This award supports fundamental research to provide the needed knowledge for the development of soft wet adhesives to achieve extremely high mechanical strength and toughness. In nature, soft wet materials can form extremely tough and strong bonding to other materials. Examples include mussel plaques on rocks, tendons on bones, and bonding between the epidermis and dermis. In contrast, the mechanical properties of most synthetic soft wet adhesives are much inferior to their natural counterparts, which severely hampers their potential applications and innovations. Robust synthetic adhesives based on soft wet materials will find diverse applications in healthcare, biomedical, chemical and marine industries. For instance, tough bio-adhesives for suture-less surgical glues can avoid many inherent complications and drawbacks in conventional suturing, and soft wet adhesives can also be used as biocompatible coatings of various medical devices such as neural probes, bio-sensors and metallic prosthesis. Therefore, results from this research will benefit the U.S. economy and society. This research also includes a coordinated effort to recruit students from underrepresented populations in science and engineering to enter into the exciting new field of mechanics of soft materials.
Soft wet adhesives are widely found in nature and have broad engineering and technological applications. However, existing synthetic soft wet adhesives are severely limited by their low mechanical strength and toughness. This research is to design extremely tough and strong soft wet adhesives by exploiting the molecular-scale reversible crosslinks and macro-scale mechanical instabilities in soft wet materials. The research team will develop a multi-scale model to understand the relationships between molecular-scale reversible crosslinks and macro-scale energy dissipation, construct a phase diagram to elucidate the formation and interaction among different modes of mechanical instabilities in constrained soft adhesives, and develop a set of guidelines for the design of the soft wet adhesives to achieve extraordinary interfacial properties by exploiting reversible crosslinks and instabilities.