"Over the past years, carbon nanomaterial such as graphene and carbon nanotubes (CNTs) have attracted the interest of scientists, because some of their properties are unlike any other engineering material. Individual graphene sheets and CNTs have shown a Youngs Modulus of 1 TPa and a tensile strength of 100 GPa, hereby exceeding steel at only a fraction of its weight. Further, they offer high currents carrying capacities of 10^9 A/cm², and thermal conductivities up to 3500 W/mK, exceeding diamond. Importantly, these off-the-chart properties are only valid for high quality individualized nanotubes or sheets. However, most engineering applications require the assembly of tens to millions of these nanoparticles into one device. Unfortunately, the mechanical and electronic figures of merit of such assembled materials typically drop by at least an order of magnitude in comparison to the constituent nanoparticles.In this ERC project, we aim at the development of new techniques to create structured assemblies of carbon nanoparticles. Herein we emphasize the importance of controlling hierarchical arrangement at different length scales in order to engineer the properties of the final device. The project will follow a methodical approach, bringing together different fields of expertise ranging from macro- and microscale manufacturing, to nanoscale material synthesis and mesoscale chemical surface modification. For instance, we will pursue combined top-down microfabrication and bottom-up self-assembly, accompanied with surface modification through hydrothermal processing.This research will impact scientific understanding of how nanotubes and nanosheets interact, and will create new hierarchical assembly techniques for nanomaterials. Further, this ERC project pursues applications with high societal impact, including energy storage and water filtration. Finally, HIENA will tie relations with EU’s rich CNT industry to disseminate its technologic achievements."