Rice grain behavior inspires new smart material, scientists report
6 reported
Scientists at the University of Birmingham have discovered that packed rice grains behave unusually under pressure, weakening under rapid compression but staying stronger when pressure is applied slowly. The international research team used this property to engineer a new metamaterial that can automatically adjust its stiffness without electronics or sensors. The findings were published in the journal Matter. The material combines rice-based granular units with sand, which strengthens under rapid loading, to create a speed-sensitive composite. Researchers say the material could be used in soft robots that adapt to tasks and in protective equipment that responds differently depending on impact speed. Dr. Mingchao Liu of the University of Birmingham stated that the work turns a curious phenomenon into a design principle, letting physics decide how the material behaves.
What’s reported
Packed rice grains weaken under rapid compression but remain stronger under slow compression, a phenomenon called "rate softening."
The effect occurs because friction between rice grains drops sharply when forces are applied rapidly.
Researchers combined rice-based granular units with sand to create a granular metamaterial.
The material can bend, buckle, or stiffen differently under slow movements versus sudden impacts without electronics, sensors, or active control.
Potential applications include soft robots for working alongside people, operating in challenging environments, and assisting with surgery, as well as protective equipment that absorbs energy during collisions.
The research was led by the University of Birmingham and reported in the journal Matter.
Key figures
Dr. Mingchao Liu, University of Birmingham
Sources: ScienceDaily
