| The connection between the macroscopic properties of bulk material and the microscopic features of the constituent molecules is the essential theme that permeates the field of liquid crystals. Here, relying on the unique features of DNA origami structures and filamentous viruses, we engineer the shape and interaction of the microscopic building blocks. These versatile building blocks assemble into macroscopic soft material with novel structural, optical and mechanical properties. In the first part, we demonstrate robust assembly of DNA origami filaments into bulk cholesteric liquid crystals, 1D supramolecular twisted ribbons and 2D colloidal membranes. By precise control over the chirality of the DNA origami filaments, we establish a quantitative relationship between the microscopic filament structure and the macroscopic cholesteric pitch. Furthermore, we show that 1D twisted ribbons that are assembled from DNA origami filaments, behave as effective supramolecular polymers. Their structural and mechanical properties can be precisely tuned by controlling the geometry of the building blocks. We also show that stability of colloidal membranes is a consequence of universal excluded volume interactions. In the second part, we use filamentous viruses of two different lengths, to study formation of colloidal membranes that are simultaneously monolayers and bilayers. At low volume fraction, short rods dissolve in the membrane of long rods by dimerizing through end-to-end stacking interactions. At high volume fraction, we observe a composite structure comprised of bilayer droplets enriched in short rods that coexist with the background monolayer membrane. Taken together, these findings establish a quantitative link between the structural, mechanical and optical properties of macroscopic materials to the microscopic features of the constituent molecules, which can provide fundamentally new insights into self-assembly of colloidal liquid crystals. |
