Discovery could lead to self-propelled robots

Army-funded researchers have discovered how to make materials capable of self-propelling, allowing materials to move without motors or hands.

Researchers at the University of Massachusetts at Amherst have discovered how to make materials that break and reset, relying only on the flow of energy from their surroundings. This research, published in Materials from nature and funded by the US military, could allow future military robots to use their own energy.

“This work is part of a larger multidisciplinary effort that seeks to understand the biological and technical impulse systems that will lay the foundations for evolutionary methods to generate forces for mechanical action and energy storage structures and materials”, said Dr Ralph Anthenien, Chief Branch of the Army Research Bureau, part of the US Army’s Combat Capability Development Command, now known as Army Research Lab DEVCOM. “The work will have a myriad of possible future applications in actuation and engine systems for the military and DOD.”

The researchers discovered the physics during a mundane experiment that involved watching a strip of gel dry. The researchers observed that when the long elastic gel band lost internal fluid due to evaporation, the band shifted. Most of the movements were slow, but every now and then they speeded up.

Scientists are finding out how to make materials that break and reset, relying only on the energy flow of their surroundings. This research could allow future military robots to get rid of their own energy.

These faster movements were instant instabilities that continued to occur as the liquid evaporated further. Further studies revealed that the shape of the material mattered and the bands could reset to continue their movements.

“Many plants and animals, especially small ones, use special parts that act like springs and latches to help them move really fast, much faster than animals with only muscles,” Dr Al said. Crosby, professor of polymer science and engineering at the College of Natural Sciences, UMass Amherst. “Plants like fly traps in Venus are good examples of this type of movement, as are grasshoppers and jaw-trap ants in the animal world.”

Pressure instabilities are one way that nature combines a spring and a latch and are increasingly used to create rapid movements in small robots and other devices as well as toys like rubber poppers.

“However, most of these capture devices need a motor or a human hand to keep moving,” Crosby said. “With this discovery, there could be various applications that do not require batteries or motors to power the movement.”

Scientists are discovering how future military robots might be able to move around solely on their own energy.

After learning the essential physics of drying belts, the team experimented with different shapes to find which ones were most likely to react in the expected way, and which would move repeatedly without any motor or hand. reset. The team even showed that the reshaped bands can work, like 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 the design of new robots, especially in small sizes where it is difficult to have motors. , batteries or other sources of energy “. Crosby said.