A select number of researchers are already looking to add yet another dimension to the technology: time.

4D printing creates moveable and shape variable objects such as flat components that can be folded into three-dimensional objects at a later point, or even objects that can change their shape as a function of external influences.

3D printed tetrahedron
This is a tetrahedron. (Credit: ETH Zurich / Tian Chen)

The Engineering Design and Computing Lab at ETH Zurich has taken this approach one step further by developing a construction principle that allows them to control the deformation. The flat structures they6 produce do not change their configuration randomly, but rather exactly in the way they design them. The structures can also support weight. The ETH scientists are the first to create these kinds of load-bearing 4D printed objects.

The scientists printed their structures with a professional multi-material 3D printer, which can print objects from up to 40 different materials. The objects created by the ETH scientists comprise two of them: a rigid polymer that makes up most of the structure and an elastic polymer for the moving parts. The researchers print all parts in a single step.

Printing a flat initial form with rigid and elastic sections in a single step is highly efficient. Plus, the flat structure saves space in transport and can then be deployed at the final destination. Similar approaches have been used in aerospace for quite some time now.

Aerospace is thus one possible application for 4D printing. But the scientists are also considering the simple construction of ventilation systems, systems for opening and closing valves or medical applications, such as stents.

>> Read more by ETH Zurich at Science Daily, May 8, 2017

Fabrication technology in the fourth dimension