low cost robot fish

A fish robot, equipped with an innovative propulsion system, promises to substantially lower the cost of underwater exploration.

The team led by Tsam Lung You, from the University of Bristol in the United Kingdom, has provided its new model of robot fish with a coiled polymer that allows it to propel it forward. This cheap and lightweight system uses temperature changes to generate movement, although its speed is modest.

The coiled polymer works by contracting like a muscle when heated, thus generating mechanical movement.

The rolled polymer is heated by passing current through an electrical conductor. The current heats the conductor and the conductor, in turn, heats the polymer. By reducing the distance between the coiled polymer on one side of the robot fish and a spring on the other, the tail fin is actuated, allowing the robot fish to accelerate.

Rolled polymers are emerging as a new and promising option when it comes to manufacturing actuators for robotic mechanical systems. The creators of the new robot highlight the low cost, low weight, high energy density and the simplicity of the manufacturing process, as the main advantages of this propulsion system.

Basic structure of the new fish robot. (Image: Tsam Lung You)

Until now, coiled polymers have been used primarily for applications such as wearable devices and robotic hands. The new use that the Tsam Lung You team has given them now opens the door to more potential applications in which to use them, such as aquatic robots for underwater exploration and surveillance.

The creators of the new robot presented the technical details of their innovation at the recent RoboSoft 2023 congress, under the title “Robotic Fish driven by Twisted and Coiled Polymer Actuators at High Frequencies”. (Fountain: NCYT by Amazings)