Membrane replaces propellers in fish-fin inspired outboard

Paris-based FinX says it’ll launch its first product, the Fin5, later this year. The outboard engine composes of fish-fin inspired undulating membrane that replaces a propeller and is 100 per cent electric.

The product is in its final stages of development and will be a ‘world-first’ for the marine industry. The 2kW outboard engine, equivalent in thrust to a 5 HP standard engine, is designed for small boats and sail boats up to 3 tons. It will be powered by a hydrogen fuel cell.

The system works in the same way as a loudspeaker. There is a coil and a magnet, with an alternative current running through the coil to make the magnet oscillate and vibrate.

The design was inspired by fish and how they swim. To move, dolphins wave their caudal fin with a high amplitude at a low frequency. FinX uses this wave pattern to propel a watercraft using an undulating elastomer membrane. In order to mitigate the effects of pitching and maximise the power density of its engines, the FinX ‘fin’ is operated at low amplitude and high frequency.

This technology is totally safe, says FinX, with no risk of injury, and the membrane won’t get tangled in any ropes.

Harold Guillemin, founder of FinX, was working on medical pumps when he discovered that the same technology would be well suited to the boat engines.

“We have adapted bio-inspired technology from medical pumps to marine propulsion. Our motor is completely safe, it is quieter than its thermal equivalent and does not emit any greenhouse gases, being electric,” says Guillemin, who started development in June 2019.

Yachtsman Loïck Peyron is helping FinX to develop the engine with sailors in mind. The product uses a reverse gear system, with a pivot system that moves and allows the rotation of the engine – using the same hand movement you would use on a sailing boat.

The Parisian start-up is currently in the final stages of its second round of fundraising, Series A. This money will allow FinX to move on to industrialisation and commercialisation. Its first round of fundraising achieved around €1 million.

FinX is also beginning the development of the Fin150 for the Olympics in Paris in 2024. The Fin150, also 100 per cent electric, will be dedicated to bigger boats of 100kW, equivalent to 150 CV.

FinX was one of the winners of the Paris Olympics Call for Innovations, led by the French Ministry of Ecological Transition, aimed at promoting green mobilities during this worldwide event.

The Fin5 is available to pre-order now. Prices start at €3,200.