Developing a reliable method to connect conductors to 3D printed conducting structures

In this assignment, a predictable and reliable method of connecting a conductor to a 3D printed structure made of conductive filament (ETPU and/or EPLA) is being investigated. The goal is to understand what makes a good mechanical and electrical robust connection between both dissimilar materials. The contacts that will be designed, investigated, and tested will be from such a size that they can be implemented in 3D printed RAM sensors.

The reason for this investigation is that there is not yet a standard for the connection between a conductor to a 3D printed conductive part. Many methods have been used: silver paint, copper tape, wires molten in with soldering iron, clamps, or any combination. The problem is that concrete reliable and robust (electrical and mechanical) contact resistance is not yet defined and tested. The flexible sensors at RAM fare quite some heavy use and therefore can benefit from a reliable contact resistance.

The core difficulty lies in the 3D printed conductive parts, it’s important to attempt to separate the contact resistance from the resistance of the 3D printed parts. Experiments have to be chosen in such a way that this isolation of the contact resistance possible. Furthermore, the contact will be tested under a load of some sort to simulate pulling on the contact. This will happen in the daily use of the sensors for which the contacts will be investigated. So, the relation between loading a contact with different properties will be investigated versus the resistance (change).