A Frequency-Switching Inductive Power Transfer System for Wireless, Miniaturised and Large-Scale Neural Interfaces

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Neuroscience

Background:

• Three-coil inductive power transfer is standard for powering neural implants.
• Existing methods face limitations in delivered power due to efficiency and safety constraints.

Purpose of the Study:

• To introduce a frequency-switching inductive link to overcome power limitations in neural implant systems.
• To enhance wireless power transfer for large-scale neural interfaces.

Main Methods:

• Replaced the passive resonator in a three-coil link with an active resonator.
• Utilized a two-coil link at 13.56 MHz for initial power reception.
• Switched frequency to 433.92 MHz for power transmission to 1024 implants via a three-coil link with 37 focusing resonators.

Main Results:

• Achieved a power transfer efficiency of 0.013%.
• Delivered a maximum power of 1970 μW to the load within safety limits.
• Demonstrated improvements of two orders of magnitude in efficiency and over six decades in power delivery compared to passive links.

Conclusions:

• The frequency-switching inductive system offers a scalable and versatile solution for wireless neural interfaces.
• This technology significantly advances the capabilities for powering miniaturized and large-scale neural implants.