A team of Imperial alumni and postdocs are combining silk with graphene to produce next generation armor for people, vehicles and buildings.
“If you were shot by a handgun, Kevlar body armor will save you.” said Dr Gareth Tear, postgraduate researcher in shock physics, and one of the leads on the project. “But the armor required to stop high-caliber rifle rounds and shrapnel requires an outer layer of ceramic, which makes the vest much heavier, hampering movement.”
During the recent war in Iraq, it was reported that the ceramic plates were so unwieldy that British troops actually preferred to remove them in a firefight, further endangering their lives.
This problem inspired Gareth and two colleagues, Dr Gianmaria Bullegas and Dr Jose Videira, to look at fresh ideas for materials that could significantly reduce the weight of body armor. After some investigation, they hypothesized that combining silk with graphene – often called a ‘super material’ for its incredible properties – might be a solution.
The team figured that by improving on the Kevlar layer, then they could reduce the size of the ceramic outer layer, making the vest much more wearable. The researchers turned to silk from silkworms, produced for thousands of years through sericulture. But while this is much easier to produce, it is not as tough as spider silk. To improve this, they added a modern twist – graphene.
The team decided to set up a company – Synbiosys – to explore this idea further, and received project funding from The Defence Science and Security Accelerator (DASA).
The silk-graphene composite is transparent and lightweight, properties that make the material suitable for applications beyond body armor. The team are working to expand on this, and have already seen interest from manufacturers of bullet-resistant glass.
Other areas they think their material will be useful include space, where lightweight materials are needed to protect against fast-moving debris, and medicine, where another characteristics of silk, biocompatibility, is advantageous.