MIT engineers build tougher shock-absorbing materials patterned like leaf veins, a possible step toward better helmets and packaging
The 3D-printed samples held up to impacts and crushing better than materials built from neat, repeating grids. So far they are credit-card-size lab samples.
Engineers at MIT and Northeastern University have found that building a little disorder into a material’s internal structure can make it better at absorbing crashes and crushing, according to a study published Nov. 11 in the journal Nature. The researchers say the approach could lead to better helmets, packaging and armor.
The materials are metamaterials, which get unusual properties from the shape of their tiny internal beams rather than from what they are made of. Most metamaterials repeat one small building block over and over, like the cells of a honeycomb. The new “scale-rich” designs instead copy networks found in nature, such as the veins in a leaf or a dragonfly’s wing, with beams of many lengths and thicknesses crossing one another.
What they found
- The network-patterned samples were more resilient to crushing and to a heavy dropped weight than conventional lattice and honeycomb samples.
- When one part failed, the surrounding web of beams kept the whole piece from collapsing. “It’s more efficient at distributing damage and absorbing energy,” said Carlos Portela, an MIT associate professor of mechanical engineering.
- Changing just two design settings let the team make the material stiffer or softer, and stiffer in one direction than another.
- A design inspired by the thick rind of a pomelo, a large citrus fruit, cushioned and protected a fragile object embedded in its center.
- The designs can also steer vibrations and sound, the paper reports, which could be used for acoustic lenses that focus sound.
How it works
A computer program draws a line at a random angle across the space, then keeps adding shorter, thinner lines that stop when they hit an earlier one. Two numbers, how thick the first line is and how fast the lines thin out, control the final pattern. The team 3D-printed the patterns in plastic as credit-card-size squares with beams ranging from microns, millionths of a meter, to centimeters. Network scientist Albert-László Barabási of Northeastern, who studies the structure of networks such as the internet, co-led the work.
Limits
The tests used small plastic samples in a lab. The researchers have not built a helmet or other product, and the paper does not report tests in real-world gear.
Sources: MIT News, Nov. 11, 2026; Scale-rich network-based metamaterials, Nature, Nov. 11, 2026.