Magnetic-field-driven switchable adhesion of NdFeB/PDMS composite with gecko-like surface

Switchable adhesives have attracted widespread attention due to their strong reusability and adaptability to operate stably in complex environments. However, the simple fabrication of adhesive structures and reliable control of adhesion remain challenging. Here, we developed a neodymium iron boron/polydimethylsiloxane (NdFeB/PDMS) magnetic composite with optimal mechanical and magnetic performance. Then we fabricated lamellar structures and setal arrays using a molding and magnetic field-induced process, imitating the multi-level adhesion system of gecko feet. The lamellar can be deformed under the action of a magnetic field to control the adhesion, and the setal array is used to enhance adhesion and provide self-cleanability to the adhering surface. Switchable adhesion was realized by applying an external magnetic field, where the maximum adhesion strength was 5.1 kPa, and the switchable range was within 40%. Through finite element analysis simulations and experimental verification, it was proved that the adhesion force variation was ascribed to the magnetic field-induced surface deformation. Finally, we installed the adhesive on the end of the robotic arm, realizing the transfer of the target object. This work provides a simple method to fabricate a gecko-like surface and a practical strategy to realize switchable adhesion, which sheds light on broad application potential in production lines, medical products, and more.