Innovative ‘Metamaterial’ Could Revolutionize Development of Smart Materials

Jerusalem, 4 June, 2024 (TPS) -- A collaborative team of Israeli and American researchers have made a significant breakthrough in materials science by developing a mechanical metamaterial capable of remembering the order of actions performed on it. By bridging the fields of magnetism and mechanics, its inherent memory and computational capabilities could revolutionize the development of smart materials.

Typically, materials uniformly respond to external manipulations, irrespective of the sequence of actions done to them.

However, researchers from Tel Aviv University and the Los Alamos National Laboratory in New Mexico have developed a metamaterial demonstrating a unique ability to retain the sequence of operations applied to it. This novel characteristic is akin to a computer following a set of instructions, enabling it to perform complex functions based on the history of interactions it has undergone.

“This material is like a mechanical memory storage device that can remember a sequence of inputs,” explained Dor Shohat, a Ph.D. student at Tel Aviv University. “Each of its mechanical building blocks has two stable states, just like a single bit of memory.”

The team’s findings were recently published in the peer-reviewed Nature Communications.

Named ‘Chaco’ after New Mexico’s Chaco Canyon archaeological site, its history-dependent behavior opens the door to innovative applications in fields such as memory storage, robotics, and mechanical computing.

The inspiration for Chaco’s design stems from the concept of frustration found in magnetic systems, which are renowned for their memory properties. In magnetic systems, geometric frustration can inhibit magnets from reaching a simple, ordered state. Similarly, Chaco’s building blocks are arranged to prevent easy settling into an ordered, low-energy configuration. This controlled frustration generates numerous possible states, enabling the material to remember the sequence of actions it has experienced.

“By carefully designing the geometry of the material, we can control the way it responds to external forces,” said Chaviva Sirote-Katz, another Tel Aviv University Ph.D. student involved in the research. “This allows us to create disorder and complex behaviors in a simple, ordered structure.”

Chaco’s memory capabilities are further enhanced by its “non-Abelian” nature, meaning the order of operations matters significantly. For example, flipping two units within the material in one order may lead to a different final state than flipping them in the reverse order. This sensitivity to the sequence of actions allows researchers to encode information within the material and later retrieve it by observing its final state.