Research to investigate ‘living coatings’ to protect ship hulls

Marine biologists from Essex are leading innovative research to produce a “living coating” to protect ships from biofouling – the unwanted organisms such as barnacles which stick to hulls.

Biofouling and corrosion are major financial and environmental burdens to the shipping industry and Navy fleets as they produce drag, which increases fuel costs, and the antifouling coatings release harmful chemicals.

The US Navy produces the same amount of greenhouse gas emissions as all the cars in the USA combined. This fuel usage is increased significantly by the presence of biofouling which costs the Navy between $180-260m across the whole fleet every year.

However, existing synthetic coatings to counteract biofouling all have drawbacks - due to their  toxicity, fragility, cost and disposal - and none are completely effective.

This new international project, sponsored by the US Office of Naval Research Global, through its Global-X Challenge, will look into replacing the synthetic coating with a bespoke engineered biofilm - a community of microbes that will produce a protective layer that can be manipulated to perform a range of other tasks, such as environmental sensing, self-healing and decontamination. If successful, this would eliminate the challenges associated with synthetic coatings, providing a cost-effective and environmentally friendly technology to control biofouling that would have a major impact.

Project leader Dr Nick Aldred, from Essex’s School of Life Sciences, explained: “All current synthetic hull coatings have drawbacks and provide incomplete protection. However, a living coating could heal itself after damage, act as a sensor and could be automatically released from the surface naturally when necessary.

“We aim to create an engineered bacterial community that can be controlled to produce a bespoke, protective, multifunctional film for vessel hulls.”

The $1m project will also involve scientists at Clemson University in South Carolina, Copenhagen University and Pompeu Fabra University in Barcelona.

The Global-X Challenge is a new initiative to provide significant funding for international scientists and engineers to test potentially revolutionary concepts and ultimately provide a catalyst for later development and delivery of revolutionary technologies which will be of value to the US Navy and Marine Corps, businesses and the public.

“We are delighted to have been selected by ONR Global to participate in the Global-X Challenge,” added Dr Aldred, who has extensive experience in the field of marine biofouling. “Our success in this competition highlights the world-class research being undertaken by those in the team and will enable us to bring together the unique combination of skills required to deliver a transformative technology demonstrator within nine months. To have emerged as one of four successful applications from a field of about 400 initial proposals is an amazing achievement by the team. We are taking the first steps on a long and exciting journey."

The initial focus of the project will be to engineer a stable bacterial community within a robust biofilm, boasting antifouling capability, based on mechanisms found in nature. The film will ultimately protect vessel hulls and, therefore, reduce maintenance costs.

US Navy photo by John F. Williams