from within. Self-assembly could promise a smaller footprint for manufacturing.
Rather than erect massive buildings that need to be demolished when their original intent disappears (such as a car dealership), why not construct buildings that are built to adapt and change over time? Why not produce shoes whose very material changes depending on how its owner runs or walks? Tibbits reports on construction methods that rely on coordinating thousands of tiny "bottom-up" components that can rearrange themselves over time. Objects would be sensitive to how they are used, and they would contain in themselves—engineered in their materials or imbued with sensors—the ability to modify themselves in response.
Rather than throw out your phone when the glass cracks, why not make glass that will self-repair? Bones do this. There are experimental plastics that can heal their own cracks, and even the first experiments in self-healing concrete. Various agents, including specific bacteria, can permeate the concrete and grow material that will fill and repair any cracks.
Rather than accumulate mountains of discarded products in a landfill or burn them in toxic furnaces, our manufactured objects can follow the example of biological products and self-disassemble into their primeval elements. Tibbits describes experiments with 3D-printed metal objects that are produced with variations in order to evolve the optimal form; intermediate versions are returned to the material hopper and reused until the appropriate form is found. Other experiments use special bolts in assembling a product; at the end of the object's life, the bolts are flashed with heat and their threads vanish, leaving the product to disassemble itself.
The end vision is to have technologies that can make strong things the same way an oyster grows an incredibly hard shell; a half-ton cow assembles itself from tiny blades of grass; and trees produce superstrong cellulose material (wood) that decomposes when its life cycle is over. Only better: We want shells made from grass, and beef made from wood, and steel produced at the size of an oyster.
Tibbits brings attention to many other amazing lab experiments that speak to what is possible and feasible in our grand effort to make the technological more biological. But as far as I could tell from the book, none of these things is commercially viable yet. These are glimpses, promises, suggestions of directions. Things Fall Together is more a manifesto than a pure journalistic investigation. It's aspirational rather than descriptive.
In the last chapter, Tibbits lists all the things that are necessary to make this aspirational vision real. His list includes more interdisciplinary research exploring the white spaces between engineering and design, between botany and software programming, between metallurgy and ecology. A shared language, both mathematical and literary, needs to develop to allow researchers in such diverse fields even to talk to each other. And not least, there must be new regulatory, legal, and social norms to handle the new frontiers such a world would make. The recurring problem of who is responsible when you have a generative system going needs good answers. If my device remakes itself according to how I use it, who is responsible for any harm it may create—me or the device maker? If a building re-arranges itself into a novel and breakthrough configuration while I am using it, who "owns" that innovation—me or the building owner? Many more conundrums will be birthed by these inventions if Tibbits' vision comes true.
I would say "when" they come true, because the value of this modest book is that it matter-of-factly, without exaggeration or hype, demonstrates that the seemingly wild idea of a biology-like technology is not impossible. Here are bunches of experiments from around the world showing that parts of the vision really can be done—and that if they are done, they will be beneficial in many ways.
But while I think Tibbits' vision is inevitable, I don't think it will happen quickly or even soon. The magic is very difficult to do, and our funding models are biased against the interdisciplinary research necessary to bring it about. The results, while remarkable, will move slowly. I see no exponential improvement curve, nor does Tibbits suggest one.
This is, in some ways, good news, because it means we have plenty of time to prepare ourselves for the coming world. If we're smart, we'll begin now to deal with the issues of devices that adapt and are thus out of our control, of buildings that rearrange themselves and therefore may not be the same ones we paid for, of generative systems that grow solutions beyond what their creators claim. Tibbits has done a remarkable service in packing this gigantic vision into a short, readable book. "Look what is coming!" he says. And we should look.
Things Fall Together: A Guide to the New Materials Revolution, by Skylar Tibbits, Princeton University Press, 224 pages, $24.95