Creating Objects That Build Themselves
What if, in the future, a chair could morph its shape to fit your own unique body so it is truly comfortable? National Geographic Emerging Explorer Skylar Tibbits just might be able to make this a reality. As the director of the Self-Assembly Lab at MIT, Tibbits is taking 3-D printing to a whole new level by adding a fourth dimension, the element of time. Through 4-D printing, Tibbits is developing ways to program materials so they can build themselves or change shape over time, which will allow us to reinvent products and construction in the future.
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Transcript
Skylar Tibbits: We focus on designing physical components that can build themselves. The other category of research we look at is how to program physical materials to change shape and property on demand. We want to print things that transform and evolve over time. We believe that today we program computers and machines and tomorrow we'll program matter itself.
So, we all know that we've had the software revolution we're in the midst of a hardware revolution and I would argue that the next is a materials revolution. I have a background in architecture, which is quite a strange place to say that from. We were building experimental installations in galleries all over the place. We were using some of the most sophisticated software tools that allowed us to produce geometry we couldn't have produced before. We were writing our own code. Code was becoming a new language for design. We could design things we couldn't have imagined before. We were also using new sophisticated fabrication tools. But the truth is the way that we put this stuff together was human labor. We were forcing this stuff together. Lots of people, lots of energy lots of time, bolts, rivets blood, sweat and tears, to make this stuff.
So then I went to MIT I started to study computer science and design computation. I started a research lab called The Self Assembly Lab. And we focus on designing physical components that can build themselves. We look at how to program these components to change shape, change property adapt to their use, adapt to their environment. And we're specifically interested in construction, manufacturing, product assembly distribution how we use products, how we interact with our environment. We're interested in fundamental components that can come together in different ways completely on their own in order to produce highly functional and drastically different things. So, we studied a system or a process called self-assembly as the name suggests, of the lab. And this is a process where you have individual components those components come together on their own without humans or machines. That sounds quite radical, but biology, chemistry, physics from the smallest of scales to the largest of scales there is no top down construction. It's through bottom up interaction.
So one of the most clear examples of this is a project we did with molecular biologist, Arthur Olson. You shake this flask hard and all the components break. And you shake it a little bit softer, still randomly and the components come back together. This is showing that random energy can produce non-random results. That there are no experts in this system. You're just as good if you're blindfolded. You don't have to have the blueprints. You don't actually have to know what you're doing. The blueprints are in the materials themselves. And we're trying to propose that we can use this at large scales. But in that last example every component was the same. And it makes the same thing over and over again. What if we could build all of the different things that we interact with? What if we could build complex, arbitrary things? In this case every component is different it has to find exactly the right place in the global structure in order to make this chair. And the chair is interesting because it's a differentiated structure. It's not symmetric in all axes, every component is unique and it has to find exactly the right place in order to build this arbitrary yet unique structure.
We're interested in scaling up. So, scaling up either means lots and lots, or big. And in this project we went big. So we look at 36-inch diameter weather balloons in trying to propose macro-scale self-assembly. So, this project proposes that you can have self-assembly at very large scales and that you could potentially construct things in the airspace above the ground. This is interesting for construction scenarios where it's hard to get to, it's dangerous there is extreme environments it's hard to get people or machines or where it's difficult to build things in space, under water, etc... that we could potentially deposit materials and they could come together to build highly functional things. In this case it's a ten-by-ten-by-ten space frame. When the helium dies you're left with a large rigid structure.
