A single-axis force sensor based on a 3D-printed elastic ring

•The force sensor uses 3D-printed elastic ring structure to measure the external force by utilizing the displacement variation of the elastic ring.•A nonlinear theory based on minimum potential energy principle is proposed to describe the nonlinear force–displacement relationship.•The force sensor shows good accuracy, low cost and low weight.•3D-printing enables fast fabrication and tunable measurement range. Force measurement is indispensable in vast engineering applications but conventional force sensors usually encounter large measurement errors or high costs. To address this problem, we develop a force sensor based on a 3D-printed elastic ring structure, which measures the external force by utilizing the displacement variation of the elastic ring. The nonlinear theory based on the minimum potential energy principle is proposed to describe the nonlinear relationship between the external force and the ring top displacement. The feasibility of the proposed force sensor scheme is validated through FEM simulations and experiments. The range of the force sensor can be adjusted by tuning the geometric parameters and the material parameters of the elastic ring, while the force sensor shows good measurement error at different measurement ranges. This force sensor possesses simple fabrication and low cost, showing good potential for various applications such as industrial automation, mechanical testing, and medical devices.