Development of a Rigid-Flexible Integrated Bionic Seal Whisker Sensor for Underwater Wake Detection

Seals utilize their specialized vibrissae for the precise detection and recognition of hydrodynamic wakes, enabling critical activities such as prey capture and environmental sensing. Inspired by the unique morphology and structural characteristics of seal whiskers, this study developed an underwater biomimetic whisker sensor (UBWS) featuring a rigid-flexible coupling design. The sensor consists of a biomimetic whisker, four flexible sensing units, and a compliant base mimicking the follicle-sinus complex. Combining simple structure, low cost, and the capacity to detect hydrodynamic responses in both the lift and drag directions, the UBWS achieves bidirectional hydrodynamic perception. Both numerical simulations and experimental results demonstrate that the UBWS effectively suppresses vortex-induced vibration (VIV) at a 0° angle of attack (AOA). Furthermore, wake detection experiments reveal that the UBWS can efficiently sense hydrodynamic signals under varying flow velocities, target displacements, and target diameters. The results suggest that the UBWS holds significant potential for identifying the spatial positioning and motion status of underwater targets.