An Intra-Body Power Transfer System via Localized Capacitive Coupling.

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Wearable Technology

Background:

• Intra-body power transfer (IBPT) utilizes the human body for batteryless wearable devices.
• Existing methods often require external grounds or infrastructure.
• Novel techniques are needed for efficient and self-contained power delivery.

Purpose of the Study:

• Introduce and evaluate Localized Capacitive Coupling (LCC) as a new IBPT technique.
• Demonstrate LCC's capability for powering short-range wearable sensors.
• Validate LCC through computational modeling and human subject experiments.

Main Methods:

• Developed and tested the LCC technique using a 40 MHz RF carrier.
• Conducted computational modeling and human subject experiments with ten participants.
• Designed and evaluated multistage Dickson charge pump (DCP) receivers for energy harvesting.

Main Results:

• LCC achieved mean path gains of 44-48 dB over 5-12 cm channels, matching models within 3 dB.
• Air-gap coupling capacitance significantly influences channel gain.
• DCP receivers successfully harvested RF power, enabling a batteryless motion sensor.

Conclusions:

• LCC is a practical and effective IBPT method for short-range wearable sensor networks.
• The technique eliminates the need for external grounds or infrastructure.
• Open-sourcing hardware designs and simulations will foster further research.