Purdue University
Denewsdec2 3 Promo 5fc7cabe92ea8

Metamaterials Store Energy in Their Skins

Dec. 2, 2020
Energy can be stored and accessed using convex and concave shapes on sheets of bistable materials.

Researchers at Purdue University have learned to take advantage of the bistability that occurs in some types of materials to form energy-storing skins. Some materials are bistable and have two separate, stable states; a patterned sheet of bistable material fashioned with certain kinds of mechanical structures can store energy in one state and release it in the other, and can be programmed to store and process data like a simple kind of mechanical computer.

The Purdue researchers have discovered that enough energy can be saved in these bistable materials to perform basic mechanical tasks. According to a Purdue assistant professor of mechanical engineering, Andres Arrieta, “Bistability is an important concept found in nature. Earwigs, for example, have bistable, foldable wings that snap to an open state with very little energy.” As Arrieta observes, the Purdue researchers are planning to learn from nature: “We are working to make programmable structures inspired from this bistability.”

Using convex and concave shapes, Arrieta’s team started experimentation with a simple structure, a pop-up dome. It was three-dimensionally (3D) printed on a 1-in.2 sheet of thermoplastic polyurethane. The dome could become either convex or concave with the press of a finger. Different formats of the domes were printed, with new behaviors becoming apparent from a 3 × 3 grid of the domes (see figure). “When you invert two domes that are close to another, they start interacting,” Arrieta said. “And when you start making patterns of these domes on a sheet, the sheet itself begins to curve globally. Depending on which domes are inverted, you get different shapes.”

Arrieta’s team has investigated larger grids of the metamaterial and has explored the use of the technology in programmable robotic grippers and mechanical batteries. Different shapes can be achieved by actuating the domes in different orders, enabling mechanical computing. “When you think about it, these up-and-down domes are a lot like the 1s and 0s of computer data,” Arrieta said. The work was funded by different agencies, including the U.S. Defense Advanced Research Projects Agency (DARPA) and the U.S. Air Force Office of Scientific Research. A provisional patent for the metamaterial technology has been filed through the Purdue Research Foundation Office of Technology Commercialization. 

Sponsored Recommendations

Wideband MMIC LNA with Bypass

June 6, 2024
Mini-Circuits’ TSY-83LN+ wideband, MMIC LNA incorporates a bypass mode feature to extend system dynamic range. This model operates from 0.4 to 8 GHz and achieves an industry leading...

Expanded Thin-Film Filter Selection

June 6, 2024
Mini-Circuits has expanded our line of thin-film filter topologies to address a wider variety of applications and requirements. Low pass and band pass architectures are available...

Mini-Circuits CEO Jin Bains Presents: The RF Engine of the 21st Century

June 6, 2024
In case you missed Jin Bains' inspiring keynote talk at the inaugural IEEE MTT-S World Microwave Congress last week, be sure to check out the session recording, now available ...

Selecting VCOs for Clock Timing Circuits A System Perspective

May 9, 2024
Clock Timing, Phase Noise and Bit Error Rate (BER) Timing is critical in digital systems, especially in electronic systems that feature high-speed data converters and high-resolution...