Researchers invent new material that can switch between being hard and soft

A group of researchers at the University of Michigan recently developed a new material that can switch between being hard and soft on demand, the university's news office reported earlier this week.

"Usually, it's hard to change the stiffness of a traditional material.The novel aspect of this metamaterial is that its surface can change between hard and soft," said Xiaoming Mao, an assistant professor of physics.

The new material was designed to change its own property from the way the material is built rather than the material that builds it. It could be easily manipulated to increase the stiffness of its surface from that of rubber to that of steel and vice versa.

Mao said the way an object came into contact with the edge of the metamaterial changes the geometry of the material's structure, and therefore how the material responded to stress at the edge.

Since the properties of the new material came from its total structure, the inside of the metamaterial would remain damage-free even if the material itself changed repeatedly between being hard and soft, the assistant professor said.

Researchers said the new material could see application in a wide range of areas, from bicycle tires that could self-adjust to road conditions to reusable rocket launch systems that could sustain multiple missions to outer space.

Mao believed that the new material would one day revolutionize the way we build cars.

"When you're driving a car, you want the car to be stiff and to support a load," Mao said. "During a collision, you want components to become softer to absorb the energy from the collision and protect the passengers in the car." Endi