A Chinese team has developed a small robot that can operate in the world's deepest sea trench under extremely high pressure, according to the Xinhua News Agency.

The robot's operational ability is an engineering marvel that was previously achievable only by large, rigid submersibles weighing several tonnes. The robot is capable of swimming, gliding and crawling.

The deep ocean, frequently referred to as Earth's "ultimate life laboratory," has fascinated scientists for many years. In the Mariana Trench – the planet's deepest abyss – pressure reaches a crushing 110 megapascals, equivalent to a one-ton mountain pressing on a human thumbnail.

Yet in these abyssal depths, a nimble 50-centimeter, 2.7-kilogram robot now swims with fish-like agility and even transforms limb-like appendages to "walk" across the seafloor.

Once considered a no-go zone for compact robots, the Mariana Trench has been conquered by a research team from Beihang University, in collaboration with the Institute of Deep-sea Science and Engineering at the Chinese Academy of Sciences and Zhejiang University. Their breakthrough, published March 20 in Science Robotics, unlocks new possibilities for deep-sea exploration.

While swimming, the robot generates thrust through its tail fin, reaching a maximum speed of 5.5 centimeters per second, and when crawling, it can move at 3 centimeters per second on sandy surfaces using its limbs, said the study, which was published this week in the Science Robotics journal, according to Xinhua.

"Pressure resistance was our initial challenge," said Pan Fei, an associate professor at the School of Aeronautic Science and Engineering at Beihang University. The team utilized a key characteristic of silicone – its ability to stiffen under pressure – to develop a flexible actuator.

"By incorporating bistable chiral metamaterials that facilitate rapid snapping motions, we converted crushing pressure into increased propulsion speed and amplitude, effectively turning a potential obstacle into an advantage."

Deep-sea temperatures presented another challenge. "We installed shape-memory alloy springs on the actuator," explained Ph.D. candidate Zuo Zonghao at Behang University. "By applying periodic electrical heating, these springs contract rhythmically, generating high-frequency oscillations."

Drawing inspiration from batfish locomotion, the team engineered a multimodal robot. "It swims, glides, and crawls–adapting dynamically to complex seabed terrain," said Wen Li, professor at School of Mechanical Engineering and Automation at Beihang University.

The researchers now aim to enhance endurance and mobility. "This paves the way for expansive deep-sea missions – from resource exploration to archaeological surveys and environmental monitoring," said another researcher Ding Xilun, professor at the Beihang University.

Source: VOC