Cochlear-like PVDF US Sensor

In-air ultrasonic sensors exploit wave propagation phenomena in order to evaluate navigation and ranging parameters. Transducer technology has been used for years in demanding severe conditions, developed using various type of materials and often directly inspired by nature. The following article focuses on the design and frequency characterization of a bio-inspired ultrasonic sensor arranged according to a shape that mimics bats’ cochlea. The sensor design involved the use of a piezoelectric polymer (polyvinylidene fluoride), which was bended in line with a logarithmic spiral geometry. The voltage output of the sensor was measured at several frequencies in the range 35 kHz–115 kHz. Experimental results show that it is possible to use a single sensor to receive ultrasonic signals, reproducing the hearing frequency range of the mustached bat.