4D printing with shape memory polymers

Abstract

3D printing has been growing in sophistication and developed into 4D printing with an extra time dimension. The technology has demonstrated an radical shift in printing field as printed objects possess the ability to transform their shapes over time according to programmed paths given their unique material properties. Shape memory polymers (SMPs), with attributes to hold temporary shapes and recover its original shape upon stimulus application, have become one of the most frequently used 4D printing materials for their high Young’s Modulus’ value (~MPa to ~GPa) and fast recovery rate (~seconds to ~minutes) [1]. In this project, shape memory polymers consist of VeroWhitePlus and TangoBlackPlus were used to investigate different material and structural factors affecting the shape transformation rate. At this stage, factors including printing orientation, material composition and geometry thickness have been studied. Tensile tests at different temperatures have been carried out to investigate printing orientation on single material and composition effect on multi-material. Well-controlled experiments have been conducted for thickness effect and accurate recovery time measurement. Transient thermal simulations have been performed to verify the accuracy of experimental methodology and examine potential problems. Final application of printed flower mimicking blossom of Vanda 'Miss Joaquim' is accomplished.