Regarding the potential application of nanoscopic materials, the research focus is shifting towards three-dimensional anisotropic nanostructures. As a current example, this talk will introduce the importance of tetrapod-shaped nanostructures towards the engineering of smart 3D nanomaterials. A simple flame based single step approach was developed for the synthesis of zinc oxide tetrapods. These tetrapods have been used as building blocks to construct highly porous interconnected 3D nanoscale networks in the form of flexible ceramics. Additionally, these smart nanoscale networks can be utilized as sacrificial templates for the development of hollow tetrapodal 3D networks from almost any desired material (e.g. carbons, nitrides, oxides, polymers, hydrogels). The sacrificial template-based strategy offers new and unique opportunities in the construction of 3D nanomaterials, which will be demonstrated in this talk with several examples. Moreover, the potential applications of these 3D structured smart materials in the fields of sensing, electronics, optoelectronics, energy, and biomedical engineering will be highlighted.