Electrostatic Energy Harvester Using Magnetically Actuated Liquid Dielectric Layers

We propose a fully liquid-based energy harvester that uses ferrofluid droplets as a movable dielectric material. The proposed device consists of top and bottom plates with conducting electrodes coated with a thin solid dielectric layer, a conducting liquid, and oil-based ferrofluid droplets as movable dielectric layers. The rotational motion of the ferrofluid droplets is actuated by a magnetic field that causes a capacitance variation that is used to generate electric power. An average output power of 19.3 μW is generated when eight ferrofluid droplets are used at a rotational speed of 180 r/min.