Ultrasonic Transducer For Broadband Applications

In-air sonar system takes advantage of transducers based on different materials and technologies for navigation in unstructured and harsh environments. Most technologies suffer from a limited frequency band and a lack of versatility in those applications where a detailed set of information is required. Herein, we propose an ultrasonic sensor inspired by bats' cochlear structure, characterized by broadband (i.e. 30-95 kHz). The transducer is manufactured by folding a thin film of Polyvinylidene Fluoride, according to a logarithmic spiral geometry. Besides the bandwidth, experimental results showed that the ultrasonic transducer working in the bimodal configuration, is characterized by omnidirectional pattern, capable of reproducing the spectrogram of most echolocating bats.