Flex your mussels: Harnessing nature's designs to build next-generation materials

Marine mussels create an array of adhesive contacts (the byssus) to secure themselves to rocks, wood, metals and other mussels in the harsh conditions of the intertidal zone. Their superb mechanical and adhesive performance has served as inspiration to create mussel-inspired materials for a wide range of applications ranging from surgical glues to primers and coatings. Historically, much of this success has relied on mimicry of the molecular properties of the mussel's adhesive interfacial proteins. By contrast, the translation of the meso- to macro-scale properties of the natural materials has been comparatively unexplored, providing rich opportunities for further property enhancement to create tough, durable, load-bearing materials. Here, I will present my laboratory's recent work characterizing the properties of natural mussel byssal plaques, and translating these discoveries to enable the design and manufacture of new materials. Experimentally, we observe the dynamics of mussel plaques as they debond from glass using a custom built load frame with integrated dual view imaging capabilities, under monotonic and cyclic loading. We pair these mechanical tests with ultrastructural analysis to understand the molecular origins of strength and toughness. Using insights from the natural materials, we then create high-performance synthetic materials that are extremely strong without compromising extensibility, as well as mussel-inspired 3D structures with tunable stiffness and strength. These innovations open new possibilities for applications of mussel-inspired materials in packaging, soft robotics, and connective tissue repair, and demonstrate the importance of understanding the multiscale, multiphase properties of biological materials.