Pearl – A Nano-Composite & Natural Super Dielectric
Pearl is a bio-originated valuable natural gem and it is also cultivated or harvested for jewellery. In this paper, the material aspects of pearl have been investigated experimentally and it has been found that it has a very high static dielectric constant ~ 105. The functional nature of the material is also established in this work. The beautiful lustre of natural pearl is explained by nano-optics and the layered structure of the material. The origin of super-dielectric nature of pearl has been explained by lightning rod effect (LRE) that causes ultra-high polarization of the dielectric background. The LRE is due to the presence of very small sized nano-particles in the natural pearl. Its electrical conductivity is mostly ionic, only less than 10% of the total conductivity is electronic. The scope of tailoring of its electro-activity has been probed.
S.S. Pradhan and A. Sarkar, "Pearl – A Nano-Composite & Natural Super Dielectric", Journal of Biomimetics, Biomaterials and Tissue Engineering, Vol. 11, pp. 1-12, 2011