“…Other wireless power transfer methods, like the capacitively coupled power transfer, are not considered. The issues of concern include principle elaboration [7], impedance matching [8], frequency splitting [9], system architecture [10], circuit topology [11], coil optimization [12], magnetic structure design [13], dynamic online charging [14] as well as power control and efficiency analysis [15,16]. Recently, metamaterial has become a new hot spot in wireless power transfer systems [17,18], which acts as a "superlens" to increase the mutual inductance, and hence, the transfer efficiency.…”