Displacement sensor fabricated by 3D additive manufacturing

This paper presents possibility of realization of capacitive displacement sensor in additive manufacturing technology. A 3D printing fused filament fabrication approach has been implemented for the creation of sensors structure. Sensor casing for bottom electrode, spacer and top cover were fabricated by employing 3D printer and Polylactic acid filament. Top capacitor's electrode (movable element) was fabricated by printing silver nanoparticle ink on polyimide foil. Measurements were performed by measuring capacitance on impedance analyzer for each displacement step while manual translation stage was used in order to achieve precise displacement steps of 100 pm. Measurement shows that for total displacement of 1000 pm, there is increase of sensors capacitance of approximately 2.68 pF. An obtained result presents inkjet printing as a good candidate for integration with 3D additive manufacturing technologies. It enables the creation of sensor structure in timely and cost effective manner.