An interesting opportunity for research in the field of 3D-printed sensors lies in the 3D printing of metamaterials. A metamaterial is an artificial structure that is designed such that it has advantageous, often uncommon, properties. These properties are different from those of the bulk material it consists of and typically occurs due to a structure on a small scale. Examples of 3D-printed metamaterials include materials that have optimized mechanical properties and materials used to create highly specialized antennas.
The most prevalently occurring method of 3D printing is the Fused Deposition Modelling (FDM) process. The FDM process produces 3D objects by laying down a molten filament in a line-by-line manner. This process causes anisotropic properties to occur, for example in heat conduction or mechanical properties. If an electrically conductive filament is used, the electrical conduction of the object will also become anisotropic. If this property of anisotropic conduction is used for a certain application, the printed material can be considered a metamaterial.
Previous research showed that it was possible to make use of anisotropic properties to create metamaterials that we're able to bend heat flux. This bending effect consists of heat flux flowing from one temperature terminal to another at an angle compared to the perpendicular path between parallel terminals. The steady-state conduction equations are analogous for heat and current conduction in a steady-state. Therefore, it should be considered possible to create anisotropic metamaterials that are able to conduct DC electricity in a similar way.
This bachelor assignment has two main focuses. Firstly, it is to understand how the knowledge from the thermal domain on steady-state metamaterials translates to the electrical domain. Specifically, how previously observed effects can be replicated for DC electricity in a 3D-printed metamaterial. The second focus is to develop methods to print these metamaterials. This mainly includes studying the effects of the printing parameters such that the anisotropic properties are optimized. The knowledge gained with this bachelor assignment could then be applied in a wide variety of different applications. Examples of further applications include sensors that have a location-dependent sensitivity, conductive sheets that can be used for targeted heating, or EMI shielding. The general knowledge on the anisotropy of 3D-printed materials and how it is affected by printing parameters can benefit any field where conductors are 3D-printed. This includes fields such as soft robotics, electrochemistry, or the 3D printing of electronics.