Mimicking the Motion of a Seahorse

Bio-inspired robotics focuses on the physics learned from animals in nature and applied to artificially design machines to perform specific functions. Although a plethora of marine animals have been used as the template bio-inspired robotic design, there is little to no research on the applications of seahorses in robotics. Applying the mechanical features of a seahorse to a robot would make the robot stable and would allow for a 360o control over the robot. In this project various materials were tested to create prototypes that could mimic a sea-horse’s buoyancy and fin and tail movements. Ionic Polymer-Metallic Composites (IPMCs) were used to create and test the buoyancy mechanism. A test was conducted to see how much voltage various resistors would give while being connected to the IPMC, thus testing their efficiency in reverse electrolysis. Nitinol wire, a Shape Memory Alloy (SMA), was used to create a prototype of the sea-horse tail. We tested the amount of opposing force needed to deform the wire to an undesirable shape. Finally, a magnetic actuator was built to mimic the fin motion. Results from the IPMC tests showed that the 220K resistor gave the highest voltage, thus should provide the highest rate of electrolysis. Additionally, it was noted that the nitinol wire retained its shape up to a force four times its weight. Furthermore, the buoyancy and precise fin and tail movements of the sea-horse robot could allow for its use in underwater explorations and missions.