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Army-funded researchers are discovering how to make materials capable of self-propelling, allowing materials to move without motors or hands. Credit: Yongjin Kim, UMass Amherst
Army-funded researchers discovered how to make materials capable of propelling themselves, allowing materials to move without motors or hands.
Researchers at the University of Massachusetts Amherst discovered how to create materials that break and reset themselves, relying solely on the energy flow from their environment. This research, published in Natural materials and funded by the US military, could enable future military robots to move from their own energy.
“This work is part of a larger multidisciplinary effort that aims to understand biological and evolved impulsive systems that will lay the groundwork for scalable methods of generating forces for mechanical action and energy storage structures and materials,” said Dr. Ralph Anthenien, branch chief of the Army Research Office, part of the US Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory. “The work will have numerous potential applications in the military and DOD drive and propulsion systems in the future.”
Researchers discovered physics during an everyday experiment where they had to watch a gel strip dry. The researchers noted that when the long, elastic gel strip lost internal moisture through evaporation, the strip moved. Most movements were slow, but they sped up now and then.
Scientists are discovering how to make materials that break and reset themselves, relying solely on the energy flow from their environment. This research could enable future military robots that can dissipate their own energy. Credit: Yongjin Kim, UMass Amherst
These faster movements were unexpected instabilities that continued to occur as the liquid evaporated further. Additional studies found that the shape of the material mattered and the strips could reset themselves to continue their movements.
“Many plants and animals, especially small ones, use special parts that act like springs and latches to help them move very quickly, much faster than animals with just muscles,” said Dr. Al Crosby, a professor of polymer science and engineering in the United States. College of Natural Sciences, UMass Amherst. “Plants love the Venus Fly traps are good examples of this type of movement, as are grasshoppers and jaw ants in the animal world. “
Snap instabilities are one way in which nature combines a spring and a latch and is increasingly used to create rapid movements in small robots and other devices as well as toys such as rubber snaps.
“However, most of these grapples require a motor or a human hand to keep moving,” said Crosby. “With this discovery, there may be several applications that do not require batteries or motors to stimulate movement.”
Scientists are discovering how future military robots may only be able to dissipate their own energy. Credit: Yongjim Kim, UMass Amherst
After learning the essential physics of the drying strips, the team experimented with different shapes to find the ones most likely to respond in the way expected, and move repeatedly without motors or hands resetting them. The team even showed that the reshaped strips could do work, such as climbing stairs on their own.
“These lessons show how materials can generate powerful movement by exploiting interactions with their environment, such as through evaporation, and they are important for designing new robots, especially at small sizes where it is difficult to drive motors, batteries or other energy sources. have, ”said Crosby.
The research team coordinates with DEVCOM Army Research Laboratory to transfer and transfer this knowledge to future army systems.
Reference: “Autonomous snapping and jumping polymer gels” by Yongjin Kim, Jay van den Berg and Alfred J. Crosby, February 1, 2021, Natural materials.
DOI: 10.1038 / s41563-020-00909-w