Abstract
We investigated wireless power transfer methods best suited for endoscopic energy devices. In order to insert the device into a body the transmitter and receiver need to have small tube-like bendable structures, and to avoid heating, the system needs to have high transmission efficiency. In this investigation, we used an electric field coupling method with stainless-steel monocoil electrodes (~φ3 mm), which was analytically and experimentally predicted to fulfill all the above conditions. The efficiency of a prototype was confirmed to be about 94% in the worst possible situation where the electrodes were severely bent. The proposed system was stable under the following conditions: transmission of electrical power up to 100 W; motion corresponding to insert and remove of the endoscopic energy devices; close approach of a human body to the electrodes.
