Design for multi-material 4D printing: Development of an algorithm for interlocking blocks assembly generation

4D printing involves smart materials (SMs) that can respond to stimulation energy by changing their shape/property. Current advances in digital materials require addressing heterogeneous (multi-material deposition) 4D printing to attain targeted shape-changes. However, innovative structures embedding inert and SMs simultaneously are yet difficult to build. To overcome this challenge, we propose a genuine computational design approach addressed to heterogeneous additive manufacturing (AM). The main idea is to resort to an efficient algorithm capable of converting a computed digital multi-material distribution in a voxel-based 3D/4D structure to interlocking blocks intended to be printed separately with different AM techniques and then assembled.