Dynamics of Cellulose Nanocrystal Alignment During 3D Printing Michael K. Hausmann 1,2 , Patrick A. Rühs 1* , Gilberto Siqueira 1,2* , Jörg Läuger 3 , Rafael Libanori 1 , Tanja Zimmermann 2 , André R. Studart 1* 1 Complex Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland 2 Empa, Swiss Federal Laboratories for Materials Science and Technology, Applied Wood Materials La- boratory, 8600 Dübendorf, Switzerland 3 Anton Paar Germany GmbH, Helmuth-Hirth-Strasse 6, D-73760 Ostfildern, Germany Keywords cellulose nanocrystals, rheology, polarized light, alignment, 3d printing, birefringence, shear stress, direct ink writing *Corresponding Author patrick.ruehs@mat.ethz.ch gilberto.siqueira@empa.ch andre.studart@mat.ethz.ch