Imagine a swimsuit that makes you glide through water like a shark — faster, smoother, and with less effort. Sounds like something out of a sci-fi movie, right? Well, after a fun collaboration with Prof. Shivendu Ranjan, Nano Bio Research Lab, Dept. Of Nano Science and Technology, IIT Kharagpur, we believe this is a real possibility. Here, we discuss one of the coolest examples of biomimicry — the art of taking inspiration from nature to solve human problems.

What’s So Special About Sharkskin?

According to an article published by Royal Society Publishing Organisation, Sharks are built for speed. Their skin isn’t smooth at all — it’s covered with tiny, tooth-like scales called dermal denticles. These denticles create tiny grooves along the shark’s body that reduce drag and turbulence in the water. These denticles have pulp and cavity covered with enamel or vitrodentine. Micro/Nano hierarchical structures on the Sharkskin have been discovered and 2–7% drag reduction rate observed due to Microgroove Riblet like structure.

How It Actually Works

It solves one of nature's most fundamental problems. Friction drag is the most basic type of fluid drag where the water right next to the body moves very slowly (almost stuck), the water farther away moves faster. This difference in speed creates the drag. The Sharkskin’s microscopic ridges do something special! They control the boundary layer, keeping the faster-moving water from mixing too much with the slower layer close to the skin, hence reducing drag.

Here's an interesting fact: During the 2008 Beijing Olympics, swimmers wearing Sharkskin-inspired suits broke more than 90 world records! The suits were so effective that the International Swimming Federation (FINA) eventually had to ban full-body versions to keep the competition fair. Talk about performance bordering on cheating!

Many Television Series have explored the idea of applying Nanomaterials Biomimicry such as the 'Iron Man' Suit or Memory Chips from 'Black Mirror', but none have applied the possibility of a cutting-edge Sharkskin based Outfit. Viewers will get inspired by the awesomeness of this technology only if they notice something similar worn by the heroes they idolise.

Technologies to make it Industry Specific

When scientists decided to copy Sharkskin, the challenge was clear: "How do we make millions of microscopic grooves just like a shark’s skin on man-made materials?” Some methods discussed by Prof. Ranjan include Laser based micro-etching or lithography, like making computer chips. They engrave minute ridges and grooves using lasers. Another is Nanoparticle-based paints or polymers, applied on the surface. When they dry, they auto-organize to produce riblet patterns like Sharkskin. Industries have full liberty to use any other method and innovation to design such Swimsuits with more emphasis on R&D.

What Challenges associated?

He also highlighted some of the major challenges associated with replicating it. The biggest challenge is reproducing Sharkskin’s microscopic patterns on a large, industrial surface. Most of the materials come in the Nano/Micro Scale and the accuracy along with compatibility with the user wearing it needs to be spot on. Surface abrasion and loss of sensitivity as well as Biofouling (marine organism buildup) lead to decrease in effectiveness. The agonising aspect is regulation and standardization whereby they must undergo rigorous safety and performance certifications.

An interesting observation is that the grooves inside the material guide air or rainwater in ways that keep dust and dirt from settling. So, building materials that have self-cleaning property, can also be applied in architecture and Medical Technology. Sharklet, a surface pattern used on medical devices reduces bacterial growth without using antibiotics or chemicals. Now, that is Real innovation!

Sharkskin didn’t just help sharks swim faster, it helped humans reimagine the way we move, build, and protect our civilization. We have applied the idea on many technologies and real-world applications. This has motivated building of more efficient Ships, Aeroplanes, Motorbikes and other transport phenomena.

Conclusion

Limitless possibilities arising out of a simple idea has proved our resourcefulness from time to time. Innovation such as these have allowed us to create solutions that are smarter, greener, and more efficient. A new generation of enthusiastic researchers have a responsibility to go deeper into the intricacies of such a revolutionary technology. A technology that can very easily redefine how we swim, fly, and move across the world. In fact, it probably is nature's way of telling us “The answers have always been here. You just had to look closer.”