Transparent and Conformal Microcoil Arrays for Spatially Selective Neuronal Activation

Area of Science:

• Neuroscience
• Biomedical Engineering
• Materials Science

Background:

• Micromagnetic stimulation (microMS) offers high spatial resolution for neuronal activation.
• Current microMS technologies face challenges in precise targeting and biocompatibility.

Purpose of the Study:

• To develop and validate a microcoil array for localized activation of cortical neurons and retinal ganglion cells.
• To establish a computational model for optimizing microcoil design for targeted neural stimulation.

Main Methods:

• Designed and fabricated a flexible, transparent SU-8/Cu/SU-8 tri-layer microcoil array with four individually-addressable microcoils.
• Developed a computational model to predict the electric field gradient and activation region.
• Tested the device on mouse cortex and retina explants expressing GCaMP6.

Main Results:

• Achieved localized neuronal activation with an anisotropic region of activation <50 microm wide.
• Demonstrated repeated, dose-dependent activation of individual neurons within 40 microm of microcoil tips.
• Confirmed the device's flexibility, transparency, and conformal properties.

Conclusions:

• The developed microcoil array enables precise, localized neural activation via microMS.
• This technology holds significant potential for advancing brain-machine interfaces and bioelectronic therapies, including prosthetic vision.