Reverse Engineering (Industrial Application)

The Animal

The hedgehog is an animal with sharp little spines protruding from its back as a form of their defense mechanism. Belonging to the subfamily of Erinaceinae, there are a total of 17 different types of hedgehog species and they are found throughout the parts of Asia, Europe and Africa. The hedgehog has evolved very little over the years and this makes the hedgehog fall under the ‘first mammal’ category and are therefore nocturnal creatures. The diet of hedgehog consists of mainly insects, snails, fruits berries and others.

Figure: Hedgehog

How it works?

The hedgehog is recognized by its spines which are actually hollow hairs made stiff by keratin. The spines are neither poisonous nor barbed unlike their older cousin, the porcupine. The spines are controlled by large muscles which control the position of the quills. When threatened, the hedgehog rolls into a ball to protect its soft belly.

Figure: Quill of a hedgehog

The development of the continuous spiny cover and the adaptation to passive defence in mammals have resulted also in notable morphological transformations of the subcutaneous muscles. Their functional significance is to serve the entire spiny armour mobility. Hedgehogs are characterized by the most complicated, three-layered structure of the m. cutaneus maximus. In hedgehog tenures and echidnas, the transformation of the subcutaneous muscles proceeded in the same direction as in hedgehogs, although was not as deep, being confined to two-layered structure.

Figure 2: Scheme of transverse (a) and tangential (b) sections of a skin in region of the spine ar-mour from: 1 - Erinaceus concolor; 2 - Echinops telfairi; 3 - Tachyglossus aculeatus; 4 - Hystrix indica; 5 - Hemicentetes semispinosus. AP - mm. arrectores pilorum; CM - m. cutaneus maximus; SB - spine bulb; SC - spine case.

Thus, it can be noted the most advanced mechanism of passive defence has undoubtedly developed in hedgehogs. The passive defence in echidnas is also sufficiently effective although it is based upon essentially different and probably more ancient and primitive mechanism.

The other pathway of spiny mammals' specialization is related to the active defence by means of the spines. Such strategy is a characteristic of some tenrecs (Hemicentetes) and porcupines (Hystrix). A common feature of their spines is the unique ability to be easily detached from the animals and to be attached to enemy skin. Different tactics however can be used by these mammals in dangerous situations.

The Product

The product which is inspired by the hedgehog is the safety helmet. The spines act as a damper inside the helmet to dissipate energy when it comes into contact with pressure. It could totally alter the helmets which are used now in terms of safety and comfort.

Figure: A curled hedgehog compared to the safety helmet

As viewed in the image above, the similarities compared to a hedgehog in a defensive position is similar to that of the newly designed helmet. The helmet would consist of light weight material such as polycarbonate to withstand the initial impact and a memory foam to further absorb energy before being experienced by the wearer.

Other biomimicry examples

Engineers and other researchers have long been using nature as a reference in order to improve their innovation. From the replication of the denticles on the shark skin in order to reduce drag while moving, to the invention of Velcro from the Burdock plant, many inventions are based on nature. Therefore in order to achieve sustainability, biomimicry should be implemented in every aspect of innovation. In order to achieve this, the term biomimicry and its importance should be highlighted during early stages such as schools all the way to the working world.