Rotational-pinch-inspired method and soft gripper for layer-by-layer fabric separation

Automating the layer-by-layer separation of stacked fabrics remains a major bottleneck in garment manufacturing due to the high deformability of textiles and the difficulty of isolating the top layer without disturbing adjacent layers. To address this challenge, this work proposes a rotational-pinch-inspired layered grasping method and a soft pneumatic gripper capable of reproducing the coordinated pressing-rotating-pinching behavior observed in human fingers. The gripper integrates a cavity-based pneumatic actuation module and a mechanical torsion module that collaboratively regulate the fingertip opening distance, normal force, and rotation angle-three key parameters governing layered fabric separation. A mechanical analysis establishes the relationship between these parameters and the evolution of shear deformation that triggers interlayer detachment. Experiments including parameter-impact, adaptability, and stability tests were conducted using six representative garment fabrics with diverse physical properties. Results demonstrate that the proposed grasping method enables nondestructive, continuous, and stable separation under different stacking layers and grasping positions, achieving success rates exceeding 96.7% on most fabrics. Overall, this work provides reliable technical support for garment manufacturing and is expected to facilitate the transition toward more efficient, precise, and intelligent production.