Multifunctional Soft Gripper With Microneedles and Integrated Sensing for Robotic Fabric Handling

This study proposes a multifunctional soft robotic gripper for handling fabrics that are unstructured and flexible. The multifunctional finger design allows the gripper to change its gripping mode between pinching and suction, depending on the air permeability of the fabric. The gripper is able to separate a single fabric from a stack with success rates of 95% and 100% for air-permeable and non-air-permeable fabrics using pinching and suction, respectively. The actuation time is as short as 0.65 s for the two gripping modes. During gripping, the compliant body structure distributes the stress and endures up to 50 N of pressing force at the tip, thus preventing damage to both the fabrics and the gripper. In addition, the integrated air pressure sensor detects the contact and enables control of the pressing force. Before gripping the fabric, the air permeability of the fabric is first detected by the pressure sensor in the vacuum regulator, and the gripping mode is then selected accordingly. The proposed gripper demonstrates reliability in performance and structural robustness over 10 000 cycles of repeated actuation, showing a high potential in automation of garment manufacturing, in which repetitive and delicate handling of various types of fabrics is one of the key requirements.