Magnetic Pin-Array Gripper Mechanism that Propagates Magnetic Flux to MR Fluid in Pouches

- Evaluation of Magnetic Flux Propagation, Stiffness Variability, and Object Grasping -

Abstract

Grippers with soft structures can be adapted to the object shapes, making it possible to handle various items without complicated control. They can change their apparent stiffness, for example, by using MR fluids or pin-array structures. However, MR fluid grippers have difficulty propagating magnetic flux to MR fluids. Pin-array grippers also have a problem that they need many pins to transfer object shapes. This paper proposes a magnetic pin-array gripper mechanism that combines MR fluid and pin-array structure. Each pin-unit has a flexible pouch filled with MR fluid, and a magnet can be inserted into the pipe inside the pouch. We conducted some experiments on magnetic flux density, pouch hardness, and object grasping. The results showed that the proposed mechanism can change the stiffness by effectively propagating magnetic flux to the pouches’ MR fluid. We also confirmed that it could grasp objects by its shape adaptability and stiffness variability.