We can now build materials that are 100 times more 'one-sided' than anything found in nature, being rock-hard in one direction and soft in another.
April 17, 2026
Original Paper
Preserving elastic anisotropy with tessellations of granular packings
arXiv · 2604.12098
The Takeaway
In nature, crystals have 'anisotropy,' meaning they might be slightly stiffer if you push them from the top versus the side. But by using 'tessellated granular packings'—essentially specially shaped interlocking bricks—scientists have created materials with 100 times more directional difference than any known natural compound. You could build a bridge that is incredibly strong against gravity but moves like rubber during an earthquake. This level of control over physical properties was thought to be impossible with simple granular materials. It opens the door to 'smart' structures that can be customized to handle specific stresses while remaining incredibly light and flexible where they need to be.
From the abstract
Multiscale periodic metamaterials have been designed for numerous applications, such as impact absorption, acoustic cloaking, photonic band gaps, and mechanical logic gates. This prior work has focused on optimizing mesoscale structure for desired bulk isotropic properties. In contrast, we seek to develop materials with highly anisotropic elastic properties. To quantify elastic anisotropy, we introduce two rotationally invariant, normalized quantities that characterize the anisotropic response t