Bridging the gap between biology and engineering.

Dr Rolf Müller, associate professor of mechanical engineering at Virginia Tech is an exponent of bridging the gap between biology and engineering. His research is focused on getting to know how biological sensory systems can achieve their best performances.    His latest research is another step in this direction and it has uncovered the acoustic effect of non-rigid ear deformations in bats. His associates are Li Gao of Shandong, China, a Ph.D. student with Müller, Sreenath Balakrishnan of Thrissur, Kerala, India, a master's candidate with Virginia Tech's Department of Mechanical Engineering, and Weikai He and Zhen Yan, of the School of Physics at Shandong University.

The researchers discovered that within one tenth of a second, certain bats are able to change the shape of their outer ear from one extreme configuration to another in order to fine-tune their hearing. In about 100 milliseconds certain bats can alter their ear shape significantly in ways that would suit different acoustic sensing tasks. By way of contrast a human blink of an eye takes two to three times as long. Using computer analysis of the deforming shapes, the researchers found that the ultrasonic hearing spotlights associated with the different ear configurations could suit different hearing tasks performed by the animals.

Journal reference

Ear Deformations Give Bats a Physical Mechanism for Fast Adaptation of Ultrasonic Beam Patterns

Li Gao, Sreenath Balakrishnan, Weikai He, Zhen Yan, and Rolf Müller

Phys. Rev. Lett. 107, 214301 (2011) – Published November 14, 2011