Multi jet fusion printing of graphene-carbon nanotubes/thermoplastic polyurethane shape memory composites

Abstract

The shape memory effect first identified in 1952 has opened new doors for researchers to understand the characteristics of various materials in categories like alloys, polymers, ceramics, gels, and hybrids. They have the properties to change its shape with exposure to external stimulus and return to its original state after the removal of said stimulus. When this phenomenon is combined with the well-known technology of additive manufacturing (also known as 3D printing), a new future excites researchers known as 4D printing. 4D printing of shape memory materials, or materials which could assist in producing the shape memory effect, can be applied in various industries, moreover the biomedical industry. It can assist in drug delivery systems as well as other biomedical related fields.

It is first important to understand the characteristics and properties of the materials used in such fields. As for this project, graphene, carbon nanotubes, polyvinylpyrrolidone and thermoplastic polyurethane are the main elements used. These materials will be studied for its shape memory characteristics and its ability to react to the electrothermal stimulus. The graphene, carbon nanotubes and polyvinylpyrrolidone will be bonded together to form a composite while the thermoplastic polyurethane will be 3D printed via multi jet fusion printing technique. These 2 components will then be bonded together for further testing. The resistance and electrothermal conductivity will be studied to understand its characteristics before studying its shape memory effect.