scientists from cornell university and the university of pennsylvania have developed a robotic lionfish that uses hydraulic blood to swim around like the real thing. the robotic fish has its own artificial circulatory system that moves the ‘electric blood’ around the body, powering pumps in its tail, dorsal and pectoral fins.




robert shepherd at cornell university and his colleagues developed the robot, modelling the design after a lionfish. the roughly 40-centimetre soft robot is powered by flow batteries, systems that consist of two electrodes and a liquid electrolyte that flows between them.

scientists develop robotic fish that uses hydraulic blood to swim for 36 hours designboom

image © james pikul

cover image: the real-life inspiration for the new robotic lionfish



james pikul, a co-author of the study and a researcher at the university of pennsylvania’s department of mechanical engineering and applied mechanics, said his team came up with the idea while trying to find new ways of making robots more independent.


the flow of the liquid works like the air in a balloon, giving the fish its shape and stiffness. to enable the necessary flexibility, electrodes in the fish are made from bendable nickel wire mesh. the robot’s watertight exterior is made from silicone.

scientists develop robotic fish that uses hydraulic blood to swim for 36 hours

image © james pikul



according to shepherd, the robot’s design means it can store a large amount of energy. the team calculated that the robot would be able to function for 37 hours without requiring recharging. the lionfish and swim autonomously at a speed of more than 1.5 body lengths per minute, which is around 15 centimetres per minute or around 0.01 kilometres per hour.


project info


researcher body: cornell university

authors: cameron a. aubin, snehashis choudhury, rhiannon jerch, lynden a. archer, james h. pikul & robert f. shepherd

paper: nature