With the increasing frequency of laparoscopic surgery, interest in the application of polymeric ligation clips as a method for ligating blood vessels has grown. Automatic clip appliers with built-in polymeric ligation clips have been developed to reduce ligation time. As the built-in clip is loaded into the jaw of the applier for ligation, a high spring constant, the elastic property of the clip is required to load properly. As the built-in clip loses its elastic properties due to stress relaxation over time, a polymeric ligation clip with a high spring constant is needed to increase the shelf life of the applier. In this study, four design factors of the cavity at the clip hinge (length, width, eccentricity, and angle of the cavity) were derived and applied to the Taguchi optimization method using finite element analysis to evaluate which factor was critical. The four design factors explained 93.5% of the variation in the spring constant. The factors related to cavity width and eccentricity were significant at p<0.05. Cavity width was the most crucial factor, explaining 70.8% of the variation in the spring constant. The spring constant of the improved clip model increased by 55.4% compared with the existing model.

This study introduces a novel tip-tilt-piston aligner based on aligned folded beam flexure. It was designed to enhance precision positioning by minimizing parasitic motion. Through finite element analysis, we compared this aligner with a traditional folded beam flexure-based mechanism, revealing a remarkable 135% increase in translational stiffness and superior rotational stiffness ratios. These advancements are expected to reduce parasitic motion arising from actuator misalignment and external disturbances, ultimately elevating positioning accuracy. The aligner’s suitability as a guiding device was affirmed and optimal actuator placement positions were determined. This research provides valuable insights into precision positioning mechanism design, underscoring the role of flexure geometry and precise actuator placement in minimizing parasitic motion for improved accuracy.