This paper presents a novel approach to developing a universal robotic gripper based on the jamming of granular material. Traditional multi-fingered grippers are complex and require force sensing and computational overhead, making them challenging to adapt to unfamiliar objects. The proposed gripper uses a single mass of granular material that conforms to the shape of the object when pressed onto it and hardens upon vacuum application, providing a secure grip without sensory feedback. The gripping process is controlled by a reversible jamming transition, where small changes in packing density lead to significant changes in mechanical response. The gripper's performance is influenced by three mechanisms: friction, suction, and interlocking. A simple model relating these mechanisms to the mechanical strength of the jammed state is developed, demonstrating that the holding force scales with the confining pressure and the stress-strain relationship of the granular material. The gripper can handle a wide range of objects, including those with varying shapes and surfaces, and can lift objects up to several times their weight. The study highlights the potential of this passive, adaptive system for applications requiring rapid and reliable gripping of complex objects.This paper presents a novel approach to developing a universal robotic gripper based on the jamming of granular material. Traditional multi-fingered grippers are complex and require force sensing and computational overhead, making them challenging to adapt to unfamiliar objects. The proposed gripper uses a single mass of granular material that conforms to the shape of the object when pressed onto it and hardens upon vacuum application, providing a secure grip without sensory feedback. The gripping process is controlled by a reversible jamming transition, where small changes in packing density lead to significant changes in mechanical response. The gripper's performance is influenced by three mechanisms: friction, suction, and interlocking. A simple model relating these mechanisms to the mechanical strength of the jammed state is developed, demonstrating that the holding force scales with the confining pressure and the stress-strain relationship of the granular material. The gripper can handle a wide range of objects, including those with varying shapes and surfaces, and can lift objects up to several times their weight. The study highlights the potential of this passive, adaptive system for applications requiring rapid and reliable gripping of complex objects.