Many biological materials display contradicting properties, such as high stiffness yet high toughness, all while containing high water content. Creating synthetic materials with this balance of properties has not been achieved with homogenous materials. Our goal is to develop new, robust composite materials, which exhibit advanced properties, by learning from unique materials in nature.
The laboratory for Soft and Wet Matter has performed pioneering research on developing tough and resilient hydrogels. Although hydrogels are typically weak and brittle, two general approaches lead to an increase in hydrogel toughness: double network hydrogels and polyampholyte hydrogels. Double network hydrogels dissipate energy by repeatedly breaking sacrificial covalent bonds, while polyampholyte hydrogels dissipate energy by breaking re-formable ionic bonds. These mechanisms take place at the molecular level, enabling hydrogels to dissipate large amounts of energy before fracture.
Our current interest lies in exploiting our knowledge of these two systems to develop tough composite materials by utilizing analogous energy dissipating mechanisms at larger length scales. Within a soft, hydrogel matrix, we are incorporating liquid-crystalline polymers, metal alloys, and textiles to develop unique composites which approach the strength of strength of structural materials yet possess the biocompatible attributes of hydrogels.