What if things could be made to have a kind of memory, allowing it to transform, assemble or replicate itself? While 3D printed products now becoming mainstream, recent developments at MIT are poised to change the face of production and manufacturing further with what they are calling 4D printing, where materials are “programmed” to change shape, assemble or even repair themselves, adapting to various functions, over time.
The extra d in 4D printing stands for “dynamic,” to reflect this extra factor of time. 4D printing involves multi-material objects that are 3D printed, but the different, stratified materials are integrated so that when changes in temperature, pressure or energy occur, the cellular or geometric transformation of these various materials are responsively differentiated, making new forms and properties possible. While these kinds of environmental interactions are already being engineered at much smaller scales with nanotechnology, scaling it up for industrial applications will be a challenge.
‘Robots without robots’
But it’s a challenge that the some of the best and brightest are already tackling. As architect and research director Skylar Tibbits of MIT’s Self-Assembly Lab explains on FastCo.Design, 4D printing is essentially about creating objects that can transform and work without motors, wires or a power source:
What we’re really trying to make is robots without robots. We want to design materials that can transform themselves when exposed to energy, but which don’t necessarily require circuit boards, electronics, or other moving parts to operate.
Tibbits’ foray onto the cutting edge of this new technology was compelled by his earlier work with design installations consisting of thousands of components, many of which were painstakingly assembled by hand — the very opposite of self-assembly. His interest in biological systems and self-organization has also played a huge part informing this current research into programmable materials.
So how is a material ‘programmed’? Most of us are familiar with the additive process of 3D printing, where material is added, layer upon layer, to create the desired product. The fourth dimension in this experimental manufacturing process is inserted via a customized “code” that is embedded into the 3D printed material. These predefined instructions are dependent upon the object’s constructed geometry, and would also predictably dictate the direction, the iterations and the angles of its transformation, and is activated only when certain environmental conditions change.
There are some potential advantages to 4D printing: programmable materials are less complex and less likely to fail compared to moving components like sensors and other electronics, says Tibbits. They also weigh less, giving 4D printed materials an edge for applications in areas like transportation, aerospace or aviation. The Self Assembly Lab, in collaboration with companies like Stratasys, Airbus and Carbitex are already testing various materials like carbon fiber, rubber, fabrics, and wood for their ability to be programmed and 4D printed, using Autodesk’s cloud-based computation and simulation platform called Project Cyborg.
Transformer shoes, tires & clothing
The implications of 4D printing would be enormous: it would mean products could be designed to shapeshift of their own accord, depending on the situation. Shoes, tires and clothing could be made to respond to weather conditions, changing their surface grip or their permeability; furniture could be made to self-assemble and cars to self-modify their aerodynamic components, thus increasing their speed. Materials like wood, which usually needs a lot of time and energy if it is to be bent or molded into unconventional shapes, could instead become a 4D printed composite with a particular grain pattern that controls its self-deformation into a desired shape.
To see some of these transforming materials in action, take a look at some of Self Assembly Lab’s demo videos on programmed carbon fibers and wood, and watch Tibbits give a view on the bigger picture of 4D printing in the TED video below:
Materials that transform on their own is something that may be hard to imagine, but is tantalizingly possible, says Tibbits: “We are looking at the ability to programme physical and biological materials to change shape, change properties and even compute outside of silicon-based matter.” As digital fabrication and the creative commons begins to democratize design, production and dissemination, 4D printing points to a even more distant future where things could potentially be programmed to have a ‘life’ of their own.
Images courtesy of MIT Self Assembly Lab