---
title: Tuna-Inspired Mechanical Fin Could Boost Underwater Drone Power
date: 2025-04-01T05:30:00-04:00
author: University of Maryland
canonical_url: "https://today.umd.edu/tuna-inspired-mechanical-fin-could-boost-underwater-drone-power"
section: Articles
---
# Tuna-Inspired Mechanical Fin Could Boost Underwater Drone Power

*April 1, 2025* — by [John Tucker](/author/john-tucker)


> UMD Engineer Aims to Help Robots Undertake Tasks Often Costly, Unsafe for Humans

*IMG 20240514 114400 821 1920x1080 — A prototype of soft-robotic fin built by a UMD researcher's team can change its stiffness distribution as the underwater drone swims, improving its performance.*

Growing up in Spain, Cecilia Huertas Cerdeira was captivated by the elegant movements of aquatic life during frequent vacations to the Atlantic coast. Later, as a doctoral student at the California Institute of Technology, she steered her surfboard into Pacific waves.

Now a University of Maryland assistant professor of mechanical engineering, she retains this oceanic focus as she works to improve underwater drones, which have progressed in recent years but lack the speed and agility of their airborne cousins. Huertas Cerdeira plans to help them catch up.

She has launched a project to build an unmanned underwater vehicle (UUV) powered by a robotic fin. Modeled after the rear fin of a tuna fish, the replica will propel the drone into deep waters with more quickness and maneuverability than present-day versions.

“I’m taking inspiration from biological swimmers that have evolved over millions of years and can move more efficiently than anything with a rotating propeller,” Huertas Cerdeira said. “We can’t build a fish. But we can build a robot that moves like a fish and optimize it.”

Funded by a National Science Foundation grant [awarded in December](https://www.nsf.gov/awardsearch/showAward?AWD_ID=2443309&HistoricalAwards=false), the project is based on a research paper cowritten by Huertas Cerdeira and [recently published](https://www.nature.com/articles/s41598-024-67798-w)in *Scientific Reports*. (Another of her drone projects—one aimed at developing an on-board energy harvesting system for long endurance earth observation unmanned aircraft—received a UMD [Grand Challenges individual project grant](https://research.umd.edu/energy-uavs).)

Her research team aims to build the fin and test it in a water tunnel at UMD’s Hydrodynamics Lab by the end of the year. Once the drone is complete, hopefully in two or three years, they will perform tests at the Maryland Autonomous Technologies Research Innovation and eXploration lab in Southern Maryland.

\[[*UMD to Develop Drone-Delivery Program for Patients on Rural Island*](https://today.umd.edu/umd-to-develop-drone-delivery-program-for-patients-on-rural-island)\]

Huertas Cerdeira’s research dovetails with increasing global reliance on UUVs for tasks that would be too expensive or dangerous for submarine crews. Underwater drones are cheaper to build and operate, and they poke around aquatic crannies in unique ways, photographing leaky oil pipes, measuring polar ice shelf temperatures, cleaning up waste, studying marine life and conducting military tasks like blowing up mines.

But often, their voyages are neither smooth nor speedy. Conventional UUV thrusters jut out sideways, reducing clearance and increasing drag, while whirring motors can spook fish or blow the cover of stealthy military.


*underwater drone — Design of the underwater drone, which mimics a tuna fish, without the fin.*




**Topics:** [Research](https://today.umd.edu/tags/research)


**Tags:** [Mechanical Engineering](https://today.umd.edu/topic/mechanical-engineering), [Robotics](https://today.umd.edu/topic/robotics), [Research](https://today.umd.edu/topic/research)


**Units:** [A. James Clark School of Engineering](https://today.umd.edu/topic/james-clark-school-engineering)