Chitosan extraction (IMAGE) Optica Caption The researchers ground dried crab shells into a powder (left) and then used a chemical process to create a solution suitable for making a diffraction grating (right). Credit Efren G. Gumayan, Ateneo de Manila University Usage Restrictions None License Original content 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.