A computational design approach for multi-material 4D printing based on interlocking blocks assembly

4D printing is considered as a disruptive manufacturing technology for creating innovative devices able to evolve in their usage environment. By coupling additive manufacturing (AM) processes and active/passive materials under the effect of an energy stimulation, objects can change properties, shapes, or even functionalities. To achieve a desired shape-change, recent advances in computational design around digital materials require tackling multi-material 4D printing. However, the deposition of active and passive materials in a single run remains difficult due to the different AM techniques required. To overcome this limitation in the context of complex materials distributions, an original approach is to address multi-material 4D printing from the perspective of interlocking blocks assembly. Therefore, the objective of the paper is to propose a computational design approach that converts a multi-material 4D object with a computed digital materials distribution into suitable interlocking blocks. The latter can be printed separately using single material AM and then assembled to achieve the targeted shape change. An implementation of the approach via a dedicated plugin within a computer-aided design environment is presented. A case study is introduced to illustrate the relevance and the applicability of the proposed approach.