Just When You Thought 3D Printing Was the Coolest Thing Ever ... Along Comes 4D

We've been hearing a lot about 3D printing and all the cool things you can make with this technology. But now, people are starting to talk about 4D printing. What on Earth is that? The following is a brief overview of what you need to know when it comes to this next step in printing technology.

What is 4D printing?

via Pixabay.com

The concept of 4D printing is based on the principles of 3D except you add the element of time and its effect on the material used. For example, by combining or coding printing material with different properties, scientists can create a 3D-printed object that will expand or move into a specified shape over time with the help of a trigger such as heat or humidity.

Why should we care?

via www.selfassemblylab.net/ActiveShoes.php

Well, for one thing, there are several useful applications for this technology that research labs are exploring. Here are just a few examples that explain why this topic is trending:

• Footwear. Scientists are exploring ways to make athletic shoes adaptable to the activity of the wearer. For example, if the wearer is running, the soles of the shoe will change to provide more cushioning.
• Biomedical splints. These splints are inserted into patients to allow the body to heal over time. If the splints are created using 4D technology, the splints can adjust itself as the body changes. There's no need to perform invasive surgery to replace these splints.
• Human Tissue. Researchers have discovered a material that produces a reaction, similar to what's found in nature, when exposed to a trigger such as water and light. This discovery could be used to create molecules that may help to heal human tissue one day.

Who or what is leading the way?

via www.selfassemblylab.net/laboratory_team.php

• Skylar Tibbits is a pioneer in this technology and the founder of the Self-Assembly Lab at MIT. According to the mission statement on their website, the Self-Assembly Lab is a "cross-disciplinary research lab at MIT inventing self-assembly and programmable material technologies aimed at reimagining construction, manufacturing, product assembly and performance."
• Tibbits works in collaboration with a company called Stratasys which is one of the top companies in the world for 3D printing. They produce rapid prototyping models using multi-material technology that allows researchers to incorporate characteristics from various materials into each printed particle--a key component in 4D printing.
• Jennifer Lewis is a professor at Harvard University’s Wyss Institute for Biologically Inspired Engineering. Her team created a process that involves printing with hydrogel ink which creates objects that move in a similar way to real plants when immersed in water. This breakthrough could be applied to areas such as smart textiles and tissue engineering. 

Want to learn more?

There are several excellent sources of information for anyone wishing to learn more about this exciting new technology.

• One of the earliest articles I found was on Smithsonian.com. Published in 2014, the article, "Forget the 3D Printer: 4D Printing Could Change Everything," briefly describes the history of this technology, what the science behind it is, and its future applications in a clear, non-academic way.
• New Scientist posted an interesting article back in April of this year called, "4D Printing Makes Objects That Assemble Themselves When Heated." It describes new research from Singapore University of Technology and Design that uses material that is much faster at forming rigid structures in 4D printing. Normally, the process takes multiple steps or uses hydrogels which are very soft. But with this new technique, there are more applications for this technology such as self-assembling flat-packed furniture and pill capsules that can bend or break once the body reaches a certain temperature.
• And finally, there is a great 2013 TED Talk done by Skylar Tibbits. In it, he talks about what 4D printing is and what its applications are. He also shows videos demonstrating the process and what it means for our future.