基于纤维包覆式气动结构的柔性手术臂刚度调节性能研究

In view of the future development requirements of the minimally invasive surgical arm, a method using the principle of negative pressure to enhance the interactions between discrete structures is proposed to adjust the stiffness of flexible surgical arms. A pneumatic multilayered fiber braid structure is specially designed and fabricated, cladded on the outer surface of the tube arm. For this structure, negative pressure can be obtained in the interlayer of the sealed fiber filaments by a vacuum pump, and the extrusion pressure and friction force between them increase consequently, leading to a stiffness enhancement of the arm. A semi-analytical method for quantitatively evaluate the flexural stiffness of the large-deformed arm is then studied. Finally, the experimental investigations are performed, focused on the influences of some key parameters on the stiffness adjustment effect of the arm, such as vacuum degree, the size of fiber filaments, the thickness of the packaging film, the cross section of the fiber layer, etc.