The proposed research will use the stresses in out-of-equilibrium 3-D printing processes to dial-in hierarchical structural features in printed structures. A class of candidate materials known as bottlebrush block copolymers can form nanometer structures that readily deform under an applied stress. Bottlebrush block copolymers are a promising materials platform because they possess a large molecular design space. The PIs will develop and implement a screening methodology to explore this design space and determine optimal bottlebrush block copolymers for hierarchical printable materials. A holistic approach to computer-driven design will combine scalable synthesis, large-scale simulation, and rheological characterization to systematically design polymer molecules to yield desired, flow-induced nano-structures. This design procedure will be implemented to optimize 3-D printed nanostructured materials ‘on-the-fly’, culminating in a proof-of-concept of 3-D printed materials with heterogeneous photonic (i.e. color) properties. Along with this broad goal, this research will address fundamental questions in developing new, scalable polymer chemistry, driven self-assembly, and the rheology of bottlebrush block copolymers.