A pressure difference sensor inspired by fish canal lateral line.

It is of interest to exploit the insight from the lateral line system of fish for flow sensing applications. In this paper, a novel fish canal lateral line-inspired pressure difference sensor is proposed by embedding an ionic polymer-metal composite (IPMC) sensor within a canal filled with viscous fluid. Such a sensor could be used by underwater robots and vehicles for object detection, angle of attack measurement, and source localization. Unlike the biological counterpart that has open ends on the surface of the body, the proposed sensor has two pores covered with a latex membrane, which prevents the canal fluid from mixing with the ambient fluid. The design and fabrication of the sensor are presented, where the sensor is integrated with a fish-like body. The sensor output is experimentally characterized as the fish-like body is rotated with respect to a dipole source, which confirms that the sensor is capable of capturing the pressure difference between the two pores. Finite element modeling and simulation that capture fluid-structure interactions and IPMC physics are conducted to shed light on the sensor behavior. Finally, the utility of the sensor in underwater robotics is illustrated via orienting the fish-like body towards the dipole source using feedback from the proposed sensor.