Nowadays many functional printing materials are available for 3D printing like flexible or conductive materials. In the latter situation conductivity is for example obtained by mixing in carbon powder. Although the resistivity of the composites is mainly determined by the conductive additives, the process technique and the process parameters are also important factors that influence resistivity. The printing parameters remarkably affect the resistivity due to the influence of voids and the bonding condition between adjacent fibers. Since the 3D printed fiber structure is anisotropic, the electrical properties of the printed structure also becomes anisotropic. Hence by adjusting the printing parameters the resistivity anisotropy of the printed parts can be manipulated.
In this research the anisotropic electrical properties of 3D printed thermal polyurethane-carbon black structures and the way the printing parameters affect the electrical properties will be studied. Current analytical models will be improved upon and numerical simulations will be performed with COMSOL for verification. Experiments will be done with the printing material as well as with the printed structures to study the anisotropic electrical properties and to validate the analytical models. Finally the gained knowledge on printing parameters and electrical properties will be used to make a capacitive force sensor.
The essay that describes the results from this assignment can be found here