Enhanced water flow sensing performance based on multi-ciliated structure of ionic polymer–metal composite

Ionic polymer–metal composite (IPMC) is a promising candidate for underwater sensing due to the merits of rapid response, flexibility, miniaturization, and self-powered nature. The high sensitivity of a sensor is vital for underwater robots. Inspired by the lateral line cilia of fish, a new water flow sensor system based on the multi-ciliated structure of the IPMC is presented to improve the sensitivity of the sensor. As illustrated by the experiments on oscillatory flow, the sensitivity and detection range of the multi-ciliated sensor reached 3.83 times and increased by about 39%, respectively, compared with that of a single sensor. In addition, an array composed of multi-ciliated systems of IPMCs was successfully applied to the location of a vibrating dipole, while the velocity prediction of underwater moving objects was also realized with a minimum average error rate of 1.70%. The system with high sensitivity proposed in this paper is promising to be an effective supplement to traditional underwater detection methods.