Just when you thought a new era of disruption is upon us, another one comes rolling along right behind it. The latest disruption, 3D printing, is by some estimates predicted to have a greater impact on the world over the next 20 years than all of the innovations from the industrial revolution combined. Yet 4D printing is a further evolution of 3D printing and is set to completely alter how we create and produce materials by adding the dimension of transformation over time into the creation process.
3D printing currently is transforming the manufacturing of everything from shoes, cars, space stations parts, buildings and much more by allowing us to produce custom materials and products on location. The benefits of 3D printing are numerous, including rapid response, reduced lead times, rapid innovation, rapid manufacturing, reduced overhead, mass customization, mass production, use of unique materials and economies of scale, according to Deloitte.
The technology holds as much promise that some companies are looking to build entire cities from massive 3D printers. A 3D-printing crane dubbed the Minitank can layer up to 2,153 square feet of concrete per day for the construction of buildings, making it 50 percent faster than traditional construction methods.
Yet as 3D printing is now steadily changing the way we produce items, 4D printing is evolving right behind it. 4D printing is basically 3D printing objects that can self assemble and transform based on some external stimuli. So, 4D printing is similar to 3D printing, since it uses the same techniques of computer-programmed “printing” of layered materials to create a three-dimensional object. However, during the fabrication process of 4D printing, the printed produce reacts to external stimuli — heat, water, chemical, pressure, etc. — to self assemble or change.
For instance, imagine purchasing a table in a flat box at a furniture store. Once you arrive home, you simply open the box, touch a certain part of the table and it assembles itself. This has already been created by MIT’s Self-Assembly Lab and is consumer ready — although it is not yet for sale.
MIT’s Self-Assembly Lab is at the forefront of the 4D printing movement. The lab was created to see how researchers could 3D print an object without relying on sensors or chips. In order to make something “4D” — assemble itself, or change precisely under certain conditions — a precise geometric code is used based on the object’s angles and dimensions, as well as measurements that dictate how it should change shape when interacting with outside forces.
“Normally, we print things and we think they’re done,” said Skylar Tibbits, a research scientist at MIT. “That’s the final output and then we assemble them. But we want them to be able to transform and change shape over time. And we want them to assemble themselves.”
Tibbits sees numerous uses for 4D printing technology, including footwear that can adapt to particular sports: “If I start running,” he said, “[the sneakers] should adapt to being running shoes. If I play basketball, they adapt to support my ankles more. If I go on grass, they should grow cleats or become waterproof if it’s raining. It’s not like the shoe would understand that you’re playing basketball, of course, but it can tell what kind of energy or what type of forces are being applied by your foot. It could transform based on pressure. Or it could be moisture or temperature change.”
Numerous organizations are pouring money in 4D printing research and development, including Airbus SAS who is using 4D-related “smart” material that reacts to temperature to cool jet engines and a wing that morphs according to aerodynamic conditions to decrease air resistance. Briggs Automotive Company is developing a morphable wing for its supercar that can adjust to external weather conditions and automatically adjust itself to provide maximum downforce to the car. The
The U.S. Army Research Center is developing numerous applications including a soldiers uniform that can alter its camouflage or provide more effective protection against poisonous gases or shrapnel upon contact. Plus, the U.S. Army gave a grant to Harvard University, University of Pittsburgh and University of Illinois to explore ways the military could use self-assembling objects, including the possibility of shelters or bridges that assemble themselves
“That is what 4D printing is about, self assembly,” said Shane Wall, chief technology officer at Hewlett-Packard. “The ability to program a particular area of the material and be able to active it through heat, water, chemical reaction, pressure and many other external influences to actually do self assembly. Altogether these represent we believe will be the next industrial revolution and a fundamental transformation in manufacturing overall.”
Wall said 4D printing technology is not merely a novelty, but a necessity due to massive urbanization caused by world population growth that is expected to reach 8 billion people over the next 30 years. This will cause an increase in “megacities — or cities with populations over 10 million people — from 10 in 1990 to 41 over the next ten years. This massive urbanization will put incredible demand on manufacturing and the distribution of materials.
The 4D printing industry is expected to be worth upwards of $537 million by 2025 and grow by a
CAGR of 42.95 percent between 2019 and 2025. This is being driven by the need to reduce the costs of manufacturing and processing in the face of an increasing focus to ensure a sustainable environment.
“A 4D printed product would incur lesser manufacturing, transportation, and handling costs, which, in turn, would lead to the saving of resources and efforts, thereby sustaining the environment,” according to a report by Grandview Research.
The primary materials segments used for 4D printing are programmable carbon fiber, programmable wood grain, and programmable textiles, with the programmable carbon fiber segment expected to be the largest segment in the overall 4D printing market, according the Grandview Research.
Since programmable carbon fiber has high stiffness, low weight, and tensile strength, it can be beneficial for many industrial applications, says Grandview Research. It can be autonomously transformed by printing active material on flexible carbon fiber using heat as an activator and it doesn’t require complex electronics, actuators, or sensors.
4D Printing to Save Lives
The healthcare industry is set to take advantage of 4D printing since 4D printed products will be responsive to body needs once ejected in the human body. This could be used for tissue engineering, self-assembling human-scale biomaterials, design of nanoparticles, and nanorobots for chemotherapy. A Frost & Sullivan report finds that 4D printing is still in its infancy and not yet ready for widespread use, yet the potential for the technology in the medical field is big.
“The potential of this technology to create programmable biological materials that can change shape and properties can be a foundation for enabling smart pharmacology, personalized medicine, and programmable cells and tissues that could be employed in precisely targeted treatments for a number of diseases,” the report notes.
A researcher at the University of Michigan developed a 3D printed splint that can hold open airways of newborn children for two to three years, than absorb into the body. The device was successfully implanted in four babies. Medical researchers are also looking into using 4D biomaterials to help adults correct skeletal applications like facial reconstruction or rebuilding ears.
4D in Construction and Building
DARPA’s Engineered Living Materials (ELM) program are currently looking at 4D technology to develop “living biomaterials” that combine the structural properties of traditional building materials with the ability to rapidly grow, self-repair, and adapt to the environment.
The DARPA ELM website states: “ELM specifically aims to develop design tools and methods that enable the engineering of structural features into cellular systems that function as living materials, thereby opening up a new design space for building technology. The program aims to validate these new methods through the production of living materials that can reproduce, self-organize, and self-heal.”
Researchers are now looking at numerous futuristic concepts for construction and building including chimneys that self-repair, roofs capable of manipulating and controlling airflow and driveways that can absorb oil stains.
While 3D printing technology is set to transform and disrupt entire industries including consumer products, healthcare, automotive, construction and aerospace, 4D printing will accelerate right along with it. Imagine a world of materials that adapt to their environments, assemble themselves, and are basically “smart” enough to adjust to the world around it. That world will soon be here.
Chandler Harris 