Structural material from MIT is a nanofibrous hydrogel arranged in a bouligand structure which helps mitigate damage from external forces.


  • Stronger
  • Flexible
  • Biocompatible


  • Armor and protection
  • Medical implants

UN Sustainable Development Goals Addressed

  • Goal 3: Good Health & Wellbeing

  • Goal 9: Industry Innovation & Infrastructure

The Challenge

Protection gear such as helmets and guards are often made of plastic or styrofoam. These materials decompose slowly and are susceptible to cracking, making them both environmentally harmful and ineffective as protective equipment. Often additional material must be added to the product to ensure sufficient function, making gear bulky and resource-consuming.

Innovation Details

The flexible and resistant protective material is made of nanofibrous hydrogels stacked in a bouligand structure. The ultrathin fibers of hydrogel (approximately 800 s in diameter, a fraction of the diameter of human hair) are created through a process called electrospinning in which the threads of hydrogel are drawn out of a solution using an electric charge. The hydrogels are then made into a film and placed in a stack to be welded together in a high-humidity chamber. The films are stacked in a rotating pattern called the bouligand structure, resembling a spiral staircase or a twisted deck of cards. After welding, the film stack is set using an incubator to crystallize the nanofibers, further strengthening the material. The resulting material is more fatigue-resistant and durable than traditional nanofibrous hydrogels.

Biomimicry Story

Lobsters have hard shells that protect them from predators and other sea creatures, but the underbelly of their shells are soft and flexible, allowing them to maneuver easily along the seafloor. The fatigue-resistant hydrogels in the protective material mimic the bouligand structure of the natural hydrogel occurring in lobster underbellies. The bouligand structure gives the natural hydrogel high tensile strength and fracture toughness, which is also observed in the improved protective material.