BTO/P(VDF-TrFE) Nanofiber-based Artificial Lateral Line Sensor with Drag Enhancement Structures

A flexible Artificial Lateral Line (ALL) sensor is presented in this paper, featuring a barium titanate/polyvinylidene fluoride-trifluoroethylene [BTO/P(VDF-TrFE)] nanofiber mat, a hydrogel cupula, and a constriction structure in the canal. The excellent piezoelectric performance of the BTO/P(VDF-TrFE) nanofiber, superior to that of a pristine P(VDF-TrFE) nanofiber, helps improve the sensitivity of the ALL sensor. The hydrogel cupula imitating the cupula in a fish lateral line system enhances the ALL sensitivity through a material-induced drag enhancement mechanism. The constriction mimics the diminution structure found in fish canal lateral line systems, endowing the canal ALL sensor with enhanced sensitivity through a structure-induced drag enhancement mechanism. The contributions of the hydrogel cupula and constriction structure in offering an enhanced sensing performance are studied experimentally, in comparison with conventional ALL sensors. The constriction structure in the canal helps modify the frequency response of the canal ALL sensor, i.e., attenuating low frequencies while amplifying high frequencies. The proposed biomimetic flow sensor is expected to aid in the development of smart skins for underwater robotics applications.