Advanced Engineering Materials
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
(Advanced Biomaterials 7/2010)
The siliceous spicules from sponges (diameter approximately 25 μm) are fabricated enzymatically. These star-like skeletal structures act as light optical fibers. It is amazing that those waveguides still retain that property after 400 million years; (a fossil from the famous Chinese fossil area Chengjiang).