Monolithic 3D-printed three-chamber pneumatic soft gripper for delicate bra cup Manipulation

Abstract

The apparel industry has yet to integrate soft grippers, particularly within intimate apparel production, where automation is becoming increasingly necessary to handle delicate items such as fabrics and bra cups. The sensitivity of these materials to mechanical contact and stresses has highlighted the need for innovative solutions. This study proposes a novel approach to gripping breathable soft bra cups, utilizing a pneumatically actuated three-chamber soft bending actuator with three independently controllable degrees of freedom. The three sections allow independently controlled actuation on a monolithic structure 3D printed from TPU. This design enables a gripper that combines three such actuators to adapt its shape to the complex contours of a bra cup. Experimental evaluation of actuator flexural ability and blocking force demonstrated a maximum bending angle of 34°, a vertical travel of 53 mm, and a blocking force of 1.7N at the tip at 0.7MPa. The gripper developed using the proposed actuator successfully gripped and lifted soft fabric bra cups without any noticeable damage to the fabric.