Well protected from deep fall - pomelo and coconut

From nature ...

Seeds contained in fruits ensure the persistence of a plant species. Animals, wind or water spread them in many ways, even over long distances. Heavy fruits, when ripe, sometimes fall directly to the ground from great heights. The pericarp cushions the impact, so that the seeds of coconuts or citrus fruits survive unscathed. In the course of evolution, "protective shells" with excellent shock-absorbing, puncture-resistant properties and relatively low weight have developed.

To mitigate the impact consequences, fruit walls combine the shock-absorbing effect of fibrous or highly aerated tissue with hard or tough components as puncture protection.

... to technology

The biological model inspired the idea of fiber-reinforced metal foams with puncture-resistant top layers. In protective clothing, helmets and protectors, this material can also protect people from the consequences of an impact. Researchers from Freiburg, Berlin and Aachen are working together on an interdisciplinary basis to develop the material.

Image captions

Pomelo shells consist of air-containing tissue and a tough outer wall.

Coconut (Cocos nucifera L.) in longitudinal section: a cushioning fibrous and a puncture-resistant solid pericarp layer protect the embryo. The fibrous layer is usually removed before sale.

Schematic structure of the fiber-reinforced metal foam.

Text of the information board in the Botanical Garden