A team of innovative engineering students at Rice University has designed and built a groundbreaking remotely operated underwater robot that pioneers a new approach to controlling buoyancy. The robot, constructed over the course of a year-long senior capstone design course, uses water-splitting fuel cells to achieve neutral buoyancy in a more energy-efficient manner than traditional methods.

Named Team BayMax, the students - Andrew Bare, Spencer Darwall, Noah Elzner, Rafe Neathery, Ethan Peck, and Dan Zislis - took inspiration from academic research by professors at Rice and the University of Houston. This research showed that fuel cell-based buoyancy control could reduce energy consumption in underwater vehicles by up to 85% compared to conventional thruster designs.

"The BayMax student team was excited to implement an innovative research idea based on electrolysis," said Professor Fathi Ghorbel, the team's sponsor from Rice's mechanical engineering and bioengineering departments. "The idea involves the transformation of water into hydrogen and oxygen gases to control buoyancy, mimicking how fish use swim bladders."

Traditional underwater robots rely on power-hungry thrusters or propellers to change depth. In contrast, BayMax's robot incorporates reversible hydrogen fuel cells connected to balloons. By applying an electrical voltage, the fuel cells split water into hydrogen and oxygen gases which inflate the balloons, increasing buoyancy. Reversing the voltage recombines the gases into water, releasing energy and decreasing buoyancy.

"It's a technology that's really cutting edge, it's something that hasn't been done before exactly the way we're doing it," Bare explained. "We're the first ones to implement this in a device with pitch, roll and extensive controls."

The buoyancy control system is complemented by an array of sensors monitoring the robot's position, orientation, and system vitals. This data streams to a dashboard providing a real-time visualization for the operators, who can manually control the robot's movements with a video game joystick while the software stabilizes the robot's attitude.

"Having spent a year on it now and putting so much time into it, getting to see the result of all that work come together is really rewarding," noted Peck. The project's innovative nature impressed judges at the annual Engineering Design Showcase, where it took second place for Outstanding Innovation.

Beyond its achievements, the project provided invaluable learning experiences for the students in areas like control theory, software integration, and systems engineering tradeoffs. "Another takeaway for me is the importance of determining a clear scope for any given project," reflected Zislis. "This kind of decision-making process is not just part of good engineering, but it's relevant with everything in life."

With potential applications across industries from environmental monitoring to maritime operations, the team's fuel cell buoyancy control robot demonstrates the power of multidisciplinary student innovation. By pioneering this cutting-edge approach, Rice engineers are opening new frontiers for more efficient and capable underwater robotic systems.