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Compliant joint plays a vital role in micro-positioning systems, robotics, and precision instruments due to its friction-free and fine motion. However, the existing joints are limited in range of motions and degrees of freedom. Thus, this paper proposes a new compliant joint (CJ) which is inspired from the dragonfly's wing. The proposed joint can provide two translational motions with a large range of motion. The CJ has six curvilinear shapes which are arranged in a parallel architecture. Besides, the proposed joint has a thin-wall structure to enlarge the deformation capacity. Based on the Euler–Bernoulli beam theory, the analytical model is established to describe the stiffness and displacement of the joint. Effects of the joint's geometries on the stiffness are investigated. The deformation and load capacities of the CJ are determined. The results showed that the displacement of the CJ in the y-axis is increased to 43.5% and 5.95% in comparison with the circular notch hinge and rectangular flexure hinge, respectively. Besides, the results determined that the displacements of the CJ in the x-axis are 58.57 times and 51.25 times larger than those of the traditional flexure hinges, respectively. The errors between the simulation, analytical model, and experiment are around 5%. It means that the closed-form model is validated for the proposed joint. The proposed CJ is a potential joint for micro-positioning technologies. [ABSTRACT FROM AUTHOR]

This paper proposes a new butterfly-inspired compliant joint by combining a butterfly's profile and a foldable mechanism. The joint can achieve three degrees of freedom in its fabrication plane, including two translations in the x- and y-axes and a rotary motion around the z-axis. Equivalent spring stiffness of the joint is easy to be adjusted by adopting a foldable mechanism, while a butterfly's profile gives better compliance. Closed-form model of the joint is established to calculate stiffness, displacement, and rotational angle. Performances and effectiveness of the proposed joint are verified by comparing with other joints. A prototype is fabricated, and experiments are conducted. The results show a good agreement between the analytical model, simulation, and experiment. Compared with a conventional rectangular flexure joint in terms of bending displacement and compressive displacement, the results found that performances of the joint are greatly improved. Bending displacement and angular displacement of the joint are increased by up to 14.6% and 12.6%, respectively. The proposed joint can be considered as a potential candidate for a precise positioning system. [ABSTRACT FROM AUTHOR]