Inspired by seashells, engineers have built synthetic materials with programmable layers that adapt to impact.

To reduce irritation, the mollusk coats the intruder with the same secretion it uses for shell-building, nacre. To culture freshwater mussels, workers slightly open their shells, cut small slits ...

This creates a material called nacre, also known as mother-of-pearl, which encases the irritant and protects the mollusc from it. When pearls are cultured commercially an irritant is manually inserted ...