Squid power slithers into dock

Vortex thrusters inspired by squid, jellyfish and other cephalopods could make it easier for scientists to manoeuvre and dock underwater vehicles at low speeds and with greater precision.

The University of Colorado at Boulder research may even allow doctors to guide tiny capsules with jet thrusters through the human digestive tract, enabling them to diagnose disease and dispense medications.

Researcher Kamran Mohseni, said: ‘Reliable docking mechanisms are essential for the operation of underwater vehicles, especially in harsh environments. We set out to resolve the trade off that many researchers settle for, which is a faster, but less precise, vehicle or a boxier one that is not as fast and more difficult to transport to work locations.’

While the torpedo shape of some underwater vehicles ensures rapid deployment and high cruising speeds with minimal energy, their hydrodynamic design makes them more difficult to manoeuvre or dock at low speeds and in tight spaces, or to hover in precise locations.

Underwater craft with boxier designs are easier to dock and manoeuvre, but speed is sacrificed in the process. The new vortex thrusters offer speed with versatility and may enable researchers to explore previously inaccessible places. Currently, many designers are trying to devise better docking systems for underwater vehicles, but Mohseni said he and his collaborators wanted to improve the watercrafts' actual manoeuvring capabilities.

‘We didn't want to treat the symptom alone,’ Mohseni said. ‘We made it our goal to resolve a widespread problem.’

Mohseni created his new generators after studying the formation of vortex rings, much like those formed by squid and jellyfish to move themselves underwater. Vortex rings are formed when a burst of fluid shoots out of an opening, moving in one direction and spreading out as it curls back.

The researcher's nature-inspired vortex generators could be used in a wide array of applications. One of them employs tiny capsules that could travel through the human digestive tract to diagnose and treat diseases and disperse medications.

To date, Mohseni and his collaborators in the CU-Boulder aerospace engineering department have designed and tested three separate unmanned underwater vehicles. With the latest model, the team successfully conducted a parallel parking test. The team also has designed a series of other micro vehicles for air and underwater use.