Fascinating World of Underwater Robots

Very large part of our planet is covered with oceans and seas which sustain diverse marine life. There may be several thousands to millions of species living in these oceans and, marine biodiversity is such that it never fails to surprise the explorers. There are many underwater robots available that allow scientists and explorers to study marine life with ease and without running into too many risks. These robots are called ROVs or Remotely Operated Underwater Robots that are used for variety of applications other than studying the marine life; like for example surveillance, military applications, applications in oil and gas fields etc.

Coming back to exploring marine life with robots, the one obvious downside of using robots is that they are made up of hard components and could kill delicate sea creatures like plankton, anemones, jellyfishes etc while capturing them. Wyss Institute for Biologically Inspired Engineering at Harvard University has published a paper very recently in Science Robotics journal in which they have discussed a soft and flexible underwater robot. The robot is consisted of four-fingered claw made up of soft plastic and is driven by a single motor. It can be folded along all its joints forming a hollow container that captures the creature without harming it. Fig. 1 shows the prototype of this underwater robot developed by Harvard University and it is called Rotary Actuated Dodecahedron (RAD). Researchers tested it in an Aquarium as well as in Open Ocean.

Fig. 1 Underwater robot developed by Harvard University

There are many such fascinating underwater robots available today and this article aims to discuss some of them.

Deep Tracker
We know ocean is saline and due to the electrical conductivity radio communication is very difficult and therefore underwater robots are controlled using umbilical cables. Deep Tracker is controlled using video link headset and multibeam sonar system so that it can also work in murky water as well. It is used by Scuba divers for exploration.

Yellow Marlin Drone
Oil and gas industry are today relying on fully autonomous underwater robots and example of one such robot is Yellow Marlin Drone as shown in Fig. 2. It is used to inspect underwater pipelines and offshore rigs. It can operate continuously for 16 hours and reach depths of upto 1000 feet.

Fig. 2 Yellow Marlin Drone

Nereus
Mariana Trench is the deepest point of the Ocean surveyed so far. Its depth is around 11000 meters from the sea level (Mount Everest is 8848 meters above the sea level). Nereus which is a hybrid of drone and remote controlled robot was built by Woods Hole Oceanographic Institution to explore Challenger Deep in Marina Trench.

Wave Gliders
US tech firm Liquid Robotics has built an underwater robot called Wave Glider that requires no fuel for operation and it runs on ocean wave energy and solar energy. It has surfboard-sized float and a wing-shaped sub and can remain upto 8 meter under water. These autonomous robots have covered more than 1.4 million miles in sea and are used for environmental monitoring, surveillance and remote monitoring.

Similarly there are many underwater robots available today for diverse applications like robot for mapping ocean floor, swarm underwater robots, plankton mapping robots, ship wreck search robots etc.

By: Ms. Sandhya Sharma - Asst. Professor (ECE), Chitakara University, H.P.

References

1. https://www.livescience.com/63105-harvard-underwater-pokeball.html