Piezoceramic Electrodynamic Wireless Power Receiver Using Torsion Mode Meandering Suspension

This paper reports the design, fabrication and experimental characterization of an electrodynamic wireless power transmission (WPT) receiver that utilizes a meander-shaped suspension and two piezo-ceramic transducers to achieve up to 8.2 mW/cm$^{3}\cdot$ mT2 normalized power density (NPD). The system operates at its torsion mode mechanical resonance of 211 Hz. The 2.5 cm3 prototype generates 3.3 mW average power (1.3 mW/cm3 power density) at a distance of 3 cm from a transmitter coil that is operating at the maximum allowable human exposure limit (a maximum 2 mTrms field generated at the center of the coil). Compared to prior works, the proposed design affords the use of multiple piezo transducers within a compact footprint while maintaining a form factor suitable for low-profile system implementation for bio-implantable and wearable applications.