A Cavity-Type Pressure Sensor Array with High Anti-Disturbance Performance Inspired by Fish Lateral Line Canal

Effective sensing is challenging in real underwater environment swarming with various disturbances. However, most research on underwater sensors has been conducted in still water, which may not provide sufficient insights for environments with disturbances. In addressing this issue, our paper not only proposes the development of anti-disturbance sensor units but also delves into evaluating the localization capabilities of artificial lateral line arrays in disturbed water environments. Concretely, inspired by the lateral line canal system of fish, we proposed a cavity-type pressure sensing device (denoted as a C-sensor) with notable anti-disturbance performance. On one hand, a 3D-printed resin cavity is filled with silicone oil, with flexible latex film packaging the upper and lower openings to achieve anti-disturbance capabilities akin to those of fish lateral line canals. On the other hand, employing IPMC materials based on ion sensing principles, the sensor generates electrical signals similar to sensing cilia in fish lateral line systems. The results demonstrated that the cavityless sensor (denoted as N-sensor) showed self-oscillation behavior, leading to significant errors in weak target signal detection and even sensor failure in extreme cases. However, the C-sensor exhibits remarkable sensing performance in still water and water disturbances, thereby confirming the effectiveness of its cavity-type structure in mitigating the impact of water disturbances. Furthermore, we developed two distinct artificial lateral line arrays based on the above sensors (C-array and N-array). The experimental results showed a marked 78% reduction in mean localization error for C-array compared to N-array. Additonally, the C-array also exhibited good ability in multiple dipoles detection. Such results indicate the superior applicability of the C-array within real complex underwater environments, promoting the practical application of IPMC sensors.