Wireless Pressure Loop: Inductively Powered Buoyant Coil Submarines in a Harvest Tube

This paper presents a closed-loop energy harvesting system that integrates wireless inductive charging with buoyancy-driven motion. The design uses millimeter-scale “coil submarines” that cyclically rise and fall within a sealed fluid column, each carrying an internal coil. External coils surrounding the tube provide inductive charging to maintain submarine operation, while the majority of the tube’s length is reserved for energy harvesting through electromagnetic induction. This modular, pump-free design exploits buoyancy, gravity, and wireless power transfer to create a self-contained generator concept. The approach offers a scalable, low-cost pathway toward distributed, off-grid kinetic energy systems.