4D Printing: aka 3D Printing Self Evolving Structures
4D Printing adds the dimension of time to 3D Printing. Instead of printing stable and static objects, with multi-material printing we are starting to manufacture soft and active objects that can react to their environment. In our post on Synthetic Biology for Architects we talk about the potential of growing a house from a seed. In this post we'll talk about some of the steps being taken by the Autodesk Research Programmable Matter team to get there.
Other than growing a house, why else might you want a 3D printed object to change over time?
Soft robotics and bio-inspired robotics are one popular reason. These soft machines inspired by nature are particularly interesting to medical science at smaller scales that can be applied within a body. Another reason might be that the object being manufactured is larger than the printer but it can be folded up.
With this research we are using the Nucleus Physics solver to help simulate the behaviour of the objects - they can bend and stretch.
The objects are composed of bars and disks. The disks in the center act as stoppers. By adjusting the distances between the stoppers it is possible to set the final folding angle.
The magic of this process is the combination of two materials at printing time. We use a rigid plastic base and a material that expands upon exposure to water. The expanding material is a UV curable polymer that when exposed to water absorbs and creates a hydrogel with up to 200% of the original volume.
With this system we've been able to create a variety of shapes getting as complicated as this undulating grid pictured below.
In the video below you can see the objects change over time as they are immersed in water.
You can read more about this exciting project on the Autodesk Research site.