“…To overcome these limitations of PSs and the irradiation light, wireless power transmission (WPT) has gained considerable interest for possible use in transferring electric energy from a transmitter coil (transmitting device) to a receiver coil (receiving device) without a direct connection [ 31 , 32 , 33 ]. In WPT, a transmitting device driven by electric power transfers electric energy from a transmitting device to a receiving device through microwaves, ultrasonic waves, magnetic coupling, and electronic coupling without a direct electrical cable [ 34 , 35 , 36 , 37 , 38 , 39 ], and this technology has been applied to electric vehicles (EVs) [ 40 , 41 , 42 , 43 ], the Internet of Things (IoT) [ 44 , 45 ], and medicinal implants [ 46 , 47 ], as well as related fields. Applications of WPT to PDT have also been reported, in which receiving devices containing light-emitting diodes (LEDs) are implanted onto tumors in living animals, and power is wirelessly transferred from the transmitting device through magnetic coupling to photoirradiate (green or red light) PSs such as photofrin and chlorin e6; this approach has been reported to cause a decrease in tumor volume [ 48 , 49 , 50 , 51 ].…”