4D printing turns materials into smart self-assembling objects

3D printing has the potential to revolutionize manufacturing. One of the greatest advantages lies in the fact that almost any shape can be printed and product designers can really focus on functionality rather than on shapes that current mainstream production methods allow. An innovative process like that almost automatically entices researchers to ask: What if?

Skylar Tibitt, researcher at the Self Assembly Lab at MIT, is no exception. “What if we could add another dimension”, he pondered and started experimenting. Turning 3D into 4D printing means adding the dimension of time. The 3D printed object changes its shape over time after being exposed to a physical impulse, also described as passive energy, such as humidity, sound waves, and higher or lower temperatures.

Currently, Tibbit is working on a method for programming materials like hybrid plastics, wood grains, textiles and carbon fibers. The programming will “teach” these materials to adjust their shapes and properties when certain conditions in the environment change. The 3D printed parts thus behave like little robots, folding, curling, stretching or twisting, without a programmed chip or engine and an outside energy source.

When adding a 4^th factor, product functionalities become almost unlimited. One example Skylar Tibbit likes to give is that of water pipes changing shape in intermittent intervals and thus moving the water forward. Medical devices are another area where 4D printing could bring rapid progress. According to an article in the German newspaper “Die Welt”, researchers at the laser center in Hannover, Germany, are developing cochlear implants that adapt exactly to the shape of the inner ear of the person wearing it after surgery.

Car tires made of rubber that changes its flexibility, firmness and grip when exposed to rain or ice are another area where researchers see instant possibilities for 4D printing. Tibbit also envisions shoes that change their properties when runners steps onto grass, asphalt or ice. The shoes could become more or less insulated when temperatures change and waterproof when it rains or snows.

Simply put: 4D printing is a way to make things not only more functional but smarter.  It is also a process that has the potential to reduce labor costs in production – the products are unspecific and can be mass produced in 3D printers and only develop their special functions when they are exposed to the environment.

Market researchers at Frost & Sullivan predict that biomaterials, nanotechnology and medical devices are the areas that are most likely to rapidly adopt 4D printing. Other industries are the automotive, the aerospace and defense industry; these industries are also early adopters of 3D printing.

Printing and software companies also took notice. Tibbits is currently working with Stratasys and Autodesk to further develop his ideas and designs and to develop products that are fit for use in actual industrial production. It may be a few years before we see the first self-repairing, smart material in cars or airplanes but watching Tibbits talk about self-assembling skyscrapers at the TED conference certainly makes you think differently about the future of manufacturing.