KOLKATA: At 28, she has created an underwater drone that can map ocean floors and explore the deep sea, where even GPS doesn't work. Kolkata girl Sampriti Bhattacharya's invention -the Hydroswarm -has been patented and is quite a rage with the defence sector and oil giants.What's more, Forbes has featured her among the top 30 most powerful young change agents of the world.Sampriti, who left the city about seven years back for her masters, is now a PhD scholar at Massachusetts Institute of Technology (MIT).Hydroswarm was created as part of her research thesis.“Underwater navigation has been a reality for many years but for advanced searches you need maps that are as refined as, say , the Google map. This is where my drone comes in. It can map the ocean, sitting on its bed, and you can zero in on the minutest objects, living or non-living.You can even map underwater pollution with the help of his drone,“ said Sampriti, who was in Kolkata for a short while and returned to he US on Thursday .A South Point alumnus, she studied engineering at St Thomas College and did her masters in aerospace engineering at Ohio State University before switching to robotics at MIT. She told TOI that she always wanted to create an underwater robot because here was no easy way to study the ocean floor. The only option was the very expensive remotely operated underwater vehicles generally used to track warships. Sampriti explained: “The word drone came in much later. Remotely opera ted vehicles have been around -one was used to locate the Titanic, for example.Also, the defence-run autonomous drone that searched 21,000 sq km in search of the missing Malaysian MH370 plane. But these cannot be used for study or everyday quest that might be treated as lesser priority by the government. This is where the Hydroswarm comes in.“The Hydroswarm is a start-up that creates swarms of small, autonomous, underwater drones shaped like an egg and roughly the size of a football. They can withstand the tremendous pressures of the deep and swim across the ocean floor as sensors map out the topography , study aquatic life or monitor ocean pollution.The drones can cover up to 100 sq km in just four hours.Sampriti decided to commercialize her drone through her start-up and joined a business programme at Harvard Business School. She was also among the top eight contenders out of 200 to make it to the fi nals of the MIT $100K Entrepreneurship Competition, winning $15,000. After that, Sampriti made the finals of the MassChallenge Accelerator out of 2,500 contending start-ups and ended up among the top 16, winning $50,000.Director of IIT-Kharagpur, Partha Pratim Chakraborty , said: “Indeed, it is a rare honour for a Bengal-bred engineer. Underwater robots are the latest in the world of robotics and the need of the hour is to build robots that are relatively cheap and easier to manoeuvre because this is a less explored area.“