Microwaves for bi-modal neuromodulation: mechanisms and translation
OA Version
Citation
Abstract
Electrical neuromodulation, the current clinical standard, is invasive, expensive, and prone to malfunction. A broad range of electromagnetic waves have been investigated for noninvasive neuromodulation, but existing methods are limited by the tradeoff between penetration depth and spatial precision. Microwaves in the 0.1 – 6 GHz range are widely used for telecommunications and can penetrate to the deep brain. Microwaves have been shown to nonthermally modulate neural activity, but the acute bioeffects remain unclear and under-studied. Additionally, microwaves alone do not provide sufficient spatial precision to modulate target neurons without affecting surrounding tissues. In this thesis, we have developed two miniature microwave resonators – the split-ring resonator (SRR) and the microwave-powered injectable neuromodulation implant (MINI) – which generate enhanced microwave fields with submillimeter spatial precision. With the SRR and the MINI, microwaves at dosages below the safe exposure limit are shown to modulate neuronal activity. First, we employ the microwave resonators to demonstrate bi-modal neuromodulation via thermal and nonthermal mechanisms. Next, using the microwave resonators, we perform electrophysiological recordings of neurons exposed to microwaves to elucidate the differential effects of pulsed and continuous microwaves on neurons. Finally, we demonstrate an application of precision microwave neuromodulation in an in vivo model of epilepsy.
Description
2025
License
Attribution 4.0 International