Bioinspired Dynamic Sensing of Acoustic Waves

Biosonar is one of the most capable active senses found in nature and in engineering. It enables certain bat species, such as the horseshoe bats (family Rhinolophidae) and the Old World leaf-nosed bats (family Hipposideridae) to navigate and pursue prey in dense natural environments. Bats from these families also stand out for the dynamics of their biosonar systems that is evident in shape-changing baffles that diffract the ultrasonic wave packets on emission as well as on reception. Some of the acoustic effects predicted for the dynamics in bats have been reproduced qualitatively with a simple biomimetic sonar head. Experimentation with this biomimetic system shows that the dynamic baffles are capable of creating time-variant signatures that could be employed to enhance the encoding of sensory information. Such time-variant sensing paradigms may not be unique to biosonar but may also play a role in the control of the bat’s time-variant flight.