For much of this millennium, 3D printing has been the darling of the micro-manufacturing world. Rapid advances in the industry have taken it from a one-off curiosity into a thriving industry.
Three-dimensional printing is the process of manufacturing physical objects from digital files and has revolutionized industries such as creating low-cost prostheses for children, rapid prototyping and even allowed astronauts to print a usable wrench on the International Space Station.
But, the progress doesn’t stop there. Researchers at Harvard recently unveiled their latest advances in 4D printing that they feel with create even more opportunities.
With 4D printing, the fourth dimension refers to time. Simply stated, objects that are printed with a 4D printer can change their shape over time.
Using their new technique, objects can be drawn onto a flat surface using a special gel, then expand into a three-dimensional shape when submerged in water. The gel resembles a plant structure, and contains tiny fibers of cellulose. the substance that provides the plant with much of its structure. Depending on how these fibers are aligned, the object will shift and swell when placed in water.
The Harvard team, led by Jennifer Lewis at the university’s Wyss Institute, was inspired by the way plants change their shape in response to outside stimuli like sunlight, temperature, or humidity.
This is not the first 4D printer to be demonstrated: MIT professor Skylar Tibbits first started speaking about it at a TED conference in 2013. Tibbits’s process required two materials, one soft and one hard, while the Harvard team’s uses just one.
This process also allows the team to create a wide variety of objects: one, two or three dimensional objects that can all change their shape.
In the case of 3D objects, a 4D printed organ could be designed to grow and change with the host person’s body – although researched readily admit that this kind of technology is a long way off yet. A 2D object could fold itself into a wide variety of 3D shapes. A single dimensional object, similar to a string, could also be designed to be folded into almost any 3 dimensional shape.
While it is not clear exactly what problems 4D printing will be capable of solving, the hope is that it will add to the still growing technology of 3D printing. After all, the human body is in a very real sense, 4D printed. Our bodies are printed in two dimensional from the DNA in each cell of our bodies. This 2D printed strand then folds into complex proteins that eventually form every cell, every tissue and every organ of our bodies.
Keeping this in mind, the potential structures that 4D printing will be able to create truly are limitless!