Dutch artist Jalila Essaïdi in collaboration with the Forensic Genomics Consortium Netherlands (FGCN) created a material that can repel a moving bullet made out of spider silk and human skin cells. Bulletproof Skin uses spider silk because it is proportionately stronger than steel. It was able to repel a reduced speed bullet however it failed to repel a normal speed rifle, but they may perfect it one day. 

[via Designboom]