filename : Schu15a.pdf entry : toappear conference : SIGGRAPH 2015, Los Angeles, USA, 9-13 August, 2015 pages : 13 year : 2015 month : August title : Microstructures to Control Elasticity in 3D Printing subtitle : author : Schumacher, Christian and Bickel, Bernd and Rys, Jan and Marschner, Steve and Daraio, Chiara and Gross, Markus booktitle : ACM Transactions on Graphics (TOG) - SIGGRAPH 2015 Conference Proceedings ISSN/ISBN : editor : publisher : ACM publ.place : New York, NY, USA volume : 34 issue : 4 language : english keywords : fabrication, topology optimization, 3D printing abstract : We propose a method for fabricating deformable objects with spatially varying elasticity using 3D printing. Using a single, relatively stiff printer material, our method designs an assembly of small-scale microstructures that have the effect of a softer material at the object scale, with properties depending on the microstructure used in each part of the object. We build on work in the area of metamaterials, using numerical optimization to design tiled microstructures with desired properties, but with the key difference that our method designs families of related structures that can be interpolated to smoothly vary the material properties over a wide range. To create an object with spatially varying elastic properties, we tile the object's interior with microstructures drawn from these families, generating a different microstructure for each cell using an efficient algorithm to select compatible structures for neighboring cells. We show results computed for both 2D and 3D objects, validating several 2D and 3D printed structures using standard material tests as well as demonstrating various example applications.