01 Oct 2018 |
World innovation news |
Innovative Materials and Advanced Manufacturing
Diving in Icy Waters Using a Biomimetic Material
Header image purchased on Istock.com. Protected by copyright.
Today, garments owe their functional efficiency to intelligent materials and fabrics. These fabrics expand a garment’s usage and optimize its protective function. Since the development of the biomimetic approach in the early 2000s, engineers, architects and designers have been resolving conceptual issues by mimicking nature. A team from the Massachusetts Institute of Technology found inspiration in the animal world, using two systems to outfit an elite unit of the US Army, producing a garment that will also prove useful in other areas.
As its name suggests, artificial blubber is a material that mimics fat. That is to say that the material performs the same function as body fat in protecting from the cold. It is used in the design of diving suits that can withstand icy water temperatures. The artificial blubber is the result of a two year-long collaboration between Michael Strano professor of chemical engineering, Jacopo Buongiorno, professor and director of the Department of Nuclear Science and Engineering, and the United States Navy. The technology meets requirements expressed by the Navy SEALs, the US Navy’s special force, to optimize and make scuba diving safer. Indeed, the best diving suits on the market are not warm enough to allow for submersion in Arctic waters, rivers, or ponds covered with ice for more than ten minutes. Some models can be easily tampered with, which can be life-threatening for users, as in the case of dry suits whose internal surface is kept away from the skin by a pump operated by divers to blow air inside the suit.
This type of suit involves special diving techniques and a pump malfunction can be fatal for the diver.
Researchers at MIT and George Mason University have designed a material that can be used to make a simple suit that does not require special systems or manipulation by divers.
Source of Inspiration
The team was inspired by two animal strategies to fight against the cold. In order to maintain their body temperature, species living in polar areas have special protection systems:
- A layer of insulating material that significantly slows body heat loss, for example seal and whale fat.
- Air pockets trapped in fur or feathers, as found in otters and penguins.
The artificial blubber is made from standard neoprene wetsuits. These suits are placed in high pressure, 243 kPa, in a heavy inert gas environment for about one day. The technique involves replacing trapped air in the neoprene structure with the heavy, inert gas (such as xenon or krypton). The study showed that a diver wearing this type of treated suit can withstand temperatures below 10 °C for 2 to 3 hours.
The next step is to find a manufacturing process that can trap xenon or krypton in the neoprene structure. The material obtained with the current study method will be tested by users to collect more information on its performance.
The study entitled “Noble-gas-infused neoprene closed-cell foams achieving ultra-low thermal conductivity fabrics,” published in the RCS Advanced journal in June 2018, was co-authored by Jeffrey L. Moran, Anton L. Cottrill, Jesse D. Benck, Pingwei Liu, Zhe Yuan, Michael S. Strano and Jacopo Buongiorno.