Soft grippers have excellent adaptability for a variety of objects and tasks. Jamming-based variable stiffness materials can further increase soft grippers' gripping force and capacity. Previous universal grippers enabled by granular jamming have shown great capability of handling objects with various shapes and weight. However, they require a large pushing force on the object during gripping, which is not suitable for very soft or free-hanging objects. In this paper, we create a novel palm-shape anthropomorphic variable-stiffness gripper enabled by jamming of 3D printed fabrics. This gripper is conformable and gentle to objects with different shapes, requires little pushing force, and increases gripping strength only when necessary. We present the design, fabrication and performance of this gripper and tested its conformability and gripping capacity. Our design utilizes soft pneumatic actuators to drive two wide palms to enclose objects, thanks to the excellent conformability of the structured fabrics. While the pinch force is low, the palm can significantly increase stiffness to lift heavy objects with a maximum gripping force of $17\,$N and grip-to-pinch force ratio of $42$. We also explore different variable-stiffness materials in the gripper, including sheets for layer jamming, to compare their performances. We conduct gripping tests on standard objects and daily items to show the great capacity of our gripper design.

翻译：软夹具具有优异的适应性，可以用于各种物体和任务。基于堵塞的可变刚度材料可以进一步增加软夹具的抓握力和容量。以前的基于粒状堵塞的通用夹具展示了处理各种形状和重量物体的强大能力。然而，它们在抓握时需要大量推力，这对于非常软的或自由悬挂的物体不适用。本文创建了一种由3D印刷织物堵塞驱动的新型手掌形人形可变刚度夹具。该夹具具有良好的适应性，适用于不同形状的物体，需要很少的推力，在必要时增加了抓握力。我们介绍了该夹具的设计、制造和性能，并测试了其适应性和抓握能力。我们的设计利用了软气动执行器驱动两个宽的手掌夹住物体，得益于结构织物的优异适应性。虽然夹力很低，但手掌可以显著增加刚度以举起重物，最大抓握力为17N，抓握力与夹力比为42。我们还探索了夹具中不同的可变刚度材料，包括用于层状堵塞的片材，以比较它们的性能。我们对标准物体和日常物品进行了抓握测试，以展示我们夹具设计的巨大容量。