Shark-inspired chemical sensors

Researchers at Bath University are attempting to discover how hammerhead sharks are able to sniff out their prey.

The scientists hope their research could be used in future to design chemical sensors for underwater exploration, medicine and counter-terrorism.

Dr Jonathan Cox from the university’s Department of Chemistry has been working with researchers from Cambridge University and the Natural History Museum in London, testing a scale model of a hammerhead shark in a flow tank to see how the water flows around the nasal cavity of its strange flattened head.

The model was created using a CT scan of a shark’s head from the Natural History Museum’s collection, which was then used in a 3D printer to make an accurate model of the head and nasal cavity.

Dr Cox said: ‘Whereas humans use their lungs like bellows to inhale air through their noses to smell, the hammerhead shark smells as it swims forwards, propelling water through its nose.

‘The nasal cavity of the hammerhead is like a labyrinth of pipes, with a central U-shaped channel and lots of smaller channels leading off it. The smaller channels contain the olfactory receptors and so we’re looking at how the water flows through these channels as the shark swims forwards.’

Sharks sweep their heads from side to side when they swim, so to simulate this, the researchers change the angle of the head model in the tank and observe the flow at each angle.

Dr Timothy Nickels, reader in experimental fluid mechanics at Cambridge University, said: ‘We are really excited to be involved in this project — it’s a perfect example of the strength of interdisciplinary research, with Cox providing the in-depth knowledge of shark olfaction while we contribute in measuring and understanding the fluid mechanics side of the processes.’

Dr Richard Abel, from London’s Natural History Museum, added: ‘This exciting study manages to combine 3D imaging of 50-year-old museum specimens with wild observations of living sharks and experimental flow research to determine how hammerhead nostrils function.’