Nanomaterials are key to many modern applications in sensing, health, energy, and information technologies. But the fabrication of nanomaterials usually relies on unsustainable use of rare earth materials and environmentally unfriendly and techniques up to cleanroom standard. Recent investigations showed that microscopic algae named diatoms evolved highly periodic nanomaterials with photonic properties. The nanomaterials form in a bio-silicification process in vivo, bearing highly reproducible, low cost, environmentally friendly, and high-quality properties on the same standard as artificially produced nanomaterials. The objective of InterNano is to prospect the use of diatoms, especially the benthic forms that inhabit coastal sediments, as a future natural and alternative resource for nanomaterials.