Shape reconfiguring bistable structures using heat activated fibers

For my Master's thesis I collaborated with MIT's Self-Assembly Lab where I conducted research on 4D printed (i.e. 3D printed structures that undergo a shape transformation after being activated) bistable structures. Th The structuers were creating using a FDM 3D printer equiped with off-the-shelf shape-memory polymers. The nature of the printing process pre-programs a shape activation into the printed specimens. This is due to the extruded material being stretched as it undergoes a rather rapid heating and cooling cycle as it is being printed. This activation is primarily determined by the print path used to create the structure. However it is also partially influenced by the printing parameters.

To design these structures a FEA simulation was made that utilizes a novel approach that is highly simplified. The model was used to accurately predict the activation geometry which in turn was analyzed to see if it is bistable or not.

The thesis introduces a new design process to creating 4D printing structures. By utilizing a simplified computational model (that only requires a single experiment) as well as off-the-shelf materials and 3D printer. This work was eventually published in the journal "Engineering Structures", research paper link