3D printed fish scales inspires new types of body armor

Future soldiers may be wearing fish-inspired body armor

That industrial designers can learn from nature is not such as strange notion, but the extent to which that counts is astounding. After several billion years of organism evolution, nature has pretty much done it all – from gecko’s who can climb walls with special feet, incredibly effective snake venom, to extremely lightweight and powerful spiderwebs, we can learn a thing or two from mother nature.

That’s exactly approach Ranajay Ghosh, associate research scientist at the College of Engineering at Northeastern University has been doing. His forte is skin, and he has been combining 3D printing with mother nature’s incredible dermatological varieties to develop the next generation armor, and the results are pretty impressive.

Design inspired by nature is called biomimetics or biomimicry, but until recently scientists hardly had the technology to truly recreate natural patterns. But 3D printing, among others, has so far proven to be very capable of competing. ‘Dermal modification is a significant part of evolution,’ Ghosh reveals. ‘Almost every organism has something on its skin that provides important survival properties such as protection from predators, camouflaging, thermal regulation, and sensorial functions. In many animals, this evolution has led to the formation of scales.’

That is exactly why Ghosh and his research team, led by associate professor Ashkan Vaziri, have been looking at various animals with scales to be inspired to develop the newest generation of armor systems. Specifically, they have been studying the mechanical behaviour of scales of animals such as snakes, fish and butterflies (who have miniscule scales on their wings. This has resulted in a very interesting article, recently published in the December issue of the Journal Applied Physics Letters.

While you might not immediately realize, fish and snake scales, actually provide a great balance between mobility and protection, thanks to millions of years of natural selection. The tiny scales on butterfly wings, instead, have very useful optical properties that can be mimicked to create camouflage. These properties, if transported to humans, could be very useful indeed. ‘The next generation of armor systems are light, perform a lot of functions, and at the same time do not compromise on protection, Ghosh explain, and nature provides very important information in terms of armor development.’

As they reveal in their article, Ghosh and his team have therefore used 3D printing to recreate fish scales which proved to be very successful in combination with a soft substrate (such as your body). As they discovered, these very thin 3D printed fish scales made the substrate far less penetrable and much stiffer, while weighing very little. ‘This is very different from what people have been working on before, which is focusing on the very nature of the scales themselves, how they will behave, and whether they break easily or not,’ Ghosh added. ‘Here, our focus is simply the effect of simple scales and their mutual contact and interaction with the soft substrate.’

As revealed in their paper, these fish-like scales were simply 3D printed in ABS using an Objet Eden333 3D printer. The substrate used to represent man was made from VPS silicon, shaped using a 3D printed ABS mold printed with the same machine.

Theoretically, fish scale armor could therefore be used to make much tougher and more versatile armor, though the research team ultimately hopes to combine properties of a number of nature’s scales into a single system. The mobility of snake scales, for instance, is also a very welcome addition. ‘We can synthesize what nature could not do because we have more flexibility with the materials we use,’ Ghosh said.

In the coming months, the team now hopes to use their combination of 3D printing and nano-fabrication to further combine various natural characteristics, to create a truly modern piece of armor.