Biomimicry

"The pomelo is a large citrus fruit, somewhat like a grapefruit, and the structure of its thick rind provides great impact protection when the fruit falls off the tree. BMW, along with a group of German companies and universities, have taken inspiration from nature’s design for new protective gear as part of the Bio-Inspired Safety Systems project. The pomelo’s rind is especially good at impact absorption because it is an auxetic material. This means that when the stuff stretches the substance becomes thicker."

"If you ever find yourself watching hedgehog go about its day, you’ll notice that they tend to fall out of trees — a lot. Wild hedgehogs climb trees as high as 30 feet, looking for insects and food to eat. Sometimes they fall by accident, other times they fall on purpose to evade a predator or because falling is a lot faster than climbing down. As a hedgehog falls toward the ground, it keeps itself safe by rolling into a ball to surround itself with “spines” that absorb the impact. (Hedgehog spines are colloquially referred to as “quills,” which is the official term for what porcupines have. Hedgehog spines function differently, however, than porcupine quills.) It’s an effective method of protection — and one that humans want to steal."