Transcutaneous transfer energy system designing for electronic pills

This paper proposes a system capable of transcutaneous electric power delivery by means of a non-guided electromagnetic field, suitable for electronic pill technology to be continually powered without the limitations imposed by batteries. This system consists of a Class-E power oscillator, with a crystal-based feedback network to compensate automatically for changes in the operational frequency, multi-turn spiral coupled coils and a power recovery circuit providing a stable output voltage. The synthesis procedure is based on designing equations for optimizing the link efficiency. The proposed transcutaneous transfer energy system aims at transferring 100 mW and providing a stable 3.3 V DC output voltage, tuned at a transmission frequency of 1 MHz, has been simulated with the electronics workbench MULTISIM 12 and it has been able to achieve 43.8% link efficiency for an inter-coil distance of 75 mm. Also, a proof-of-concept prototype has been built, yielding an efficiency of 21.0%.