Insects inspire new acoustic sensors

The way a male mosquito senses the flapping wings of a potential mate is inspiring researchers in Scotland to develop new types of acoustic sensors.

A team from the University of Strathclyde is studying the hearing mechanisms of insects and finding ways to engineer these naturally designed systems into new bio-inspired sensors.

It is proposed these sensors have the potential to improve the industrial use of acoustic sensors and actuators, from medical ultrasound imaging, non-destructive testing of materials and even robot guidance.

Principal investigator Dr Joseph Jackson said the work will require coupling together arrays of sensors and actuators and making them behave in a matter as complex as the interactions on an insect’s antennae.

The work follows studies Jackson did prior to his PhD at the University of Bristol. There Jackson studied the complexity of mosquitoes’ sensory systems. Using focused lasers, he was able to observe the way the mosquitoes’ brush-like antennae, which project away from their head, oscillate when sound is present.

Jackson said at the base of the antenna there are approximately 16,000 neurones that can both sense and generate force. With so many neurones sensing and feeding back a force to the antenna, some complex dynamic behaviour can occur. Sound can be amplified, frequencies accepted or rejected and signals can be ’locked’ to zoom in on the source.

The ability to harness this behaviour in an engineered system, Jackson said, could give transducers, for example, the ability to be multifunctional and work without restriction to any bandwidth.

‘It would be able change bandwidths and change sensitivity on the fly, such that you could have a multipurpose transducer for a variety of applications,’ he said.

‘One of the things that would be very interesting is drug delivery using capsules that have drugs inside them that you could burst using ultrasound. To image them and burst them now requires two different types of transducers. One eventual application would be to have a multipurpose transducer that could do imaging and deliver drug at the same time.’

Yet the overall goal for the project, Jackson said, is to make a general improvement on transducer technology, which could benefit a wide variety of industries.

This work is one of several bio-inspired efforts to improve transducer technology at the University of Strathclyde. The Engineer reported in October 2007 (Animal Magic) Professor Gordon Hayward’s research into new ultrasonic imaging systems that mimic the complex acoustic waveforms bats use for object identification and navigation.