Nanofabrication Using Silk (image) Tufts University Share Print E-Mail Caption At Tufts University School of Engineering, optical-grade silk fibroin aqueous solution, obtained from the cocoons of the Bombyx mori caterpillar, was placed on a substrate and spin-coated to form a silk film. Both positive and negative resists were formed and developed using water. Credit Tufts University Usage Restrictions For education and news use only with proper credit and caption Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.