Fully Integrated On-Chip Coil in 0.13 μm CMOS for Wireless Power Transfer Through Biological Media.

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Materials Science

Background:

• Wireless power transfer (WPT) is crucial for biomedical devices, requiring efficient, integrated receivers.
• Current solutions often need external components or complex post-processing, limiting miniaturization.
• On-chip integration in standard CMOS offers a path to fully integrated WPT systems.

Purpose of the Study:

• To develop and demonstrate a fully integrated, on-chip wireless power transfer receiver coil.
• To achieve milliwatt power delivery at centimeter distances for biomedical applications.
• To validate the performance of the on-chip receiver in various environments.

Main Methods:

• Fabrication of a 2 × 2.18 mm² on-chip WPT receiver (Rx) coil using 0.13 μm CMOS technology.
• Design of a 14.5 × 14.5 mm² transmitter (Tx) coil on an FR4 substrate.
• Testing of the WPT system efficiency at a 10 mm separation distance through air, bovine muscle, and saline solution.

Main Results:

• Demonstrated peak wireless power transfer efficiencies of -18.47 dB (air), -20.96 dB (bovine muscle), and -20.15 dB (0.2 M NaCl).
• Achieved milliwatt power delivery capabilities suitable for biomedical circuits.
• Confirmed operation within safe electromagnetic exposure limits.

Conclusions:

• The developed on-chip WPT receiver coil is a viable solution for integrated biomedical power systems.
• CMOS fabrication enables compact and efficient wireless power harvesting.
• The system performance is robust across different media, including biological tissue.