At the recent Hannover Fair, Festo demonstrated the latest in its series of innovations inspired by nature. One was a gripper called the NanoForceGripper with suction components modelled on the footpads of a gecko. The second was a device called the PowerGripper modelled on the kinematics of a bird’s beak.

Geckos cling to the surfaces using tiny, intermolecular forces of attraction known as van der Waal’s forces. A key component of Festo’s NanoForceGripper (shown above holding a phone) is a tape with 29,000 gripping elements per square centimetre. The gripper can hold delicate objects with smooth surfaces, such as glass, using almost no energy. According to Festo, this type of energy-free holding of objects has not been possible before.

Once a part is gripped, it is held permanently. To release the gripped object, a counteracting force is needed and this is achieved using a structure modelled on the tailfin of a fish, to peel off the tape. A push-push mechanism deforms the structure from a straight surface to a curved one, and the holding surface covered by the tape gets smaller until the gripped object is released, gently.

The second development, the PowerGripper (above) has emerged from a university project where students examined various planar, spatial and point grippers, modelled on birds’ beaks. The principle employed is known as Watt’s linkage. The gripper uses Festo’s fluidic muscle technology, combined with a titanium alloy, to produce a lightweight, efficient gripper with a good force-to-weight ratio.