The secrets of the deep may soon be further revealed, thanks to the world's first "soft robot" developed by Chinese scientists – which takes the form of a deep sea fish called a snailfish.
The lack of knowledge of the deepest depths of the planet's oceans is often compared to man's search for knowledge of deep space – but robots like that devised by a joint research team from China's Zhejiang Lab (ZJ Lab) and Zhejiang University could have a role to play in exploration of the deepest parts of the ocean.
Deep-sea trenches – like the Pacific Ocean's Mariana Trench – teem with microbial life feeding on organic material, including algae and animal matter, that makes its way to the bottom of the sea. That microbial activity leads scientists to think the trenches may play a significant role in Earth's carbon cycle, now firmly linked to climate change.
The Mariana Trench, the deepest known point in Earth's oceans, is called the "fourth pole of the Earth" for its high hydrostatic pressure, low temperature and complete darkness. Challenger Deep is the deepest part of the Trench, bottoming out at about 10,900m below sea level – and where the water pressure is about 1000 times that of atmospheric pressure at sea level, compared to having an elephant stand on top of your thumb.
Traditional deep-sea robots or manned submersibles are heavily reinforced with rigid metal frames so as not to crumple — but are heavy and cumbersome and at high risk of structural failure.
Instead, the Chinese scientists have looked to the snailfish, a translucent fish with a gelatinous body that lives deep in the Mariana Trench. Into these crushing waters, the research team released the world's first soft robot – resembling the snailfish – and successfully completed the world's first deep-sea free-swimming test of a soft robot.
The snailfish is able to survive that intense deep sea pressure thanks to its structure - bones distributed in tiny parts in its soft gelatinous body. The self-powered soft robot is shaped like a fish, with a length of 22 cm and a wingspan of 28cm, approximately as large as A4 sheets of paper.
Hard components, including control circuits and batteries, are distributed across the gel-like body of the robot. The materials, structure of components and the robot body enable it to resist hydrostatic pressure 10,000m under the ocean surface without any hard shell.
"Compared to traditional high pressure-resistant deep diving equipment, the deep-sea soft robot was developed with brand new technologies, expected to significantly reduce the difficulty and cost of deep-sea exploration," says Li Guorui, a senior researcher with the ZJ Lab.
In December 2019, the robot performed steady wing-flapping movement at a depth of 10,900m in the Mariana Trench. Around nine months later, it successfully completed free swimming at a depth of 3224m in the South China Sea.
Autonomous exploration robots require electronics not only to power their movement, but also to perform various tasks, whether testing water chemistry, lighting up and filming the denizens of deep ocean trenches, or collecting samples to bring back to the surface. Under the crushing grip of water pressure, these electronics can grind against one another. The Chinese researchers seem to have met that challenge and such robots may soon help answer lingering questions about the mysterious reaches of the ocean.
Li says: "Our robot enjoys bright application prospects in harsh and extreme environments such as deep sea, polar regions and high-impact scenarios."
This article was originally produced and published by People's Daily Online.
View the original at en.people.cn