The other category of research we look at is much more applied. We consider this our programmable materials. How to program physical materials to change shape and property on demand. On the top left is our materials and geometry. That's the obvious stuff. Everything we know in the physical world is made out of materials and geometry. Each one of those though responds to different types of energy. If you have moisture, you might want to use wood. If you have metal, you might want to use heat to activate it. And the way that we design the geometry and how those materials come together creates mechanical transformation and allows us to control how it folds, curls, bends or twists. One of the most clear examples of this is a project we did a number of years ago called 4D Printing. We want to print things that transform and evolve over time. So, the way that we do that is we multi-material print. One of the materials is a rigid plastic. This rigid plastic is the structure, the backbone the joints, the precision. I consider it the Braille. It's the geometric information that encodes what this thing is gonna do. The other material is an expanding polymer. It expands a 150 percent when it meets moisture. And that gives you the information and the energy to go from one shape to another. We developed all sorts of prototypes that go from single strands that fold into 3D objects. Strands that fold into really nice letters, MIT. Surfaces that fold into polyhedra flat sheets that fold into double curvature for clothing and apparel. Aviation, building components, there's lots of industries where you have flat rigid sheets and you need to force them into place. Our materials transform themselves into place. But one main question came up. Lots of companies came to us, lots of collaborators and they said, “How do we program every material? Tell me how to program materials I use.” So we started to create a wider body of materials that we call programmable materials. And we've released three materials so far.
The first one is programmable carbon fiber, textiles, and wood. With wood there's a long history of using wood as an active building material. From Japanese joinery that would use moisture to make more precise tight joints to contemporary examples. But there's two main problems. One of the problems is that there's a lot of energy that goes into forcing plywood to form into arbitrary shapes. You have to force it and steam it and have molds. The other is that you are constrained by the grain direction that you can find in the forest. So, we print wood, we actually deposit wood we chop it up into a pulp with sawdust and adhesive or plastics we're able to print different grain directions. Two-dimensional patterns, three-dimensional patterns that allow it to fold, curl, twist and go from any one arbitrary shape into any other arbitrary shape.
With textiles the way that we do it is pre-stretching. So, we pre-stretch this textile depending on the amount of force the direction of the force, the behavior of the textile you can embed different patterns of energy. And then we laminate, bond, print, knit we add a constraint. So, a geometric constraint now embedded in that textile that encodes the geometric information to transform. So, when we simply cut the textile out it then jumps into shape, into a pre-determined shape based solely on the stretch and the constraint material.
With carbon fiber, we work with a company, Carbotex who make flexible carbon fiber. It's the first fully cured flexible so it's super light and strong but can flex and we print active materials on top of that. Those materials are heat active, in this case. We can make heat active, light active moisture active, and we're able to control how it transforms. It's almost instantaneous, it's very repeatable. We can go to any arbitrary angle we can get it to fold, curl, twist etc... There's one interesting example that I'll point out. We're working with Airbus on a component for their plane. So, the top of their jet engine has this air inlet, and as air flows over the engine, it then cools the engine and it's very important for cooling the engine. But the problem is it causes drag which reduces efficiency in the plane. So, they would normally create a mechanical flap just like on the wings, but that mechanical flap is heavy it adds components and it fails. So, we've started to develop a single sheet of carbon fiber that can autonomously open and close to activate and control the airflow in that engine. We're using heat, in this case, and now we've developed some that are wind tunnel tested in Toulouse that are using pressure differential. As the plane speeds up, the pressure differential builds and it can jump into a second state. So, no external control, super light and strong and can autonomously control the airflow.
So, where do we think all of these materials are going? These crazy construction scenarios and programmable materials. We think it reinvents the product lifecycle. It allows us to create what we call the programmable product lifecycle to reinvent construction and products themselves. And that starts with new materials. And it's not just that we have to invent new materials. We look at it as macro scale material science that would create new materials from existing materials by combining them in new ways. By rethinking those material properties to allow them to transform and have radical behaviors that they never had before. But it also means that they are abundantly available. Cheap and accessible and we can just give them a new life to have new behavior. It allows us to have new construction processes either where it's difficult to build today it's expensive to build or potentially far more efficient construction processes where the components can come together on their own or help us build better structures. And in terms of products, we can now rethink products or have products we haven't thought about before. Products that respond to how I'm, uh, what I'm doing. How I need that product to change. How the environment changes. Every chair in here doesn't care if you sit there or I sit there. My shoes don't care if I start running or walking doesn't care if I'm sweating or the environment is changing outside. So, we want highly active intelligent products that can respond to us. And probably most important is that we want our products to be able to self-disassemble for recyclability. Separate all the different materials and allow us to recycle these products in better ways. So, we believe that today we program computers and machines and tomorrow we'll program matter itself. Thank you.