Festo FinGripper

The FinGripper has been designed to handle fruit, bulbs or pressure-sensitive food reliably.

The bionic FinGripper is light, flexible and adaptive. It consists of a pneumatic actuator in the form of a bellows and three gripper fingers arranged in a pattern like the tail fin of a fish. The basic structure is made up of two flexible bands which meet at one end to form a triangle. Intermediate stays are connected to the bands at regular intervals by articulated joints.

The flexible design enables the gripper fingers to adapt to the shape of a workpiece when pressure is applied laterally - just like a human hand.

This bionic gripper operates on the same principle in a sorting station for chocolate eggs. The gripper fingers fully enclose the chocolate eggs without crushing them or damaging the aluminium wrapping and they can still be gripped if they are leaning to one side or are incorrectly positioned.

The proportional pneumatic valve VPPM ensures that the pressure is correct, allowing individual acceleration and pressure ramps to be applied. The variable flow rates provided by these proportional valves allow the cylinder pressures to be adapted to a given production or sorting process.

Everything is connected to the robotic controller CMXR, which controls the tripod robotic handling unit. The tripod moves the FinGripper quickly towards the chocolate eggs.

The device is manufactured using selective laser sintering with successive layers of polyamide powder of a thickness of 0.1 mm being applied and allowed to harden to form a solid component. This reduces the weight acting on the tool carrier by no less than 90% compared with a conventional metal gripper.

The advantages of these lightweight and adaptive bionic grippers are also used by Total Systems, a Dutch company producing machines and systems for handling flowers and bulbs. The company uses the gripper to sort the bulbs according to size and quality.