# Scalable robot fish revolutionizes underwater research A single design producing fish robots in multiple sizes could transform marine studies. - **Source:** [Popular Science](https://brifing.si/source/cc3d313a-759c-4802-b881-fc8585f35ef9) - **Published:** 2026-08-27 - **Topic:** [Data & AI](https://brifing.si/c/data-ai) - **Original article:** - **On Brifing:** https://brifing.si/s/635e2d59-85b3-4e8b-a8f2-cdcccbe268fa ## Evolution of robotic fish From simple toys in the 1990s to today's advanced robotic fish, underwater research technologies have made significant progress. Modern versions monitor coral reefs, combat invasive species, and perform various tasks. However, most current designs come in fixed sizes, making parallel observations in different environments challenging. ## ScaFi's innovative design Engineers from EPFL and Queensland University developed ScaFi, a scalable robotic fish inspired by Atlantic cod and mackerel movements. The robot features a rigid front section and a flexible tail made of fabric-covered fiberglass rods. A single motor drives internal tendons to create natural S-shaped swimming motions. ## One design, three sizes Researchers produced three models from the same blueprint: a 2-foot small version, 3.6-foot medium, and massive 9-foot large model. All share identical motor and tendon systems, with only tail rod diameter changing. This eliminates the need for separate robots designed for different aquatic environments. ## Pool test revelations Controlled pool tests showed the smallest model was most agile while the largest maintained course best against disturbances. Smaller versions proved more energy-efficient, though the large model's absolute speed was considerably lower. These findings mirror characteristics seen in real fish across ecological niches. ## Real-world trials Field tests deployed robots in natural settings: small in a shallow creek, medium in a Swiss stream, and large in Lake Geneva. The 9-foot robotic giant dwarfed most native fish, including the lake's largest natural species (catfish), which reach only half its size. ## Complexity of biological systems Researchers highlight challenges in replicating biological scaling complexities in robotics. Balancing speed and energy efficiency at larger sizes demonstrates how robotic systems must account for evolutionary processes observed in nature. ## Resource and time savings This innovative approach offers significant resource savings for marine researchers. Scaling a single design rather than developing separate robots for different environments reduces costs and accelerates research processes. The team believes this methodology could extend to other biomimetic robots. ## Milestone for marine research The ScaFi project represents a watershed moment in underwater robotics. Its scalable design philosophy offers new perspectives for future aquatic vehicles, particularly in monitoring climate-threatened ecosystems where adaptable tools are increasingly crucial. ## Sources covering this story - https://www.popsci.com/technology/robot-fish-three-sizes/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._