Design of a Pneumatic-Actuated Soft Robotic End-Effector with Variable Stiffness via Positive Pressure Layer-Jamming

While soft robotic end-effectors excel in unstructured environments due to their inherent flexibility, they often lack the required stiffness for precise grasping tasks. This paper presents a pneumatic-actuated soft robotic end-effector designed to improve adaptability and precision in handling delicate objects. A variable-stiffness mechanism based on positive-pressure layer jamming is developed, allowing for stiffness modulation by adjusting the friction between internal layers. The paper provides a detailed description of the design, manufacturing process, and experimental testing of the end-effector. Experimental evaluations assess both the stiffness modulation range and load-bearing capacity. The results demonstrate that the proposed design offers a wide range of stiffness adjustments and substantial load capacity, making it well-suited for applications that require a balance of high flexibility and precise stiffness control.