As 3-D printing, also known as additive manufacturing, picks up steam in industrial manufacturing and spurs the public imagination, scientists say the next frontier is 4-D printing: materials that fabricate themselves.
3-D printing is now an established, popular manufacturing technique used to create rapid prototypes and production components with reduced lead times and costs. 3-D printing can be performed by desktop printers operating in the plastic medium or by larger industrial-strength devices that can make steel and stainless steel components.
Although 3-D printing has been around for years and still has an exciting and dynamic future, it remains relatively misunderstood by the general public, which often overestimates its current capabilities. 3-D printing is already making an impact in various industrial markets, in the production of automobiles, aerospace vehicles, and other sectors. While it can work in many applications, 3-D printing is not yet robust enough for large-scale manufacturing or meeting the majority of end-user needs.
But scientists are already looking into 4-D printing.
Scientist, architect, and designer Skylar Tibbits has been working for years on cross-disciplinary methods of introducing “self-assembling” materials to create products that can use various energy sources to build themselves. His mission is to “embed smartness” in materials so they can form structures and components without relying on outside manufacturing processes.
At a recent TED conference in Los Angeles, Tibbits showcased some of the work from MIT’s Self-Assembly Lab. Tibbits and his team, supported by software from Autodesk and a specialized 3-D printer supplied by Stratasys, have developed a layered material that is composed of one part standard plastic and one part 3-D printed water-absorbent material. The water-absorbent material uses water as an energy source to activate its motion. Once the material begins absorbing water, it changes shape, bending the plastic attached to it and creating a new structure.
“The rigid material becomes a structure and the other layer is the force that can start bending and twisting it,” Tibbits explained to the TED audience. “Essentially the printing is nothing new, it is about what happens after.”
Tibbits went on to explain possible applications for this type of “smart” material, noting that it could be used to create parts that need to change shape due to environmental pressures, such as water pipes or construction supplies. Additionally, one of the team members described the possibilities of consumer furniture that builds itself.
“Imagine a scenario where you go to Ikea and buy a chair, put it in your room and it self-assembles,” Carlo Olguin, Autodesk principal research scientist, explained.
3-D printing has been mentioned as a lightweight construction technique to send into space to help astronauts with replacement material in long-term living quarters, or even to help build space stations. 4-D printing could bypass the energy required to operate a 3-D printer and construct a Mars base to be ready by the time astronauts arrived on the planet.
Currently, Tibbits and his team can only print thin strands, as you can see in the video above, but they hope to find a manufacturing partner to explore broader applications and scale up the production techniques. The team is also investigating the possibility of using different energy sources, such as heat, vibration, sound, gravity, and pneumatics, to drive the process.
The Self-Assembly Lab claims that it has identified the key ingredients for 4-D printing “as a simple set of responsive building blocks, energy, and interactions that can be designed within nearly every material and machining process available.” Its stated goal is to explore processes outside of 4-D printing to conceive more efficient and cost-effective methods of applying self-assembly to other industrial and consumer products.