Technology Overview

Sharklet Technology Overview

The Sharklet Micropattern

The primary Sharklet micropattern is very small – about 3 microns tall and 2 microns wide. You cannot see the micropattern with the naked eye and you can’t feel it with your finger, but it’s there, protecting the surface against bacteria and other microorganisms.

There are many variations of the Sharklet pattern that we make. Positive patterns protrude from the surface, and inverse patterns are recessed into the surface of the material. We can also modify the dimensions of the pattern depending on the application. Wider patterns have increased optical clarity due to less diffraction of light. These wider patterns are useful for applications where Sharklet will be covering something that needs to be observed, like a phone screen or a computer monitor in a hospital.

The positive Sharklet micropattern. This specific shape – uniform widths, diamond pattern, shared small feature – are all contributors to Sharklet’s antimicrobial properties

Sharklet Antimicrobial

Why Sharklet?

Many industries use a variety of tools to combat the spread of bacteria. These include:

  • Personal maintenance – Washing your hands, using hand sanitizer, avoiding contact with eyes and face
  • Antibiotics – Powerful medications that kill bacteria
  • Chemicals – Sprays and solutions meant to sterilize surfaces

These precautions are effective and work most of the time – but each has a shortfall. The passenger next to you on the train is not as diligent with hand washing as you would hope. The door handle has all sorts of bacteria on the surface, even between cleanings. Antibiotics are effective, but eventually some strains of bacteria become resistant to antibiotics. Using chemicals comes with a heavy cost, between their environmentally unfriendly manufacturing and dangerous side effects.

Sharklet is the solution. The antibacterial properties of Sharklet are not a result of harsh chemicals or antibiotics – they are purely structural. This is due to the unique shape and configuration of the Sharklet micropattern.

Inspired by Nature: The Discovery of Sharklet

While Sharklet holds great promise to improve the way humans co-exist with microorganisms, the pattern was developed far outside of a laboratory. In fact, Sharklet was discovered via a seemingly unrelated problem: how to keep algae from coating the hulls of submarines and ships. In 2002, Dr. Anthony Brennan, a materials science and engineering professor at the University of Florida, was visiting the U.S. naval base at Pearl Harbor in Oahu as part of Navy-sponsored research. The U.S. Office of Naval Research solicited Dr. Brennan to find new antifouling strategies to reduce use of toxic antifouling paints and trim costs associated with dry dock and drag.

Dr. Brennan was convinced that using an engineered topography could be a key to new antifouling technologies. Clarity struck as he and several colleagues watched an algae-coated nuclear submarine return to port. Dr. Brennan remarked that the submarine looked like a whale lumbering into the harbor. In turn, he asked which slow moving marine animals don’t foul. The only one? The shark.

Dr. Brennan was inspired to take an actual impression of shark skin, or more specifically, the dermal denticles. Examining the impression with scanning electron microscopy, Dr. Brennan confirmed his theory. Shark skin denticles are arranged in a distinct diamond pattern with tiny riblets. Dr. Brennan measured the ribs’ width-to-height ratios which corresponded to his mathematical model for roughness – one that would discourage microorganisms from settling. The first test of Sharklet yielded impressive results. Sharklet reduced green algae settlement by 85 percent compared to smooth surfaces.

While the U.S. Office of Naval Research continued to fund Dr. Brennan’s work for antifouling strategies, new applications for the pattern emerged. Brennan evaluated Sharklet’s ability to inhibit the growth of other microorganisms. Sharklet proved to be a mighty defense against bacteria.

Similar to algae, bacteria take root singly or in small groups with the intent to establish large colonies, or biofilms.

Similar to other organisms, bacteria seek the path of least energy resistance. Research results suggest that Sharklet keeps biofilms from forming because the pattern requires too much energy for bacteria to colonize. The consequence is that organisms find another place to grow or simply die from inability to signal to other bacteria.

Dr. Brennan’s and Sharklet Technologies’ research has demonstrated Sharklet’s success in inhibiting the growth of S. aureusP. aeruginosa, VRE, E. coli, MRSA and other microbial species that cause illness and even death.

Sharklet Technologies is proud to produce products with the Sharklet pattern to help make the world a healthier, environmentally safer and better place. We’re equally honored to offer a biomimetic technology inspired by the shark which will allow humans and microorganisms to coexist in a sustainable and healthy way.

Understanding Biomimicry

While human engineers work to solve all manner of problems the world faces, animals and plants have had a 4 billion year head start. Many of the species around today have already optimized themselves to face these challenges – they wouldn’t be around otherwise. By examining nature, we can extrapolate ideas and designs to solve similar problems faced by humans.

As The Biomimicry Institute puts it:

The core idea is that nature has already solved many of the problems we are grappling with. Animals, plants, and microbes are the consummate engineers. After billions of years of research and development, failures are fossils, and what surrounds us is the secret to survival.

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Sharks are unique creatures. Whales, ships, and other objects that travel through the water accumulate algae, seaweed, barnacles, and other types of bio-fouling that decrease their swimming efficiency. But sharks are different – despite moving slowly through the water, their skin remains clean. If you take the design of shark skin and shrink it down, smaller than what humans can see, it has the same effect on bacteria. The same pattern that prevents algae from sticking to the skin of sharks prevents bacteria from sticking to Sharklet.

Sharks evolved to have this pattern on their skin. Our micropatterns were inspired by this pattern and use it to protect humans. Sharklet is one of countless advances in the field of biomimicry. Dr. Anthony Brennan was inspired by both the practical function and mechanical design of shark skin. This inspiration is reflected in the design of the Sharklet micropattern.

Image 1: Shark Skin Inspired Microbiological Control

On the left is an image of a shark skin denticle. On the right is the Sharklet micropattern. Note the similarities in design – diamond pattern and ordered feature lengths.

Image 2: Whale Flipper Inspired Wings

Research has shown that the flippers of humpback whales are grooved, which provides superior dexterity and speed in the water. The same design that helps these massive creatures move quickly in the water can be applied to increase efficiency in wind turbines and aircraft wings and rotors. Read more at www.AskNature.org.

Image 3: Gecko Inspired Adhesives

Scientists have studied the feet of geckos and have found that they contain physical properties that promote stickiness. This stickiness lets geckos hang in precarious positions, yet easily release when they are ready to move again. This structure is being mimicked in adhesives and has wide ranging potential, from fun activities like rock climbing to a role as an adhesive in important medical devices. Read more at www.LiveScience.com