Study of octopus flexibility informs design of search-and-rescue robots

Robots deployed after earthquakes, train crashes or other disasters often struggle to fit into narrow gaps, limiting their ability to locate survivors and deliver supplies. Researchers at the Singapore-MIT Alliance for Research and Technology, led by roboticist Wenci Xin, examined the natural contortion abilities of octopuses to address this challenge.

In experiments at a Vienna aquarium, the team observed common octopuses and Mayan octopuses navigating holes of varying sizes cut into an acrylic partition. The animals typically extended one arm to probe a hole, then moved three to five arms through before pulling the rest of their bodies across. When openings were large enough, the octopuses used their arms to press against the partition and draw their bodies through; when holes were smaller than the distance between the eyes, Mayan octopuses did not attempt passage, while common octopuses compressed their bodies and internal organs to fit.

"People are fascinated by the escape-artist aspect of octopuses," biologist Tamar Gutnick said.

"We know that they can squeeze through all these spaces, but nobody's actually looked at how they do this," Gutnick added.

"We usually want to send robots to do dangerous work, dull work or dirty work," robot engineer Mishu Duduta of the University of Connecticut noted.

The researchers aim to translate the octopuses' pulling strategy into robotic mechanisms, arguing that a pull-based approach may be more effective than pushing for navigating tight, irregular passages. Potential applications include not only disaster zones but also exploration of submerged wrecks. The findings are detailed in the Journal of Experimental Biology.