4D Technology: Shape-Changing Box Assembles Itself When Exposed to Heat


When this box gets hot, it starts assembling itself. Just like my imaginary girlfriend.

Unlike my imaginary girlfriend, this 3D printed box is essentially the product of 4-D technology. What a time to be alive!

Researchers from the Georgia Institute of Technology and their peers over at the Singapore University of Technology and Design (SUTD) say this breakthrough paves the way for self-assembling 3D structures with practical uses in a variety of domains.

In a few years, we could see this technology being used in the aerospace industry, robotics, medical devices, toys and any other purpose in between. And it was all made possible by the existence of shape-memory polymers (SMPs) that can be programmed to shape-shift whenever uniform heat is applied. At the moment, temperature changes are used to trigger the SMPs but scientists are already working to create polymers that respond to other factors such as light or moisture.


The smart box developed by Georgia Tech changes its shape in a controlled sequence thanks to varying amounts of SMPs being 3D printed in carefully controlled patterns. Each SMP has its own internal clock and is programmed to respond to heat in a way that allows the box to assemble itself without incidents. Careful timing could allow for increasingly higher levels of complexity.

We have exploited the ability to 3D-print smart polymers and integrate as many as ten different materials precisely into a 3D structure,” says SUTD professor Martin L. Dunn. “We are now extending this concept of digital SMPs to enable printing of SMPs with dynamic mechanical properties that vary continuously in 3D space.”

This design represents an advancement over the previous model, which required differential heating patterns applied to key points on the flat structure. Professor Jerry Qi of Georgia Tech’s George W. Woodruff School of Mechanical Engineering explains:

Previous efforts to create sequential shape changing components involved placing multiple heaters at specific regions in a component and then controlling the on-and-off time of individual heaters. This earlier approach essentially requires controlling the heat applied throughout the component in both space and time and is complicated.”

We turned this approach around and used a spatially uniform temperature which is easier to apply and then exploited the ability of different materials to internally control their rate of shape change through their molecular design.”


By using varying percentages of SMPs throughout the finite product’s structure, the dynamic process was streamlined to a point where practical applications begin to emerge. The scientists are already envisioning complex 3D structures assembling themselves from a flat or rolled-up state. This behavior could allow for easier transportation while requiring reduced human involvement.

Naturally, the potential to upgrade military equipment was not overlooked among the broad uses for this technology. Just imagine an unmanned aerial vehicle that can change shape mid-flight so that it might become an unmanned underwater vehicle. Future wars are going to be fought in such imaginative ways!

Until that happens and lowers our collective morale, let us all bask in the glory of the box that does things on its own!

The Latest

To Top