Marine mussel plaque-inspired anchoring systems for offshore floating structures

Marine mussels can survive the harsh marine environment at intertidal zones by anchoring themselves to various wet surfaces through adhesive plaques. Recent research progress has highlighted that, in addition to the interaction of protein-based chemistry at the adhesion sites, the unique adhesive structure of a mussel plaque plays an important role. Motivated by this natural phenomenon, the proposal aims to establish the knowledge on the underwater adhesive behaviours of mussel plaque-inspired anchoring systems for the applications of the offshore floating structures.

The existing deep water anchoring systems such as drilled piles, suction anchors, and gravity anchors may be subject to various limitations with respect to the cost, the seabed conditions, and the installation; and can cause significant impact on the local marine environment. In addition, removal of these anchoring systems at the decommissioning phase could be difficult and expensive. In comparison, the plaque-like anchoring systems can potentially have the following ground-breaking features: (a) the adhesion at the anchoring systems can be switched on and off based on the requirement, which can lead to revolution in the design, construction, sustainability, and life cycle operation of the offshore floating structures, (b) by using advanced composite materials, the anchoring systems can be applied to a wide range of seabed conditions, i.e., rocky surfaces and soil surfaces, with minimum impact on the local marine environment ( i.e., no drilling or excavation on the seabed is required), and (c) the manufacturing and installation processes can be much more simplified, which leads to cost-effective solutions.

The proposed research has the potential for substantial impact on various applications involving offshore floating structures such as offshore floating wind turbine (OFWT) systems, offshore oil rigs, tidal current turbine systems, and subsea infrastructure. Among these applications, it is worth noting that the requirement for developing novel OFWT systems has been highlighted by the offshore renewable energy sector and the recent governmental strategy- the UK Government has already committed to 1 GW of floating wind by 2030.

The research will establish lab-scale prototypes of the mussel plaque-inspired anchoring systems. Using a combination of experimental techniques, adhesion theories and numerical modelling approaches, we will (1) evaluate the performance of the prototypes, and (2) examine the failure modes, detachment forces, traction force distributions and ductility under controlled external factors. The scaling up effect will be studied by examining the performance of the prototypes at different length scales. Investigation will also be conducted to examine the adhesion on different types of substrates, i.e., rock and soil. The optimised designs will be achieved via verified parameter studies, which can act as the guidance for engineering designs. Assessment in terms of likely cost and technical effectiveness will also be conducted based on the optimised designs.