suction gripper
A suction gripper holds an object not by clamping it between fingers but by sucking onto its surface, the way a rubber sucker sticks to a window or an octopus arm grips glass. Instead of jaws, it has one or more soft cups pressed against the object; a pump pulls the air out from inside each cup, and the ordinary air pressure all around then pushes the object firmly up against it. Cut off the suction and the object simply lets go.
Its great strength is grabbing things from one flat or smooth side without needing room to reach around them — perfect for a sheet of glass, a cardboard box, a phone screen, or a single item lying flat in a crowded bin where fingers could not fit. It is fast, gentle, and needs only one point of contact. Its weakness is the flip side of the same trick: it struggles with rough, porous, dusty, or sharply curved surfaces that let air leak in and break the seal, and it pulls mainly straight off the surface, so a heavy object can peel away if swung around too quickly.
Because it relies on a tight seal and on the air around it doing the gripping, a suction gripper usually comes with a pump or compressed-air supply, a valve to switch the grip on and off, and often a sensor that watches the vacuum level so the robot knows whether it actually caught the object. Many modern picking robots carry both a suction cup and a finger gripper and choose between them depending on the shape of whatever they are about to grab.
Warehouse picking robots often pluck items from a bin with a single suction cup on a flexible hose, sucking onto the top face of a boxed product and lifting it straight up.
One soft cup, one flat surface, no fingers needed.
It is the air pressure of the surrounding atmosphere, not the pump itself, that does the actual holding — the pump only removes the air so that outside pressure has nothing pushing back.