Richard Palmer and Philip Green

Flexible armour that hardens on impact

Technical field
After years of trial and error in both their kitchen and the lab, British material scientists and passionate snowboarders Richard Palmer and Philip Green developed a material which is flexible but stiffens on impact. The unusual properties of dilatant liquids to absorb and disperse energy made this invention perfect for a wide range of protective applications.

Finalists for the European Inventor Award 2019

In many sports, protection from sudden collision is a must in order to avoid serious injury. Until recently, the only protection available to sportspeople came in the form of rigid and uncomfortable padding, the inflexibility of which could hinder performance. Putting their engineering backgrounds to good use, the pair were determined to improve protective clothing.

In the late 1990s, Palmer and Green began experimenting with a dilatant liquid that had never found a commercial application beyond children's toys. The liquid has non-Newtonian properties, meaning that unlike water, it is free-flowing when stationary but becomes instantly rigid upon impact. As keen snowboarders, they drew inspiration from snow and decided to replicate its matrix-like quality to develop a flexible material that incorporated the dilatant fluid. Palmer and Green experimented with many different materials but soon realised that the liquid needed to be dissolved into a liquid precursor of polyurethane foam as a true composite and not an impregnation or coating. It was through this discovery that the duo invented a flexible, pliable material that locks together and solidifies in the event of a collision. When incorporated into clothing, the material - named D3O after the laboratory in which they had been working - moves with the wearer but still offers comprehensive protection.

After perfecting their formula, a patent application was successfully filed, and Palmer and Green were able to use it as the foundation for commercialising their invention.

The company that Palmer and Green originally set up - which trades under the name D3O - is today a fast growing engineering, design and technology-focussed SME based in London, in the UK. It also has offices in China and the US. D3O is now sold in more than 50 countries and has been adopted by leading brands such as 3M, CCM, Scott Sports and Triumph. Now established beyond the sporting goods market, D3O is being used in motorcycle gear, protective cases for consumer electronics including phones, industrial workwear and military protection including helmet pads and limb protectors.

Palmer, originally from Birmingham, and Green, from Hertfordshire, both met in the late 1990s while working together at the University of Hertfordshire, near St. Albans, UK. After developing the material, Palmer and Green set up their own business in 1999. Although D3O is now highly successful, Palmer and Green's journey required dedication and commitment. But their belief in its potential was so strong that Palmer even sold his house and belongings to raise funds, sleeping on a friend's sofa for many months.

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