what is 4D printing?

Do you remember making paper boats during your childhood? Not just boats, the same paper turned into rockets or planes and always hit the wrong person's head in the classroom . It was always a fun and exciting process of converting a 2D source(paper) to a 3D structure(boat). Now imagine, what if you could discover a paper that turns itself to a boat when it is raining or a plane when it is windy, and again recovers back to a paper. Sounds crazy and impossible right?
But don't be surprised to know that 4D printing is all about this!
That was just a basic introduction to the concept , let's discuss more about this tech in today's blog.

What is 4D printing ?

3D -----to---- 4D.

The fourth dimension that we are talking about here is “ time”. In simple words it is the ability of a 3d printed component to change its shape over time. It is all a game of high level material science.

The process starts very much similar to a 3D printing process, except that the material is also programmable. Likewise ,we export the CAD model as a .stl file and slice it. But here the generated G-code is not just instructions for the 3d printer, it's for the material as well. The code carries additional instructions on how the material will move or change its shape over time.

But how is that instruction executed?

 We need an external catalyst to trigger this process. Remember the boat example in the introduction? Here wind and rain can be considered as the stimulants. The commonly used stimuli based on which many researchers are working include triggers like water, heat, light and electric current.

Material selection is as important as stimuli selection, because the material should be programmable and be able to respond as expected to the generated stimuli. These programmable materials should follow both “geometric code” while being printed and the “genetic code” for the transformation.
While few are working on simplistic convertible designs , many researchers are focusing on developing this programmable shapeshifting composites. With many more years of research, experimenting and testing ahead we can expect more amazing inventions based on this technology. It could be adaptive medical implants, self assembling furniture , soft robots , self assembling buildings and what not ?

Although it might take many more years of research and work for 4D printing to evolve as a mainstream technology, this technology truly has its own potential to become the next disruptive tech in manufacturing when it overcomes the current challenges in inaccurate actuation, inability to control intermediate stages of deformation and difficulty of material availability.