The U.S. Army is upping its investment in genetically engineered spider silk for body armor. Last year, the service paid almost $100,000 to Kraig Biocraft Laboratories, which makes spider silk that can be produced at scale — with silkworms. On Wednesday, the company announced that the Army will move to the second phase of the contract and will look to Kraig to produce a customized strain of the silk for “high-performance fibers for protective apparel applications.” That is: flexible body armor made from genetically engineered spider silk. The total contract amount would reach $900,000 if parameters are met. Army representatives said that interested in the material purely from a research perspective, for now.

Kraig Biocraft injects spider DNA into silkworm eggs, enabling the worms to produce its custom silk. The researchers describe the process in this 2011 PNAS paper.

Depiction of spider protein modifications to the Bombyx mori genome to create transgenic spider silk in silk worms. PNAS vol. 109 no. 3 > Florence Teulé, 923–928, doi: 10.1073/pnas.1109420109

Spider silk is much tougher than regular worm silk, and about half as tough as Kevlar. But it’s far more flexible, (3 percent elasticity for kevlar versus nearly 40 percent for spider silk.) The Army believes that the energy absorption of the material could be much higher than kevlar (as determined by multiplying the strength of the fiber by the elongation.) Full Article