Abstract: A wireless charging method for charging an underwater moving device is implemented by a charging device. The charging device receives electricity from a cable, and includes a first underwater wireless communication unit, a position holding unit, a first control unit, and a wireless charging transmitter. The underwater moving device includes a second underwater wireless communication unit, a wireless charging receiver, and a rechargeable battery. The first underwater wireless communication unit obtains moving device information by communicating with the second underwater wireless communication unit. The position holding unit holds the underwater moving device at a charging location, and generates a positioning success signal after the underwater moving device is held at the charging location. Upon receiving the positioning success signal, the first control unit controls the wireless charging transmitter to charge the rechargeable battery based on the moving device information.

Abstract: A robot fish system includes a robot fish, and a light-emitting device emitting a light signal. The robot fish includes a housing, on which first and second light receivers, a driving module and a processor are disposed. The processor is connected to the first and second light receivers and the driving module. The processor controls the driving module to operate in a left-turn mode to make the robot fish turn left when only the first light receiver receives the light signal, in a right-turn mode to make the robot fish turn right when only the second light receiver receives the light signal, in a straight-moving mode to make the robot fish move straight when both the first and second light receivers receive the light signal, and in a random mode to make the robot fish move randomly when none of the first and second light receivers receives the light signal.

Abstract: A biomimetic waterfowl includes a housing, two waterfowl legs, and a driving module. The waterfowl legs are spaced apart from each other in a left-right direction and are mounted to a bottom portion of the housing. Each waterfowl leg includes a first segment mounted to the housing and rotatable about a first axis parallel to the left-right direction, and a second segment rotatable about a second axis parallel to the first axis. The driving module is mounted to the housing and is configured to drive the waterfowl legs. Each of the waterfowl legs is movable between a retracted state, where the first segment extends forwardly from the housing and the second segment extends rearwardly from the first segment, and a propelling state, where the first segment extends rearwardly from the housing and the second segment extends rearwardly from the first segment.

Abstract: An internal printed antenna is revealed. The internal printed antenna includes a dielectric substrate, a ground plane, a metal loop radiating portion, and a microstrip feed line. The metal loop radiating portion includes a plurality of bends and a gap area is formed between adjacent bends. Two short circuit parts are arranged at the gap area.

Abstract: An internal printed antenna is revealed. The internal printed antenna includes a dielectric substrate, a ground plane, a metal loop radiating portion, and a microstrip feed line. The metal loop radiating portion includes a plurality of bends and a gap area is formed between adjacent bends. Two short circuit parts are arranged at the gap area.