Fully FFF-Printed Capacitive Displacement Sensor Based on Graphene/PLA Composite and Thermoplastic Elastomer Filaments

In this paper, an organic capacitive displacement sensor was fully realized using Fused Filament Fabrication (FFF) technology. The fabricated sensor consists of two circular electrodes, the spacer, and the casing. The FFF-printed electrodes were made of a conductive graphene/Polylactic acid (PLA) composite filament. For sensor's spacer a thermoplastic elastomer filament was used. Using these filaments gives us the possibility to design the extremely simple sensor with good sensitivity. The casing of the sensor and the applicator used for applying the displacement on the sensor were fabricated using a PLA. The sensor with three setup of spacer with different infill densities of the spacer (50%, 80%, and 100%) were realized and their characteristics were compared. The highest sensitivity was obtained for the sensor with infill density of spacer of 50%. The measurement results confirm the possibility of using FFF technology for the fabrication of low-cost and all organic and fully FFF-printed sensor with good characteristics.