Abstract: In a method of depositing a fibroin structure, a fibroin ink is generated. The fibroin ink is aerosol jet printed onto a substrate. To prepare the ink, a plurality of biologically-generated silk cocoons are each cut into at least two pieces of raw silk and are degummed to remove sericin, leaving fibroin fibers. The fibroin fibers are dissolved into a lithium bromide solution. The salt is removed by placing the fibroin/salt solution in a dialysis membrane tube and submerging it in deionized water. The fibroin solution is centrifuged to remove impurities therefrom, leaving fibroin ink. The fibroin ink is atomized into a fibroin ink aerosol, which is directed to a print nozzle. A focusing gas sheath is directed around the print nozzle to deposit fibroin onto a surface.