Smart Memory Materials That Self-Assemble Turn 3D into 4D Printing. The concept of 4D printing, a term coined by Skylar Tibbits in his 2013 Ted Talk, was developed to create materials that could be manufactured or assembled in one configuration and then alter themselves by self-assembling into a second programmable configuration. The transformation could be controlled using smart materials that alter themselves based on a pre-set series of movements that would be entirely programmable. We have already seen simple 4D objects transform themselves, but until now more complex self-assembly required multiple types of stimulus that would need to be applied at specific intervals.
However a group of researchers at the Georgia Institute of Technology and the Singapore University of Technology and Design developed a new 4D process that demonstrated the ability to create complex self-folding structures that would only need a single type of stimulus. The 4D capable components were made by combining several smart shape-memory materials that each have slightly different responses to heat. The materials were combined in such a way that when exposed to a single source of heat the material would move in precise and timed actions that allowed three-dimensional structures to self assemble without the various parts colliding.