INFLUENCE AND REGULATION OF INTERFACIAL ADHESION PROPERTIES OF A MAGNETIC SENSITIVE FILM/SUBSTRATE BY MAGNETIC FORCE AND FILM'S CURVATURE

The controllable interface adhesion of attachment and detachment has important application requirements in climbing devices, adhesion switches and mechanical grippers. In present paper, the influence mechanism of external magnetic field and film's initial curvature on the interfacial adhesion of a magnetic sensitive film/substrate is studied. The peel-test of the magnetic sensitive thin film with initial curvature on a substrate as well as the corresponding theoretical study are respectively carried out. Both the experimental and theoretical results indicate that the interfacial adhesion force of the magnetic sensitive thin film/substrate increases with increasing the initial curvature of the film, and the external magnetic field can enhance the interfacial adhesion force. Compared with the steady-state peel-off force of a flat thin film that is independent on the bending stiffness, the bending stiffness would decrease the steady-state peel-off force of the film with initial curvature. The interface effective adhesion energy is further considered from the energy point of view, which can disclose the comparing mechanisms of the film's bending energy, the potential energy of external magnetic field and the adhesion energy. Lastly, based on the experimental and theoretical results, a simply mechanical gripper controlled by both the magnetic field and film's initial curvature is proposed, which can continuously realize the gripping, transport and release of an object. The results obtained in the present paper can not only be helpful for understanding the interface reversible adhesion mechanism actuated by multi-field, but also provide a novel approach to design functional devices with controllable interface adhesion.