Molecular self-assembly, whereby molecules position themselves into defined arrangements, is commonplace in biological systems and nanotechnology. But researchers at MIT are working on so called "4D printing" technology that aims to bring the process up to the macro scale, enabling 3D-printed materials to be programmed to self-assemble into predefined shapes and structures. Just imagine buying some flat-pack furniture, bringing it home and enjoying a coffee whilst you watch it assemble itself.

This month, Skylar Tibbits, director of the MIT Self-Assembly lab, was named as one of the six Architectural League winners for collaborative research into programmable materials. The 4D printing process (with the 4th dimension being self-assembly over time) involves the use of materials that change their shape in response to movement or environmental factors, such as the presence of water, air, and/or temperature changes.

The technology has the potential to change the face of construction and manufacturing and could make it easier to build in extreme environments (including space or other planets) where construction is dangerous or expensive.

Tibbits demonstrates the process in this TED talk, where a self-folding strand that is 3D printed using a "smart" material developed by Stratasys folds into the MIT logo when placed in water, while another object folds into a cube. These are thought to be the first times that a program of transformation has been embedded directly into a material itself.

A 3D-printed self-folding strand of “smart” material developed by Stratasys that subsequently folds into the MIT logo when placed in water (Image: Skylar Tibbits)

Tibbits confirms that to apply 4D printing at the macro scale, you would need to combine the right materials and geometry with a tightly coupled energy source, while designing the material interactions that allow it to transform. For the design process, the Self-Assembly Lab team use new Autodesk software called Project Cyborg, which allows them to simulate how and when the various components fold at both a nano and macro scale.

According to Tibbits, as well as providing the ability to embed shape-changing programming into non-electronic materials, the technology could also usher in materials that could perform computing functions at a nano scale.

The Self-Assembly Lab believes the technology has the potential to revolutionize a wide variety of fields, including "biology, material science, software, robotics, manufacturing, transportation, infrastructure, construction, the arts, and even space exploration."

Collaborators on the project include Shelly Linor & Daniel Dikovsky, Education & Research & Development, Stratasys and Carlos Olguin, Bio/Nano Programmable Matter Research Group, Autodesk.

Source: Self Assembly Lab, SJET, The Architectural League New York