Shrilk

Another interesting one from CleanTechnica:

Shrilk is composed of fibroin protein from silk and from chitin. The material is similar in strength and toughness to aluminum alloys, but is only half the weight. Since chitin can be extracted from discarded shrimp shells it can be produced at very low cost. It is also biodegradable and can be molded into complex shapes. By controlling the water content in the fabrication process, the researchers were also able to vary the stiffness of the material, ranging from elastic to rigid.