Magnetically Reconfigurable Wettability‐Adhesion Coupling for Adaptive Lubrication

Reversible and synchronized regulation of wettability and adhesion remains elusive in adaptive lubrication, where structural rigidity and chemical fixation constrain interfacial responsiveness to external fields. In this study, we introduce a magnetically reconfigurable lubrication strategy that integrates magneto-responsive lubricants with oleophobic surfaces to achieve field-driven modulation of wettability, adhesion, and friction. Under magnetic actuation, nanoparticles assemble into chain-like anisotropic structures, generating directional magnetic forces that compete with surface tension to reconfigure droplet morphology. The balance of these forces, defined by the magnetic Bond number, governs the wetting transition, as reflected by a reduction of the apparent contact angle from 153° to 114° and nearly threefold expansion of the wetted area. Enhanced interfacial pinning expands hysteresis from 5° to 42°, enabling reversible droplet manipulation. Meanwhile, field-induced nanoparticle aggregation at the solid-liquid interface generates vertical magnetic gradients and localized negative pressures below -100 kPa, yielding reversible adhesion up to 12 N. These coupled effects enable magnetic tuning of interfacial friction, with the coefficient varying from 0.15 to 0.55 and torque from 0.005 to 0.10 N·m. This work establishes a quantitative, field-driven framework for magnetically regulated interfacial control, enabling adaptive lubrication in applications such as robotic joints, adaptive bearings, and precision motion systems.