If they’re unlikely to fracture, they’re still getting fatigue-damaged through continual stress, but if they’re good at resisting fatigue-damage, they may snap from shock or extreme stretching. Now researchers at Switzerland’s École Polytechnique Fédérale de Lausanne (EPFL) have developed a solution: a 3D-printable elastomer that resists damage from single, extreme shock and from continual wear-and-tear. That’s because DNGEs shift mechanical strain during stretching from their stiff particles to the soft matter connecting them. By spreading stress via polymer chain rearrangement instead of allowing polymer bonds to break, the DNGEs continually reduce the risk of sudden snapping or fatigue-degradation. “Essentially, the two different networks – one made of granular elastomer particles and one of soft elastomer – share mechanical strain between them, making the material stronger overall,” says Amstad.