The properties ofvan der Waals heterostructures can be precisely controlled by twisting the stacked atomic layers, opening the way for the use of this unique degree of freedom for the nanoscale control of composite materials and nano-devices in future technologies. New work suggests that all 2D materials could also be rolled into their 1D counterparts and a plethora of function-designable 1D heterostructures could be realized. Unlike semiconductor nanowires or mono-elemental nanotubes, ...