The propellor was recently trialed on a 300,000 ton very large crude carrier (VLCC), which completed three oil delivery trips, with China claiming that the bionic skin on the propeller resulted in a 2% reduction in the crude carrier’s fuel consumption.

Source: Quora/China Focus

As such, China believes that the propeller is expected to save an average of 1.5% energy within a 2.5 year maintenance cycle. Further, due to the decreased energy consumption, the researchers suggest that the VLCC will save over 300 tons of fuel annually, thus resulting in economic benefits estimated around $140,000 and a reduction of more than 900 tons of carbon dioxide emissions.

The researchers developed the marine bionic skin to enhance propeller efficiency and potentially save energy in marine transportation. To accomplish this, the team looked at the swimming behavior of dolphins and sharks, which experience minimal resistance in water thanks to their surface micro-structure, flexibility and mucus secretion.

Specifically, dolphins’ skin creates a micro-structure in the water flow, forming micro-eddy currents that transform sliding friction between the skin and the water flow into rolling friction. Meanwhile, the epidermal mucus offers lubrication to minimize the turbulent kinetic energy of the water flow.

Applying the artificial skin synthesis method, the team created the bionic skin taking inspiration from the skin of dolphins, with the researchers describing the material as composed of liquid-like dynamic interfacial components and flexible materials with a microstructure between 0.1 mm and 0.2 mm.

The researchers added that when placed on the propeller’s surface, the bionic skin will likely reduce the shear force with the water, counteract the work of the reverse thrust on the water, improve propeller efficiency and subsequently reduce energy consumption.