Engineers develop polycatenated architected materials for innovative 3D designs

A 3D-printed polycatenated architected material (PAM) sphere made of interlocked acrylic rings, naturally deformed by gravity. Credit: Zhou et al.

A team of engineers at the California Institute of Technology, working with colleagues from Lawrence Livermore National Laboratory and Princeton University, has developed what they have named polycatenated architected materials (PAMs) that can be used as wireframe elements to create novel 3D structures with interesting properties.

In their paper published in Science, the group describes how they came up with the idea for creating the materials, some of their properties that have been discovered so far, and possible uses for them. Sameh Tawfick and Ignacio Arretche with the University of Illinois Urbana-Champaign have published a Perspective piece in the same journal issue outlining the work done by the team on this new effort.

As the use of 3D printing continues to mature, scientists continue to find new ways to use it to create not just interesting objects, but base materials to use in creating other objects. In this new study, the researchers have developed a new material that can be used to build new types of architectural constructs.

The PAMs created by the team are similar to links in a chain, the difference being the material from which they are made and their shape. They are still used in the same basic way—by linking them together, either in a chain, or in other ways that seem desirable. 

Comparison of a flexible PAM ball adapting to the shape of a cup versus a fused PAM ball that remains rigid and cannot conform. Credit: Zhou et al.

In their lab, the researchers printed very small PAMs, just millimeters across, in the shape of rings, hexagons, cubes, triangles, pyramids and even an icosahedra with 20 sides. They then tried connecting them together in different ways and then tested the properties of the resulting objects.

Side-by-side comparison of a fused J-4-ring PAM and a regular, flexible J-4-ring PAM. Credit: Zhou et al.

They found that they could create some objects that behaved like a flowing liquid when left alone but became rigid when a force was used to hold the object together. They also printed some PAMs that repelled each other and after being hooked together, they could contract or flex, like muscles.

Real-time video showing electrostatic reconfiguration of microscale PAMs on a Van de Graaff generator. Credit: Zhou et al.

The research team suggests products made from their PAMs could include things like space-based materials that could be flexed on-demand to control how materials behave in exotic environments. 

by Bob Yirka , Tech Xplore

Source: Engineers develop polycatenated architected materials for innovative 3D designs