Soft materials are irreplaceable in applications where large reversible deformations are needed. These include elastomers for engineering (e.g. rubber, soft robotics, wearable electronics) and hydrogels for life sciences (e.g., artificial tissues, soft prosthetics). Although mechanical strength is only essential for some applications, poor fracture toughness, durability, and lifetime remain important limitations. Our laboratory uses molecular design as a tool to fundamentally understand the structure-property relationships to design the soft, tough, and processable (i.e., recyclable) materials necessary for a more energy-efficient and healthy society.