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Inspired by mussels protein adhesives, two series of catechol‐functionalized Linear‐Dendritic Block Copolymer (LDBC) adhesives are synthesized. They show lap shear adhesion strength as high as 7 MPa on aluminum substrates and adhesion up to 3 kPa on porcine skin. These water‐soluble LDBCs are composed of i) either poly(ethylene glycol) (PEG) or poly(ethylene glycol)‐poly(propylene glycol)‐poly(ethylene glycol) triblock copolymer (Pluronic F‐127) as linear polymers, ii) Bis‐MPA dendrons of generation 0, 1, and 2 as dendritic parts, and iii) 2, 4, or 8 terminal catechol moieties. A LDBCs generation comparative test on aluminum reveals a clear dendritic effect: the LDBCs of second generation display higher adhesion than the LDBCs of first generation that also display higher adhesion than the LDBCs of generation 0 for both series, assessing thus a positive dendritic effect in adhesion. Second, a comparative study is carried out between the LDBCs based on PEG and the ones based on Pluronic. The ability of the Pluronic LDBCs to self‐assemble in water appears to reduce adhesion when applied on aluminum whereas it is essential to obtain adhesion on porcine skin, thanks to the formation of hydrogels, as observed by the vial inversion technique and electron microscopy. [ABSTRACT FROM AUTHOR]

Biological organisms exist in an astounding array of habitats. The materials produced by these organisms correspondingly exhibit significant diversity in function and form. Highly ordered and structured biological materials have been the subject of intense scientific investigation, especially in the context of exploring possible models for functional materials. Biological materials lacking in organized structure, on the other hand, such as barnacle exoskeletons, have largely been ignored. Here disordered biological materials falling into four different classes are discussed: soft and organic, hard and organic, soft and a composite of organic and inorganic, and hard and a composite of organic and inorganic. Across the examples within each class of materials one can see disorder at different length scales providing increases in fracture resistance or flexibility, suggesting disordered biological materials have much to teach us in terms of materials design. Disordered biological materials are found throughout biology. Herein, materials from four different classes are explored: soft and organic (mussel byssus, human skin), hard and organic (hedgehog quills), soft and an organic/inorganic composite (oyster adhesive, tuatara shells), and hard and an organic/inorganic composite (barnacle exoskeleton, oyster shells). Within each class disorder is found to provide increased flexibility and fracture resistance. [ABSTRACT FROM AUTHOR]