Researcher Randy Lewis of Utah and his collaborators gained worldwide attention recently when they found a commercially viable way to manufacture silk fibres using goats and silkworms that had spider genes inserted into their make-up. Spider silk is one of the strongest fibres known and five times stronger than steel. Lewis's fibres are not that strong but much stronger than silk spun by ordinary worms. genetically engineered spider silk can be used to help surgeons heal large wounds and create artificial tendons and ligaments. He has about three dozen of the genetically engineered goats. He extracts proteins from the special milk then spins them in a way that replicates a spider's method, resulting in a strong, light-weight fibre. 'Bulletproof' skin: researcher creates silk that helps stop bullets Scientists are amazing. No wonder many think what they do a "magical".