Design and Fabrication of a Novel Miniature Magnetic Gripper

Small-scale robots hold significant promise in the field of minimally invasive surgery (MIS). In this paper, we present a miniature magnetic gripper and develop a data-driven kinematic model. The gripper comprises four fingers, wherein each finger has a maximum size not exceeding 3mm, 4mm and 5.5mm in three dimensions. By integrating permanent magnets and elastic ropes as internal actuation elements into the fingers, the gripper is equipped with the capability to open-close under an external magnetic field, facilitating the manipulation of small objects in confined spaces. Modeling and analysis of the magnetic gripper are undertaken, wherein the relationship between the open angle and the external magnetic field is established. The average error between the experimentally observed open angles and the model-predicted values is 2.31°. Subsequent experiments demonstrated the necessity of the magnetic gripper model for precise manipulation, verified its excellent sensitivity to magnetic fields, and demonstrated its potential for future applications in MIS.