Student by day, a tester of diving robots by night

Jonas and Pragash, in June the whole world was following the story of the lost submarine Titan. You manage the ETH spin-off Tethy Robotics and have developed an autonomous underwater robot, which can be used in circumstances considered too dangerous for people. How did you follow the story?

Jonas: It was certainly a dramatic story. A lot of people talked to us about it and of course we followed the story in the media. But from a technical standpoint, there is nothing to link our robot, which can only be used in depths of up to 300 metres, with this submarine. We are focusing on developing safe (unmanned) diving robots for the underwater world.

When and how is your robot already being used?

Pragash: Since May 2022, our prototype has been successfully deployed by the Swiss military to monitor and recover munitions in inshore waters. There are 8000 tons of this in Swiss rivers and lakes. This should demonstrate that the robot works well in real-life applicatio

Jonas: The diving robot can also be used to look for people. The police are already testing it out for this purpose.

Sounds like you are heading for success: you started out in the Student Project House and in 2019 were the first Swiss team to take part in the MATE ROV Competition, an international diving robot contest for students in Tennessee, where you finished in the top 10. Your latest robot Proteus is already being deployed by local authorities for underwater search and rescue missions. What distinguishes your robot from other diving robots

Pragash: There is a vast range of different diving robots, some are the size of containers and are deployed in deep water. Our “Proteus” is more of a compact robot, weighing around 25 kilograms; the heaviest element of which is the batteries. It can be used in rivers and lakes, especially those with strong currents and poor visibility.

Jonas: Our robot is highly autonomous; thanks to its software, it always knows exactly where it is. This can be very important in rivers with strong currents. This very precise and rapid localisation function is what distinguishes it from other diving robots. Our lab is highly advanced in terms of flight robotics and this is what we aim to achieve with our diving robot. You could say that it’s an underwater drone.

You two don't work alone. Tethys is a team of seven working in different disciplines. How did it all start?

Pragash: Things got off the ground in 2018 during our undergraduate course. There were eight of us studying mechanical engineering, electrical engineering and information technology and through our various personal contacts, we all found one another in the ETH Student Project House.

Jonas: I think it’s great that right from the outset we were able to bring together our different skills and abilities. Especially because we had to build the robot for the competition in the US in a very short amount of time; just four months. Then, five of us stuck with the project and two new people joined us. Since 2020, we have been working on founding a start-up.

How did you get the idea of producing an underwater robot?

Pragash: We are all fascinated by technology and by robotics. At ETH, you will find flying, running and crawling drones but there has never before been an underwater drone. The project has intensified over time with various sub-projects, and I like that.

Jonas: I have always been excited by the fact that you can advance very quickly in a field of robotics where no-one has ever attempted anything before. We are able to undertake a lot of pioneering work. One benefit is that we work very closely with other ETH researchers in our lab and can exchange ideas and incorporate what we learn for the benefit of underwater robotics. I simply love trying out new things. The project has also “grown up”, we now want to commercialise it all. And that’s fun too.

When you look back on your journey so far, what have been the positives? Have there been any stumbling blocks?

Pragash: Personally, I thought it was fantastic that we launched the project so early on in our time at university and translated the theory from our studies into something practical. That really gave us a good start.

Jonas: The work was related to our courses. We received ideal support from ETH, most especially from the AEL (Autonomous Systems Lab: https://asl.ethz.ch/). This was crucial to driving the project forwards. Time management was a critical topic for us all: we were full-time students, working part time on a project that was growing at breakneck speed. It shapes you, but also helps with what you do later in life. The imminent founding of our start-up comes with a huge range of tasks: the financial and legal matters are challenging us as, of course, is the hunt for potential customers.

Have you ever thought about throwing in the towel?

Pragash: No, I’ve never considered that. It’s a huge project and it’s important for us to have sufficient resources and to coordinatethem.

Jonas: On the one hand, a robot like this is a complex system and needs a lot of our attention and resources. On the other hand, we have tasks like running tests, holding meetings and, of course, keeping our eye on the finances. It sometimes swings between highs and lows. But we’re rising to the challenge (laughs).

What was your first/greatest success with Tethys?

Pragash: Personally, I always consider it a huge success when each prototype robot is put into water and actually works.

Jonas: I also like it when we get positive feedback on our work from partners. And that's really rewarding.

You both graduated from ETH in 2022, Jonas having studied mechanical engineering and Pragash biotechnology and have turned your work at Tethys into your career. What made you decide to press ahead with your company and what was it like entering the world of work?

Jonas: All of us had work placements in industry during our time at university, where we gained our first professional experiences. So we were able to compare industry with our work in an ETH spin-off. On that basis, we were all able to individually consider whether we wanted to stick with our project or not. When we were studying for our Masters’, we then decided to apply for a Pioneer Fellowship. Once we had secured the finances, things just proceeded from there.

How do you feel when you look back to your time at university? What do you remember most from back then?

Pragash: For me, I’ve lots of memories of the time when I was combining my ETH course with work for Tethy Robotics. For the competition, we had to test our diving robot, of course, and spent our nights in a swimming pool in the city doing just that. So our days often looked something like: 8am, go to ETH, then go into the lab to work a bit more on the diving robot and then between 10pm and 5am, we were diving with our robot in the swimming pool.

Do you have any tips for ETH students about how to find a job after graduating?

Jonas: For all engineering professions, I think it’s a good idea if you can get some experience in a related project. On our course, there are lots of opportunities to get involved in projects and to think beyond the pure science. Even if you aren't interested in treading the path of your own start-up, getting involved in one will bring so much useful input and you will gain experiences which will help you in your future career.

Learn more about external page Tethys Robotics.