Diseño y simulación de una aleta bioinspirada en el pargo rojo (Lutjanus campechanus) mediante el control de actuadores de Nitinol

Bio-inspired robotics aims to replicate biomechanical principles of living organisms to optimize the efficiency of robotic systems, highlighting the red snapper (Lutjanus campechanus) as a relevant model due to its aquatic maneuverability. This study aimed to design and implement a bioinspired robotic caudal fin using nitinol wire as a shape memory actuator. It adopted a quantitative approach with an experimental design and was framed within applied research. A functional prototype was developed based on a CAD model in Fusion 360, featuring a modular structure composed of three links connected by pairs of nitinol cables, activated by PWM signals from an Arduino Nano microcontroller. Finite element simulations allowed optimization of the fin curvature to 30°, achieving an oscillation of 15° and a 25% reduction in internal stresses compared to initial models. Additionally, a 20% improvement in propulsion efficiency was obtained. The estimated contraction force value for the 0.2 mm diameter wire was 0.196 N, sufficient to emulate the natural movement of the fish. These experimental results demonstrate that the integration of nitinol and PWM control constitutes an effective and viable alternative for underwater soft robotics locomotion, offering structural flexibility without the need for traditional mechanical components.