4D printing of heat-driven self assembly structures (Part 1)
Lim, Joel Chin Huat
Date of Issue2015
School of Mechanical and Aerospace Engineering
Fourth Dimension (4D) printing is a process of printing out 3D structures that is capable of changing their shapes over time. It is activated through the materials’ properties to change shape by an external stimulus such as heat or chemical. Such materials are usually referred as smart materials or shape memory materials which can be either metal alloys or polymers. This report discusses about shape memory polymers and how heat as an external stimulus affects it. The shape memory polymers that this report will focus are VeroWhitePlus and TangoBlackPlus and their various different combinations from the DM85XX and DM98XX series. To determine the main characteristic of the polymers, Differential Scanning Calorimetric (DSC) tests were performed to determine the Glass Transition temperatures of the polymers. The preparation and procedure will be explained further in the report. Dynamic Mechanical Analysis (DMA) is carried out as another way of means to determine the Glass Transition temperature of the polymers. Through it the state and characteristic of the polymers can be determined. It will also be compared with the result from the DSC tests. The many different polymers specimens are also tested under tensile tests through various different temperatures. This is to investigate the stress, strain and shape memory effects of the polymers. The changes in the properties of the polymers due to different temperature are also observed. The various designs and tests and that were done in collaboration with another student who doing part II of the project will also be discussed in Chapter 5. The information on the properties of the materials will be used to design structures such as a square pyramid or origami gilder to showcase that heat can be used to self-assembly a structure through multi-folding. The design and the suitability of the different polymers due to its properties will be discussed in the report.
Final Year Project (FYP)
Nanyang Technological University