Gripper Technology Mimics Gecko Feet to Grab Smooth Surfaces with no Smudges

Schunk says its new Adheso Gripper applies the principles of Van der Waals forces for handling components providing outsized adhesion coming from very small surfaces. The patented surface architecture made of special polymers consists of finely structured “hairs” that adhere to different materials and objects. The Gripper pad has a foam subtsrate with three different durometers of materials. Attached to that are the “hairs” with lengths ranging from 25 to 700 microns.

On a perfectly smooth surface, like glass, one square centimeter of the Adheso pad can lift 1 kg of weight. Put another way, Schunk says a dime-sized piece could grip 5.5 lb. In another example, Schunk says a 50-by-50-mm Adheso gripper could lift 25 kg, while only weighing 9.5g. In this way, the gripper has minimal impact on the robot arm’s payload, freeing it up to carry more weight.

Schunk says the unique technology can meet diverse applications, ranging from glass fibers; micro-mechanical parts; sensitive battery components; plastic films; and more. Gripping of components weighing as much as 33 lb is also possible. Schunk says automated separation of breathable components is also feasible, and the gripper can be tailored to each customer’s individual needs.

The adhesion gripping process works by applying Van der Waals forces and gently pressing the face of the gripper onto the workpiece. This increases the contact surface and locks the grip into place. The effect is reversed by applying slight pressure or a rotary movement, which loosens the gripper from the object without leaving any residue or marking.

The respective adhesive forces and removal of Adheso depend on the type of material, surface roughness or flatness, and miniaturization, and can be customized. Schunk says this high degree of individualization ensures that components ranging in size from a few hundred micrometers to those measuring several meters can be handled reliably.

A completely passive device, the Adheso Gripper doesn’t require compressed air, vacuum, or current to operate. An external energy supply is not necessary for gripping or maintaining the gripping force. In case of a power failure in the handling system, Schunk says the gripper’s holding forces are maintained. Schunk Adheso allows gripping times of less than 100 msec. It can be used in conventional industrial environments, but also in cleanrooms. In micro handling, repetitive positioning accuracies of less than 0.01 mm can be achieved. The Adheso grippers connects via a bayonet lock allowing them to be exchanged in a few steps.