Nottingham University scientists have found a new source of inspiration for anchoring floating wind farms to the sea bed securely: Mussels.
Sea mussels stick to wet and wave-hit rocks using collagen-rich sticky threads, ending in adhesive pads known as plaques. The design principles of this natural phenomenon could inspire new ways to securely join dissimilar man-made materials, preventing them from pulling apart when subjected to stress and weight.
One such example is the floating foundations of an off-shore wind farm that need to be anchored securely to the sea bed.
Engineers are yet to find a reliable way to fix cables from the foundation into the ground, in a system that can withstand the weight of the turbines and the forces of rough oceans and high winds.
The three-year Nottingham project also aims to mimic the unique structural characteristics of sea mussel plaques and develop ultra-lightweight, porous and durable materials for the aerospace and transportation industries.
Existing research has demonstrated that a plaque core – similar to that of mussels – can achieve good load bearing capacity and strength under tension and shear (forces that cause layers or parts to slide against each other in opposite directions).
In contrast, manmade porous materials such as foams or honeycombs have very limited load bearing capacity and strength under the same forces.
The team will also characterize the adhesive structure of a mussel plaque using advanced imaging facilities at the University.
They plan to use 3D printing technology or Electron Beam Lithography to recreate surface texture patterns of materials such as silica glass, silicone rubber and polycarbonate down to the micron-scale.
Once this is done, they will use those findings to manipulate the stiffness and the surface texture pattern of materials to understand how this can influence plaque adherence.
The Nottingham team is also mulling on building a test rig to analyse how the plaque responds to various loading scenarios when it is attached to different materials.
They will further adopt Traction Force Microscopy (TFM) to measure the forces exerted by a mussel plaque on a surface it is gripping.
Image and content: WindEurope.Org via Forbes/University of Nottingham