Electric Power Generated from Magnetic Nanofluid Droplets Sliding upon Superslippery Surfaces

An enduring challenge in the field of electric power generation employing magnetic nanofluids pertains to the inherent issue of solid-liquid adhesion, which results in random residue deposition of magnetic nanofluids on solid substrates during motion. Superslippery surfaces, characterized by their exceptional repellent properties and ultralow adhesion characteristics toward an extensive spectrum of fluids, offer an effective approach to ameliorate the aforementioned adhesive problem. Herein, it is demonstrated that electric power can be generated through the sliding of magnetic nanofluid droplets on superslippery surfaces. The electric power generation can be attributed to the change in magnetic flux caused by the magnetic nanofluid droplet passing or leaving a bottom coil associated with a magnet. By tailoring system parameters, such as the volume of the magnetic nanofluid or the vibration speed, the resulting maximal current can exceed 6 μA. An integrated device, featuring enclosed superslippery inner surfaces, can be securely attached to the arm of a volunteer, allowing for the conversion of mechanical energy into electricity. When the volunteer's arm moves, the electrical energy generated by the device can be utilized to light an LED lamp bead. The proposed strategy using superslippery surfaces facilitates low-adhesion transport of magnetic nanofluids, presenting an alternative solution to the development of next-generation solid/liquid energy harvesting devices.