Self-tracking Energy Transfer for Neural Stimulation in Untethered Mice

TL;DR

This paper introduces a wireless energy transfer system enabling untethered neural stimulation in mice, allowing natural behavior studies without bulky equipment, by leveraging resonant RF cavity interactions for self-tracking power delivery.

Contribution

The study presents a novel self-tracking wireless power system for small implants, facilitating untethered neural stimulation in freely moving mice, which improves upon existing tethered methods.

Findings

Achieved wireless activation of cortical neurons in mice

Demonstrated stable power transfer over a 16 cm area

Developed miniaturized, fully implantable stimulators

Abstract

Optical or electrical stimulation of neural circuits in mice during natural behavior is an important paradigm for studying brain function. Conventional systems for optogenetics and electrical microstimulation require tethers or large head-mounted devices that disrupt animal behavior. We report a method for wireless powering of small-scale implanted devices based on the strong localization of energy that occurs during resonant interaction between a radio-frequency cavity and intrinsic modes in mice. The system features self-tracking over a wide (16 cm diameter) operational area, and is used to demonstrate wireless activation of cortical neurons with miniaturized stimulators (10 mm$^{3}$, 20 mg) fully implanted under the skin.