Single-Step Fabrication of a Six-Axial Force Plate Using an FDM 3-D Printer

Simple fabrication of customizable sensors is necessary for unique but important measurement objects. As force-sensing devices require multiple steps for fabrication, conventional techniques are not convenient for realizing tailor-made instruments. Recently, three-dimensionally (3-D) printed devices have become highly popular, especially for rapid prototyping. A 3-D printer can be used to fabricate complex structures in a single step and is ideal for fabricating custom sensors with advanced applications. In this study, we proposed a single-step fabrication method for a six-axial force plate using a fused deposition modeling dual-nozzle 3-D printer. The sensing elements were 3-D printed using electrically conductive polylactic acid filaments, and the entire force plate was fabricated in approximately one day. The device measured 230 mm, and the plate was square-shaped with dimensions of 100 mm. Calibration experiments were conducted, which confirmed that the fabricated force plate responded independently to the six-axial forces as designed. The resonant frequency was confirmed to be at least 45 Hz, and the force and moment resolutions were <5.9 mN and <4.2 mNm, respectively. Furthermore, the positional error was <3% in the Fz -direction. Therefore, the proposed fabrication method using a 3-D printer is useful for realizing a compact square-shaped sensing force plate, with a high degree of design freedom.