SNAPP, developed by a team at HKU, is the world’s fastest robotic fish

The world’s fastest robotic fish, designed and built in Hong Kong, could soon be deployed on the city’s ferries, cruise ships, promenades and beaches as a valuable life-saving and signalling tool, according to its inventors.

At 2.18 m/s SNAPP swims faster than Michael Phelps, twice as fast as Harvard University’s Tunabot, and holds the Guinness World Record for the fastest 50-metre swim by a robotic fish. The highly efficient ichthyoid was developed by a team at Hong Kong University’s Mechanical Engineering Department, with search-and-rescue operations as a potentially life-saving application.

“We actually have a prototype idea for the robot fish to be used for lifesaving activities,” says Timothy Ng, project lead at the Hong Kong University team.

“In a drowning situation, timing is essential,” says Ng.

“As this fish is capable of fast swims and is quick to be deployed, it can be potentially be deployed off any water-based transport,” he says. “Be it a cruise-ship, or a ferry, it’s light and easy to move around. In fact, it’s possible to use it to patrol open promenades and beaches as well, where it can actively signal people away from danger zones.”

According to the World Health Organization, around 40 people lose their life to drowning every hour, while there were 1,404 incidents and drownings at Hong Kong’s pools and beaches in 2019.

The question of lifejackets and safety equipment was repeatedly raised in the enquiry into one of Hong Kong’s worst maritime tragedies, the sinking of the Lamma IV in October 2012 in which 31 adults and 8 children perished. The inquiry found there were no child life jackets aboard the Lamma IV, with Marine Department officials claiming memory loss when questioned over the shortcomings.

Ng’s robotics team is also working on using SNAPP to address ocean pollution and to scout for underwater garbage patches. With a flexible tail, the robot emulates the motions and profile of a real fish, hence it is able to integrate with the ocean environment seamlessly, says the invention team. “Its fish-like gait produces low acoustic noise, keeping underwater sound pollution to a minimal.”

The current prototype allows it to accelerate to a maximum speed within half a second, make tight turns with its caudal fin, and swim continuously for hours on a 850 mAh battery.